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{{Adams
| number = ML100191690
| issue date = 01/11/2010
| title = Final Safety Analysis Report, Amendment 97, Section 9 - Auxiliary System, Pages 9.4-1 Through Figure 9.5-31, Page 9.5-66
| author name = 
| author affiliation = Tennessee Valley Authority
| addressee name = 
| addressee affiliation = NRC/NRR
| docket = 05000391
| license number = 
| contact person = 
| document type = Final Safety Analysis Report (FSAR)
| page count = 364
}}

=Text=
{{#Wiki_filter:WATTS BAR                                                                                    WBNP-97 9.4 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS 9.4.1 Control Room Area Ventilation System 9.4.1.1 Design Bases The Control Building heating, ventilating, air-conditioning (HVAC), and air cleanup systems are designed to maintain temperature and humidity conditions throughout the building for the protection, operation, and maintenance and testing of plant controls, and for the safe, uninterrupted occupancy of the main control room habitability system (MCRHS) area during an accident and the subsequent recovery period. Refer to Section 6.4 for further information regarding control room habitability and definition of MCRHS area. The main control room habitability zone (MCRHZ) is designed to maintain a positive pressure relative to the outdoors and to the adjacent areas at all times, except during a tornado warning, to minimize air inleakage.
The Control Building air-conditioned equipment areas and normally occupied personnel spaces are maintained in the range of 60&deg;F minimum to 104&deg;F maximum temperature during all modes of operation.Adequate envirionmental conditions are provided for equipment operation and protection, and personnel comfort in the control room during normal, accident, and post-accident recovery conditions.
The Control Building outside air intakes are provided with radiation monitors, and smoke detectors. Indicators are provided with the radiation monitors. Main Control Room (MCR) common annunciation is provided. Isolation of the MCRHZ occurs automatically upon the actuation of a safety injection signal from either unit or upon indication of high radiation, or smoke concentrations in the outside air supply stream to the building. The Control Building HVAC outside air intakes can also be isolated by closing the tornado dampers. The tornado dampers are closed manually from the MCR during a tornado warning to protect the Control Building from tornado depressurization effects.
Upon receipt of a signal for MCRHS area isolation, Control Room Isolation (CRI), the following conditions are automatically implemented:
(1)  The Control Building emergency air cleanup fans operate to recirculate a portion of the MCRHS area air-conditioning system return air through the cleanup trains composed of HEPA filters and charcoal adsorbers.
(2)  The Control Building emergency pressurizing air supply fan operates to supply a reduced stream of outside air to the MCR air-conditioning system to maintain the MCRHZ pressurized relative to outside and the adjacent areas.
This fresh air is routed through the emergency air cleanup trains.
(3)  The control room electrical board rooms (EBR) air handling units continue to draw outside air to maintain the lower floor spaces at atmospheric pressure.
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                      9.4-1

WATTS BAR                                                                                WBNP-97 (4)   The exhaust fan in the toilet rooms is stopped, and double isolation dampers are closed.
(5)   The spreading room supply and exhaust fans are stopped and any operating battery room exhaust fan continues to run.
(6)   Double isolation dampers in the spreading room supply duct and isolation dampers in the exhaust duct close.
(7)   The Auxiliary Building Elevation 757 shutdown board rooms pressurizing air supply fans are automatically de-energized.
(8)   Double isolation valves close to isolate the normal pressurizing supply to the MCRHZ.
MCRHZ isolation may be accomplished manually at any time by the control room operators.
The following building air-conditioning and ventilating system components are each provided with two 100% capacity units. Each meets the single failure criterion, and automatic switchover is assured if one of the units fails. These systems include the:
(1)   MCR air-conditioning system, water chillers, air handling units, and piping.
(2)   Control Building emergency air cleanup supply fans and filter assemblies.
(3)   Control Building emergency pressurizing air supply fans.
The EBR air conditioning system is provided with two 100% capacity package water chillers and four 50% capacity air handling units with associated piping, valves, and controls. This system meets the single failure criterion, and automatic switchover is assured if one of the components fails.
Two existing isolation valves, O-FCV-31-36 and O-FCV-31-37, in the fresh air supply duct to the spreading room remain closed and the outlet is blanked off.
Fresh air for control room emergency pressurizing is taken from the outdoors from either of two intakes. One is the emergency air intake, located on the east end of the Control Building roof at Elevation 775 and the other is connected to the fresh air intake on the roof at the west end of the Control Building. Both intakes are isolated during a tornado warning.
All essential air-conditioning equipment, ventilating equipment, isolation dampers, and ducts are designed to withstand the safe shutdown earthquake (SSE). Nonessential components are seismically designed to the extent that they will not affect system operation if they should fail due to a seismic event. All air-conditioning and essential ventilating equipment are protected from the effects of a design basis tornado (Section 3.3.2), by isolation dampers located at all external openings to the Control Building. A 9.4-2                                AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                      WBNP-97 concrete hood located over the air intake provides additional protection from the effects of tornado generated missiles.
All air conditioning equipment necessary to ensure main control room habitability in the event of a flood is located in the Auxiliary and Control Buildings at elevations where the equipment remains functional during flooding up to the design basis flood elevation. The EBR air conditioning system is not required during a flood Piping which could be a source of pipe whip (i.e., high energy lines) does not pass through areas containing essential Control Building air conditioning or air cleanup equipment. The equipment is also separated from and protected from potential sources of missiles and jet impingement which could adversely affect operation of the system. See Section 3.5.1.1.4 for further discussion on Control Buiding internal missiles.
System and component quality group classification for the Control Building heating, ventilating, air conditioning and air cleanup systems is commensurate with the importance to safety of the function performed by the systems. For further discussion of quality group classification refer to Section 3.2.2.
9.4.1.2 System Description The Control Building HVAC, and air cleanup systems are shown on Figures 9.4-1, 9.4-2, and 9.4-3 and the logic and control on Figures 9.4-4, 9.4-4a, 9.4-5, 9.4-6 and 9.4-7 and consist of the following systems:
(1)   MCR air-conditioning system (2)   EBR air-conditioning system.
(3)   Control Building emergency air cleanup system.
(4)   Control Building emergency pressurizing system.
(5)   Battery room ventilating system.
(6)   Miscellaneous ventilating systems.
The MCR air-conditioning system water chillers are located in the Auxiliary Building at Elevation 737.0. The associated air handling units are located in the Control Building in the mechanical equipment room at Elevation 755.0. The area served by this system includes the MCR, the relay room, the DPSO engineers shop, Control Building offices, the technical support center (TSC), conference rooms, kitchen, toilets, locker rooms, the mechanical equipment room and the NRC Office at Elevation 755.0.
The EBR air-conditioning system water chillers are located in the Control Building in the east mechanical equipment room at Elevation 692.0. The associated air handling units are located in the west mechanical equipment room at Elevation 692.0. Rooms served by this system include the battery board rooms, battery rooms, battery room AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                        9.4-3

WATTS BAR                                                                                WBNP-97 exhaust fan room, the communications room, the secondary alarm station at Elevation 692.0, and the computer and auxiliary instrument rooms at Elevation 708.0.
The communications room located on Elevation 692.0 has two nonsafety-related air conditioning units to supplement the electric board room air conditioning system. The units receive cooling water from the raw service water system. The units are provided with local controls.
The MCR air conditioning system is provided with two 100% capacity package water chillers, two 100% capacity fan-coil type air handling units, and associated pumps, piping, ductwork, and controls.
The EBR air conditioning system is provided with two 100% capacity package water chillers, four 50% capacity fan-coil type air handling units, and associated pumps, piping, ductwork, and controls.
Fresh air is drawn in from the air intake by the operating MCR air handling unit to replace that mechanically exhausted to the outdoors plus makeup for leakage in order to pressurize the MCRHZ.
Fresh air is drawn in by the operating EBR air handling unit and supplied to spaces on Elevations 692.0 and 708.0. System airflow balancing provides for makeup air which replaces that mechanically exhausted to the outdoors and maintains atmospheric pressure at these floors.
During normal and CRI operating modes, all MCRHS air, fresh and recirculated, is filtered by passing through an air handling unit containing a bank of filters. Filters associated with an inactive air handling unit are available for servicing.
During normal operations, all fresh air supplied to the air conditioning systems is heated by a thermostatically controlled duct heater to maintain spaces within design temperature limits. Additional electric heaters are located in air supply ducts serving the battery board rooms at Elevation 692.0; the auxiliary instrument and computer rooms at Elevation 708.0; and the relay room, TSC, Control Building offices, conference rooms, toilets, locker room and kitchen at Elevation 755.0. The above heaters are each thermostatically controlled to maintain room design conditions.
During a CRI, air is exhausted from the Control Building by the toilet and locker room exhaust fan, a spreading room exhaust fan, and a battery room exhaust fan. The spreading room supply fan transfers air from the mechanical equipment room on Elevation 755.0 to the spreading room. The makeup air and pressurizing air is drawn into the Control Building by the operating MCR and EBR air handling units. The air supply quantity is manually preadjusted by balancing dampers, as required, to maintain a minimum 1/8-inch positive static pressure in the main control room and atmospheric pressure in the remainder of the building, except the spreading room which is manually preset at a slight negative pressure relative to outdoors.
During accident conditions, double isolation valves automatically close to terminate the normal supply of fresh air to the MCRHZ. The EBR air handling units continue to draw 9.4-4                                AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                      WBNP-97 a measured quantity of outside air to maintain the lower floors at approximately atmospheric pressure.
In the event of a single active failure which causes the MCRHZ pressure to drop below 1/8-inch water gage positive pressure, any of the four differential pressure switches activate an alarm in the MCR. The control room operator provides corrective action in the normal operating mode and has the option of starting the standby air handling unit.
If there is a single failure during the isolation mode, the differential pressure switches automatically start the standby emergency pressurizing fan and its associated air cleanup unit to maintain the pressure in the MCRHZ. The switches also activate an alarm in the MCR.
The Control Building emergency air cleanup system is located within the mechanical equipment room at Elevation 755. This system is provided with two 100% capacity emergency air cleanup fans, and two 100% capacity air cleanup filter assemblies arranged in two parallel 100% capacity fan-filter trains. Refer to Section 6.5 for further information related to the emergency air cleanup units.
The emergency air cleanup system automatically operates upon a safety injection signal, indication of high radiation, or smoke concentrations in the building fresh air supply. This system can also be manually started from the MCR at any time. During an accident, both of the emergency air cleanup supply fans are started. Controls are provided to permit the control room operators to shut down either one of the air cleanup units and to keep it as a backup. The backup unit automatically starts in the event the operating unit fails.
During air cleanup system operation, a portion of the MCR air conditioning system return air is continuously routed through one or both of the air cleanup units and then to the system return air plenum. The cleaned air is thus recirculated to the MCR by the air-conditioning system. The system may be manually operated from the MCR at any time as required for periodic testing in accordance with the technical specifications filter testing program.
The Control Building emergency air cleanup fans are engineered safety features (ESF) equipment and are connected to separate divisions of the emergency power system.
The MCRHZ is pressurized with cleaned outdoor air during operation of the control room emergency air cleanup system. The minimum 1/8-inch positive pressure of the MCRHS area relative to the outdoors and adjoining spaces minimizes the inleakage of unprocessed air during the emergency mode. Section 6.4.3 discusses the three modes of system operation. The control room emergency pressurization system is provided with two 100% capacity emergency pressurizing air supply fans located within the mechanical equipment room Elevation 755. The fresh or pressurizing air is taken from either of two air intakes, one located on the Control Building roof at Elevation 775 near the east end of the building and the other located on the west end of the building. Each fan is duct-connected to an intake hood to provide two separate 100% capacity air supply systems. Air from each emergency intake is ducted to the associated emergency pressurizing fan. A cross-connection is provided just upstream of the fans AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                         9.4-5

WATTS BAR                                                                                 WBNP-89 (refer to Figure 9.4-1) which allows either emergency pressurization fan to draw air from either emergency air intake if necessary. The manual damper in the cross connection is normally in the closed position. The damper, which is accessible from within the habitability area, is opened only if one of the emergency pressurizing fans has failed and contamination of the air intake associated with the non-failed fan is great enough to require air to be drawn from the other emergency intake. Determination of contamination level is discussed in Section 6.4.3.
Emergency pressurization air supply fans which discharge to the control room air-conditioning system return air upstream of the air cleanup filter assembly trains.
The emergency pressurizing fans are the vaneaxial type with a capacity to deliver 711 cfm. These fans (one redundant) are ESF equipment and are connected to separate divisions of the emergency power system.
Both emergency pressurizing fans (100% redundant) are started by the same accident signal that starts the air cleanup units. The capability is provided to place either of the operating air cleanup units and the associated emergency pressurizing fans in the standby mode. The standby components start automatically in the event of a failure of the operating air cleanup unit or its emergency pressurizing fan.
During non-tornado operation, power is removed from tornado isolation dampers 0-FCO-31-21 and 0-FCO-31-34, which are located in the ductwork connected to the two fresh air intakes. The dampers control circuits remain de-energized during all plant conditions, except tornado warning, to preclude the possibility of a single failure in their control circuit isolating both air intakes.
The battery rooms ventilation system consists of two 100% capacity and one reduced capacity exhaust fans. The fans are located on the Elevation 692.0 floor with the two 100% capacity fans located near the west end of the building and the other fan located in the east mechanical equipment room.
Fire dampers provided in each room's air exhaust duct and air supply opening operate to isolate the room upon high temperature due to fire.
The battery room ventilation system is required to operate at all times except during the design basis flood and during a 72-hour period following a fire. A standby fan automatically starts upon failure of the operating fan to produce airflow. The battery room fans are ESF equipment and are connected to the emergency power system.
The reduced capacity exhaust fan C-B is normally unpowered, but can be manually started if needed to control hydrogen in the battery rooms.
The spreading room is ventilated by one of two 100% capacity exhaust fans (one being on manual standby) located at the east end of the spreading room at Elevation 729.0. One spreading room supply fan, located in the mechanical equipment room at Elevation 755.0, supplies air from the mechanical equipment room. Because the spreading room is maintained at a slight negative pressure during normal operation, some air enters via leakage from the MCR and the electrical board room areas.
9.4-6                                 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                  WBNP-89 The spreading room supply and exhaust fans are nonsafety-related and are notconnected to the emergency power system. During MCR isolation, the spreading room fans are automatically shut off and isolation dampers closed.
The mechanical equipment room at Elevation 755.0 is normally ventilated by the passage of air-conditioning system supply air from the system air handling unit.
The mechanical equipment room at Elevation 692.0 is ventilated at all times with air supplied by the EBR air-conditioning system supply and with air drawn through the room to the air-conditioning return air duct.
The kitchen, toilet, and locker rooms at Elevation 755.0 are ventilated by exhausting a portion of the MCRHZ conditioned air through the rooms. The toilet and locker room exhaust fan is located in the Elevation 755.0 mechanical equipment room and discharges directly to the outdoors.
The toilet and locker rooms exhaust fan is nonsafety-related and is not connected to the emergency power system. During MCR isolation the toilet and locker room exhaust fan is automatically shut down, and double isolation dampers close.
Dampers used to isolate the MCRHZ area from the outside and from portions of the ventilation systems serving other areas of the Control Building are low leakage type dampers. They are heavy-duty dampers provided with resilient seals along the blade edges. These dampers close following detection of high levels of radiation, concentrations of smoke, or receipt of an isolation signal. Refer to Section 6.4 for further information regarding damper leakage.
9.4.1.3 Safety Evaluation The Control Building air-conditioning systems are ESF. Each pair of full-capacity (one redundant) water chillers and each redundant set of air handling units is served from a separate train of the emergency power system and from a coordinated separate loop of the essential raw cooling water system (ERCW). Upon loss of offsite power, emergency power to the MCR and EBR chiller packages is automatically reestablished in sequence by the diesel generator in accordance with FSAR Table 8.3-3. The failure modes and effects analysis presented in Table 9.4-7 verifies the capability of the system to maintain acceptable environmental conditions within the Control Building during any mode of system operation following any single active failure.
All MCR equipment operates normally at an ambient temperature of 75&deg;F. Abnormal excursions of short duration (12 hours or less) to 104&deg;F maximum and 60&deg;F minimum may occur without adverse effects on the equipment. Loss of ventilation is discussed further in Section 3.11.6.
The air cleanup equipment installed to purify air supplied to the MCRHZ during emergencies is classified as an ESF air cleanup system. Good general agreement with Regulatory Guide 1.52 standards for air cleanup equipment is achieved. Details on this compliance are given in Table 6.5-4.
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                     9.4-7

WATTS BAR                                                                                      WBNP-97 Each of the Control Building emergency air cleanup units consists of a bank of HEPA filter cells and a bank of carbon adsorber modules. Test connections and appropriate instrumentation are also provided for each air cleanup unit. For further details refer to Section 6.5.1.
Filter banks are provided in the suction-side of each MCR and EBR air handling unit.
For discussions on radioactivity dose levels and detection of airborne contaminants, refer to Section 12.4 and 12.3.4.
Tornado dampers are provided to isolate the Control Building HVAC outside air intakes during a tornado warning. The isolation is provided upon damper closure during either normal system operation or MCR Isolation. The loss of MCRHZ pressurization during this time will not result in contaminated air leaking into the MCRHZ since a LOCA is not postulated concurrent with a tornado.
The only heating, ventilating, and air conditioning required in the Control Building in the event of a flood above plant grade is for the Elevation 755.0 rooms, including the MCR.
Equipment used during the flood mode operation includes the MCR air-conditioning subsystem components on Control Building Elevation 755.0 and the water chillers and the chilled water circulating pumps on Auxiliary Building Elevation 737.0. Equipment located at floor Elevation 755 of the Control Building is unaffected by the design basis flood. The water chillers and chilled water circulating pumps serving the MCR air handling units located in the Auxiliary Building at floor Elevation 737 are functional for floods up to the design basis flood level. Refer to Section 2.4.14 for additional discussion of the plant flood protection plan.
9.4.1.4 Tests and Inspection Historical Information: The system was tested initially as part of the preoperational test program (Chapter 14.0)
The Control Building air-conditioning systems are in continuous operation and are accessible for periodic inspection. After maintenance or modification activities that affect a system function, testing is done to reverify the system or component operation.
The building emergency pressurizing air supply fans and air cleanup assemblies are tested periodically. Details of the testing program for the air cleanup units are included in Section 6.5.
Details of the radiation monitors are included in Section 11.4.
The battery rooms ventilating system is in continuous operation. The exhaust fans are accessible for periodic inspection.
9.4-8                                      AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                       WBNP-97 9.4.2 Fuel Handling Area Ventilation System 9.4.2.1 Design Bases The fuel handling area ventilation system, a subsystem of the Auxiliary Building ventilating system, serves the fuel-handling area at Elevation 757, the penetration rooms at Elevation 737,Elevation 757 and Elevation 782, and the fuel, waste, and cask handling areas at Elevation 729 and Elevation 692.
The system is designed to: (1) maintain acceptable environmental conditions for personnel access, operation, inspection, maintenance, and testing, (2) protect mechanical and electrical equipment and controls, and (3) limit the release of radioactivity to the environment during all weather conditions. The environmental control system is designed to maintain building temperatures between 60&deg;F minimum and 104&deg;F maximum.
During accident conditions, the fuel handling area ventilation system is shut down and all environmental control is handled by the Auxiliary Building gas treatment system (ABGTS), described in Section 6.2.3.
All ductwork, dampers, and grilles of the fuel handling area ventilation system essential to operation of the ABGTS are designed to Seismic Category I and Safety Class 2b requirements. Each fueling handling area exhaust fan is provided with a primary circuit breaker and a shunt trip isolation switch which is tripped by a signal of the opposite train from that for the primary circuit breaker to ensure that power is isolated from the fan. All other system components, including exhaust fans and remaining ductwork and dampers, are designed to Seismic Category I(L) requirements.
To control airborne activity, ventilation air is supplied to clean areas, then routed to areas of progressively greater contamination potential. The fuel handling area is maintained at a slightly negative pressure to limit outleakage, and can be physically isolated from the outdoors in case of radiological contamination.
Air utilized to ventilate the fuel handling area, waste packaging, and cask shipping area is exhausted through the fuel handling area exhaust fans. An exhaust duct system from the waste packaging area and cask loading area is connected to a duct system around the periphery of the spent fuel pit and fuel transfer canal. Thus, exhaust air from the fuel handling area passes across the spent fuel pit forming an air curtain across the pool. During periods of irradiated fuel movement in the fuel transfer canal, air curtain exhaust flow at the fuel transfer canal area is required to be interrupted. The fuel transfer canal exhaust flow is isolated to prevent the uptake of source terms emitted during a postulated fuel handling accident in the fuel transfer canal and to support proper spent fuel pool accident radiation monitor operation.
Exhaust is provided by two 100% capacity fuel handling area exhaust fans. During normal operation one fan is in operation with the other on standby. Both fans discharge to the Auxiliary Building exhaust stack.
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                         9.4-9

WATTS BAR                                                                                   WBNP-97 An inlet damper furnished with each fuel handling area exhaust fan is used to regulate the volume of air exhausted as required to maintain a 1/4 inch negative pressure within the building. These dampers are automatically operated by static pressure controllers.
During periods of high radiation in the fuel handling area or upon initiation of a containment isolation signal, or for high air temperature at the supply intake the Auxiliary Building supply and exhaust fans and the fuel handling exhaust fans are automatically stopped and isolation ldampers located in the ducts that penetrate the Auxiliary Building Secondary Containment Enclosure (ABSCE) are closed.
Additionally, during refueling operations when containment and/or the annulus is open to the Auxiliary Building ABSCE space, a Containment Vent Isolation (CVI) signal will automatically stop the above described fans and close the same isolation dampers as described above. Sinilarly, the high radiation signal in the fuel handling area can also automatically initiate a CVI during refueling operations when containment and/or the annulus is open to the Auxiliary Building ABSCE spaces.
An isolation barrier is thus formed between the building and the outdoor environment, and the Auxiliary Building gas treatment system (ABGTS) is started up automatically (see Section 6.2.3) to maintain the ABSCE at less than a 1/4-inch water gauge negative pressure during these high radiation or accident periods.
The fuel-handling area ventilation system is located completely within Seismic Category I structures and all safety-related components are fully protected from floods and tornado-missile damage.
9.4.2.2 System Description The fuel-handling area ventilation system is shown on Figure 9.4-8, on logic Figures 9.4-9 and 9.4-10, and on control Figures 9.4-11 and 9.4-17.
The fuel-handling area is supplied with outdoor air from the Auxiliary Building general ventilation air supply system, described in Section 9.4.3. All supply air is ducted to clean areas of the fuel-handling area from where it flows to areas of progressively greater contamination potential before being exhausted through a duct system by the exhaust fans. The fuel-handling area exhaust fans are capable of being connected to emergency power.
The cask decontamination area on Elevation 729 is ventilated by a separate supply fan which circulate air through the area when the decontamination room is in use. This air flow assures an acceptable environment for motor reliability and preservation.
The cask decontamination room is kept under negative pressure at all times since the room is connected to the fuel handling area exhaust ductwork.
9.4.2.3 Safety Evaluation A fuel handling accident in the Auxiliary Building is detected by the two gamma radiation detectors mounted above the fuel pool, as shown in Figure 9.4-12. The high radiation signals via redundant trains will then shut off the fuel handling and Auxiliary Building general supply and exhaust fans and start the ABGTS, as shown in Figures 9.4-10                                  AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                     WBNP-97 9.4-9 and 9.4-10. To accomplish its safety function following a fuel handling accident, the fuel handling area ventilation system must accomplish the following functions:
(1)   Isolate the normal ventilation pathways between the spent fuel pool and the environment.
(2)  Filter the contaminants out of the air by the ABGTS before exhausting it to the environment.
The two redundant radiation monitors (safety-related) located above the spent fuel pit assure that the accident is promptly detected and that a high radiation signal is provided to each ventilation train, even if one monitor fails. Also,during refueling operations when containment and/or the annulus is open to the Auciliary Building ABSCE spaces, a Containment Vent Isolation (CVI) signal is procedurally configured to assure that a fuel handling accident in containment is promptly detected and the CVI signal is provided to each ventilation train.
In addition, the Auxiliary Building radiation monitor (non-safety related) which monitors the Auxiliary Building exhaust vent is also capable of providing a high radiation signal to the MCR.
A high radiation signal from either of the monitors located above the spent fuel pitor a CVI signal whenever containment and/or the annulus is open to the Auxiliary Building ABSCE spaces during refueling operations causes the fuel handling area (FHA) and Auxiliary Building general supply and exhaust fans to shut down and their associated dampers to close, as shown in Figures 9.4-9 and 9.4-10. Each of the two FHA exhaust fans has both train A and train B dampers, to ensure building isolation in the event of one dampers failure to close. As an added safety feature, all ABSCE boundary isolation dampers are designed to fail-closed on loss of instrument air or electrical power..
These two monitors also start the ABGTS upon detection of a high radiation signal in the Auxiliary Building spent fuel pool area. See Section 6.2.3 for a further analysis of the ABGTS.
From the study of anticipated failure modes and the analysis of their associated effects, it has been determined that the safety-related portions of the system are capable of functioning in spite of the loss of any active component. See Tables 9.4-8, 9.4-8A, and 9.4-8B for a detailed failure modes and effects analysis (FMEA) on the Auxiliary Building (including fuel handling area) HVAC system.
During normal operation the fuel handling areas are continuously maintained at a slightly negative pressure relative to outdoors to minimize outleakage.
During periods of high radiation or upon initiation of a Auxiliary Building isolation signal, the ABSCE , which includes the fuel handling areas, is maintained at a nominal AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                       9.4-11

WATTS BAR                                                                                    WBNP-97 1/4-inch water gauge negative pressure by the ABGTS. See Sections 9.4.3 and 6.2.3 for further information.
9.4.2.4 Inspection and Testing Historical Information: The system is tested initially as part of the preoperational test program.
The fuel handling area ventilation system is in continuous operation and is accessible for periodic inspection. After maintenance or modification activities that affect a system function, testing is done to reverify the system or component operational/functional integrity.
Details of the radiation monitors are included in Section 11.4.
See Section 6.2.3.4 for inspection and testing requirements for the ABGTS.
9.4.3 Auxiliary Building and Radwaste Area Ventilation System 9.4.3.1 Design Bases The Auxiliary Building ventilating systems serve all areas of the Auxiliary Building including the fuel handling area (see Section 9.4.2) and the radwaste areas. Separate subsystems are utilized for the environmental control of the shutdown board rooms, auxiliary board rooms, and other miscellaneous rooms and laboratories. The ventilating systems also incorporate individual cubicle coolers to provide supplementary cooling to specific safety feature equipment.
The Auxiliary Building ventilating systems are designed to: (1) maintain acceptable environmental conditions for personnel access, operation, inspection, maintenance and testing, and for protection of mechanical and electrical equipment and controls, and (2) control airborne activity during outside environmental conditions as stated on the Environmental Data drawings.
The shutdown board, auxiliary control, and battery board rooms at Elevation 757 and the auxiliary board and battery rooms at Elevation 772 are cooled by mechanical refrigeration to maintain the room temperatures within the range for which the equipment is environmentally qualified.
To control airborne activity, ventilation air is supplied to clean areas, then exhausted through areas of progressively greater contamination potential. Ventilation system design ensures that the areas of the building which are subject to radioactive contamination are maintained at a slightly more negative pressure to limit outleakage.
All exhaust air from the Auxiliary Building is routed through a duct system, and is discharged past a radiation monitor and into the Auxiliary Building exhaust vent, except the shutdown board rooms, auxiliary control room, battery board rooms on Elevation 757, and auxiliary board rooms, battery rooms, and transformer rooms on Elevation 772, which are not tied to the Auxiliary Building exhaust.
9.4-12                                   AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                      WBNP-97 Upon indication of high radiation in the fuel handling area of the Auxiliary Building, high temperature in the Auxiliary Building air intake(s), or upon a safety injection signal from either reactor unit, the Auxiliary Building supply and exhaust fans are automatically stopped and isolation dampers located in the ducts which penetrate the ABSCE are closed to complete the isolation barrier. In addition, a containment vent isolation signal during fuel handling operations with containment and/or the annulus open to the Auxiliary Building ABSCE spaces will result in the above actions. Two 100% capacity gas treatment system filter trains consisting of air heaters, prefilters, HEPA filters and carbon absorbers, are automatically energized and a reduced quantity of building exhaust is diverted through the filter trains and discharged into the Shield Building exhaust vent (see Section 6.2.3). The exhaust vent is located within the annulus space of the Reactor Building and extends to the top of the Reactor Building.
Upon detection of smoke in the Auxiliary Building air intake rooms (Units 1 and 2), the affected units Auxiliary Building general ventilation air supply fans are automatically stopped and their isolation dampers closed.
The HVAC components in the shutdown board rooms, auxiliary board rooms, shutdown transformer rooms, ABGTS, and Auxiliary Building ESF coolers, associated ductwork and piping are designed to Seismic Category I requirements. Other parts of the Auxiliary and Radwaste Area ventilation system are designed to meet Seismic Category I(L) requirements.
For safety-related portions of the system, components are designed to assure that a single active failure cannot result in the loss of a safety-related function. This is accomplished by using 100% redundancy where required as described in the following sections. The Auxiliary Building is structurally designed to resist damage by missiles, either internally or externally produced. Specific design considerations for missile protection are also described in the following subsections 9.4.3.2 System Description The Auxiliary Building ventilation systems are shown on Figures 9.4-13, to 9.4-16, on logic Figures 9.4-9 and 9.4-10, and on control Figures 9.4-11 and 9.4-17. The auxiliary and radwaste area ventilation systems consist of the following subsystems:
(1)   Building air supply and exhaust system (general ventilation)
(2)   Building cooling system (chilled water)
(3)   Safety features equipment coolers (4)   Shutdown board room air-conditioning system (5)   Auxiliary board and battery room air-conditioning system (6)   Shutdown transformer room ventilation system (7)   Miscellaneous ventilation and air-conditioning system AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                         9.4-13

WATTS BAR                                                                                     WBNP-97 9.4.3.2.1 Building Air Supply and Exhaust Systems (General Ventilation)
The Auxiliary Building air supply system filters 100% of outdoor air through a bank of filters for each of two mechanical equipment rooms located at opposite ends of the building at Elevation 737.0.
Ventilation supply air is heated or cooled at the air intake, as needed, to maintain suitable temperatures in the Auxiliary Building general spaces, for equipment protection and personnel comfort during normal operation.
The air supply system utilizes four 50% capacity supply fans, two being located in each of the two mechanical equipment rooms at Elevation 737.0. During normal operation, one fan in each equipment room is in operation with the other fan in the standby mode.
Supply air is ducted to various clean or accessible areas of the Auxiliary Building from which it flows to areas of progressively greater contamination potential before being exhausted through a duct system by the building exhaust fans. In the event of a fuel-handling accident, radiation monitors in the vicinity of the spent fuel pool initiate an Auxiliary Building isolation (ABI) signal which stops the building ventilation system and starts the ABGTS fans (see Sections 9.4.2 and 6.2.3). An ABI signal can also be initiated manually. In addition, during fuel handling operations when the containment and/or the annulus is open to the Auxiliary Building ABSCE spaces, a high radiation signal from the spent fuel pool radiation monitors will result in a containment ventilation isolation (CVI) in addition to an Auxiliary Building isolation and ABGTS start. Further, a CVI signal, including a CVI signal generated by a high radiation signal from the containment purge air exhaust radiation monitors, will initiate an Auxiliary Building isolation and start of ABGTS. These actions will ensure proper operation of the ABSCE.
The building supply air is provided by centrifugal fans located downstream of the heating/cooling coils. These fans which operate only during normal operating conditions, are not engineered safety features.
The general exhaust air from the Auxiliary Building is provided by four exhaust fans each rated at 50% of system capacity. These fans are located on the roof of the Auxiliary Building and discharge into the Auxiliary Building exhaust stack.
An inlet damper in series with each Auxiliary Building exhaust fan is used to regulate the volume of air exhausted as required to maintain the required negative pressure within the building with respect to the outside environment.
The isolation dampers and the ductwork between these dampers that make up part of the ABSCE are designed to the requirements of Safety Class 2b and Seismic Category I. For the exhaust fans, the trip circuits for the primary circuit breaker and the shunt trip isolation switch arranged in series with the primary circuit breaker are designed as Class 1E. All other portions of this system are Seismic Category I(L).
9.4-14                                   AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                     WBNP-97 9.4.3.2.2 Building Cooling System (Chilled Water)
The purpose of the Auxiliary Building chlled water cooling system is to supplement the general ventilation system and to maintain temperatures within design limits in the general spaces of the Auxiliary Building during normal plant operating conditions. The cooling system consists of two 100% capacity packaged water chillers, two 100%
capacity primary loop circulating pumps, two 100% capacity secondary loop circulating pumps, heating/cooling coils, fan-coil type air handling units, and associated piping, ductwork, and controls.
9.4.3.2.3 Safety Feature Equipment Coolers The safety feature equipment coolers are described in Section 9.4.5.3.
9.4.3.2.4 Shutdown Board Room Air-Conditioning System Shutdown board rooms are located on Elevation 757.0 of the Auxiliary Building with a firewall separating Units 1 and 2 equipment. The electrical boards for either unit can provide the service necessary for the safe shutdown of both plant units following an accident in either unit. Environmental control is provided by four fan-coil air-handling units supplied with chilled water from two 100% redundant water chillers.
Environmental control for the auxiliary control room is maintained by the SDBR air-conditioning system. The four SDBR air-handling units are arranged so that each shutdown board room and battery board room is cooled by either of two redundant (train A or B) air-handling units. Each pair of Train A and Train B units is located in its respective reactor unit's mechanical equipment room. The air distribution system is arranged such that the auxiliary control room is cooled by two of the four fan-coil units from different equipment rooms. Four unit heaters provide heating as required to maintain the minimum design ambient conditions. Each SDBR air-conditioning system is connected to an emergency power source and rejects heat to the ERCW system.
Upon loss of offsite power, emergency power to both SDBR air-conditioning system chillers is automatically re-established in sequence by the diesel generator in accordance with FSAR Table 8.3-3. One of the two redundant chillers is normally operating and the other is in standby. The standby chiller starts if the operating chiller fails. The SDBR air-conditioning system is designed to meet Safety Class 2b and Seismic Category I requirements.
Each of two pairs of 100% capacity pressurizing fans is designed to maintain the SDBRs at a slight positive pressure with respect to the outdoors.
Each of the two air-handling units and each of the two pressurizing air supply fans serving one set of SDBRs is powered by different power trains.
Redundant tornado dampers are installed in the Elevation 757 shutdown board room pressurizing supply fan ductwork which extends to Elevation 772; this ductwork is designed for a pressure differential of 3 lb/inch2. In addition, ductwork penetrating the Elevation 757 personnel and equipment access rooms from the emergency gas treatment system and blowdown treatment rooms is designed for 3 lb/inch2. Thus, the AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                       9.4-15

WATTS BAR                                                                                    WBNP-92 Elevation 757 electrical equipment areas are protected from tornado-induced depressurization.
9.4.3.2.5 Auxiliary Board Rooms Air-Conditioning Systems The Auxiliary Building electrical boards, located on floor Elevation 772.0, are separated into two sub-areas per unit corresponding to Train A and Train B emergency power. Four separate air-conditioning systems are provided, one to serve each of the four board room sub-areas. Train B areas which contain both Train A and Train B electrical equipment are cooled by Train A and Train B air conditioning subsystems.
Following an accident, the electrical boards in either sub-area have the capability to support a safe shutdown of the unit. Because each sub-area is served by an attendant air-conditioning system sized to remove 100% of the heat produced by electrical equipment in that sub-area, full redundancy is provided.
The Train A air-conditioning equipment located within the Elevation 772.0 mechanical equipment room and the Train B air-conditioning equipment located on the roof above are provided structural protection from environmental hazards, including tornado missiles, and floods. The system is also designed to meet Safety Class 2b and Seismic Category I requirements.
Each board room air-conditioning system contains a refrigerant compressor, air-cooled condenser, fan-coil air handling unit with direct expansion cooling coils, two 100%
pressurizing air supply fans, air supply distribution system and control and safety devices.
Two 100%-capacity roof ventilator exhaust fans located on the roof of each of the four separate battery rooms on Elevation 772.0 provide continuous ventilation to prevent the possible accumulation of dangerous hydrogen gas.
The two 100%-capacity pressurizing air supply fans per air-conditioning system serve a twofold purpose. One is to replace a portion of air-conditioning system air exhausted through the battery room and the other is to pressurize the electrical board room to prevent infiltration of contaminated air. The mixture of this makeup air and board room return air is conditioned upon passing through the air handling unit.
One pressurizing air supply fan and one battery room exhaust fan in each individual air-conditioning system are connected to Train A electric power, and the remaining fans are connected to Train B power. Control system interlocks provide simultaneous operation of the pressurizing air supply fan and battery room exhaust fan. The availability of this fan combination on either power train ensures continuous ventilation in each battery room regardless of operability of the direct-expansion air-conditioning equipment. In the event of air-conditioning system failure, pressurizing fan air is drawn through the normal board room supply ducts by the battery room exhaust fan.
Condensing unit cooling air for the Train A air-conditioning system of each plant unit is routed from intakes located on the roof at Elevation 786, through the condenser, and discharged through a roof-mounted exhaust housing. The Train B system condenser 9.4-16                                   AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                     WBNP-97 cooling air is drawn through an intake on the side of the equipment housing on the roof and is discharged through an exhaust opening atop the equipment housing.
Each Train A and each Train B room air conditioning system air handling unit is designed to maintain the room temperature within the range for which the equipment is environmentally qualified. The minimum temperature is 50&deg;F for the board rooms and the battery rooms. The maximum temperature for each room is 104&deg;F. This ensures that the equipment and components are not exposed to environmental conditions that could degrade the operability of safety-related equipment.
Each battery room exhaust fan has a damper capable of withstanding pressure differentials imposed by tornado conditions. The dampers are mounted below the fans at Elevation 786.0. Small ventilation holes are provided in each damper frame between the exhaust fan and the damper to allow continuous venting of hydrogen gas even when the damper is closed. Each of these dampers is interlocked with its respective exhaust fan such that it will provide isolation of the fan when it is not operating. These dampers are locally operated and will automatically close when the exhaust fans are turned off upon tornado warning.
The fifth vital battery room exhaust fans also have dampers capable of withstanding pressure differentials imposed by tornado conditions. The dampers are mounted below the Elevation 786.0 between the ceiling and the in-line fan.The fifth vital battery room is cooled by air which is drawn from the 480 V Board Room 1A through an opening in the common partition wall at the T line and is exhausted directly to the outside. This configuration is similar to that of the four battery rooms discussed above, with the exception that the exhaust fans are in-line axial fans and are located in the room. The cooling system is designed to maintain temperatures in this room within the range of 50&deg;F to 104&deg;F, and for continuous venting of hydrogen gas.
9.4.3.2.6 Shutdown Transformer Room Ventilating Systems The shutdown transformers, located on Elevation 772.0, are located in Unit 1 and Unit 2 sub-areas. Each one of these two sub-areas contains three Train A, three Train B and one nondivisional transformers.
Outside air enters each sub-area through air intake structures located on the Auxiliary Building roof. Each roof-mounted exhaust ventilator is energized from the same train of the emergency power system that supplies power to the transformer for which it provides ventilation. Exceeding the temperature setpoints in a room automatically starts the exhaust fans, and open the air operated dampers in the two air intake structures. Manually starting the exhaust fans also opens the air-operated dampers in the two air intake structures.
Electric motor-driven centrifugal-type roof exhaust fans in the individual transformer rooms are staged by thermostatic control to maintain the transformer temperatures within the range for which the safety-related equipment is environmentally qualified.
The pneumatically-operated air intake dampers have the capability of being manually powered to the open position without regard to thermostatic control by starting a fan.
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                      9.4-17

WATTS BAR                                                                                   WBNP-97 This ventilation system is designed to maintain the temperature in the transformer rooms within the range 19&deg;F minimum and 110&deg;F for which the equipment is environmentally qualified.
The system is designed to meet Safety Class 2b and Seismic Category I requirements.
9.4.3.2.7 Auxiliary Building Miscellaneous Ventilation and Air Conditioning Systems The control rod drive equipment room design temperature limits are maintained by two 100% capacity non-safety air-conditioning units located in each room. During normal operation, one of the air-conditioning units in each room is in operation with the other on standby. Each unit is automatically controlled by a self-contained thermostat.
Electric unit heaters are located in each room to provide heating during cold weather.
The hot instrument shop is cooled by a chilled water cooling coil which utilizes 100%
makeup air to prevent the recirculation of any contaminants. The hot instrument shop exhaust is provided by a lab exhaust hood which is connected to the general building exhaust duct system.
The sample room is ventilated by five lab hoods, each with an exhaust fan. Air enters the sample room through doors with transfer grilles and back draft dampers. Each hood is provided with a separate exhaust fan and HEPA filter assembly. A differential pressure gauge is used to indicate the need for filter replacement. Each hood exhaust fan discharges into the general building exhaust system.
The Additional Equipment Buildings are cooled by non-safety related packaged air-conditioning units.
The Reactor Building steam valve rooms are cooled by independent ventilation systems, each consisting of two roof mounted exhaust fans. (See Failure Modes and Effects Analysis in Table 9.4-10).The fans draw outside ventilation air for room cooling through a wall opening near the floor. Space temperature is controlled by dampers which modulate airflow in response to a wall mounted thermostat. The exhaust fans operate until a low temperature setpoint is reached when the fans automatically stop.
9.4.3.3 Safety Evaluation Functional analyses and failure modes and effects analyses have shown that the auxiliary and radwaste area ventilation system has the capabilities needed for normal operations and for accident mitigation. These are described in the sections that follow.
9.4.3.3.1 Auxiliary Building General Ventilation System A functional analysis of the general ventilation system shows that:
(1)   Adequate ventilation is provided to achieve acceptable air flow patterns needed for airborne activity control. See Section 9.4.3.2.1.
9.4-18                                  AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                     WBNP-97 (2)   There are three different signals that will automatically cause the system to change from the normal operating mode to the accident mode, the Phase A containment isolation signal, the high temperature signal from the Auxiliary Building air intakes, and the high radiation signal from the fuel handling area radiation monitors. Either a Train A or a Train B signal from any of these sources will cause the system to change to the accident mode of operation.
(3)   Ventilation fan operations cease and isolation dampers in the intake and exhaust ducting close in the accident mode of operation. Air flow patterns and air cleanup operations appropriate for accident mitigation during the accident mode of operation are established and maintained by the ABGTS.
See Section 6.2.3 for further information.
(4)   A smoke detection signal from either the Unit 1 or the Unit 2 Auxiliary Building air intake, will shut down that units supply fans and close their discharge isolation dampers.
(5)   During normal mode operations, substandard airflow are detected by a low flow sensor and this sensor signals the MCR for operators to verify automatic start up of fan(s). Each redundant Auxiliary Building general ventilation supply and exhaust fan is automatically started upon low flow detection of the operating fan.
The failure modes and effects analyses performed on safety related systems interfacing with the general ventilation system have shown that:
(1)   A failure of any one of the two radiation monitors above the spent fuel pool does not prevent a high radiation signal from being relayed to necessary isolation components.
(2)   A failure of the whole or any part of either Train A or Train B components to complete isolation does not prevent total isolation. Each supply and exhaust line to the environment is equipped with both Train A and Train B low leakage isolation dampers.
(3)   Essential portions of the system remain functional after a seismic event because of their design to Seismic Category I requirements. Nonessential portions of the system and other systems located close to essential components and not designed to Seismic Category I standards are designed to Seismic Category I(L) standards to prevent their failure from precluding operation of essential system components.
(4)   All essential isolation valves and their associated ductwork are located above the maximum flood level in a Seismic Category I building that is designed to resist damage by tornado missiles.
(5)   A loss of power causes closure of the isolation dampers by virtue of their fail-safe design (closed when unpowered). Preferred air flows will be maintained by the ABGTS.
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                       9.4-19

WATTS BAR                                                                                    WBNP-97 9.4.3.3.2 Building Cooling System This system serves no safety-related function. The air handling units and their associated piping, valves, ductwork, and dampers are all designed to Seismic Category I(L) requirements to prevent their failure from endangering safety-related equipment.
9.4.3.3.3 Safety Feature Equipment Coolers This system is discussed in Section 9.4.5.3.
9.4.3.3.4 Shutdown Board Room Air-Conditioning System A functional analysis of the shutdown board room air-conditioning system shows that:
(1)   During all modes of operation, the system will maintain adequate air temperatures to assure optimum operation of the safety-related equipment it serves. See Section 9.4.3.2.4.
(2)   There are redundant pressurizing air supply fans serving each of the two sub-areas to maintain a slightly positive pressure in the shutdown board areas to minimize contaminated inleakage.
The failure modes and effects analyses provided in Table 9.4-9 has shown that:
(1)   During all operational modes, substandard cooling or pressurizing air flows are detected by local sensors and a corresponding warning is provided to the main control room.
(2)   A failure of one air handling unit initiates the startup and loading of the standby redundant unit.
(3)   The failure of one of the two pressurizing air supply fans serving each shutdown board area is detected by local sensors and a signal is provided to activate the standby redundant fan.
(4)   The essential components of the system are designed to Seismic Category I standards to assure that they remain functional after a seismic event.
(5)   All components of this system are located above the maximum probable flood level and are in a Seismic Category I building that is designed to resist damage by tornado missiles.
(6)   Electrical components of this system are powered by one of two trains of emergency electrical power to ensure their operability upon loss of offsite power.
9.4.3.3.5 Auxiliary Board Rooms Air-Conditioning System A functional analysis of the auxiliary board rooms air-conditioning system shows that:
9.4-20                                   AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                    WBNP-97 (1)   During all modes of operation, the system maintains adequate air cooling to assure optimum operation of the safety-related equipment it serves. See Section 9.4.3.2.5.
(2)   Two redundant pressurizing air supply fans serve each of the four sub-areas to maintain a slightly positive pressure in the sub-area to minimize contaminated inleakage.
(3)   The four battery rooms receive continuous ventilation air supplies to prevent any accumulation of hydrogen gas.
The failure modes and effects analysis in Table 9.4-5 has shown that:
(1)   During all operations, substandard cooling or pressurizing air flows are detected by local sensors and a corresponding warning is provided in the main control room.
(2)   Failure of the air handling unit serving one of the two sub-areas per plant unit does not prevent the remaining sub-area and its air handling unit from accomplishing all the safety-related functions of the auxiliary board area for that unit. Essential Train A electrical equipment located in the Train B 480V board rooms is spot cooled by the Train A HVAC system, assuring it's operability should the Train B HVAC system fail.
(3)   The failure of one of the two pressurizing air supply fans serving each of the four auxiliary board sub-areas is detected by local sensors and a signal is provided to activate the standby redundant fan.
(4)   A battery room exhaust fan failure causes automatic activation of the standby exhaust fan and activates an alarm in the MCR. If the air supply to a battery room from the corresponding air handling unit is lost, air is provided by the associated pressurizing air supply fan.
(5)   Essential portions of the system are designed to Seismic Category I standards to assure that they remain functional after a seismic event.
Nonessential portions of this system and other systems located close to essential components are designed to Seismic Category I(L) requirements to prevent their failure from precluding operation of essential system components.
(6)   All components of this system are located above the maximum probable flood level and are in a Seismic Category I building that is designed to resist damage by tornado missiles.
(7)   Upon a loss of offsite power, all essential functions provided by this system are powered by two trains of emergency electrical power.
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                      9.4-21

WATTS BAR                                                                                    WBNP-97 9.4.3.3.6 Shutdown Transformer Room Ventilating System A functional analysis of the shutdown transformer room ventilating system shows that adequate ventilation air flow is provided to the transformer rooms to maintain environmental conditions conducive to optimum transformer operation.
The failure modes and effects analyses in Table 9.4-6 indicate that:
(1)   Failure of one or more fans in each room results in room temperature rise which is detected by temperature sensors located in the room. This alerts the operators to activate other available exhaust fans in the same room to replace the damaged unit(s).
(2)   Loss of flow through one of the two intake structures serving each transformer room would be no safety concern since the second intake opening also opens (both intake structures open simultaneously).
(3)   All required portions of this system are designed to Seismic Category I requirements to assure that they remain functional after a seismic event.
Other components, and systems, located close to this system are qualified to either Seismic Category I or I(L) standards; therefore, their failure can not preclude operation of this system.
(4)   All components of this system are located above the maximum probable flood level and are in a Seismic Category I building that is designed to withstand the effects of tornado missiles. Where components are subject to tornado-generated missile damage, operator actions have been defined in the event of damage.
(5)   In the event of a loss of offsite power, emergency electrical power is provided to the transformers and their associated exhaust fans. One of the two sub-areas serving each unit is provided with Train A power and the other with Train B power.
9.4.3.3.7 Auxiliary Building Miscellaneous Ventilation and Air-Conditioning System The miscellaneous ventilation and air-conditioning systems do not perform a safety function, however, the system components are designed to seismic category I(L) as necessary for the protection of safety related features.
The main steam valve vault ventilation exhaust airflow is regulated to maintain an adequate temperature environment for the main steam safety valves. During low temperature conditions, the exhaust fans are shutdown and electric heating is provided. The ambient temperature in the valve vault is periodically monitored in accordance with the Technical Requirements Manual area temperature monitoring program.
9.4-22                                   AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                      WBNP-97 9.4.3.4 Inspection and Testing Requirements Historical Information: The system is tested initially as part of the preoperational test program. See Section 14.2 for testing acceptance criteria.
The Auxiliary Building environmental control systems are in continuous operation and are accessible for periodic inspection. After maintenance or modification activities that affect a system function, testing is done to reverify the system or component operation.
See Sections 6.2.3.4 and 9.4.5.3.4 for inspection and testing requirements of the ABGTS and the ESF coolers.
Details of the radiation monitors are discussed in Section 11.4.
9.4.4Turbine Building Area Ventilation System 9.4.4.1 Design Bases The turbine building heating, cooling and ventilating systems are designed to maintain an acceptable building environment for the protection of plant equipment and controls; for the comfort and safety of operating personnel; and to allow personnel access for the operation, inspection, maintenance, and testing of mechanical and electrical equipment. The areas served by these systems are not considered potentially radioactive because the reactor is of the pressurized water type which does not normally produce radioactive steam. Potential sources of radioactivity were not, therefore, considered in establishing air flow paths, and the air flows are not monitored for radiation. For additional information on facility design features for radiation protection, refer to Section 12.3.1 The building's environmental control systems are designed to maintain building temperatures between a minimum of 50&deg;F and a maximum of 110&deg;F, by use of forced ventilation, mechanical cooling, and heating systems.
9.4.4.2 System Description The building can be considered to contain four large rooms: El 755.0 turbine room, El 729.0 spaces, El 708.0 spaces, and elevation 685.5 spaces. See Figure 9.4-18.
Because the El 755.0 floor is predominantly concrete and thus isolated from the floors below, the turbine building ventilation is provided by two separate systems. One system serves El 755.0 spaces, and the other system provides ventilation for the spaces on El 729.0 and El 708.0. Because the El 708.0 floor is predominantly grating, air supplied to El 708.0 spaces also provides ventilation for spaces on El 685.5.
Both ventilation systems operate on the basis of mechanically supplying the required flow of outside air to spaces being ventilated, and exhausting the building air to outdoors.
Each supply and exhaust fan is provided with a motor operated damper designed to automatically close when the fan is stopped, in order to prevent air back flow. Outside air is distributed to areas of heat concentration either by duct distribution systems or by AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                        9.4-23

WATTS BAR                                                                                     WBNP-94 induction using the negative pressure caused by operation of roof exhaust fans, through strategically located air intake openings.
9.4.4.2.1 Elevation 755.0 Ventilation The ventilation system for elevation 755.0 consists of two mechanical air supply systems, one on the north side and the other on the south, free-air-intake openings on the east and west walls, and exhaust fans on the elevation 820.0 roof. Total air exhausted is 570,000 cfm, whereas only 206,000 cfm is mechanically supplied through supply ducts. The remaining 364,000 cfm is drawn through the east and west free-air-intake openings by the negative pressure created by the operation of exhaust fans.
9.4.4.2.2 Elevation 729.0 and Elevation 708.0 Ventilation The elevation 729.0 and elevation 708.0 ventilation system consists of two mechanical air supply systems, one on the north side and the other on the south, and exhaust fans on the elevation 755.0 roof. A total of 412,000 cfm is exhausted, and a total of 412,000 cfm outside air is supplied.
9.4.4.2.3 El. 685.5 Ventilation There is no direct air supply to, or exhaust from, the El. 685.5 areas. However, the El.
708.0 floor above it is predominately grating; therefore, the air supplied to El. 708.0 spaces, and the circulation effected by the space and pump coolers located on El.
685.5, together, provide adequate ventilation for spaces on this floor.
9.4.4.2.4 Cold Weather Building Pressurization During cold weather, all supply and exhaust systems can be isolated by closing the motor operated dampers to conserve heat. However, the two supply fans serving north elevation 708.0 floor may be operated at half speed since two hot water heating coils located in the supply duct connected to each of these fans heat the incoming air. With no exhaust fan running, the operation of these two supply fans will pressurize the entire Turbine Building to prevent infiltration of cold outside air. However the very slight positive pressure within the Turbine Building at the Main Control Room Habitability Zone (MCRHZ) elevation does not challenge the MCRHZ required positive minimum pressure of +1/8 inch water gage with respect to the outdoors and adjacent areas during both normal or emergency modes of operation.
9.4.4.2.5 Miscellaneous Ventilating Systems The three toilet rooms and three janitor's closets are each ventilated by roof-mounted, roof-ventilator type exhaust fans. Plant air enters each room through a louvered door and is exhausted into the main room.
The lubricating oil purification room at elevation 708.0 is ventilated by a centrifugal fan mounted on the room wall, which discharges to the outdoors by means of a duct routed to a basement exhaust housing. A fire damper, mounted in the exhaust opening, and the room firedoor are designed to shut off all airflow in case of fire.
9.4-24                                    AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                     WBNP-94 The elevator machinery room at elevation 708.0 is ventilated by a wall-exhauster type fan. The lubricating oil dispensing room at elevation 708.0 is ventilated by a wall-exhauster type fan. A fire damper mounted in the exhaust opening and the room's firedoor are designed to shut off all airflow in case of fire.
9.4.4.2.6 Coolers Fan-coil type raw water cooled cooling units have been installed throughout the Turbine Building to supplement the building ventilation system during peak cooling load conditions. Each cooling unit consists of a centrifugal fan and its motor, and a finned tube type water coil through which raw cooling water is circulated and over which air is passed and cooled.
Space coolers located on different elevations help prevent concentration of heat produced by various plant equipment by recirculating air in their immediate vicinities and so establishing the desired airflow patterns.
Pump coolers located in areas where miscellaneous turbine building pumps dissipate large amounts of heat, are each designed to remove heat produced by its pump to maintain maximum ambient temperature at 110&deg;F.
9.4.4.2.6.1 Space Coolers Space coolers are located on elevation 729.0, elevation 708.0, and elevation 685.5 floors. A thermostat located near the return airflow to each cooler controls a solenoid valve on the raw cooling water supply line to each coil and the cooler fan. The solenoid valve and the fan on each cooler are interlocked to operate together.
9.4.4.2.6.2 Pump Coolers Pumps and the fans of the coolers assigned to them are interlocked to run simultaneously. However, raw cooling water to each cooling coil can be turned off and on manually to conserve water during off time. These coolers are not controlled thermostatically.
9.4.4.2.7 Building Heating System The building heating system serves the Turbine Building and the air preheating coils belonging to the auxiliary building general ventilation system, and the Reactor Building purge air preheating coils.
The heating system is a high-temperature hot water, closed, forced-circulation loop.
The system consists of two 100% capacity water circulating pumps, two 70% capacity steam to water heat exchangers, tanks, heating coils, space and unit heaters, nitrogen pressurization, demineralized water makeup, chemical treatment, controls, and supply and return water distribution piping.
Steam is normally taken from the turbo-generator cold reheat cycle during operation of either unit, or is taken from the plant auxiliary boiler during plant shutdown or when AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                     9.4-25

WATTS BAR                                                                                    WBNP-94 both units are operating at less than 55% power. The heating system heat exchangers, pumps, and tanks are located at elevation 729.0 along the north end of Unit 2.
The heating system is designed to maintain the Turbine Building at a minimum temperature of 50&deg;F with both units shutdown and a 13&deg;F outdoor temperature. Heat is distributed by thermostatically controlled hot water unit and space heaters strategically located throughout the Turbine Building and by hot water heating coils mounted in the north elevation 708.0 air supply ducts. See Figures 9.4-19 and 9.4-20.
Fresh air may be supplied (136,000 cfm for plant) through the north elevation 708.0 air supply ducts. The hot water heating coils mounted in the ducts heat the incoming air.
The auxiliary building air preheating portion of the heating system consists of a secondary forced-circulation loop system for each plant unit containing two pumps and a 3-way temperature control valve. The valve is thermo-statically controlled to supply outdoor air heated to approximately 60&deg;F.
9.4.4.3 Safety Evaluation The turbine building ventilating and heating systems are designed to assure their reliable operation during normal plant operation and are not safety related. The free air intake dampers, located along the east and west walls of the elevation 755.0 turbine room are designed to close if a power failure occurs. There is no safety related equipment located in their immediate vicinity. Portions of the building heating system piping which supply hot water to the Auxiliary Building Unit 1 and 2 air intake air-preheating coils, are supported to seismic Category I (L) requirements to preclude any adverse effects on nearby safely related equipment.
9.4.4.4 Inspection and Testing Requirements The Turbine Building environmental control systems are in continuous operation and are accessible for periodic inspection.
9.4.5 Engineered Safety Feature Ventilation Systems The function of the engineered safety features ventilation systems is to provide a suitable and controlled environment for engineered safety feature components during normal plant operation, during adverse environmental transients, and following design basis accidents.
9.4.5.1 ERCW Intake Pumping Station (IPS) 9.4.5.1.1 Design Bases The ERCW and the high pressure fire protection (HPFP) pump area at Elevation 741 and the raw cooling water and cooling tower makeup pump area at Elevation 728 are open to the outside environment and are therefore cooled by natural convection. The ERCW and HPFP pump area, the electrical equipment room, and the 100% redundant mechanical equipment rooms are the only areas containing safety-related equipment.
The nature of the ventilation system in the ERCW and HPFP pump area provides 9.4-26                                   AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                     WBNP-97 assurance that a single active failure cannot result in loss of the ERCW and HPFP system functional performance capabilities.
The mechanical and electrical equipment rooms heating and ventilation systems are not safety-related. Their primary function is to maintain the room temperatures within the maximum and minimum design values during normal plant operation. Operator action is taken to periodically monitor the IPS mechanical and electrical equipment rooms space temperatures to ensure that the maximum and minimum design values are not exceeded.
The ERCW and HPFP pump areas may experience a maximum ambient air temperature of 120&deg;F when the surrounding outside air is 95&deg;F. Since they are exposed to the outside environment the pumps and their associated equipment are designed to withstand low ambient air temperatures, or else they are protected by periodic temperature monitoring and providing supplemental heating as necessary.
Electrical and mechanical equipment rooms are individually ventilated and heated during operation to maintain the room temperatures within the range of 40 to 115&deg;F.
Low temperature is limited by means of thermostatically controlled electric duct heaters and unit heaters,to above 32&deg;F during extreme outside conditions by periodic temperature monitoring and providing supplemental heating, as necessary.
Because the IPScontains no sources of potential radioactivity, there are no safety-related airflow directions that must be maintained and no required radiation monitors.
The IPS is a Seismic Category I structure that is protected from the threats of tornado missiles and floods. A grid-type roof system is utilized to provide both missile protection and allow natural ventilation to the ERCW and HPFP pump area. The roof is composed of a series of horizontal 'I' beams rotated 45&deg; about their longitudinal axes.
The beams are supported by steel members which are in turn supported by concrete walls. The grillage is designed to meet Seismic Category I(L) requirements. The heating and ventilation equipment, ductwork, dampers, supply and exhaust fans, duct heater, and unit heater serving the electrical equipment and the mechanical equipment rooms meet Seismic Category I(L) requirements.
9.4.5.1.2 System Description The IPSheating and ventilating systems for the electrical and mechanical equipment areas are shown in Figure 9.4-21. The pump areas are cooled by natural convection.
The electrical equipment room and mechanical equipment rooms are individually ventilated by separate ventilation systems. Each system is provided with 100%
capacity supply and exhaust fans. The supply fan delivers air through a short vertical duct which encases the duct heater, a motor operated isolation damper, and a discharge grille. Two electric unit heaters are provided in each room. The duct heater and the unit heaters are thermostatically controlled.
Periodic temperature monitoring is necessary to ensure that the equipment room temperatures are maintained within design limits. Equipment room space AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                       9.4-27

WATTS BAR                                                                                       WBNP-97 temperatures are monitored during all plant conditions. Ventilation fans are shut down during subfreezing outdoor temperatures, and portable electric heaters and power generators are utilized as necessary during potential loss of heating to prevent freezing conditions in the equipment rooms. Non-essential cooling loads are manually shut down as necessary to maintain the space temperatures within design limits if ventilation is not available.
9.4.5.1.3 Safety Evaluation The analysis of the ventilation system shows that:
(1)   Adequate flow-through ventilation is provided for the ERCW and HPFP pump area by natural convection during all credible environmental conditions.
Compensatory actins are taken during severe environmental conditions. A structural failure of the grillage roof will not prevent supply of adequate ventilation air to the pump deck (2)   Adequate heating and forced air ventilation are provided to each mechanical equipment room and electrical equipment room to maintain acceptable temperatures during normal operation. Compensatory actions are taken during abnormal or accident conditions, as needed. See Section 9.4.5.1.2 and Table 9.4-2.
(3)
A failure modes and effects analysis as shown in Table 9.4-2 indicates that the IPS ventilations sysems have the capabilities needed for normal operations, abnormal, and accident conditions. The IPS ventilations sysems are not classified as safety-related.
However, operator actions are taken to peridocially monitor mechanical and electrical room temperatures, and provide supplementary heating, shutdown fans, or shed nonsafety-related heat loads, as necessary, to maintain room temperatures between the minimum and maximum design values. The systems are also desinged to maintain their structural integrity during a seismic event to not damage safety-related equipment in their vicinity.
9.4.5.1.4 Inspection and Testing Requirements The IPS ventilating and heating system is accessible for periodic inspection and testing.
9.4.5.2 Diesel Generator Buildings 9.4.5.2.1 Diesel Generator Building 9.4.5.2.1.1 Design Bases The Diesel Generator Building (DGB) ventilating system is designed to provide adequate ventilation to the DGB spaces to maintain the required environmental 9.4-28                                      AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                   WBNP-97 conditions for safety-related equipment and prevent hydrogen buildup in the battery area during normal operation and design basis events (DBE) conditions. The diesel units are redundant and are each served by a separate ventilation system consisting of two 50% capacity exhaust fans. Each ventilation system maintains a proper environment for the operation of safety-related components.
Each diesel engine room ventilation subsystem consists of two room exhaust fans and one generator and electrical panel cooling fan. Each EBR is ventilated by a separate fan. Battery area is ventilated by its associated diesel generator room exhaust fans.
These are safety-related fans which are designed to provide adequate ventilation to maintain the required ambient temperature limits.
A backdraft damper is installed in the duct between the air intake room 1A-A and the carbon dioxide storage room in order to prevent carbon dioxide backflow into the diesel generator air intake room in the event of a carbon dioxide system rupture.
Each diesel generator unit room and electrical board rooms are separately ventilated in order to limit average room temperatures to a design maximum of 120&deg;F respectively when outdoor air entering the room is 95&deg;F and the diesel generator is in operation. Remaining areas of the DGB are ventilated to maintain maximum air temperatures within design limits. Personnel comfort conditions are maintained as required during low outside temperatures by means of thermostatically controlled electric unit heaters. Battery areas are ventilated by the operation of the diesel generator room exhaust fans. There is not a separate battery area ventilation system.
The diesels are started up and load-tested at least every 31 days. Although the DG room exhaust fans may not auto start and run during DG surveillance testing in the winter months, normal operation of theexhaust fans during surveillance testing of the DGs at the other times of the year in addition to the fans running during the summer months (without concurrent DG operation) will assure that the hydrogen concentration does not reach the Lower Explosion Limit (LEL) of 2% by volume. In addition, the exhaust fans operate whenever their room thermostats call for cooling, as described in Section 9.4.5.2.1.2 The generator for each engine room is supplied with outside air and the electrical control panels within the engine rooms are forced ventilated to assure adequate cooling.
Because the DGB contains no sources of potential radioactivity, there are no safety-related airflow directions that must be maintained and no required radiation monitors.
The DGB is a Seismic Category I structure that is designed to withstand the effects of tornado missiles and flood. The diesel generator room exhaust fans, the generator and electrical panel cooling fans, electrical board room exhaust fans, and all associated ductwork, fittings and dampers are located within the building and are designed to meet Safety Class 2b and Seismic Category I requirements. The portions of these systems, located on the roof of the building, are protected against missile damage by missile shields. These fans, their associated controls, and motor-operated dampers AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                    9.4-29

WATTS BAR                                                                                     WBNP-97 are connected to emergency power. The use of concrete air intake and exhaust hoods provides additional protection from the effects of missiles.
9.4.5.2.1.2 System Description One diesel generator room exhaust fan automatically starts upon diesel startup. The second exhaust fan starts when the upper setpoint of a temperature switch mounted in the air exhaust-room is reached or on low flow of the first fan. The generator and electrical panel cooling fan can start along with either exhaust fan. The temperature switches mounted in the air exhaust room monitor the temperature of the air as it leaves the diesel generator room. Each switch may actuate its respective room exhaust fan upon detection of high diesel generator room temperature conditions or may deenergize its respective fan, as necessary, in order to maintain the diesel generator room exhaust temperature between 50&deg;F and 120&deg;F. All three fans automatically stop if the diesel generator room carbon dioxide fire suppression system is activated. Switches for manual operator action are provided to override the carbon dioxide system interlocks and start fans, open dampers to restore ventilation and fulfill the safety function if the carbon dioxide is activated by a failure in the carbon dioxide or fire detection systems.
The toilet room is ventilated by a manually controlled fan. The electrical board rooms, lube oil storage room, and fuel oil transfer room are ventilated by manually controlled fans at all times except when their respective carbon dioxide fire suppression systems are activated. The muffler rooms are ventilated as required to remove heat during warm weather. Muffler room exhaust fans are manually operated from hand switches located on the electrical board that serves the particular fan, or start along with the diesel when in the auto mode.
Fire dampers are provided in each air supply and exhaust opening to the diesel generator room, electrical board room, lube oil storage room, and oil-transfer room.
Motor-operated dampers located at the air intake to each diesel generator room are automatically opened whenever either of the exhaust fans starts. All fans except for the generator and electrical panel cooling fans are equipped with motor operated shutoff dampers which close when their associated fan is not operating. Similarly, all relief vents are provided with motor operated shutoff dampers except the electrical board room intake vents which are provided with fire dampers instead.
The DGB heating and ventilating system is shown on Figures 9.4-22,-23,-24,-24A and 9.4-25. Two diesel generator room exhaust fans, and one electrical board room exhaust fan are located in the air exhaust room at Elevation 760.5 for each of the four diesel generator units. These fans discharge to the outdoors. One generator and electrical panel cooling fan is located within each diesel generator room.
During tornadoes, the essential components of the system remain functinal because the components are located in a Seismic Category I structure that is designed to resist damage by tornado missiles. For tornado depressurization mitigation, intake, and exhaust dampers are opened to assist in pressure equalization.
9.4-30                                    AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                      WBNP-97 Fresh air is introduced through each air intake room and drawn to the corresponding diesel generator room. The generator and electrical panel cooling fan draws air from the room intake vicinity for distribution to the generator air intake and to the electrical panel. Following absorption of the heat load in the room the air is drawn into the air exhaust room by the room exhaust fan(s) and is discharged through the air exhaust hood.
Each battery area is ventilated by the operation of its respective diesel generator room exhaust fan during the periodic diesel generator testing as required by the Technical Specifications.
Each of the electrical board rooms is ventilated by a centrifugal exhaust fan . The fan draws outside air into the board room through its associated electrical board room intake vent.
Other building exhaust fans provide individual ventilation for the lubricating oil storage room, fuel oil transfer room, carbon dioxide storage room, toilet room, and muffler rooms.
The thermostatically controlled electric unit heaters located within the diesel generator rooms are designed to maintain the 50&deg;F minimum temperature. Electric unit heaters in the equipment access corridor, storage rooms, radiation shelter rooms, and toilet room are designed to maintain normal temperature within these areas at not less than 40&deg;F.
Thermostats in the diesel generator air exhaust rooms are designed to automatically stop all operating diesel generator room exhaust fans upon a drop in room exhaust air temperature toa low setpoint and to automatically start the exhaust fans upon a room temperature rise to a high setpoint. The thermostats will also start the standby exhaust fan during diesel generator operation, when the room exhaust air temperature exceedsthe high setpoint.
9.4.5.2.1.3 Safety Evaluation A functional analysis and a failure modes and effects analysis have shown that the Diesel Generator Building ventilation system has the capabilities needed for normal operations and for accident mitigation. The functional analysis shows that:
(1)  Adequate ventilation is provided to maintain the required environmental conditions for optimum equipment operation during all operational modes.
See Section 9.4.5.2.1.1.
(2)  The battery area is adequately ventilated (except for system shutdown after a CO2 system actuation signal) to prevent hydrogen buildup in the diesel generator room.
(3)  The lack of a dedicated battery hood exhaust fan will not prevent forced air circulation past the batteries. During testing of the diesel generators, the diesel room exhaust fans start automatically in response to diesel start if the AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                        9.4-31

WATTS BAR                                                                                 WBNP-97 temperature at the local temperature switches located in the exhaust fan rooms is greater than the required set point. Concurrent with fan operation, dampers in the diesel room exhaust structure and at the air intake to each diesel generator room also open to facilitate adequate air flow to pass through the diesel generator room. Although the DG room exhaust fans may not auto start and run during monthly testing in the winter months, normal operation of the exhaust fans during testing of the diesel generators at other times of the year in addition to the fans running during the summer months (without concurrent DG operation) prevents a buildup of hydrogen gas above the Lower Explosion Limit (LEL) of 2% by volume.
(4)    Essential portions of this system remain functional during and after a seismic event because of their design to Seismic Category I requiements.
Nonessential portions of this system and other system located close to essential components are designed to Seismic Category I(L) requirements to prevent their failure from precluding operation of essential system components.
The failure modes and effects analysis, as shown in Table 9.4-4, confirms that:
(1)    During diesel generator operation, low air flows through the fans serving the diesel generator room and generator and electrical panels is detected by flow sensors. The failure will annunciate in the MCR.
(2)
(3)    A failure of an electrical board room exhaust fan, and the resulting heat buildup in the room to above 110&deg;F, may cause loss of the associated diesel generator. However, the redundant train diesel generator provides power to safely shut down the unit.
(4)
(5)    During flooding conditions, all essential components of this system will remain functional because they are located above the maximum possible flood level.
(6)    During tornadoes, the essential components of the system remain functional because they are located in a Seismic Category I structure that is designed to resist damage by tornado missiles. For tornado depressurization mitigation, intake, and exhaust dampers are opened to assist in pressure equalization.
(7)    Upon loss of offsite power, each diesel generator provides emergency electrical power to its associated ventilation components. All are connected to their respective diesel generator engineered safety power supply, so operation of a diesel generator assure power to the corresponding fans.
9.4-32                                AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                     WBNP-97 9.4.5.2.1.4 Tests and Inspections Historical Information: This system is tested initially as part of the preoperational test program. See section 14.2 for testing acceptance criteria.
The Diesel Generator Building ventilating and heating systems are accessible for periodic inspection. After maintenance or modification activities that affect a system function, testing is performed as necessary to reverify the system or component operation.
9.4.5.3 Auxiliary Building Engineered Safety Features (ESF) Equipment Coolers 9.4.5.3.1 Design Bases The Auxiliary Building ESF equipment coolers are designed to maintain acceptable environmental conditions for (1) personnel access, operation, inspection, maintenance and testing and (2) the protection of safety-related mechanical and electrical equipment and controls. The system utilizes fan/coil type safety-related air cooling units. Air cooling units are provided for the following rooms and areas:
(1)   Residual heat removal pump room (2)   Safety injection pump room (3)   Containment spray pump room (4)   Centrifugal charging pump room (5)   Reciprocating charging pump room*
(6)   Unit 1 auxiliary feedwater and component cooling water pumps area (7)   Unit 2 auxiliary feedwater and boric acid transfer pumps area (8)   Component cooling water booster and spent fuel pool pumps area (9)   Emergency gas treatment system filter room (10) Elevation 692.0 penetration rooms (11) Elevation 713.0 penetration rooms (12) Elevation 737.0 penetration rooms (13) Pipe chases
            *Not safety-related AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                       9.4-33

WATTS BAR                                                                                    WBNP-97 All air coolers listed above, except the reciprocating charging pump coolers (indicated with an asterisk), are ESF equipment and are provided with coordinated emergency power and ERCW water sources (see Sections 8.3 and 9.2). Pumps 1 through 5 in the above list are each located in a separate room with their corresponding cooler. Safety-related pump rooms are paired with a 100% redundant room containing another pump/cooler set. Pumps and equipment listed in Items 6 through 13 are each provided with two 100% coolers in the room/area. In addition to the above coolers, this system includes two 100% emergency exhaust fans, one safety-related and the other nonsafety-related, in each turbine-driven auxiliary feedwater pump room. Each of these fans is capable of providing the required air flow in the room for the volume changes method of cooling.
Rooms and areas containing ESF equipment are ventilated by airflows induced by the building ventilation exhaust subsystem during normal plant operation and when equipment is not required to operate. All air cooling units are thermostatically controlled to automatically operate upon room temperature rise above the setpoint. Air cooling units for pumps 1 through 4 will automatically start to provide the necessary additional cooling in the space whenever their associated pumps are operated. All other coolers for ESF equipment will automatically start on an Auxiliary Building isolation signal. If cooler starts due to ABI signal, it remains on until ABI is reset or hand switch position is changed. If cooler starts due to high temperature, a thermostat, located near the return airflow to each cooler, allows the cooler to remain in operation until the low limit temperature setpoint is reached. The cooling water valve and fan are interlocked to operate together for all coolers, except for the residual heat removal and centrifugal charging pump rooms, whose cooling water valves are electrically disconnected in the open position due to 100 CFR 50 Appendix R considerations.
The ESF equipment ventilation system is designed to maintain temperatures within the range for which the equipment is environmentally qualified, to ensure that equipment and components are not exposed to environmental conditions that could degrade the operability of safety-related equipment.
All components of this system, including air cooling units, fans, ductwork, dampers, valves, and grilles, are designed to meet Seismic Category I and Safety Class 2b requirements. The system is completely enclosed in a Seismic Category I structure that is designed against flood and tornado missile threats.
9.4.5.3.2 System Description The Auxiliary Building ESF coolers are shown on Figures 9.4-10, 9.4-13, 9.4-14, 9.4-16, 9.4-26, and 9.4-27. The individual coolers are listed below:
Number RHR Pump Room                                        4 Safety Injection Pump Room                           4 Containment Spray Pump Room                          4 9.4-34                                   AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                      WBNP-97 Number Centrifugal Charging Pump Room                          4 Reciprocating Charging Pump Room                        2 Unit 1 Auxiliary Feedwater and Component                2 Cooling Water Pumps Unit 2 Auxiliary Feedwater and Boric Acid               2 Treatment Pumps Emergency Gas Treatment Room                            2 Component Cooling Water Booster and Spent               2 Fuel Pool Pumps Pipe Chases                                             4 Elevation 692.0 Penetration Room                        4 Elevation 713.0 Penetration Room                        4 Elevation 737.0 Penetration Rooms                       4 The turbine-driven auxiliary feedwater pump (TDAFWP) rooms are normally cooled by the Auxiliary Building general ventilation system. For emergency ventilation, two roof ventilator type exhaust fans are located on the roof of each room (See Figure 9.4-13),
venting into the general spaces of the Auxiliary Building. One of the two fans per room operateson 115v, 60 Hz ac emergency power while the other on 115V dc station vital battery power. The ac-powered fan is nonsafety-related and the dc-powered fan is safety-related. Both fans in each room are thermostatically controlled to automatically operate upon room temperature rise above setpoint . The dc powered fan also automatically runs upon pump start. Each fan is rated at 1200 cfm and designed to circulate a sufficient quantity of building air through their rooms to limit the maximum temperature rise to approximately 20&deg;F above ambient.
In the event of a steam line break within the room, two isolation valves are provided in the common portion of the steam supply piping to the TDAFWP, to close on high room temperature.
9.4.5.3.3 Safety Evaluation A functional analysis and failure modes and effects analysis have shown that the Auxiliary Building esf coolers have the capabilities needed for normal operations and for accident mitigation. These are described in the paragraphs that follow.
A functional analysis of the system shows that:
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                       9.4-35

WATTS BAR                                                                                  WBNP-97 (1)    Adequate ventilation is provided during normal operations by the auxiliary Building general ventilation system. When the applicable equipment is operating, the ESF equipment area and TDAFWP room fans provide adequate temperature control to assure reliable equipment operation.
(2)    The containment isolation Phase A signal, high radiation in the spent fuel pool area,aCVI signal when containment and/or the annulus is open to the Auxiliary Building ABSCE spaces, and high air temperature in the Auxiliary Building air intakes provide for a two-train isolation signal for the Auxiliary Building. Isolation of the general ventilation system, described in Section 9.4.3, results in the disruption of normal airflow patterns; and thus, provide for an effectively sealed ABSCE boundary.
(3)    After the building is isolated from the environment, airflow patterns and air cleanup operations appropriate for accident mitigation during the accident mode of operation are established and maintained by the ABGTS, as described in Section 6.2.3.
The failure modes and effects analysis, as shown in Table 9.4-3, indicates that:
(1)     The safety-related radiation monitors in the Auxiliary Building refueling area provide redundant signals, for isolation of the Auxiliary Building.
(2)    During normal operation, each each ESF space is cooled by the general ventilation system and an ESF cooler. During accident conditions, cooling of the ESF equipment is provided by the ESF coolers. In the event of failure of one ESF area cooler,the redundant cooler is available.In the event of failure of one pump room cooler, the redundant pump and its associated room cooler are also available.
(3)    During its emergency mode of operation, the TDAFWP receives cooling from the dc-driven TDAFW pump room fan, the failure of which is not postulated since a single failure in the two 50% capacity motor-driven AFW pumps would have already been postulated.
(4)     fFailure of any portion of this system as the result of a seismic event is prevented by use of only Seismic Category I components in this system.
(5)    During the accident mode of operations, emergency electrical power is provided to the ESF pumps and their corresponding coolers or fans. In the event one emergency power train fails, the essential safety-related functions of the system are accomplished by the redundant parts of the system powered by the remaining power train.
(6)    Water is supplied to each cooler from the ERCW system described in Section 9.2.1. Failure of one ERCW supply train, and the resulting failure of thearea coolers supplied by that train, will not prevent the redundant coolers, supplied 9.4-36                                 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                       WBNP-97 by a different ERCW train from supporting shutdown of the reactor unit. In the case of the loss of ERCW supply to a pump room cooler, the redundant pump is available.
9.4.5.3.4 Inspection and Testing Requirements Historical Information: The system is tested initially as part of the preoperational test program. See Section 14.2 for testing acceptance criteria.
The Auxiliary Building ESFcoolers are designed to be available for continuous operation and are accessible for periodic maintenance. After maintenance or modification activities that affect a system function, testing is done to reverify the system or component operation.
9.4.6 Reactor Building Purge Ventilating System (RBPVS) 9.4.6.1 Design Bases The RBPVS is designed to maintain the environment in the primary and Shield Building annulus within acceptable limits for equipment operation and for personnel access during inspection, testing, maintenance, and refueling operations; and to provide a filtration path for any through-duct outleakage from the primary containment to limit the release of radioactivity to the environment.
The RBPVS performs three distinct functions, the forced air purge function, the continuous pressure relief function, and the alternate containment pressure relief function.
The forced air purge function is performed by a purge supply and purge exhaust system consisting of two trains, each of which is desgined to provide 50% of the capacity needed for normal purging. Each train consists of a supply fan, an exhaust fan, a HEPA filter-charcoal adsorber assembly, containment isolation valves and associated dampers and ductwork. This function provides a means by which containment air may be forcibly exchanged and filtered. The purge function provides a means by which containment air may be forcibly exchanged and filtered. The purge function of the RBPVS is not a safety-related function. However, the filtration units are required to provide a safety related filtration path following a fuel handling accident until all containment isolation valves are closed. The safety functions are to assure isolation of primary containment during an accident and to isolate the purge air supply intake upon receipt of an Auxiliary Building Isolation (ABI) signal.
During Operating Modes 1 thru 5, continuous pressure relief is provided by a passive ducting system which passes through containment penetration X-80, through two 100% redundant containment vent air cleanup units (CVACU) containing HEPA filters with charcoal adsorbers. Containment air is moved into the annulus by the motive force created by differential pressure between the two spaces. Filtration redudancy allows maintenance on one unit at a time while maintaining an open pathway through the other. This ventilation pathway is isolable using containment isolation valves FCV             40 and FCV-30-37 which are closed during Mode 6 or when containment isolation is AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                         9.4-37

WATTS BAR                                                                                    WBNP-97 required. This system is not required for fuel handling accident mitigation and is not available for that purpose since it is essentially isolated by containment isolation valves during fuel loading or handling activities (Mode 6).
The alternate pressure relief function is provided by way of a configuration alignment in the forced air purge system. This function is accomplished by opening lower compartment purge lines (one supply and one exhaust) or one of the two pairs of lines (one supply and one exhaust) in the upper compartment. During purging mode, the purge air fans may or may not be used. To prevent inadvertent pressurization of containment due to supply and exhaust side ductwork flow imbalances, the supply ductwork airflow may be temporarily throttled as needed.
The purge function of the RBPVS is not a safety-related function. However, the filtration units are required to provide a safety-related filtration path following a fuel-handling accident.
The design bases include provisions to:
(1)   Supply fresh air for breathing and contamination control when the primary containment or annulus is occupied.
(2)   Exhaust primary containment and annulus air to the outdoors whenever the purge air supply system is operated.
(3)   Clean up containment exhaust during normal operation by routing the air through HEPA-carbon filter trains before release to the atmosphere to limit potential release of radioactivity to the environment.
(4)   Provide a reduced quantity of ventilating air to permit occupancy of the instrument room during reactor operation. The provisions for 1, 2, and 3 above will apply.
(5)   Assure closure of primary and secondary containment isolation valves following accidents which result in the initiation of a containment ventilation isolation signal.
(6)   Assure closure of the system air intake dampers, which form part of the ABSCE (see Section 6.2.3.2.1), upon receipt of a signal for Auxiliary Building isolation.
(7)   Provide continuous containment pressure relief path through HEPA-carbon filter trains before release to the atmosphere during normal operations.
Items 5 and 6 above are safety-related functions.
The primary containment penetrations for the ventilation supply and exhaust subsystems are designed to primary containment structural standards. These are discussed in detail in Section 6.2.4.
9.4-38                                   AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                      WBNP-97 The RBPVS is sized to maintain an acceptable working environment within the containment during all normal operations. The system has the capabilities to provide a filtration path for outleakage from the primary containment, and clean up containment atmosphere following a design basis accident. It also has provisions to filter air flow exhausted from containment for pressure control, during normal operation.
The controls are designed to have simultaneous starting and stopping of the matching supply and exhaust equipment and to initiate an automatic shutdown and isolation upon receipt of the containment ventilation isolation signal.
In addition, RBPVS supply fans will shut down and the ABSCE isolation dampers in purge air supply ducts will close on an ABI signal.
The containment RBPVS exhaust cleanup equipment assures that activity released inside containment from a refueling accident and prior to containment isolation, is processed through both HEPA filters and carbon adsorbers before release to the atmosphere. Fuel handling operations inside the primary containment are constrained by the operability requirement for the RBPVS air cleanup units contained in the plant technical specifications.
The RBPVS components are designed or qualified to meet Seismic Category I requirements, except all purge ductwork within the containment, up to the inboard isolation valves, and the supply air ductwork from the downstream flange of the ABSCE isolation dampers to the upstream flange of the Shield Building isolation valves, which are designed to meet Seismic Category I(L) requirements.
The primary containment exhaust is monitored by redundant radiation detectors which provide automatic RBPVS isolation upon detecting the setpoint radioactivity in the exhaust air stream. The RBPVS isolation valves automatically close upon the actuation of a containment ventilation isolation signal or upon manual actuation from the MCR. In addition, during fuel handling operations in the Auxiliary Building with containment and/or the annulus open to the Auxiliary Building ABSCE spaces, the RBPVS isolation valves will close upon a high radiation signal from the spent fuel pool radiation monitors via a CVI signal.
The system air supply and exhaust ducts are routed through the ShieldBuilding annulus to several primary containment penetrations. Two air supply locations are provided for each of the upper and lower compartments and one for the instrument room. Air is supplied to areas of low potential radioactivity and is allowed to flow to the air pickup exhaust points in areas of higher potential radioactivity. The air pickup points, located to exhaust air from the lower compartment and instrument room, also provide an air sweep across the surface of the refueling canal.
During cold shutdown and refueling operations, the entire containment may be purged using any number and size of purge supply and exhaust lines.
During reactor operation, the number and size of lines used for containment purging, are restricted to two 24-inch diameter lines (i.e., one supply line with 50&deg;-open valves, AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                        9.4-39

WATTS BAR                                                                                   WBNP-97 and one exhaust line with 50&deg;-open valves), or two 24-inch diameter lines with wide-open valves (i.e., one supply line and one exhaust line).
9.4.6.2 System Description The RBPVS is shown schematically in Figures 9.4-28 to 9.4-30. One complete and independent RBPVS is provided for each unit.
The containment upper and/or lower compartments are purged with fresh air by the RBPVS before occupancy. The annulus can be purged with fresh air during reactor shutdown or at times when the annulus vacuum control system of the EGTS is shut down. The instrument room is purged with fresh air during operation of the RBPVS or is separately purged by the instrument room purge subsystem.
The containment is vented into the annulus, during normal operation, continuously, through the containment vent air cleanup units (CVACU)s, which contain HEPA and charcoal filters, to maintain the containment pressure within the Technical Specification limits. Exhaust air mixes with the annulus atmosphere before it is discharged into the Auxiliary Building exhaust stack by the annulus vacuum control fan(s) (See Section 6.3.2.2).
RBPVS for each unit consists of two trains, each designed to provide 50% of the capacity required for normal operation. Each train contains an air supply fan, an air exhaust fan, a cleanup filter unit, containment isolation valves, system air flow control valves, and all necessary ductwork. The system also includes single air supply distribution and air exhaust collection subsystems as well as an instrument room supply fan and an instrument room exhaust fan.
The RBPVS supply fans are located in the penetration room at elevation 737.0 in the Auxiliary Building. Filtered fresh air, heated when required, is taken from the Auxiliary Building air supply systems located in the mechanical equipment rooms at elevation 737.0. These fans are of centrifugal type and belt-driven, with adequate system air flowrate (See Figure 9.4-28.
The filtered air is discharged to the outdoors by means of the Shield Building exhaust vent located in the annular space of the Reactor Building and extending through the roof of the Reactor Building. The purge air exhaust fans are centrifugal type and belt-driven, with a combined flow of 22,949 ft3/min. The air cleanup units are described in Section 6.5.1.
Annulus purging air is taken from system ducts and routed through the annulus. The air supply and exhaust duct openings are located approximately 180&deg; apart for maximum ventilation.
To permit personnel access to the instrument room during reactor operation or during RBPVS shutdown, the room can be purged by the instrument room purge subsystem fans. These supply and exhaust fans are located alongside the main system supply and exhaust fans and use the main system ducts and one of the filter trains. Butterfly valves are positioned to allow only the instrument room to be served.
9.4-40                                  AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                       WBNP-97 Each RBPVS containment penetration is provided with both inboard and outboard air-operated isolation butterfly valves designed for minimum leakage in their closed position. A similar type of valve is mounted in each purge supply and exhaust air opening for the annulus, and in each of the main supply and exhaust ducts located exterior to the Shield Building. The purge air supply line is provided with two air-operated isolation dampers in series for ABSCE isolation. Each of the above butterfly valves and the intake dampers are designed to fail closed and are normally closed during purge system shutdown. See Section 6.2.4 for more on the containment isolation system.
The single air supply duct serving the two purge air supply fans and the instrument room supply fan is provided with two isolation dampers. These dampers are air operated, normally closed, failed closed dampers which close automatically on receipt of Auxiliary Building isolation or high radiation in refueling area signals. These dampers establish the boundary for the ABSCE. See Section 6.2.3.
Since the annulus is maintained at a 5-inch water gauge negative pressure by the annulus vacuum control system, the annulus portion of the purge system ducts is maintained at the negative pressure by four 1/2-inch leakoffs. This arrangement is designed to prevent containment contamination leakage from escaping through the purge system ducts into the Auxiliary Building.
The purge function of the RBPVS is not a safety-related function. However, the filtration units are required to provide a safety-related filtration path following a fuel-handling accident. The primary containment isolation valves and intermediate piping of the RBPVS are designed in accordance with ANS safety class 2A; other portions are designated ANS safety class 2B except the purge fans, all purge ductwork within the containment, purge supply air ductwork from the ABSCE boundary, fire protection, and drain piping. The instrument room purge subsystem is not an engineered safety feature, and credit for its operability for a LOCA or a fuel-handling accident is not claimed.
A containment ventilation isolation signal automatically shuts down the fans and isolate the RBPVS by closing its respective dampers and butterfly valves.
EachRBPVSprimary containment isolation valve is designed for fail safe closing within 4 seconds of receipt of a closure signal for containment penetrations (See Tables 6.2.4-1 through 6.2.4-4 and Figure 6.2.4-21). . TheRBPVS primary containment isolation valve locations and descriptions are given in Table 6.2.4-1. Each valve is provided with an air cylinder valve operator, control air solenoid valve, and valve position indicating limit switches.
Smoke detectors, located in the Auxiliary Building air intake and the general ventilation supply ducts, shut down the purge air supply and the incore instrument room purge supply fans and their isolation dampers.
9.4.6.3 Safety Evaluation Functional analyses and failure modes and effects analysis have shown that the RBPVS meets the containment isolation requirements. The purge air filtration units AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                         9.4-41

WATTS BAR                                                                                  WBNP-97 and associated exhaust ductwork provide a safety-related filtration path following a fuel-handling accident. The CVACUs, performing a continuously filtered containment vent function during normal operation, are isolated by the closure of their containment isolation valves; therefore are not operable after accidents. In addition, the containment ventilation system is not allowed to be used during Mode 6.
A functional analysis of the system shows that:
(1)   During normal operation, adequate fresh air is provided for breathing and for contamination control when the primary or secondary containment (annulus) is occupied.
(2)   Primary and secondary containment exhaust air is cleaned up during normal operations and following a fuel handling accident.
(3)   Purge supply and exhaust fan operations cease and isolation dampers in the intake and exhaust ducting close when the system is in the accident mode of operation.
(4)   Three signals cause the system to change from the normal purge mode to the accident isolation mode. These signals, which include manual, SIS auto-initiate, and high purge exhaust radiation (automatic), initiate a containment ventilation isolation signal. Additionally, during refueling operations whenever containment and/or the annulus is open to the Auxiliary Building ABSCE spaces, a high radiation signal from the spent fuel pool accident radiation monitors automatically cause the system to change from the purge mode to the accident isolation mode.
(5)   Discharges from the annulus, during normal operation, which are exhausted through the Auxiliary Building exhaust stack, are monitored at the stack.
Although, these radiation monitors do not initiate an automatic containment isolation signal, radioactive release limits have been established as a basis for controlling plant discharge during operation. Radioactive releases from the plant resulting from equipment faults of moderate frequency are within 10 CFR 50 Appendix I and 40 CFR 190 limits as specified in the ODCM (See Section 11.3 for further details). In addition, analyses have shown that any accident with the potential consequence to exceed the 10 CFR 100 limits, would be detected by other indicators (see item 4 above) and cause an automatic primary and/or secondary containment isolation.
Containment vent system is not allowed to be used during Mode 6.
The failure modes and effects analyses show that:
(1)   Two filtration exhaust paths are provided to assure that particulate releases are within 10CFR100 guidelines following a fuel-handling accident and prior to closure of the associated isolation valves.
9.4-42                                 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                     WBNP-97 (2)   Each purge supply and exhaust line is equipped with two primary containment isolation valves, each connected to different control and power trains. Failure of one train does not prevent the remaining isolation valve from providing the required isolation capability.
(3)   Essential portions of the system remain functional after a seismic event because of their design to Seismic Category I requirements. Nonessential portions of the system and other systems located close to essential components and not designed to Seismic Category I standards are designed to meet Seismic Category I(L) requirements to prevent their failure from precluding operation of essential safety-related equipment.
(4)   All essential equipment is located above the maximum possible flood level in a Seismic Category I building that is designed to resist tornado missiles.
(5)   A loss of offsite power causes closure of the isolation valves.
(6)   ABGTS safety-related functions are not impeded by the worst-case failure in the RBPVS; i.e., one train of ABI signal failing, thus resulting in only one ABGTS train starting, one RBPVS supply fan and the Incore Instrument Room supply fan continuing to run, all the ABSCE isolation dampers of the same train remaining open, and all RBPVS exhaust fans shutting down.
9.4.6.4 Inspection and Testing Requirements Before power operation, tests are conducted to assure that the RBPVS performs as designed. The system is tested initially as part of the preoperational test program.
After maintenance or modification activities that affect a system function, testing is done to reverify the system or component operation. Purge system containment penetration isolation valves are tested for inplace closing speed and leak tested in the closed position to comply with the requirements of 10 CFR 50, Appendix J. The inspection and testing of these valves is discussed in Section 6.2.4.
Details of the testing program for the air-cleanup units are included in Section 6.5.
9.4.7 Containment Air Cooling System 9.4.7.1 Design Bases The containment air cooling systems are designed to maintain acceptable temperatures within the reactor building upper and lower compartments, reactor well, control rod drive mechanism (CRDM) shroud, and instrument room for the protection of equipment and controls during normal reactor operation and normal shutdown. The instrument room is mechanically cooled to permit personnel access during normal reactor operation.
The lower compartment cooling (LLC) air system, together with operation of the CRDM air cooling system, is designed to maintain a maximum weighted average air AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                       9.4-43

WATTS BAR                                                                                 WBNP-97 temperature of 120&deg;F in most lower compartment spaces during normal reactor operation. These spaces include the steam generator and pressurizer compartments, the space below the reactor vessel, the space around the reactor vessel, the spaces around the reactor vessel nozzles and supports and the upper reactor cavity well space around the CRDM shroud. For Unit 2, four 33-1/3% capacity and for Unit 1, three 33-1/3% and one 29.2% LCC fan coil assemblies are provided to allow three or less to operate during reactor normal operation with one or more on standby.
The LCC air system manual dampers are adjusted to provide sufficient air flow through the reactor well to maintain an approximate air temperature of 120&deg;F. The system is designed for two of four units to recirculate air through the lower containment and equipment compartments, although all four may be operated, anytime there is a loss of normal containment cooling following any non-LOCA design basis event which results in a hot standby condition. The LCC system is not required to operate after a LOCA. See Section 6.2.2.1 for detailed information and operation after a MSLB.
The CRDM air cooling system is designed to operate during normal reactor operation in conjunction with the LCC air system to maintain a maximum air temperature within the upper reactor cavity of 120&deg;F and to route all of the reactor well air through the CRDM shroud to maintain a maximum air temperature of 185&deg;F. Air drawn through the CRDM shroud is cooled by the active fan-coil assemblies to approximately 120&deg;F and discharged into the lower compartment of the Reactor Building.
When additional cooling in the lower compartment is required, an arrangement of dampers allows either or both standby CRDM fan-coil assemblies to be operated to recirculate and supplement the LCC system capacity.
The upper compartment cooling (UCC) air system is designed to maintain the upper compartment weighted average temperature at a maximum of 110&deg;F during normal reactor operation.
The Reactor Building instrument room air cooling system is designed to automatically maintain the room air temperature between 50&deg;F and 120&deg;F during normal reactor operation. t The heat sink for each LCC, UCC, and CRDM air cooling fan-coil assembly, and for each instrument room air cooling system condensing unit, is the ERCW.
The LCC units and CRDM air cooling fan-coil assemblies are manually energized from the emergency power system upon loss of offsite power; however, these components are not required to operate during LOCA conditions. The LCC units may be operated continuously throughout all accidents, except a MALB, which do not initiate a Phase B containment isolation signal. Following a MSLB, two of the four LCCunit fans are required, but all four are started manuallywithin 1.5 to 4 hours after the detection of theMSLB accident to recirculate air in the lower compartment dead-ended spaces.
This is a safety function of the LCC units' fans.
9.4-44                                AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                     WBNP-97 9.4.7.2 System Description The containment air cooling system flow scheme is shown in Figure 9.4-28. The system's control scheme is shown in Figures 9.4-30 and 9.4-31 and the logic scheme in Figures 9.4-29 and 9.4-32 through 9.4-34. The containment air cooling system is composed of four subsystems as follows:
(1)   Lower Compartment Air Cooling (2)   CRDM Air Cooling (3)   Upper Compartment Air Cooling (4)   Reactor Building Instrument Room Air Cooling 9.4.7.2.1 Lower Compartment Air Cooling System There are four LCC air cooling fan-coil assemblies which are located in two annular concrete chambers around the periphery of the lower compartment at floor Elevation 716. Each fan-coil assembly consists of a plenum, eight air cooling coils, vaneaxial fan, backdraft damper, instruments, and controls. For Unit 1 only, LCC 1D-B has a reduced cooling capacity of approximately 12.5% due to isolation of ERCW to one of its eight cooling coils.
These fan-coil assemblies are supplied water from the plant ERCW system. A cooling water throttling valve for each assembly is automatically controlled by a temperature indicating controller which utilizes an input from a thermocouple mounted in the assembly's return air supply and set to control the cooler outlet temperature as required to maintain the required weighted average temperature The ERCW system is described in Section 9.2.1.
Lower compartment air passes directly to each active fan-coil assembly where it is cooled and supplied through a common duct distribution system to the lower compartment spaces. The system is designed for three of the four fan-coil assemblies to operate together, with one on standby. The cooled air is supplied directly to each steam-generator compartment, pressurizer compartment, letdown heat exchanger room, main lower compartment space, and to the space below the reactor vessel.
Connections are available in the A-Train ERCW supply and return headers for the lower compartment coolers that will allow chilled water from a non-safety related chiller to be used to provide additional cooling of the Unit 1 Reactor Building during outages.
9.4.7.2.2 Control Rod Drive Mechanisms Air Cooling System The four CRDM air cooling fan-coil assemblies are located in the main lower compartment space at floor elevation 702.78. Each assembly consists of a plenum, three air cooling coils, two vaneaxial fans, in series, assembly isolating motor-operated damper, instruments, and controls. Each fan-coil assembly is designed to cool the CRDM shroud to 185&deg;F with water from the plant ERCW system. A cooling water throttling valve for each assembly is automatically controlled by a temperature AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                      9.4-45

WATTS BAR                                                                                     WBNP-97 indicating controller which utilizes an input from a thermocouple mounted on the intake side of the CRDM cooling unit .
The four CRDM air cooling fan-coil assemblies are divided into two pairs. One fan-coil assembly in each pair is normally operated to provide adequate cooling to the CRDM shroud during normal reactor operation. Reactor well air exiting the shroud is cooled by the fan-coil assemblies and discharged into the lower compartment spaces.
9.4.7.2.3 Upper Compartment Air Cooling System The four UCC air fan-coil assemblies are located within the upper compartment at Elevation 801.69. Fan-coil assemblies consist of plenums, air cooling coils, vaneaxial fans, instruments, and controls. They are designed to maintain the upper compartment weighted average temperature at a maximum of 110&deg;F with water from the plant ERCW system. A cooling water throttling valve for each assembly is automatically controlled by a temperature indicating controller which utilizes an input from a thermocouple mounted in the return air supply.
A portion of the upper containment air is continuously recirculated and cooled by the UCC fan-coil assemblies. The system is designed for three of the four assemblies to operate together with one on standby.
9.4.7.2.4 Reactor Building Instrument Room Air Cooling System The instrument room air cooling system consists of two 100% capacity air conditioning systems. Each system consists of a serviceable, packaged water chilling unit and chilled water pump located in the Auxiliary Building penetration room at Elevation 692, a fan-coil unit with air supply duct located in the Reactor Building instrument room, connecting chilled water piping with double containment penetration isolation valves, and all necessary and customary control and indicating devices. Chiller condensers are cooled by ERCW.
The chilled water piping penetrations through the primary containment vessel (See Tables 6.2.4-1 through 6.2.4-4 and Figure 6.2.4-21). are each provided with two isolation valves, one located inside and one located outside containment for each penetration. These 2-inch valves are pneumatic-motor operated and are designed to fail closed.
9.4.7.2.5 Controls and Instrumentation Operation of each fan-coil unit (LCC, UCC, CRDM, and instrument room) is indicated in the MCR. The UCC system standby unit automatically starts when pressure differential to two of the four coolers is below the setpoint, or upon compartment high temperature signal. The LCC system standby unit automatically starts when airflow is below the setpoint in two of the four fans. A CRDM cooling system standby unit automatically starts on low air flow in an operating unit.. The instrument room standby cooler automatically starts when airflow is below the setpoint in the operating cooler.
The LCC, UCC, and CRDM coolers are administratively controlled to prevent automatic starting of the standby unit during normal operation, Air temperature is continuously monitored to evaluate system performance for each of the four cooling 9.4-46                                    AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                                                    WBNP-97 systems. Class 1E temperature elements are mounted near the intake side air stream of each LCC with direct read-out in the MCR. Containment pressure is used by the operators as input for manual initiation of the air return fans and the containment spray system to maintain lower compartment temperature within limits during events in which the ERCW supplied coils are inoperable.
9.4.7.3 Safety Evaluation The LCC fans are started(Only two are required) to recirculate air through the lower containment and equipment compartments anytime there is a loss of LCC following any non-LOCA design basis event resulting in the reactor in a hot standby condition.
After a MSLB, all four LCCs are started (only two are required) within 1.5 to 4 hours after the MSLB, to recirculate air throughout the lower compartment spaces to prevent hot spots from developing. This is a safety function. Otherwise, the containment air cooling systems are not required for maintenance of temperature limits within the primary containment in the event of an accident, and therefore, are not engineered safety features. However, the reactor containment penetration valves for the instrument room air-conditioning chilled water system have a Nuclear Safety Class designation in accordance with ANS Safety Class 2A.
The capability of assuring containment ambient temperature levels and the anticipated degradation of equipment performance if temperature levels are exceeded are discussed in Section 3.11.
To prevent damage to adjacent safety related equipment necessary for the plant safe shutdown, UCC and CRDM air cooling assemblies, instrument room fan-coil units, water cooled condenser portions of the instrument room water chillers, ductwork and duct supports, and chilled water piping and pipe supports are designed and installed to Seismic Category I(L) requirements, and the LCC units (excluding cooling coils),
fans, ductwork, and duct supports are designed to Seismic Category I requirements.
9.4.7.4 Test and Inspection Requirements Historical Information: Air-cooling assemblies and their temperature-controlling devices which are located within the containment are tested prior to reactor operation and are generally accessible for inspection only during unit shutdown. The system is tested initially as part of the preoperational test program.
Air-cooling assemblies and their temperature-controlling devices which are located within the containment are tested prior to reactor operation and are generally accessible for inspection only during unit shutdown. The system is tested initially as part of the preoperational test program. After maintenance or modification activities that affect a system function, testing is done to reverify the system or component operations. Instrument room fan-coil units, control devices, and containment-isolation chilled-water valves are accessible for periodic inspection. Water-chilling equipment, pumps, and all essential electrical starting and switchover controls located in the Auxiliary Building are available for periodic inspection.
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS                                      9.4-47

WATTS BAR                                                                                 WBNP-97 Instrument room chilled-water containment-isolation valve testing and inspection requirements are discussed in Section 6.2.4.
9.4.8 Condensate Demineralizer Waste Evaporator Building Environmental Control System The Condensate Demineralizer Waste Evaporator (CDWE) Building Environmental Control System is a separate nonsafety air conditioning system which is not required for Unit 2 operation.
The CDWE Building is inside the ABSCE boundary; therefore, it is connected to the AB ventilation exhaust system. The ventilation exhaust system provides a negative pressure inside CDWE Building.
9.4.9 Postaccident Sampling Facility (PASF) Environmental Control System UNIT 2 EQUIPMENT HAS BEEN ABANDONED IN PLACE) 9.4-48                                AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                   WBNP-63 Table 9.4-1 DELETED (DELETED)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS   9.4-49

9.4-50 WATTS BAR Table 9.4-2 FAILURE MODES AND EFFECTS ANALYSIS INTAKE PUMPING STATION VENTILATION SYSTEM (Page 1 of 7)
METHOD OF COMPONENT                           FAILURE         POTENTIAL       FAILURE        EFFECT ON       EFFECT ON
                                                              #       IDENTIFICATION     FUNCTION         MODE            CAUSE           DETECTION      SYSTEM          PLANT       REMARKS WINTER 1   All components of Provide           Total loss of   Electrical      Surveillance   Total loss of   None. See   1) Room the Intake Pumping heating during   heating         failure (Loss                  the heating     Remarks. temperature is Station Ventilation the winter.                     of power)                      system                      verified once a shift.
System. Electrical                                                                 resulting in Equipment Room                                                                     room                        2) Supplemental and Mechanical                                                                     temperatures                heating is provided AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS Equipment Rooms                                                                    lower than                  if necessary to A or B.                                                                            design value.               maintain the space temperatures above 32&deg;F.
WBNP-87

Table 9.4-2 FAILURE MODES AND EFFECTS ANALYSIS INTAKE PUMPING STATION VENTILATION SYSTEM (Continued)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Page 2 of 7)
METHOD OF COMPONENT                              FAILURE           POTENTIAL    FAILURE        EFFECT ON       EFFECT ON
                                                              #        IDENTIFICATION        FUNCTION         MODE              CAUSE        DETECTION      SYSTEM          PLANT       REMARKS SUMMER 2    All components of     Provide          Loss of all       Electrical   Surveillance   Room            None. See   1) Room the Intake Pumping    ventilation      Supply and        and/or                      temperatures    Remarks     temperature is Station Ventilation   cooling during   Exhaust Fans      mechanical                  higher than                 verified once a shift.
System; Electrical    the Summer       concurrent with   failure                     design value.
Equipment Room                         operation of a                                                            2) If the room or Mechanical                          Unit Heater                                                               temperatures are Equipment Room A                       0-HTR-30-715                                                              above 104&deg;F, or B                                   or -716 in the                                                            Operator ensures Electrical                                                                that the duct heaters Equipment                                                                 and unit heaters are Room                                                                      "OFF" and that the supply and exhaust fans are operational.
If the fans are non-operable, non-essential loads are shed if necessary to maintain the room temperatures at less than 130&deg;F.
9.4-51                                                                                                                                                                                                           WBNP-87

Table 9.4-2 FAILURE MODES AND EFFECTS ANALYSIS INTAKE PUMPING STATION VENTILATION SYSTEM (Continued) 9.4-52 WATTS BAR (Page 3 of 7)
METHOD OF COMPONENT                              FAILURE              POTENTIAL    FAILURE        EFFECT ON     EFFECT ON
                                                              #        IDENTIFICATION        FUNCTION         MODE                 CAUSE        DETECTION      SYSTEM        PLANT         REMARKS 3    All components of     Provide          Operation of         Electrical   Surveillance   Additional heat None. See   1) Room the Intake Pumping    ventilation      Supply and           and/or                      added to the    Remarks     temperature is Station Ventilation   cooling during   Exhaust Fans,        mechanical                  space. Room                 verified once a shift.
System; Electrical    the Summer       0-FAN-30-714A        failure                     temperature Equipment Room                         & -714B,                                         will be higher              2) If the room or Mechanical                          concurrent with                                  than design                 temperatures are Equipment Room A                       operation of                                     value.                      above 104&deg;F, or B                                   Duct Heater 0-                                                               Operator ensures HTR-30-714 in                                                                that the duct heaters the Electrical                                                               and unit heaters are AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS Equipment                                                                    "OFF" and that the Room. Total                                                                  supply and exhaust loss of                                                                      fans are operational.
ventilation in the Mechanical Equipment Rooms.
WBNP-87

Table 9.4-2 FAILURE MODES AND EFFECTS ANALYSIS INTAKE PUMPING STATION VENTILATION SYSTEM (Continued)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Page 4 of 7)
METHOD OF COMPONENT                             FAILURE           POTENTIAL    FAILURE        EFFECT ON       EFFECT ON
                                                              #        IDENTIFICATION       FUNCTION         MODE              CAUSE        DETECTION      SYSTEM          PLANT        REMARKS 4    All components of    Provide          Loss of all       Electrical   Surveillance   Room            None. See   1) Room temperature the intake           ventilation      Supply and        and/or                      temperatures    Remarks     is verified once a Pumping Station      cooling during   Exhaust Fans      mechanical                  higher than                 shift.
Ventilation          the Summer       concurrent with   failure                     design value.
System: Electrical                    operation of a                                                            2) If the room Equipment Room,                       Unit Heater                                                               temperatures are or Mechanical                         0-HTR-30-710                                                              above 104&deg;F, Equipment Room                        or -711 in                                                                Operator ensures A or B                                Mechanical                                                                that the duct heaters Equipment                                                                 and unit heaters are Room A                                                                    "OFF" and that the supply and exhaust fans are operational.
If the fans are non-operable, non-essential loads are shed if necessary to maintain the room temperatures at less than 130&deg;F.
9.4-53                                                                                                                                                                                                         WBNP-87

Table 9.4-2 FAILURE MODES AND EFFECTS ANALYSIS INTAKE PUMPING STATION VENTILATION SYSTEM (Continued) 9.4-54 WATTS BAR (Page 5 of 7)
METHOD OF COMPONENT                              FAILURE             POTENTIAL    FAILURE        EFFECT ON      EFFECT ON
                                                              #        IDENTIFICATION       FUNCTION          MODE                CAUSE        DETECTION      SYSTEM         PLANT         REMARKS 5    All components of    Provide          Operation of         Electrical   Surveillance   Additional heat None. See   1) Room temperature the Intake           ventilation      Supply and           and/or                      added to the    Remarks     is verified once a Pumping Station      cooling during   Exhaust Fans,        mechanical                  space. Room                 shift.
Ventilation          the Summer       0-FAN-30-708A        failure                     temperature System; Electrical                    & -708B,                                         will be higher              2) If the room Equipment Room                        concurrent with                                  than design                 temperatures are or Mechanical                         operation of                                     value.                      above 104&deg;F, Equipment Room                        Duct Heater 0-                                                               Operator ensures A or B                                HTR-30-708 in                                                                that the duct heaters Mechanical                                                                   and unit heaters are AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS Equipment                                                                    "OFF" and that the Room A. Total                                                                supply and exhaust loss of                                                                      fans are operational.
ventilation in the Electrical Equipment Room and Mechanical Equipment Room B.
WBNP-87

Table 9.4-2 FAILURE MODES AND EFFECTS ANALYSIS INTAKE PUMPING STATION VENTILATION SYSTEM (Continued)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Page 6 of 7)
METHOD OF COMPONENT                             FAILURE           POTENTIAL    FAILURE        EFFECT ON       EFFECT ON
                                                              #        IDENTIFICATION       FUNCTION         MODE              CAUSE        DETECTION      SYSTEM          PLANT        REMARKS 6    All components of    Provide          Loss of all       Electrical   Surveillance   Room            None. See   1) Room the intake           ventilation      Supply and        and/or                      temperatures    Remarks     temperature is Pumping Station      cooling during   Exhaust Fans      mechanical                  higher than                 verified once a shift.
Ventilation          the Summer       concurrent with   failure                     design value.
System: Electrical                    operation of a                                                            2) If the room Equipment Room,                       Unit Heater                                                               temperatures are or Mechanical                         0-HTR-30-712                                                              above 104&deg;F, Equipment Room                        or -713 in                                                                Operator ensures A or B                                Mechanical                                                                that the duct heaters Equipment                                                                 and unit heaters are Room B                                                                    "OFF" and that the supply and exhaust fans are operational.
If the fans are non-operable, non-essential loads are shed if necessary to maintain the room temperatures at less than 130&deg;F.
9.4-55                                                                                                                                                                                                          WBNP-87

Table 9.4-2 FAILURE MODES AND EFFECTS ANALYSIS INTAKE PUMPING STATION VENTILATION SYSTEM (Continued)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Page 7 of 7)
METHOD OF COMPONENT                              FAILURE             POTENTIAL    FAILURE        EFFECT ON      EFFECT ON
                                                              #        IDENTIFICATION       FUNCTION          MODE                CAUSE        DETECTION      SYSTEM         PLANT         REMARKS 7    All components of    Provide          Operation of         Electrical   Surveillance   Additional heat None. See   1) Room the Intake           ventilation      Supply and           and/or                      added to the    Remarks     temperature is Pumping Station      cooling during   Exhaust Fans,        mechanical                  space. Room                 verified once a shift.
Ventilation          the Summer       0-FAN-30-709A        failure                     temperature System; Electrical                    & -709B,                                         will be higher              2) If the room Equipment Room                        concurrent with                                  than design                 temperatures are or Mechanical                         operation of                                     value.                      above 104&deg;F, Equipment Room                        Duct Heater 0-                                                               Operator ensures A or B                                HTR-30-709 in                                                                that the duct heaters Mechanical                                                                   and unit heaters are Equipment                                                                    "OFF" and that the Room B. Total                                                                supply and exhaust loss of                                                                      fans are operational.
ventilation in the Electrical Equipment Room and Mechanical Equipment Room A.
9.4-56                                                                                                                                                                                                             WBNP-87

AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 1 of 22)
Item                                                                                         Method of No.      Component          Function         Failure Mode       Potential Cause             Detection            Effect on System           Effect on Plant                      Remarks 1     2-PMCL-30-180-A    Provides cooling Fails to start, fails Mechanical failure;   Status monitor light in   Loss of cooling to       None. Train B SI          1. Train A and Train B pump/cooler air to SI Pump   while running;        Train A power         MCR for 2-FCV         SIP 2A-A room with       Pump is not affected      sets are in separate rooms. Review of Safety Injection   2A-A Room        Spuriously stops. failure; auto-start       176-A fully open (2-      the potential for loss   by the failure of Train   schematics for the Train A and B Pump 2A-A Cooler                                          signal failure;       ZS-67-176). Fan           of SIP 2A-A.             A pump room cooler,       coolers shows the trains to be (Train A)                                                 Operator error        motor running light on                             and is 100%               independent. The cooler automatically (handswitch placed    MCC.                                               redundant to Train A      starts upon high temperature on 2-TS-in wrong position)                                                       pump.                     30-180-A or SI Pump 2A-A start; and, manually by local handswitch21-HS-See Remark # 3.           30-180.
: 2. The Cooler Fan and the flow control valve 2-FCV-67-176-A are interlocked to operate together.
: 3. Train B equipment is located in SIP Room 2B. Failure of the Train A equipment, will not adversely impact Train B SI pump operation.
9.4-57                                                                                                                                                                                                                                                                     WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 2 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                         Method of No.      Component          Function         Failure Mode       Potential Cause             Detection            Effect on System           Effect on Plant                      Remarks 2     2-PMCL-30-179-B    Provides cooling Fails to start, fails Mechanical failure;   Status monitor light in   Loss of cooling to       None. Train A SI          1. Train A and Train B pump/cooler air to SI Pump   while running;        Train B power         MCR for 2-FCV         SIP 2B-B room with       Pump is not affected      sets are in separate rooms. Review of Safety Injection   2B-B Room        Spuriously stops. failure; auto-start       182 fully open (2-ZS-     the potential for loss   by the failure of Train   schematics for the Train A and B Pump 2B-B Cooler                                          signal failure;       67-182). Fan motor        of SIP 2B-B.             B pump room cooler,       coolers shows the trains to be (Train B)                                                 Operator error        running light on MCC.                              and is 100%               independent. The cooler automatically (handswitch placed                                                       redundant to Train B      starts upon high temperature on 2-TS-in wrong position)                                                       pump.                     30-179-B or SI Pump 2B-B start; and, manually by local handswitch 2-HS                                                                                                                                                                                                         See Remark # 3.           179.
: 2. The Cooler Fan and the flow control valve 2-FCV-67-182 are interlocked to operate together.
: 3. Train A equipment is located in SIP Room 2A. Failure of the Train B equipment will not adversely impact Train A SI pump operation.
9.4-58                                                                                                                                                                                                                                                                     WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 3 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                         Method of No.      Component             Function        Failure Mode       Potential Cause           Detection           Effect on System         Effect on Plant                    Remarks 3     2-FCV-67-176-A       Provides         Fails to open,      Mechanical failure;    Status monitor light in Loss of cooling water   None. Train B SI        2-FCV-67-176-A flowpath for     stuck closed        Opening signal         MCR (2-ZS-67-176)       to SIP 2A-A pump        Pump is not affected FCV fails open on loss of power or air.
Essential Raw        cooling water                        failure                                        room cooler with the    by the failure of Train Cooling Water Flow from the ERCW                                                                         potential for loss of   A pump room cooler, Control Valve for    Header 2A to the                                                                    SIP2A-A.                and is 100%
the Safety Injection cooler for Pump                                                                                             redundant to Train A System Pump 2A-A 2A-A                                                                                                            pump.
Cooler.
4     2-FCV-67-182-B       Provides         Fails to open,      Mechanical failure;    Status monitor light in Loss of cooling water   None. Train A SI        2-FCV-67-182-B flowpath for     stuck closed        Opening signal         MCR (2-ZS-67-182)       to SIP 2B-B pump        Pump is not affected FCV fails open on loss of power or air.
Essential Raw        cooling water                        failure                                        room cooler with the    by the failure of Train Cooling Water Flow from the ERCW                                                                         potential for loss of   B pump room cooler, Control Valve for    Header 2B to the                                                                    SIP 2B-B.               and is 100%
the Safety Injection cooler for Pump                                                                                             redundant to Train B System Pump 2B-B 2B-B                                                                                                            pump.
Cooler.
5     2-PMCL-30-175-A     Provides cooling Fails to start, fails Mechanical failure;   Fan motor running       Loss of cooling water   None.                  Train A and Train B RHR pump/cooler air to RHR Pump while running;         Train A Power         light on MCC.           to RHR Pump 2A-A        Train B RHR Pump is    sets are in separate rooms. Review of Residual Heat       2A-A Room.       Spuriously stops. failure; Auto-start                               Room cooler with the    not affected by the    the schematics for the Train A and Removal Pump 2A-                                           signal failure;       Status monitor light in potential loss of RHR   failure of Train A     Train B coolers shows the trains to be A Cooler (Train A).                                        Operator error        MCR for 2-FCV       Pump 2A-A.              Pump Room Cooler       independent. The cooler is started (handswitch placed    188 (2-ZS-67-188)                               and is 100%            automatically upon high temperature at in wrong position).                                                   redundant to Train A   2-TS-30-175-A, or RHR Pump 2A-A Pump.                  start; Manually by local handswitch 2-HS-30-175.
9.4-59                                                                                                                                                                                                                                                                WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 4 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                          Method of No.      Component            Function         Failure Mode       Potential Cause            Detection           Effect on System          Effect on Plant                      Remarks 6     2-PMCL-30-176-B      Provides cooling Fails to start, fails Mechanical failure;   Fan motor running       Loss of cooling to      None. Train A RHR         Train A and Train B RHR pump/cooler air to RHR Pump while running;         Train B power         light on MCC.           RHR Pump 2B-B           Pump is not affected      sets are in separate rooms. Review of Residual Heat        2B-B Room        Spuriously stops. failure; auto-start                               Room with the           by the failure of Train   the schematics for the Train A and Removal Pump                                                signal failure;       Status monitor light in potential loss of RHR   B Pump Room               Train B coolers shows the trains to be 2B-B Cooler (Train                                          Operator error        MCR for 2-FCV       2B-B.                   Cooler, and is 100%       independent. The cooler started B)                                                          (handswitch placed    190 (2-ZS-67-190)                               redundant to Train A      automatically upon high temperature at in wrong position)                                                    pump.                     2-TS-30-176-B or RHR Pump 2B-B start; Manually by local handswitch 2-HS-30-176.
7     2-FCV-67-188-A     Provides            See 'remarks'       See 'remarks'          See 'remarks' column. See 'remarks'             See 'remarks'             2-FCV-67-188-A has been electrically flowpath for        column              column.                                      column.                   column.                   disconnected due to App. 'R' Essential Raw      cooling water                                                                                                                            interaction to keep the valve Cooling Water Flow from the ERCW                                                                                                                            permanently open.
Control Valve for  Header to the the Residual Heat  cooler for RHR Removal System     Pump 2A-A.
Pump 2A-A Cooler.
8     2-FCV-67-190-B     Provides            See 'remarks'       See 'remarks'          See 'remarks' column See 'remarks'              See 'remarks'             2-FCV-67-190-B has been electrically flowpath for        column              column                                      column                     column                    disconnected due to App. 'R' Essential Raw      cooling water                                                                                                                            interaction to keep the valve Cooling Water Flow from the ERCW                                                                                                                            permanently open.
Control Valve for  Header to the the Residual Heat  cooler for RHR Removal System     Pump 2B-B.
Pump 2B-B Cooler.
9.4-60                                                                                                                                                                                                                                                                    WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 5 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                          Method of No.      Component           Function         Failure Mode       Potential Cause             Detection            Effect on System           Effect on Plant                       Remarks 9     2-PMCL-30-177-A     Provides cooling Fails to start, fails Mechanical failure;   Status monitor light in   Loss of cooling to       None.                     Equipment includes fan and motor.
air to CS Pump while running;          Train A power         MCR for 2-FCV         CSP 2A-A Room            Train B Pump is not       Train A and Train B CS pump/cooler Containment Spray   2A-A Room        Spuriously stops. failure; Auto-start       184-A (2-ZS-67-184).      with the potential for   affected by the failure   sets are in separate rooms. Review of Pump 2A-A Cooler                                           signal failure;       Fan motor running         loss of CSP 2A-A.        of Train A                the schematics for the Train A and B (Train A)                                                  Operator error        light on MCC.                                      pump/cooler, and is       coolers shows the trains to be (handswitch placed                                                       100% redundant to         independent. The cooler is started in wrong position)                                                       Train A pump.             automatically upon high temperature at 2-TS-30-177-A or CS Pump 2A-A start; manually by local handswitch 2-HS                                                                                                                                                                                                                                    177.
The cooler and the flow control valve 2-FCV-67-184 are interlocked to operate together.
10     2-PMCL-30-178-B     Provides cooling Fails to start, fails Mechanical failure;   Status monitor light in   Loss of cooling to       None.                     Equipment includes fan and motor.
air to CS Pump while running;          Train B power         MCR for 2-FCV         CSP 2B-B Room            Train A Pump is not       Train A and Train B CS pump/cooler Containment Spray   2B-B Room        Spuriously stops. failure; Auto-start       186-B (2-ZS-67-186).      with the potential for   affected by the failure   sets are in separate rooms. Review of Pump 2B-B Cooler                                           signal failure;       Fan motor running         loss of CSP 2B-B.        of Train B                schematics for the Train A and B (Train B)                                                  Operator error        light on MCC.                                      pump/cooler, and is       coolers shows the trains to be (handswitch placed                                                       100% redundant to         independent. The cooler is started in wrong position)                                                       Train B pump.             automatically upon high temperature at 2-TS-30-178-B or CS Pump 2B-B start; manually by local handswitch 2-HS                                                                                                                                                                                                                                    178.
The cooler and the flow control valve 2-FCV-67-186 are interlocked to operate together.
9.4-61                                                                                                                                                                                                                                                                        WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 6 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                           Method of No.      Component            Function         Failure Mode       Potential Cause             Detection           Effect on System         Effect on Plant                    Remarks 11     2-FCV-67-184       Provides            Fails to open,      Mechanical failure;    Status monitor light in Loss of cooling to       None.                  2-FCV-67-184 fails to the open position flowpath for        stuck closed.       Opening signal         MCR (2-ZS-67-184). CSP 2A-A room with            Train B CS Pump is     on loss of power or air.
Essential Raw      cooling water                           failure.                                       the potential for loss   not affected by the Cooling Water Flow from the ERCW                                                                          of CSP 2A-A.             failure of Train A Control Valve for  Header to the                                                                                                   pump room cooler, the Containment    cooler for CS                                                                                                   and is 100%
Spray System       Pump 2A-A.                                                                                                      redundant to Train A Pump 2A-A Cooler.                                                                                                                  pump.
12     2-FCV-67-186       Provides            Fails to open,      Mechanical failure;    Status monitor light in Loss of cooling to       None.                  2-FCV-67-186-B fails to the open flowpath for        stuck closed.       Opening signal         MCR (2-ZS-67-186). CSP 2B-B room with            Train A CS Pump is     position on loss of power or air.
Essential Raw      cooling water                           failure.                                       the potential for loss   not affected by the Cooling Water Flow from the ERCW                                                                          of CSP 2B-B.             failure of Train B Control Valve for  Header to the                                                                                                   pump room cooler, the Containment    cooler for CS                                                                                                   and is 100%
Spray System       Pump 2B-B.                                                                                                      redundant to Train B Pump 2B-B Cooler.                                                                                                                  pump.
13     2-PMCL-30-183-A      Provides cooling Fails to start, fails Mechanical failure;   Fan motor running       Loss of cooling to CC    None.                  Equipment includes fan and motor.
air to CC Pump while running;          Train A power         light on MCC.           pump 2A-A Room           Train B CC pump is     Train A and Train B pump/cooler sets Centrifugal          2A-A Room.       Spuriously stops. failure; Auto-start                               with the potential for   not affected by the    are in separate rooms. Review of Charging Pump                                               signal failure;       Status monitor light in loss of CC Pump 2A-      failure of Train A     schematics for the train A and B 2A-A Cooler (Train                                          Operator error        MCR for 2-FCV       A.                       pump/cooler, and is    coolers shows the trains to be A).                                                         (handswitch placed    168 (2-ZS-168)                                   100% redundant to      independent. The cooler automatically in wrong position).                                                    Train A pump.          starts upon high temperature at 2-TS-30-183-A, or pump 2A-A start; Manually by local handswitch 2-HS                                                                                                                                                                                                                                183.
9.4-62                                                                                                                                                                                                                                                                   WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 7 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                          Method of No.      Component            Function         Failure Mode       Potential Cause            Detection            Effect on System         Effect on Plant                   Remarks 14     2-PMCL-30-182-B      Provides cooling Fails to start, fails Mechanical failure;   Fan motor running       Loss of cooling to CC    None.                 Equipment includes fan and motor.
air to CC Pump while running;          Train B power         light on MCC.           pump 2B-B Room           Train A CC pump is    Train A and Train B pump/cooler sets Centrifugal          2B-B Room        Spuriously stops. failure; Auto-start                               with the potential for   not affected by the   are in separate rooms. Review of Charging Pump                                               signal failure;       Status monitor light in loss of CC pump 2B-      failure of Train B    schematics for the Train A and B 2B-B Cooler (Train                                          Operator error        MCR for 2-FCV       B.                       pump/cooler, and is   coolers shows the trains to be B).                                                         (handswitch placed    170 (2-ZS-170)                                   100% redundant to     independent. The cooler automatically in wrong position)                                                     Train B pump.         starts upon high temperature at 2-TS-30-182-B or pump 2B-B start; Manually by local handswitch 2-HS-30-182.
15     2-FCV-67-168         Provides          See 'Remarks'       See 'Remarks'          See 'Remarks' column See 'Remarks'               See 'Remarks'         2-FCV-67-168 is electrically flowpath for      column              column                                      column                      column                disconnected to keep the valve Essential Raw        cooling water                                                                                                                       permanently open.
Cooling water Flow   from the ERCW Control Valve for    Header to the the centrifugal      cooler for CC Charging Pump        Pump 2A-A.
Room 2A-A Cooler.
16     2-FCV-67-170         Provides          See 'Remarks'       See 'Remarks'          See 'Remarks' column See 'Remarks'               See 'Remarks'         2-FCV-67-170 is electrically flowpath for      column              column                                      column                      column                disconnected to keep the valve Essential Raw        cooling water                                                                                                                       permanently open.
Cooling water Flow   from the ERCW Control Valve for    Header to the the centrifugal      cooler for CC Charging Pump        Pump 2B-B.
Room 2B-B Cooler.
9.4-63                                                                                                                                                                                                                                                                WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 8 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                            Method of No.      Component           Function         Failure Mode         Potential Cause             Detection            Effect on System        Effect on Plant                    Remarks 17     1-PMCL-30-190-A    Provides cooling Fails to start, fails   Mechanical failure;    Status monitor light in   Loss of redundancy     None.                 The cooler automatically starts upon CCS and Aux. FW    air to the CCS   while running;          Train A power          MCR for 1-FCV         in providing cooling   The Train B Cooler    Train A ABI signal or high temperature Pump Cooler A-A. and Aux. FW      Spuriously stops.       failure; Auto-         162 (1-ZS-67-162).        air for CCS and Aux    B-B is available to   sensed by 1-TS-30-190A-A. t . Cooler pumps space.                             standby start signal   Indicating light on       FW pumps space.        start on high         fan motor and 1-FSV-67-162-A are failure; Operator      MCC for fan motor                                temperature (1-TS-    interlocked to open 1-FCV-67-162-A for error (handswitch      running.                                         30-191-A-B) and is    ERCW supply on cooler start. Review placed in wrong                                                         100% redundant to     of the schematics for the coolers A-A position)                                                               the Train A cooler. and B-B shows their independence.
18     1-PMCL-30-191-B    Provides cooling Fails to start, fails   Mechanical failure;    Status monitor light in   Loss of redundancy     None.                 The cooler automatically starts upon air to the CCS   while running;          Train B power          MCR for 1-FCV         in providing cooling   The Train A Cooler    Train B ABI signal or high temperature CCS and Aux. FW    and Aux. FW      Spuriously stops.       failure; Auto-         164-B (1-ZS-67-164).      air for CCS and Aux. A-A is available to   sensed by 1-TS-30-191A-B. t Cooler Pump/Cooler B-B    pumps space.                             standby start signal   Indicating light on       FW pumps space.        start on high         fan motor and 1-FSV-67-164-B are failure; Operator      MCC for fan motor                                temperature (1-TS-    interlocked to open 1-FCV-67-164 for error (handswitch      running.                                         30-190A-A) and is     ERCW Supply on cooler start. Review placed in wrong                                                         100% redundant to     of the schematics for the coolers A-A position)                                                               Train B cooler.       and B-B shows their independence.
19     1-FCV-67-162       Provides        Fails to open,           Mechanical failure;    Status monitor light in Loss of redundancy       None.                   1-FCV-67-162 fails open on loss of flowpath for    stuck closed.            Opening signal         MCR (or                 in providing cooling     Train B pump space power or air.
Essential Raw      cooling water                            failure.               1-ZS-67-162).           to CCS and Aux FW        cooler is not affected Cooling Water Flow from the ERCW                                                                           Pump space.              by the failure of Train Control Valve for  Header to the                                                                                                    A pump room cooler, the CCS and Aux. Cooler for Pump                                                                                                  and is 100%
FW Pump Cooler A- A-A.                                                                                                              redundant to the train A.                                                                                                                                  A pump space cooler.
9.4-64                                                                                                                                                                                                                                                                  WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 9 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                          Method of No.      Component           Function         Failure Mode       Potential Cause             Detection            Effect on System        Effect on Plant                     Remarks 20     1-FCV-67-164       Provides        Fails to open,        Mechanical failure;     Status monitor light in Loss of redundancy       None.                   1-FCV-67-164 fails open on loss of flowpath for    stuck closed.         Opening signal          MCR (or 1-ZS        in providing cooling     Train A pump space power or air.
Essential Raw      cooling water                         failure.                164).                   to CCS and Aux FW        cooler is not affected Cooling Water Flow from the ERCW                                                                         Pump space.              by the failure of Train Control Valve for  Header to the                                                                                                  B pump room cooler, the CCS and Aux. Cooler for Pump                                                                                                and is 100%
FW Pump Cooler B- B-B.                                                                                                            redundant to the B.                                                                                                                                Train B pump space cooler.
21     2-CLR-30-200-A     Provides cooling Fails to start, fails Mechanical failure;    Status monitor light in   Loss of redundancy     None.                   The cooler automatically starts upon air to the EGTS while running;         Train A power          MCR for 2-FCV         in providing cooling   The Train B Cooler is   Train AB ABI signal or high EGTS Cooler A-A    Room             Spuriously stops. failure; Auto-             336 (2-ZS-67-336).        air for the EGTS       available to start on   temperature at 2-TS-30-200A-A.l standby start signal   Fan motor running         Room.                  high temperature (2-    Cooler fan motor and 2-FSV-67-336-A failure; Operator      light on MCC.                                    TS-30-207A-B) and       are interlocked to open 2-FCV-67-336 error (handswitch                                                       is 100% redundant to    for ERCW supply on cooler start.
placed in wrong                                                         Train A cooler.         Review of the schematics for the position)                                                                                       coolers A-A and B-B shows their independence.
22     2-CLR-30-207-B     Provides cooling Fails to start, fails Mechanical failure;    Status monitor light in   Loss of redundancy     None.                   The cooler automatically starts upon air to the EGTS while running;         Train B power          MCR for 2-FCV         in providing cooling   The Train A Cooler is   Train B ABI signal or high temperature EGTS Cooler B-B    Room             Spuriously stops. failure; Auto-             338 (2-ZS-67-338).        air for the EGTS       available to start on   at 2-TS-30-207A-B. Cooler fan motor standby start signal   Fan motor running         Room.                  high temperature at     and 2-FSV-67-338-B are interlocked to failure; Operator      light on MCC.                                    2-TS-30-200A-A and      open 2-FCV-67-338 for ERCW supply error (handswitch                                                       is 100% redundant to    on cooler start. Review of the placed in wrong                                                         Train B cooler.         schematics for the coolers A-A and B-B position)                                                                                       shows their independence.
9.4-65                                                                                                                                                                                                                                                                  WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 10 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                              Method of No.      Component            Function          Failure Mode         Potential Cause             Detection            Effect on System        Effect on Plant                     Remarks 23     2-FCV-67-336       Provides         Fails to open,            Mechanical failure;    Status monitor light in Loss of redundancy       None.                   2-FCV-67-336 fails open on loss of flowpath for     stuck closed.             signal failure.        MCR (2-ZS-67-336)       in providing cooling     Train B cooler is not power or air.
Essential Raw      cooling water                                                                             to EGTS room.            affected by the failure Cooling Water Flow from the ERCW                                                                                                      of Train A room Control Valve for  Header to the A-                                                                                                   cooler, and is 100%
the EGTS Room      A cooler for the                                                                                                   redundant to the Cooler A-A.        EGTS Rooms.                                                                                                        Train A room cooler.
24     2-FCV-67-338       Provides         Fails to open,            Mechanical failure;    Status monitor light in Loss of redundancy       None.                   2-FCV-67-338 fails open on loss of flowpath for     stuck closed.             signal failure.        MCR (2-ZS-67-338). in providing cooling          Train A cooler is not power or air.
Essential Raw      cooling water                                                                             to EGTS room.            affected by the failure Cooling Water Flow from the ERCW                                                                                                      of Train B room Control Valve for  Header to the B-                                                                                                   cooler, and is 100%
the EGTS Room      B cooler for the                                                                                                   redundant to the Cooler B-B         EGTS Rooms.                                                                                                        Train B room cooler.
25     0-PMCL-30-192-A      Provides cooling Fails to start, fails   Mechanical failure;    Status monitor light in   Loss of redundancy     None.                   The cooler automatically starts upon air to the CCS   while running;          Train A power          MCR for 1-FCV         in providing cooling   The Train B Cooler is   Train A ABI signal or high temperature CCS TB Booster       TB Booster and Spuriously stops.         failure; Auto-         213-A (1-ZS-67-213)       air for CCS TB         available to start on   at 0-TS-30-192A-A. Cooler fan motor and Spent Fuel Pit   Spent Fuel Pit                           standby start signal   Fan motor running         Booster and Spent      high temperature (0-    and 1-FSV-67-213-A are interlocked to Pump Cooler A-A      Cooler Space.                            failure; Operator      light on MCC.             Fuel Pit Cooler        TS-30-193A-B) and       open 1-FCV-67-213-A for ERCW error (handswitch                                Space                  is 100% redundant to    supply on cooler start. Review of the placed in wrong                                                         the Train A cooler. schematics for the coolers A-A and B-B position)                                                                                       shows their independence.
26     0-PMCL-30-193-B      Provides cooling Fails to start, fails   Mechanical failure;    Status monitor light in   Loss of redundancy     None.                   The cooler automatically starts upon air to the CCS   while running;          Train B power          MCR for 1-FCV         in providing cooling   The Train A Cooler is   Train B ABI signal or high temperature CCS TB Booster       TB Booster and Spuriously stops.         failure; Auto-         215 (1-ZS-67-215).        air for CCS TB         available to start on   at 0-TS-30-193A-B. Cooler fan motor and Spent Fuel Pit   Spent Fuel Pit                           standby start signal   Fan motor running         Booster and Spent      high temperature (0-    and 1-FSV-67-215-B are interlocked to Cooler B-B           Cooler B-B                               failure; Operator      light on MCC.             Fuel Pit Cooler        TS-30-192A-A) and       open 1-FCV-67-215-B for ERCW space.                                   error (handswitch                                space.                 is 100% redundant to    supply on cooler start. Review of the placed in wrong                                                         the Train B cooler. schematics for the coolers A-A and B-B position)                                                                                       shows their independence.
9.4-66                                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 11 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                          Method of No.      Component            Function          Failure Mode       Potential Cause           Detection           Effect on System        Effect on Plant                      Remarks 27     1-FCV-67-213-A      Provides            Fails to open,      Mechanical failure;   Status monitor light in Loss of redundancy     None.                  1-FCV-67-213-A fails open on loss of flowpath for        stuck closed.       Opening signal        MCR (1-ZS-67-213)       in providing cooling   Train B Pump area      power or air.
Essential Raw       cooling water                           failure.                                      air to CCS TB          cooler is not affected Cooling Water Flow from the ERCW                                                                          Booster and Spent      by the failure of Control Valve for   Header to the                                                                         Fuel Pit Coolers       Train A pump area the CCS TB          Cooler A-A.                                                                           space.                 cooler, and is 100%
Booster and Spent                                                                                                                redundant to the Fuel Pit Cooler A-A                                                                                                              Train A pump area cooler.
28     1-FCV-67-215-B      Provides            Fails to open,      Mechanical failure;   Status monitor light in Loss of redundancy     None.                  1-FCV-67-215-A fails open on loss of flowpath for        stuck closed.       Opening signal        MCR (1-ZS-67-215)       in providing cooling   Train A Pump area      power or air.
Essential Raw       cooling water                           failure.                                      air to CCS TB          cooler is not affected Cooling Water Flow from the ERCW                                                                          Booster and Spent      by the failure of Control Valve for   Header to the                                                                         Fuel Pit Coolers       Train B pump area the CCS TB          Cooler B-B.                                                                           space.                 cooler, and is 100%
Booster and Spent                                                                                                                redundant to the Fuel Pit Cooler B-B                                                                                                              Train B pump area cooler.
29     0-BKD-31-2956        Provides          Fails to open        Mechanical failure    Local position         Loss of redundancy      None.
flowpath for cool (stuck closed).                            indicator attachment   in providing cooling    The standby Train B CCS TB Booster       air flow from                                                on the damper would air to room.               cooler will start upon and Spent Fuel Pit   Cooler A-A to                                                indicate if damper was                         high temperature on Pump Cooler A-A      common                                                       stuck closed                                   0-TS-30-193B-B.
Backdraft Damper     discharge headers to room.
Protects standby   Fails to backseat   Mechanical failure    Local position         Loss of redundancy      None (See remarks)       Operability of the dampers is Cooler A-A from    (stuck open)                              indicator attachment   in providing cooling                             periodically verified.
reverse air flow   when Train B                              on the damper would air to room.
WBNP-97 from running       Cooler B-B is                             indicate if damper was 9.4-67                                                                                    cooler B-B.        running.                                  stuck open.

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 12 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                              Method of No.      Component            Function          Failure Mode         Potential Cause             Detection            Effect on System        Effect on Plant                      Remarks 30     0-BKD-31-2957        Provides          Fails to open          Mechanical failure     Local position         Loss of redundancy        None.                  Operability of the dampers is flowpath for cool (stuck closed).                               indicator attachment   in providing cooling      The standby Train A periodically verified.
CCS TB Booster       air flow from                                                   on the damper would air to room.                 cooler will start upon and Spent Fuel Pit   Cooler B-B to                                                   indicate if damper was                           high temperature on Pump Cooler B-B      common                                                          stuck closed.                                    0-TS-30-192B-A.
Backdraft Damper     discharge headers to room.
Protects standby   Fails to backseat     Mechanical failure     Local position         Loss of redundancy        None (See remarks)      Operability of the dampers is Cooler B-B from    (stuck open)                                 indicator attachment   in providing cooling                              periodically verified.
reverse air flow   when Train A                                 on the damper would air to room.
from running       Cooler A-A is                                indicate if damper was cooler A-A.        running.                                     stuck open.
31     2-PMCL-30-184-A      Provides cooling Fails to start, fails   Mechanical failure;    Status monitor light in   Loss of redundancy     None.                   The cooler automatically starts upon air to the AFW   while running;          Train A power          MCR for 2-FCV         in providing cooling   The Train B Cooler is   Train A ABI signal or high temperature AFW and BAT          and BAT pumps Spuriously stops.          failure; Auto-         217 (2-ZS-67-217).        air for AFW and BAT    available to start on   at 2-TS-30-184A-A. Cooler fan motor Cooler Fan A-A       space                                    standby start signal   Fan motor running         pumps Space            high temperature (2-    and 2-FSV-67-217-A are interlocked to failure; Operator      light on MCC.                                    TS-30-185A-B) and       open 2-FCV-67-217 for ERCW supply error (handswitch                                                       is 100% redundant to    on cooler start. Review of the placed in wrong                                                         Train A cooler.         schematics for the coolers A-A and B-B position)                                                                                       shows their independence.
32     2-PMCL-30-185-B      Provides cooling Fails to start, fails   Mechanical failure;    Status monitor light in   Loss of redundancy     None.                   The cooler automatically starts air to the AFW   while running;          Train B power          MCR for 2-FCV         in providing cooling   The Train A Cooler is   upon Train B ABI signal or high AFW and BAT          and BAT pumps Spuriously stops.          failure; Auto-         219-B (2-ZS-67-219).      air for AFW and BAT    available to start on   temperature at 2-TS-30-185A-B.
Cooler Fan B-B       space                                    standby start signal   Fan motor running         pumps Space            high temperature (2-    Cooler fan motor and 2-FSV                                                                                                                                    failure; Operator      light on MCC.                                    TS-30-184A-A) and       219-B are interlocked to open 2-error (handswitch                                                       is 100% redundant to    FCV-67-219 for ERCW supply on placed in wrong                                                         Train B cooler.         cooler start. Review of the position)                                                                                       schematics for the coolers A-A and B-B shows their WBNP-97 independence.
9.4-68

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 13 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                        Method of No.      Component           Function         Failure Mode       Potential Cause           Detection           Effect on System        Effect on Plant                     Remarks 33     2-FCV-67-217       Provides        Fails to open,         Mechanical failure;   Status monitor light in Loss of redundancy     None.                   2-FCV-67-217 fails open on loss flowpath for    stuck closed.          Opening signal        MCR (2-ZS-67-217)       in providing cooling   Train B Pump room of power or air.
Essential Raw      cooling water                          failure.                                      to AFW and BAT         cooler is not affected Cooling Water Flow from the ERCW                                                                        pumps Space.           by the failure of Train Control Valve for  Header to the                                                                                               A pump room cooler, the AFW and BAT    Cooler for Pump                                                                                             and is 100%
Cooler A-A         A-A.                                                                                                        redundant to the Train A pump room cooler.
34     2-FCV-67-219       Provides        Fails to open,         Mechanical failure;   Status monitor light in Loss of redundancy     None.                   2-FCV-67-219 fails open on loss of flowpath for    stuck closed.          Opening signal        MCR (2-ZS-67-219)       in providing cooling   Train A Pump room power or air.
Essential Raw      cooling water                          failure.                                      to AFW and             cooler is not affected Cooling Water Flow from the ERCW                                                                        BATpumps Space.        by the failure of Train Control Valve for  Header to the                                                                                               B pump room cooler, the AFW and BAT    Cooler for Pump                                                                                             and is 100%
Cooler B-B         B-B.                                                                                                        redundant to the Train B pump room cooler.
35     2-BKD-31-2952      Provides          Fails to open        Mechanical failure    Local position         Loss of redundancy      None.                  Operability of the dampers is flowpath for cool (stuck closed).                            indicator attachment   in providing cooling    The standby Train B peridoically verified.
Aux FW and BAT     air flow from                                                on the damper would air to room.               cooler will start upon Pump Cooler A-A    Cooler A-A to                                                indicate if damper was                         high temperature on Backdraft Damper   common                                                       stuck closed                                   2-TS-30-185B-B.
discharge header to room.
Protects standby   Fails to backseat   Mechanical failure    Local position         None                    None                  .
Cooler A-A from    (stuck open)                              indicator attachment reverse air flow   when Train B                              on the damper would from running       Cooler B-B is                             indicate if damper was cooler B-B.        running.                                  stuck open.
9.4-69                                                                                                                                                                                                                                                           WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 14 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                           Method of No.      Component           Function          Failure Mode       Potential Cause             Detection            Effect on System        Effect on Plant                     Remarks 36     2-BKD-31-2953       Provides          Fails to open        Mechanical failure     Local position         Loss of redundancy        None.                  Operability of the dampers is flowpath for cool (stuck closed).                             indicator attachment   in providing cooling      The standby Train A peridoically verified.
Aux FW and BAT      air flow from                                                 on the damper would air to room.                 cooler will start upon Pump Cooler B-B     Cooler B-B to                                                 indicate if damper was                           high temperature on Backdraft Damper    common                                                        stuck closed                                     2-TS-30-184B-A.
discharge header to room.
Protects standby   Fails to backseat   Mechanical failure     Local position         None                      None                    .
Cooler B-B from    (stuck open)                               indicator attachment reverse air flow   when Train A                               on the damper would from running       Cooler A-A is                              indicate if damper was cooler A-A.        running.                                   stuck open.
37     2-CLR-30-201-A      Provides cooling Fails to start, fails Mechanical failure;    Status monitor light in   Loss of redundancy     None. The Train B       The cooler automatically starts upon air to the pipe  while running;        Train A power          MCR for 2-FCV         in providing cooling   Cooler Fan 2B-B is      Train A ABI signal or high temperature Pipe Chase Cooler   chase.           Spuriously stops. failure; Auto-             342-A (2-ZS-67-342-       air for the Pipe       available to start on   at 2-TS-30-201A-A. Cooler fan motor Fan 2A-A                                                   standby start signal   A). Fan motor running     Chase.                 high temperature (2-    and 2-FSV-67-342-A are interlocked to failure; Operator      light on MCC.                                    TS-30-202A-B) and       open 2-FCV-67-342-A for ERCW error (handswitch                                                       is 100% redundant to    supply on cooler start. Review of the placed in wrong                                                         Train A cooler.         schematics for the coolers A-A nd B-B position)                                                                                       shows their independence.
38     2-CLR-30-202-B      Provides cooling Fails to start, fails Mechanical failure;    Status monitor light in   Loss of redundancy     None. The Train A       The cooler automatically starts upon air to the pipe  while running;        Train B power          MCR for 2-FCV         in providing cooling   Cooler Fan 2A-A is      Train B ABI signal or high temperature Pipe Chase Cooler   chase.           Spuriously stops. failure; Auto-             344-B (2-ZS-67-344).      air for the Pipe       available to start on   at 2-TS-30-202A-B. Cooler fan motor Fan 2-B-B                                                  standby start signal   Fan motor running         Chase.                 high temperature at     and 2-FSV-67-344-B are interlocked to failure; Operator      light on MCC.                                    2-TS-30-201a-A and      open 2-FCV-67-344-B for ERCW error (handswitch                                                       is 100% redundant to    supply on cooler start. Review of the placed in wrong                                                         Train B cooler.         schematics for the coolers A-A and B-B position)                                                                                       shows their independence.
9.4-70                                                                                                                                                                                                                                                                   WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 15 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                         Method of No.      Component           Function          Failure Mode       Potential Cause           Detection           Effect on System        Effect on Plant                     Remarks 39     2-FCV-67-342-A     Provides            Fails to open,      Mechanical failure;   Status monitor light in Loss of redundancy     None.                   2-FCV-67-342 fails open on loss of flowpath for        stuck closed.       Opening signal        MCR (2-ZS-67-342)       in providing cooling   Train B Pump room power or air.
Essential Raw      cooling water                           failure.                                      air to the Pipe        cooler is not affected Cooling Water Flow from the ERCW                                                                         Chase.                 by the failure of Train Control Valve for  Header to the                                                                                                A pump room cooler, the Pipe Chase     Cooler 2A-A.                                                                                                 and is 100%
Cooler 2A-A                                                                                                                     redundant to the Train A pump room cooler.
40     2-FCV-67-344-B     Provides            Fails to open,      Mechanical failure;   Status monitor light in Loss of redundancy     None.                   2-FCV-67-344 fails open on loss of flowpath for        stuck closed.       Opening signal        MCR (2-ZS-67-344)       in providing cooling   Train A Pump room power or air.
Essential Raw      cooling water                           failure.                                      air to the Pipe        cooler is not affected Cooling Water Flow from the ERCW                                                                         Chase.                 by the failure of Train Control Valve for  Header to the                                                                                                B pump room cooler, the Pipe Chase     Cooler 2B-B.                                                                                                 and is 100%
Cooler 2B-B                                                                                                                     redundant to the Train B pump room cooler.
41     2-BKD-31-2925       Provides          Fails to open        Mechanical failure    Local position         Loss of redundancy      None.                  Operability of the dampers is flowpath for cool (stuck closed).                            indicator attachment   in providing cooling    The standby Train B periodically verified.
Pipe Chase Cooler   air flow from                                                on the damper would air to Pipe Chase.         cooler will start upon 12-A Backdraft      Cooler 2A-A to                                               indicate if damper was                         high temperature on Damper              Pipe Chase                                                   stuck closed                                   2-TS-30-202B-B.
Header.
Protects standby   Fails to backseat   Mechanical failure    Local position         Loss of redundancy      None (See remarks)
Cooler 2A-A        (stuck open)                              indicator attachment from reverse air   when Train A                              on the damper would flow from          Cooler 2B-B is                            indicate if damper was running cooler     running.                                  stuck open.
2B-B.
9.4-71                                                                                                                                                                                                                                                            WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 16 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                            Method of No.      Component           Function          Failure Mode         Potential Cause            Detection            Effect on System         Effect on Plant                      Remarks 42     2-BKD-31-2937       Provides          Fails to open          Mechanical failure    Local position         Loss of redundancy         None.                  Operability of the dampers is flowpath for cool (stuck closed).                              indicator attachment   in providing cooling       The standby Train A periodically verified.
Pipe Chase Cooler   air flow from                                                  on the damper would air to Pipe Chase.            cooler will start upon 2B-B Backdraft      Cooler 2B-B to                                                 indicate if damper was                            high temperature on Damper              Pipe Chase                                                     stuck closed                                      2-TS-30-201B-A.
Header.
Protects standby   Fails to backseat     Mechanical failure    Local position         Loss of redundancy         None (See Remarks)
Cooler 2B-B        (stuck open)                                indicator attachment from reverse air   when Train B                                on the damper would flow from          Cooler 2A-A is                              indicate if damper was running cooler     running.                                    stuck open.
2A-A.
43     2-CLR-30-186-A      Provides cooling Fails to start, fails   Mechanical failure;   Status monitor light in   Loss of cooling to      None.                    The cooler automatically starts upon air to           while running;          Train A power         MCR for 2-FCV         Penetration Room        The Train B Cooler is    Train A ABI signal or high temperature Penetration Room    Penetration      Spuriously stops.       failure; Auto-start   346 fully open (2-ZS-     (El 692) with the       available to start on    at 2-TS-30-186A-A. Cooler fan motor Cooler Fan 2A-A     Room (El 692)                            signal failure;       67-346). Fan motor        potential for loss of   high temperature (2-     and 2-FSV-67-346-A are interlocked to (Train A)                                                    Operator error        running light on MCC. room equipment.         TS-30-187A-B) and        open 2-FCV-67-346 for ERCW supply (handswitch placed                                                      is 100% redundant to     on cooler start. Review of the in wrong position)                                                      Train A cooler.          schematics for the coolers A-A and B-B shows their independence.
44     2-CLR-30-187-B      Provides cooling Fails to start, fails   Mechanical failure;   Status monitor light in   Loss of cooling to      None. The Train A        The cooler automatically starts upon air to           while running;          Train B power         MCR for 2-FCV         Penetration Room        Cooler is available to   Train B ABI signal or high temperature Penetration Room    Penetration      Spuriously stops.       failure; Auto-start   348 fully open (2-ZS-     (El 692) with the       start on high            at 2-TS-30-187A-B.Cooler fan motor Cooler Fan 2B-B     Room (El 692)                            signal failure;       67-348). Fan motor        potential for loss of   temperature at 2-TS-     and 2-FSV-67-348-B are interlocked to (Train B).                                                   Operator error        running light on MCC. room equipment.         30-186A-A and is         open 2-FCV-67-348 for ERCW supply (handswitch placed                                                      100% redundant to        on cooler start. Review of the in wrong position)                                                      Train B cooler.          schematics for the coolers A-A and B-B shows their independence.
9.4-72                                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 17 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                           Method of No.      Component          Function          Failure Mode         Potential Cause            Detection            Effect on System         Effect on Plant                      Remarks 45     2-FCV-67-346-A     Provides           Fails to open,        Mechanical failure;   Status monitor light in Loss of redundancy        None.                   2-FCV-67-346-A fails open on loss of flowpath for       stuck closed.         Opening signal        MCR (2-ZS-67-346)       in providing cooling      Train B Pump room power or air.
Essential Raw      cooling water                            failure.                                      to Penetration Room       cooler is not affected Cooling Water Flow from the ERCW                                                                          (El. 692) space.          by the failure of Train Control Valve for  Header to the                                                                          .                         A pump room cooler, the Penetration    Cooler for the                                                                                                   and is 100%
Room (El. 692)     Penetration                                                                                                      redundant to the Cooler 2A-A        Room Space.                                                                                                      Train A pump room cooler.
46     2-FCV-67-348-B     Provides           Fails to open,        Mechanical failure;   Status monitor light in Loss of redundancy        None.                   2-FCV-67-348-B fails open on loss of flowpath for       stuck closed.         Opening signal        MCR (2-ZS-67-348)       in providing cooling      Train A Pump room power or air.
Essential Raw      cooling water                            failure.                                      to Penetration Room       cooler is not affected Cooling Water Flow from the ERCW                                                                          (El. 692) space.          by the failure of Train Control Valve for  Header to the                                                                                                    B pump room cooler, the Penetration    Cooler for the                                                                                                   and is 100%
Room (El. 692)     Penetration                                                                                                      redundant to the Cooler 2B-B        Room Space.                                                                                                      Train B pump room cooler.
47     2-CLR-30-196       Provides cooling Fails to start, fails   Mechanical failure;   Status monitor light in   Loss of cooling to      None. The Train B        The cooler automatically starts upon air to           while running;          Train A power         MCR for 21-FCV        Penetration Room        Cooler is available to   Train A ABI signal or high temperature Penetration Room   Penetration      Spuriously stops.       failure; Auto-start   350-A fully open (2-      (El 713) with the       start on high            (2-TS-30-196A-A). Cooler fan motor Cooler Fan 2A-A    Room (El 713)                            signal failure;       ZS-67-350). Fan           potential for loss of   temperature (2-TS-       and 2-FSV-67-350-A are interlocked to (Train A).                                                  Operator error        motor running light on    room equipment.         30-197A-B) and is        open 2-FCV-67-350-A for ERCW (handswitch placed    MCC.                                              100% redundant to        supply on cooler start. Review of the in wrong position)                                                      Train A cooler.          schematics for the coolers A-A and B-B shows their independence.
9.4-73                                                                                                                                                                                                                                                                     WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 18 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                           Method of No.      Component          Function          Failure Mode         Potential Cause            Detection            Effect on System         Effect on Plant                      Remarks 48     2-CLR-30-197       Provides cooling Fails to start, fails   Mechanical failure;   Status monitor light in   Loss of cooling to      None. The Train A        The cooler automatically starts upon air to           while running;          Train B power         MCR for 2-FCV         Penetration Room        Cooler is available to   Train B ABI signal or high temperature Penetration Room   Penetration      Spuriously stops.       failure; Auto-start   352 fully open (2-ZS-     (El 713) with the       start on high            at 2-TS-30-197A-B. Cooler fan motor Cooler Fan 2B-B    Room (el 713)                            signal failure;       67-352). Fan motor        potential for loss of   temperature (2-TS-       and 2-FSV-67-352-B are interlocked to (Train B).                                                  Operator error        running light on MCC. room equipment.         30-196A-A) and is        open 2-FCV-67-352 for ERCW supply (handswitch placed                                                      100% redundant to        on cooler start. Review of the in wrong position)                                                      Train B cooler.          schematics for the coolers A-A and B-B shows their independence.
49     2-FCV-67-350       Provides           Fails to open,        Mechanical failure;   Status monitor light in Loss of redundancy        None.                   2-FCV-67-350 fails open on loss of flowpath for       stuck closed.         Opening signal        MCR (2-ZS-67-350)       in providing cooling      Train B Penetration     power or air.
Essential Raw      cooling water                            failure.                                      to Penetration Room       Room cooler is not Cooling Water Flow from the ERCW                                                                          (El 713) Space            affected by the failure Control Valve for  Header to the                                                                                                    of Train A the Penetration    Cooler for the                                                                                                   Penetration Room Room (El 713)      Penetration                                                                                                      cooler, and is 100%
Cooler 2A-A.       Room Space.                                                                                                      redundant to the Train A Penetration Room cooler.
50     2-FCV-67-352       Provides           Fails to open,        Mechanical failure;   Status monitor light in Loss of redundancy        None.                   2-FCV-67-352 fails open on loss of flowpath for       stuck closed.         Opening signal        MCR (2-ZS-67-352)       in providing cooling      Train A Penetration     power or air.
Essential Raw      cooling water                            failure.                                      to Penetration Room       Room cooler is not Cooling Water Flow from the ERCW                                                                          (El 713) Space.           affected by the failure Control Valve for  Header to the                                                                                                    of Train B the Penetration    Cooler for the                                                                                                   Penetration Room Room (El 713)      Penetration                                                                                                      cooler, and is 100%
Cooler 2B-B        Room Space.                                                                                                      redundant to the Train B Penetration Room cooler.
9.4-74                                                                                                                                                                                                                                                                     WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 19 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                           Method of No.      Component          Function          Failure Mode         Potential Cause            Detection            Effect on System         Effect on Plant                      Remarks 51     1-CLR-30-194-A     Provides cooling Fails to start, fails   Mechanical failure;   Status monitor light in   Loss of cooling to      None. The Train B        The cooler automatically starts upon air to           while running;          Train A power         MCR for 1-FCV         Penetration Room        Cooler is available to   Train A ABI signal or high temperature Penetration Room   Penetration      Spuriously stops.       failure; Auto-start   354-A fully open (1-      (El 737) with the       start on high            at 1-TS-30-194A-A.Cooler fan motor Cooler Fan 1A-A    Room (El 737)                            signal failure;       ZS-67-354). Fan           potential for loss of   temperature (1-TS-       and 1-FSV-67-354-A are interlocked to (Train A).                                                  Operator error        motor running light on    room equipment.         30-195A-B) and is        open 1-FCV-67-354-A for ERCW (handswitch placed    MCC.                                              100% redundant to        supply on cooler start. Review of the in wrong position)                                                      Train A cooler.          schematics for the coolers A-A and B-B shows their independence.
52     1-CLR-30-195-B     Provides cooling Fails to start, fails   Mechanical failure;   Status monitor light in   Loss of cooling to      None. The Train A        The cooler automatically starts upon air to           while running;          Train B power         MCR for 1-FCV         Penetration Room (el    Cooler is available to   Train B ABI signal or high temperature Penetration Room   Penetration      Spuriously stops.       failure; Auto-start   356-B (1-ZS-67-356).      737) with the           start on high            at 1-TS-30-195A-B. Cooler fan motor Cooler Fan 1B-B    Room (el 737)                            signal failure;       Fan motor running         potential for loss of   temperature (1-TS-       and 1-FSV-67-356-B are interlocked to (Train B).                                                  Operator error        light on MCC.             room equipment.         30-194A-A) and is        open 1-FCV-67-356-B for ERCW (handswitch placed                                                      100% redundant to        supply on cooler start. Review of the in wrong position)                                                      Train B cooler.          schematics for the coolers A-A and B-B shows their independence.
53     2-FCV-67-354       Provides           Fails to open,        Mechanical failure;   Status monitor light in Loss of redundancy        None.                   2-FCV-67-354-A fails open on loss of flowpath for       stuck closed.         Opening signal        MCR (2-ZS-67-354)       in providing cooling      Train B Penetration     power or air.
Essential Raw      cooling water                            failure.                                      to Penetration Room       Room cooler is not Cooling Water Flow from the ERCW                                                                          (El 737) Space            affected by the failure Control Valve for  Header to the                                                                                                    of Train A the Penetration    Cooler for the                                                                                                   Penetration Room Room (El 737)      Penetration                                                                                                      cooler, and is 100%
Cooler 2A-A.       Room Space.                                                                                                      redundant to the Train A Penetration Room cooler.
9.4-75                                                                                                                                                                                                                                                                     WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 20 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                      Method of No.      Component          Function        Failure Mode       Potential Cause           Detection          Effect on System         Effect on Plant                     Remarks 54     2-FCV-67-356-B     Provides         Fails to open,      Mechanical failure;   Status monitor light in Loss of redundancy     None.                   2-FCV-67-356 fails open on loss of flowpath for     stuck closed.       Opening signal        MCR (2-ZS-67-356)       in providing cooling   Train A Penetration     power or air.
Essential Raw      cooling water                        failure.                                      to Penetration Room    Room cooler is not Cooling Water Flow from the ERCW                                                                      (El 737) Space.        affected by the failure Control Valve for  Header to the                                                                                             of Train B the Penetration    Cooler for the                                                                                            Penetration Room Room (El 737)      Penetration                                                                                               cooler, and is 100%
Cooler 2B-B        Room Space.                                                                                               redundant to the Train B Penetration Room cooler.
55     Backdraft          Backseat to stop Fails to backseat   Mechanical Failure                           See Remark #2           See Remark #2         1. Backdraft dampers 2-BKD-31-1790 Dampers            flow of hot air  (Stuck Open)                                                                                                   and 2-BKD-31-5093 exist so that a 2-BKD-31-3136      developed due                                                                                                                   backdraft damper is provided in every 2-BKD-31-3137      to a HELB in the                                                                                                                connection from the pipe chase to an 2-BKD-31-3138      pipe chase from                                                                                                                 adjacent room, and determined that the 2-BKD-31-3139      adjacent rooms                                                                                                                  single failure of a backdraft damper (to 2-BKD-31-3140      and maintains a                                                                                                                 close), when normal HVAC continues 2-BKD-31-3141      mild                                                                                                                            to operate, will not result in a severe 2-BKD-31-3142      environment in                                                                                                                  environment in the room with the failed 2-BKD-31-3143      rooms adjacent                                                                                                                  backdraft damper.
2-BKD-31-3144      to pipe chase.
2-BKD-31-3145                                                                                                                                      2. The ABI Signal does not 2-BKD-31-3204                                                                                                                                      automatically isolate the normal HVAC 2-BKD-31-3206                                                                                                                                      System during a HELB. As a result, the 2-BKD-31-3208                                                                                                                                      HELB in the pipe chase will not result in 2-BKD-31-3209                                                                                                                                      isolation of normal HVAC. Thus, proper air flow is maintained.
As a result, the single failure of any of the listed backdraft dampers will have no effect on the system or the plant.
9.4-76                                                                                                                                                                                                                                                              WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 21 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                           Method of No.      Component           Function          Failure Mode         Potential Cause           Detection           Effect on System         Effect on Plant                    Remarks 56     2-CLR-30-194-A      Provides cooling Fails to start, fails   Mechanical failure;   Status monitor in MCR   Loss of cooling to      None. The Train B      The cooler automatically starts upon air to           while running;          Train A power         for 2-FCV-354 fully     Penetration Room        Cooler is 100%         Train A ABI signal or high temperature Penetration Room    Penetration      Spuriously stops        failure; Auto-start   open (2-ZS-67-354 ).    (El 737) with the       redundant to train A   at 2-TS-30-194A-A. Cooler fan motor Cooler Fan 2A-A     Room (El 737)                            signal failure;       Fan motor running       potential for loss of   cooler.                and 2-FSV-67-354-A are interlocked to Operator error        light on MCC.           room equipment                                 open 2-FCV-67-354 for ERCW supply (handswitch placed                                                                           on cooler start. Review of the in wrong position)                                                                           schematics for the coolers A-A and B-B shows their independence, 57     2-CLR-30-195-B      Provides cooling Fails to start, fails   Mechanical failure;   Status monitor in       Loss of cooling to      None. The Train A      The cooler automatically starts upon air to           while running;          Train B power         MCR for 2-FCV-356       Penetration Room        Cooler is 100%         Train B ABI signal or high temperature Penetration Room    Penetration      Spuriously stops        failure; Auto-start   fully open (2-ZS    (El 737) with the       redundant to train B   at 2-TS-30-195A-B. Cooler fan motor Cooler Fan 2B-B     Room (El 737)                            signal failure;                               potential for loss of   cooler.
356 ). Fan motor                                                       and s-FSV-67-356-B are interlocked to Operator error                                room equipment running light on MCC.                                                  open 2-FCV-67-356 for ERCW supply (handswitch placed in wrong position)                                                                           on cooler start. Review of the schematics for the coolers A-A and B-B shows their independence, 58     2-FCV-67-354          Provides         Fails to open,        Mechanical failure; Status monitor light in Loss of redundancy        None. Train B          2-FCV-67-354 fails open on loss of flowpath for     stuck closed.         Open signal failure. MCR (2-ZS-67-354)      in providing cooling      Penetration Room       power or air.
Essential Raw         cooling water                                                                      to Penetration Room       cooler is not affected Cooling Water Flow from the ERCW                                                                         (El 737) Space            by the failure of Control valve for the Header to the                                                                                                Train A Penetration Penetration Room Cooler for the                                                                                                    Room cooler, and is (El 737) Cooler       Penetration                                                                                                  100% redundant to 2A-A.                 Room Space.                                                                                                  the Train A Penetration room Cooler.
9.4-77                                                                                                                                                                                                                                                                  WBNP-97

Table 9.4-3 FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: SAFETY FEATURE EQUIPMENT COOLERS (Sheet 22 of 22)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item                                                                                    Method of No.      Component           Function         Failure Mode    Potential Cause          Detection          Effect on System        Effect on Plant                    Remarks 59     2-FCV-67-356-B        Provides        Fails to open,   Mechanical failure; Status monitor light in Loss of redundancy     None. Train A          2-FCV-67-356 fails open on loss of flowpath for    stuck closed. Open signal failure. MCR (2-ZS-67-356)      in providing cooling   Penetration Room       power or air.
Essential Raw         cooling water                                                                to Penetration Room    cooler is not affected Cooling Water Flow from the ERCW                                                                   (El 737) Space         by the failure of Control valve for the Header to the                                                                                       Train B Penetration Penetration Room Cooler for the                                                                                           Room cooler, and is (El 737) Cooler       Penetration                                                                                         100% redundant to 2B-B.                 Room Space.                                                                                         the Train B Penetration Room cooler.
9.4-78                                                                                                                                                                                                                                                     WBNP-97

AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Table 9.4-3A FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: TURBINE DRIVEN AUXILIARY FEEDWATER PUMP ROOM VENTILATION (Sheet 1 of 2)
Item                                                                                     Method of No.       Component            Function         Failure Mode    Potential Cause         Detection     Effect on System        Effect on Plant                    Remarks 1      2-FAN-30-214        Provides cooling Fails to start;    Mechanical failure;   No direct      Loss of cooling        None (See Remarks    1. The dc fan is intended to mitigate the to the TDAFW     Fails while        Temperature           method of      air/ventilation to the # 3 and 4)           effects of station blackout on the TDAFW Turbine-driven      Pump Room        running;           sensing failure;      detection. TDAFW Pump Room                             Pump Room ventilation. During DBEs Auxiliary Feedwater                  Spuriously         TDAFW Pump start                     from the safety-                            the TDAFW provides backup to the two Pump Room                            stopped.           signal failure.       See Remark # 2 related dc fan.                             50% motor-driven AFW pumps. As such Ventilation Fan                                                                                                                          its operation during DBEs would imply a 125V Dc                                                                                       Loss of all                                single failure to have already occurred; cooling/ventilation to                     therefore, postulation of the failure of this the TDAFW Pump                             fan is not required.
Room during loss of all ac (LOAC).                             2. Local temperature indication.
: 3. In the event of loss of all ac the TDAFW Pump cooling is entirely dependent on the dc fan. A single active failure is not postulated during a Station Blackout event; therefore, the fan and associated components are assumed to function properly during a loss of all ac power.
: 4. The dc fan starts automatically by either TDAFW pump start, or high temperature sensed by 1-TS-30-214. It can also be started manually.
9.4-79                                                                                                                                                                                                                                                         WBNP-97

Table 9.4-3A FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: TURBINE DRIVEN AUXILIARY FEEDWATER PUMP ROOM AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR VENTILATION (Sheet 2 of 2)
Item                                                                                 Method of No.       Component          Function        Failure Mode      Potential Cause      Detection    Effect on System   Effect on Plant                   Remarks 2      2-BKD-30-3035      Provides suction Spuriously closed Mechanical failure   No direct     Loss of cooling  See Remarks           During the loss of all ac, there will be no air flow path to                                        method of     /ventilating for                      cooling/ventilating capability for TDAFW Backdraft Damper   the operating dc                                        detection     TDAFW Pump Room                       Pump room, with the possibility for loss exhaust fan                                                           from dc fan.                          of the TDAFW Pump. A non-safety, non-See Remarks                                         seismic, non- 1E ac fan is present in the room. TDAFW is the backup for the motor-driven FW and is required to operate upon failure of motor-driven FW.
Thus, postulation of this failure is not required. A single active failure is not postulated during a Station Blackout event; therefore, the fan and associated components are assumed to function properly during a loss of all ac power 9.4-80                                                                                                                                                                                                                                              WBNP-97

AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Table 9.4-4 FAILURE MODES AND EFFECTS ANALYSIS DIESEL GENERATOR VENTILATION SYSTEM (Sheet 1 of 15)
METHOD OF COMPONENT                        FAILURE      POTENTIAL         FAILURE          EFFECT ON    EFFECT ON
                                                              #   IDENTIFICATION       FUNCTION       MODE          CAUSE          DETECTION          SYSTEM        PLANT               REMARKS 1   Fire damper in Air Fire Barrier   Open during Mechanical        See Remarks      See Remarks   See Remarks     Single failures of HVAC Intake Room        between Air    fire        failure                                                          System need not to be Intake Room                                                                                 postulated as being 0-30-603 for       and Diesel                                                                                  concurrent with fire.
Train 1A-A,        Gen Room 0-30-604 for Train                Closed       Mechanical       Diesel Gen.        None (See   None            Redundant train diesel 2A-A,                             during other (fusible link)   Room exhaust       Remarks)    (See Remarks)   generator system is modes of     failure          fan low flow                                   started by operator 0-30-605 for                      operation                     alarm in Main Train 1B-B, and                                                 Control Room from fans air flow 0-30-606 for Train                                              switches 2B-B                                                            FS-30-447 or FS-30-451 for Train 1A-A, FS-30-449 or FS-30-453 for Train 1B-B, FS-30-448 or FS-30-452 for Train 2A-A,and FS-30-450 or FS-30-454 for Train 2B-B 9.4-81                                                                                                                                                                                                     WBNP-89

Table 9.4-4 FAILURE MODES AND EFFECTS ANALYSIS DIESEL GENERATOR VENTILATION SYSTEM (Sheet 2 of 15)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF COMPONENT                           FAILURE     POTENTIAL       FAILURE           EFFECT ON         EFFECT ON
                                                                  #   IDENTIFICATION       FUNCTION          MODE         CAUSE        DETECTION           SYSTEM             PLANT            REMARKS 2   Motor-operated      To prevent air   Closed or    Mechanical   Diesel Gen.         Complete or       None (See    Redundant train diesel intake dampers to   flow when        partially    Failure or   Room exh. fan       partial loss of   Remarks)     generator system is Diesel Gen.         associated       closed       Actuator     low flow alarm in   ventilation of                 started by operator. If Room                diesel           during       Failure      Main Control        associated                     closed due to spurious generator        associated                Room from air       safety train                   CO2 system actuation 1-FC0-30-443-A      exhaust fans     exhaust                   flow switches       Diesel Gen                     operator can verify and for Train 1A-A,     are              fan(s)                    FS-30-447 or        Room.                          reopen damper.
deenergized      operation                 FS-30-451 for 1-FC0-30-445-B                                                 Train 1A-A, for Train 1B-B,                                                FS-30-449 or FS-30-453 for 2-FCO-30-444-A                                                 Train 1B-B, for Train 2A-A,                                                FS-30-448, 452 for 2A-A, and 2-FCO-30-446-B                                                 FS-30-450, 454 for Train 2B-B                                                 for 2B-B.
2       (Continued)         (Contd)         Spurious   Dampers are    Diesel Gen.         Partial loss of   None (See    If closed due to spurious CO2 system spring-        Room exh. fan       ventilation of    Remarks)     CO2 system actuation, actuation  loaded to      low flow alarm in   associated                     operator can verify and open upon      Main Control        safety train                   start the fan(s), which in power loss;    Room from air       Diesel Gen                     turn reopen dampers, by however,       flow switches FS-   Room.                          use of the CO2 bypass CO2            30-447 or FS                                   switches 1-HS-30.447D, actuation      451 for Train 1A-                                  1-HS-30-449D, signal can     A,                                                 2-HS-30-448D, and close them. FS-30-449 or FS-                                   2-HS-30.450D.
30-453 for Train 1B-B, FS-30-448, 452 for 2A-A, and FS-WBNP-97 30-450, 454 for 9.4-82                                                                                                                               2B-B.

Table 9.4-4 FAILURE MODES AND EFFECTS ANALYSIS DIESEL GENERATOR VENTILATION SYSTEM (Sheet 3 of 15)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF COMPONENT                        FAILURE        POTENTIAL         FAILURE            EFFECT ON        EFFECT ON
                                                                  #   IDENTIFICATION   FUNCTION           MODE            CAUSE          DETECTION            SYSTEM            PLANT            REMARKS 2       (Continued)      To open and      Fails to        Mechanical      Diesel Gen.         Tornado           None (See   Redundant DG system is allow air flow   open, or        Failure         Room exh. fan       induced           Remarks)    available if a mechanical during           opens                           low flow alarm in   differential                  failure is the result of tornado          initially and   If the DG       Main Control        pressure                      damper failure. When a watch /          then closes     room            Room from air       across damper                 tornado watch or warning warning          during          exhaust fan flow switches FS-       in closed                     is declared by the conditions for   tornado         low             30-447 or FS    position could                National Weather Service pressure         watch or        temperature 451 for Train 1A-       damage                        for this area, the motor equalization     warning         switches        A,                  damper and                    operated intake dampers have cooled FS-30-449 or FS-        result in partial             can be opened by starting down below 30-453 for Train         or complete                   the DG room exhaust their setpoint 1B-B,                loss of                       fans. To assure that the value, they     FS-30-448, 452      ventilation to                DG room exhaust fans will prevent    for 2A-A, and FS-   DG room                       will start and continue to manual start 30-450, 454 for                                      run during conditions of the fans     2B-B.                                             when the DG exhaust fan and opening                                                       low temperature cut-out of the subject                                                    switches would normally dampers                                                           prevent operation, until the reset                                                   tornado bypass switches setpoint is                                                       have been added to the reached.                                                          control system for each exhaust fan. These switches are placed in the bypass position during the tornado watch / warning andf then returned to their NORMAL position once the tornado watch /
warning has been cancelled. .
9.4-83                                                                                                                                                                                                                  WBNP-97

Table 9.4-4 FAILURE MODES AND EFFECTS ANALYSIS DIESEL GENERATOR VENTILATION SYSTEM (Sheet 4 of 15)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF COMPONENT                          FAILURE      POTENTIAL          FAILURE           EFFECT ON         EFFECT ON
                                                                  #   IDENTIFICATION       FUNCTION         MODE          CAUSE           DETECTION           SYSTEM             PLANT               REMARKS 2       (Continued)                                                                                                             With the tornado bypass switches placed in the bypass position, the dampers can be opened by starting the DG room exhaust fans using handswitches mounted on the MCCS or locally in the exhaust fan rooms.
3   Fire damper          Fire Barrier   Open during Mechanical        See Remarks         See Remarks       See Remarks     Single failures of HVAC between Diesel       between        fire        failure                                                                 System need not be Generator Room       Diesel Gen                                                                                         postulated as being
                                                                      & Air Exhaust        Room and                                                                                           concurrent with fire.
Room                 Air Exhaust Room 0-30-607 for Train                  Closed       Mechanical       Diesel Gen          Partial loss of   None            Redundant train diesel 1A-A,                               during other (fusible link)   Room exh fan        ventilation of    (See Remarks)   generator system is modes of     failure          low flow alarm in   associated                        started by operator 0-30-609 for Train                  operation                     Main Control        safety train 1B-B,                                                             Room from fan       Diesel Gen air flow switches   Room.
0-30-608 for Train                                                FS-30-447 or 2A-A,                                                             FS-30-451 for Train 1A-A, 0-30-610 for Train                                                FS-30-449,FS-2B-B                                                              30-453 for Train 1B-B, FS-30-448 or FS-30-452 for Train 2A-A, and FS-30-450 or WBNP-97 FS-30-454 for 9.4-84                                                                                                                                  Train 2B-B

Table 9.4-4 FAILURE MODES AND EFFECTS ANALYSIS DIESEL GENERATOR VENTILATION SYSTEM (Sheet 5 of 15)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF COMPONENT                         FAILURE      POTENTIAL        FAILURE          EFFECT ON      EFFECT ON
                                                              #   IDENTIFICATION      FUNCTION         MODE          CAUSE         DETECTION          SYSTEM          PLANT            REMARKS 4   Diesel Generator   Provide         Fails to start Electrical, Diesel Gen          Partial loss of None        Redundant train diesel Room exhaust       ventilation air                Mechanical  Room exh fan        adequate                    generator system is fans                                                          low flow alarm in   ventilation for             started by operator.
Stops                       Main Control        maintenance of 1-FAN-30-447                      running                     Room (Refer to      design                      *Operator can verify if not 1-FAN-30-451 for                                              Figure 9.4-25)      temperature                 result of fire, reopen fire Train 1A-A,                                                   from air flow                                   dampers and start Stops on                    switches                                        exhaust fans from 1-FAN-30-449                      spurious      Electrical or FS-30-447 or                                    handswitches 1-FAN-30-453 for                  CO2           Mechanical    FS-30-451 for Train 1B-B,                       actuation*                  Train 1A-A, FS-30-449 or 2-FAN-30-448                      Fails to stop System logic FS-30-453 for 2-FAN-30-452 for                  on low temp Electrical      Train 1B-B, Train 2A-A, and                                               FS-30-448 or FS-30-452 for 2-FAN-30-450,                                                 Train 2A-A, and 2-FAN-30-454 for                                              FS-30-450 or Train 2B-B                                                    FS-30-454 for Train 2B-B Drop in DG                  Redundant train diesel Surveillance      Room temp      None (See    generator system is Remarks)     available.
9.4-85                                                                                                                                                                                                        WBNP-97

Table 9.4-4 FAILURE MODES AND EFFECTS ANALYSIS DIESEL GENERATOR VENTILATION SYSTEM (Sheet 6 of 15)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF COMPONENT                        FAILURE       POTENTIAL        FAILURE           EFFECT ON       EFFECT ON
                                                              #   IDENTIFICATION      FUNCTION        MODE           CAUSE         DETECTION           SYSTEM           PLANT            REMARKS 5   Motor-operated   To prevent air   Closed         Mechanical    Diesel Gen          Loss of 50%      None (See   Redundant train diesel discharge        flow when        during                       Room exh fan        ventilation flow Remarks)    generator system is dampers of dieselassociated       associated     Loss of       low flow alarm in   required to                  started by operator generator room   diesel           exhaust fan    power         Main Control        maintain the exhaust fans     generator        operation      (dampers fail Room from air       environmental exhaust fan      (see note in   as-is)        flow switches       qualification Train 1A-A       is               remarks)                     FS-30-447 or        temperatues in 1-FCO-30-447 for deenergized                                   FS-30-451 for       the DG room.
Fan 1, and                                                     Train 1A-A, FS-1-FCO-30-451 for                                               30-449, or Fan 2                                                          FS-30-453 for Train 1B-B, FS-30-448, Train 1BB                                                      FS-30-452; 1-FCO-30-449 for                                               for Train 2A-A, Fan 1, and                                                     and FS-30-450, 1-FCO-30-453 for                                               FS-30-454 Fan 2                                                          for Train 2B-B Train 2A-A, 2-FCO-30-448 for Fan 1, 2-FCO-30-452 for Fan 2 Train 2B-B 2-FCO-30-450 for Fan 1 ,
2-FCO-30-454 for Fan 2 9.4-86                                                                                                                                                                                                     WBNP-97

Table 9.4-4 FAILURE MODES AND EFFECTS ANALYSIS DIESEL GENERATOR VENTILATION SYSTEM (Sheet 7 of 15)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF COMPONENT                        FAILURE        POTENTIAL         FAILURE            EFFECT ON        EFFECT ON
                                                                  #   IDENTIFICATION    FUNCTION          MODE            CAUSE          DETECTION            SYSTEM            PLANT             REMARKS 5       (Continued)      To open and      Fails to        Mechanical      Diesel Gen.         Tornado           None (See   Redundant DG system is allow air flow   open, or        Failure         Room exh. fan       induced           Remarks)    available if a mechanical during           opens                           low flow alarm in   differential                  failure is the result of tornado          initially and   If the DG       Main Control        pressure                      damper failure. When a watch /          then closes     room            Room from air       across damper                 tornado watch or warning warning          during          exhaust fan flow switches FS-       in closed                     is declared by the conditions for   tornado         low             30-447 or FS    position could                National Weather Service pressure         watch or        temperature 451 for Train 1A-       damage                        for this area, the motor equalization     warning         switches        A,                  damper and                    operated intake dampers have cooled FS-30-449 or FS-        result in partial             can be opened by starting down below 30-453 for Train         or complete                   the DG room exhaust their setpoint 1B-B,                loss of                       fans. To assure that the value, they     FS-30-448, 452      ventilation to                DG room exhaust fans will will prevent    for 2A-A, and FS-   DG room                       start and continue to run manual start 30-450, 454 for                                      during conditions when of the fans     2B-B.                                             the DG exhaust fan low and opening                                                       temperature cut-out of the subject                                                    switches would normally dampers                                                           prevent operation, until the reset                                                   tornado bypass switches setpoint is                                                       have been added to the reached.                                                          control system for each exhaust fan. These switches are placed in the bypass position during the tornado watch / warning andf then returned to their NORMAL position once the tornado watch /
warning has been cancelled.
9.4-87                                                                                                                                                                                                                  WBNP-97

Table 9.4-4 FAILURE MODES AND EFFECTS ANALYSIS DIESEL GENERATOR VENTILATION SYSTEM (Sheet 8 of 15)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF COMPONENT                       FAILURE    POTENTIAL       FAILURE           EFFECT ON      EFFECT ON
                                                                  #   IDENTIFICATION     FUNCTION        MODE        CAUSE        DETECTION           SYSTEM          PLANT               REMARKS 5       (Continued)                                                                                                  With the tornado bypass switches placed in the bypass position, the dampers can be opened by starting the DG room exhaust fans using handswitches mounted on the MCCs or locally in thexhaust fan rooms.
6   Fire dampers of   Fire Barrier   Open during Mechanical    See Remarks        See Remarks   See Remarks      Single failures of HVAC Elec. BD Rooms    between        fire        failure       Surveillance and                                  System need not be intake vent       Elec. BD                                 Maintenance                                       postulated as being Room &                                                                                     concurrent with fire.
0-30-595          outside 0-30-596 0-30-597                         Closed       Mechanical                      Loss of        None            Redundant train diesel 0-30-598                         during other failure                         ventilation of (See Remarks)   generator system is modes of                                     associated                     started by operator operation                                    Elec. BD Room and rise of space temp.
9.4-88                                                                                                                                                                                                         WBNP-97

Table 9.4-4 FAILURE MODES AND EFFECTS ANALYSIS DIESEL GENERATOR VENTILATION SYSTEM (Sheet 9 of 15)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF COMPONENT                        FAILURE    POTENTIAL       FAILURE         EFFECT ON        EFFECT ON
                                                              #   IDENTIFICATION     FUNCTION         MODE        CAUSE        DETECTION         SYSTEM            PLANT             REMARKS 7   Fire dampers of    Fire Barrier   Open during Mechanical    See Remarks      See Remarks      See Remarks   Single failures of HVAC Elec. BD Rooms     between        fire        failure                                                       System need not be exhaust            Elec. BD                                                                                 postulated as being Rooms & Air                                                                              concurrent with fire.
0-30-599           Exh Rooms 0-30-600 0-30-601                          Closed       Mechanical   Surveillance &   Loss of        None            Redundant train diesel 0-30-602                          during other failure      Maintenance      ventilation of (See Remarks)   generator system is modes of                                   associated                     started by operator operation                                  Elec. BD Room and rise of space temp.
8   Electric BD Room Provide         Fails to     Electrical,   Surveillance &   Loss of        None (See       Redundant train diesel exhaust fans     ventilation air start; stops Mechanical    Maintenance      ventilation of Remarks)        generator system is running,                                    associated                     started by operator 1-FAN-30-459 for                 Spurious                                    Elec. BD Room Train 1A-A,                      CO2 system                                  and rise of                    *If failures resulted from actuation*                                  space temp                     spurious actuation of the 1-FAN-30-461 for                                                                                            CO2 system, operator can Train 1B-B,                                                                                                 verify and restart the fans from hand switches.
2-FAN-30-460 for                                            Surveillance Train 2A-A, and                   Operates                                   Decrease of      None (See during      Operator                       space temp.      Remarks)      Analyses have shown that 2-FAN-30-462 for                  winter      action not                     below freezing                 no adverse effect will Train 2B-B                                    performed                                                     occur on safety-related per site                                                      equipment as a result of operating                                                     below freezing procedure                                                     temperatures; therefore, operation of the fan is allowed in winter.
9.4-89                                                                                                                                                                                                      WBNP-97

Table 9.4-4 FAILURE MODES AND EFFECTS ANALYSIS DIESEL GENERATOR VENTILATION SYSTEM (Sheet 10 of 15)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF COMPONENT                        FAILURE      POTENTIAL       FAILURE        EFFECT ON      EFFECT ON
                                                              #   IDENTIFICATION     FUNCTION         MODE          CAUSE        DETECTION        SYSTEM          PLANT            REMARKS 9   Motor-operated   To prevent air   Closed        Mechanical   Surveillance &   Loss of        None (See    Redundant train diesel discharge damper flow when        during                     Mechanical       ventilation of Remarks)     generator system is of Elec. BD Room associated       associated                                  associated                  started by operator exhaust fans     Elec. BD         exhaust fan                                 Elec. BD Room Room             operation                                   and rise of 1-FCO-30-459 for exhaust fan                                                  space temp.                 NOTE: These dampers Train 1A-A,      is                                                                                       are to be open by deenergiized                                                                             handswitches 1-FCO-30-461 for                                                                                          0-HS-30-459B Train 1B-B,                                                                                               or 0-HS-30-459C for Train 1A-A, 0-HS                                                                   2-FCO-30-460 for                                                                                          461B or 0-HS-30-461C Train 2A-A, and                                                                                           for Train 1B-B, 0-HS                                                                                                                                                                             460B or 0-HS-30-460C 2-FCO-30-462 for                                                                                          for Train 2A-A and Train 2B-B                                                                                                0-HS-30-462B or 0-HS-30-462C for Train 2B-B when tornado watch or warning is declared by National Weather Service for this area.
9.4-90                                                                                                                                                                                                 WBNP-89

Table 9.4-4 FAILURE MODES AND EFFECTS ANALYSIS DIESEL GENERATOR VENTILATION SYSTEM (Sheet 11 of 15)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF COMPONENT                          FAILURE       POTENTIAL        FAILURE           EFFECT ON      EFFECT ON
                                                              #    IDENTIFICATION      FUNCTION          MODE           CAUSE         DETECTION           SYSTEM          PLANT                REMARKS 10   Generator &         Provide         Fails to       Electrical    Low air flow        Loss of         None            Redundant train diesel Electrical Panels   ventilation for start; stops   Mechanical    alarm in Main       ventilation air (See Remarks)   generator system is ventilation fans    elec. panel & running                        Control Room via    supply to                       started by operator to generator                                 air flow switches   associated 1-FAN-30-491        inlet                                        FS-30-491 for       elec. panel and for Train 1A-A,                                                  Train 1A-A,         generator inlet FS-30-493 for 1-FAN-30-493                                                     Train 1B-B, for train 1B-B,                                                  FS-30-492 for Train 2A-A, and 2-FAN-30-492                                                     FS-30-494 for for Train 2A-A,                                                  Train 2B-B 2-FAN-30-494 for Train 2B-B 11   Filters for elec    Filter the      Clogged        Accumulatio   Surveillance &      Rise of temp in None            Redundant train diesel panel ventilation   ventilation air                n of dirt     Maintenance         the elec panel (See Remarks)    generator system is air supply          supplied to                                                      due to reduced                  started by operator elec panel                                                       supply of vent 1-FLT-30-491 for                                                                     air Train 1A-A, 1-FLT-30-493 for Train 1B-B, 2-FLT-30-492 for Train 2A-A, 2-FLT-30-494 for Train 2B-B 9.4-91                                                                                                                                                                                                           WBNP-89

Table 9.4-4 FAILURE MODES AND EFFECTS ANALYSIS DIESEL GENERATOR VENTILATION SYSTEM (Sheet 12 of 15)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF COMPONENT                      FAILURE      POTENTIAL      FAILURE         EFFECT ON         EFFECT ON
                                                              #    IDENTIFICATION    FUNCTION        MODE          CAUSE       DETECTION         SYSTEM             PLANT                REMARKS 12   Class 1E AC       Provide     Loss of or      Electrical   Indication and   Loss of power     None          Redundant train diesel power             Class 1E AC inadequate                   alarms in Main   to diesel         (See Remarks) generator system is power to    power                        Control Room     generator                       available for the plant safe safety-                                                   building                        shutdown related                                                   ventilation portions of                                               system safety-the diesel                                                related generator                                                 equipment building ventilation system 13   Class 1E AC       Provide        Loss of or   Electrical   Indication and   Loss of control   None          Redundant train diesel power to          Class 1E       inadequate                alarms in main   of the diesel     (See Remarks) generator system is instrumentation   power to       power                     control room     generator                       available for the plant safe and control       safety-                                                   ventilation                     shutdown.
related diesel                                            system safety generator                                                 related building                                                  equipment ventilation system controls and instrumentati on 9.4-92                                                                                                                                                                                                        WBNP-89

Table 9.4-4 FAILURE MODES AND EFFECTS ANALYSIS DIESEL GENERATOR VENTILATION SYSTEM (Sheet 13 of 15)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF COMPONENT                         FAILURE     POTENTIAL      FAILURE         EFFECT ON         EFFECT ON
                                                              #    IDENTIFICATION      FUNCTION         MODE         CAUSE       DETECTION         SYSTEM             PLANT             REMARKS 14   Non-safety         Provide         On during    Spurious     Surveillance &   Increase of      None. (See    Redundant train diesel heaters            heating         summer       operation    Maintenance      Diesel Gen.      Remarks)      generator system is during winter   LOCA                                       Room & Air                     available for the plant safe 1-HTR-30-471,      normal          operation                                  Exh. Room                      shutdown 1-HTR-30-472       operation                                                  temp. above for Diesel Gen.                                                               environmental 1A-A Room;                                                                    design conditions 1-HTR-30-473, 1-HTR-30-474 for                                Electrical Diesel Gen. 1B-B                   Off during                Surveillance     Drop in Diesel   None. (See    Same as above Room;                              winter                                     Gen Room         Remarks) conditions                                 temp 2-HTR-30-475, 2-HTR-30-476 for diesel gen. 2A-A Room; and 2-HTR-30-477, 2-HTR-30-478 for diesel gen.
2B-B Room 9.4-93                                                                                                                                                                                                         WBNP-89

Table 9.4-4 FAILURE MODES AND EFFECTS ANALYSIS DIESEL GENERATOR VENTILATION SYSTEM (Sheet 14 of 15)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF COMPONENT                       FAILURE     POTENTIAL         FAILURE        EFFECT ON        EFFECT ON
                                                              #    IDENTIFICATION     FUNCTION        MODE         CAUSE          DETECTION        SYSTEM            PLANT               REMARKS 15   Non-safety       Provide         On during    SpuriousOpe Surveillance &      Increase 480V None. (See        Redundant train diesel heaters          heating         summer       ration      Maintenance         BD Room       Remarks)          generator system is during winter   LOCA                     (See Note in        temp. above                     available for the plant safe 1-HTR-30-487 for normal          operation                Remarks for Item    environmental                   shutdown 480V BD          operation                                #6)                 design Room 1-A-A,                                                                   conditions 1-HTR-30-489 for 480V BD                                   Electrical                      Drop in 480V Room 1B-B,                       Off during                  Surveillance     board room      None. (See      Redundant trains diesel winter                                       temp.           Remarks)        generator system is 2-HTR-30-488 for                 operation                                                                    available for the plant safe 480V BD                                                                                                       shutdown.
Room 2A-A, and 2-HTR-30-490 for 2B-B Room 16   Nonsafety heaters Provide       Off during    Electrical     Surveillance &   Decrease in     None.         Minimum temperature in heating       winter                       Maintenance      Pipe Gallery    (See Remarks) pipe gallery is calculated 0-HTR-30-479      during winter operation                                     Room temp                     to be 36.3oF.
0-HTR-30-480      normal                                                      below 0-HTR-30-481      operation                                                   environmental 0-HTR-30-482 for                                                              design the Pipe Gallery                                                              conditions 17   Toilet Room        Provide         Fails to   Electricalor   Surveillance &   Loss of         None. (See      Maximum temperature in exhaust fan        cooling and start; stops   Mechanical     Maintenance      adequate        Remarks)        corridor is calculated to be 0-FAN-469          ventilation for running                                    ventilation for                 120oF the toilet and                                             maintenance of corridor                                                   design temp 9.4-94                                                                                                                                                                                                          WBNP-97

Table 9.4-4 FAILURE MODES AND EFFECTS ANALYSIS DIESEL GENERATOR VENTILATION SYSTEM (Sheet 15 of 15)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF COMPONENT                      FAILURE     POTENTIAL      FAILURE       EFFECT ON    EFFECT ON
                                                              #    IDENTIFICATION   FUNCTION         MODE         CAUSE       DETECTION       SYSTEM        PLANT                REMARKS 18   Muffler Rm       Removes        Fails ON     Electrical   Surveillance   None. (See   None,.          Each fan, located on the Exhaust Fan      heat from      during       Operation                   Remarks)     (See Remarks)   roof, is interlocked with its Muffler Room   minimum      (Switch in                                               respective diesel. The fan 1-FAN-30-463     Area during    outside      wrong                                                    starts when its diesel 1-FAN-30-465     Diesel         design       position)                                                starts. It can also be 1-FAN-30-464     Operation      condition                                                             started from a hand 1-FAN-30-466                    and diesel                                                            switch. In the event of a not                                                                   spurious start during operating                                                             minimum outside temperature conditons, and its diesel not operating, an analysis has shown that the fan would not cause any adverse conditions on the diesel operation.
9.4-95                                                                                                                                                                                                   WBNP-97

WATTS BAR                                                                     WBNP-94 Table 9.4-4a Deleted by Amendment 94 (Refer to the FSAR for the Additional Diesel Generator Building Failure Modes and Effect Analysis) 9.4-96                     AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Table 9.4-5 (Sheet 1 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                         Method of No.      Component              Function          Failure Mode   Potential Cause            Detection             Effect on System       Effect on Plant                   Remarks 1     1-AHU-31-461-A    Provides cooling air     Fails to run;   Mechanical           Annunciation of 480 V      Loss of capability to  None; See Remarks   1. Failures of the cooling coil, fan, supply to 480 V Board Fails while        failure; Train A     Board Room 1A HVAC         provide cooling air to                     motor, and filter are enveloped by the Air Handling Unit Room 1A Battery          running         power failure;       System abnormal for        480 V Board Room                           failure of the AHU.
1A-A for 480 V    Room I, and to Train                     Control signal       1-FS-31-460 closed         1A and Battery Board Board Room 1A     A equipment in Board                     failure;             on low flow from AHU       Room I and partial                         2. The Condenser 1A-A and and Battery Room Room 1B, and Train                        Temperature          1A-A                       loss of cooling to                         Compressor 1A-A are interlocked to I (Train A)       B press fan, Fifth Vital                 control sensing                                 FVBR.                                      automatically stop or start with the Battery Rm. (FVBR)                       failure at           Indicating lights in                                                  AHU 1A-A stop or start.
1-TS-31-441A;        MCR (1-HS-31-461A).
low flow control     Motor running light on                                                3. Board Room 1B and Battery sensing failure at   MCC.                                                                  Room II provide the redundancy.
1-FS-31-460; Operator error       No indication in MCR                                                  4. Operator actions are defined to (handswitch          of a low temperature                                                  deal with loss of train A cooling 1-HS-31-461B in      sensing failure other wrong position)      than indication that the                                              5. Battery Room 1 and FVBR can be Hardware related     AHU is not running.                                                   exhausted from the pressurizing fan failures; i.e.,                                                                            supply air to provide hydrogen motor burns out,                                                                           ventilation. Prepared calculations fan drive belt                                                                             indicate that sufficient cooling is still failures, loss of                                                                          available to assure the battery rooms refrigerant to the                                                                         remain below the maximum Cooling Coil,                                                                              temperature limits.
and/or restricted air flow path.
9.4-97                                                                                                                                                                                                                                                                 WBNP-92

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 2 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                         Method of No. Component               Function          Failure Mode   Potential Cause            Detection           Effect on System       Effect on Plant                  Remarks 2     1-AHU-31-475-B      Provides cooling air  Fails to run;    Mechanical           Annunciation of 480 V    Loss of capability to  None; See Remarks   1. Failures of the cooling coil, fan, supply to 480 V Board Fails while      failure; Train B     Board Room 1B HVAC       provide cooling air to                     motor, and filter are enveloped by the Air Handling Unit   Room 1B Battery       running          power failure;       System abnormal for      480 V Board Room                           failure of the AHU.
1B-B for 480 V      Room II                                Control signal       1-FS-31-476 closed       1B and Battery Board Board Room 1B                                              failure;             on low flow from AHU     Room II                                    2. The Condenser 1B-B and and Battery Room                                           Temperature          1B-B                                                                Compressor 1B-B are interlocked to II (Train B)                                               control sensing                                                                          automatically stop or start with the failure at           Indicating lights in     Battery Room II will                       AHU 1B-B stop or start.
1-TS-31-447A;        MCR                      continue to be low flow control     (1-HS-31-475-A).         ventilated. The                            3. A review of the schemiatics sensing failure at   Motor running light on   pressurizing fan will                      establishes the separation of the AC 1-FS-31-476;         MCC.                     supply air to the                          system: for the 480V Board Room 1A Operator error                                battery room through                       with Battery Room I and its redundant (handswitch                                   the AHU duct.                              480V Board Room II.
1-HS-31-475B in wrong position)                               Loss of Train A                            4. Train A provides cooling to the No indication in MCR equipment located in                           Train A components in the 480V of a low temperature     these rooms.                               Board Room 1B.
sensing failure other than indication that the                                            5. Operator actions are defined to AHU is not running.                                                 deal with a loss of Training B cooling 9.4-98                                                                                                                                                                                                                                                            WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 3 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                        Method of No.      Component             Function          Failure Mode   Potential Cause            Detection           Effect on System       Effect on Plant                   Remarks 3     2-AHU-31-461-A    Provides cooling air   Fails to run;    Mechanical           Annunciation of 480 V    Loss of capability to  None; See Remarks   1. Failures of the cooling coil, fan, supply to 480 V Board Fails while       failure; Train A     Board Room 2A HVAC       provide cooling air to                     motor, and filter are enveloped by the Air Handling Unit Room 2A Battery        running          power failure;       System abnormal for      480 V Board Room                           failure of the AHU.
2A-A for 480 V    Room III, and to Train                  Control signal       2-FS-31-460 closed       2A and Battery Board Board Room 2A     A equipment in Board                    failure;             on low flow from AHU     Room III.                                  2. The Condenser 2A-A and and Battery Room Room 2B, and Train                       Temperature          2A-A                                                                Compressor 2A-A are interlocked to III               B press fan                             control sensing                                                                          automatically stop or start with the (Train A)                                                 failure at           Indicating lights in     Battery Room III will                      AHU 2A-A stop or start.
2-TS-31-441A;        MCR                      continue to be low flow control     (2-HS-31-461-A).         ventilated. The                            3. Board Room 2B and Battery Room sensing failure at   Motor running light on   pressurizing fan will                      IV provide the redundancy.
2-FS-31-460;         MCC.                     supply air to the Operator error                                battery room through                       4. Operator actions are identified to (handswitch                                   the AHU duct.                              deal with a loss of Train A cooling.
2-HS-31-461B in wrong position)      No indication in MCR Loss of Train A                                5. Battery Rm I can be exhausted of a low temperature     equipment located in                       from the pressurizing fan supply air to sensing failure other    these rooms.                               provide hydrogen ventilation.
than indication that the                                            Calculations indicate that sufficient AHU is not running.                                                 cooling is still available to assure the battery rooms remain below the maximum temperature limit.
9.4-99                                                                                                                                                                                                                                                             WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 4 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                         Method of No. Component               Function          Failure Mode   Potential Cause            Detection           Effect on System       Effect on Plant                  Remarks 4     2-AHU-31-475-B      Provides cooling air  Fails to run;    Mechanical           Annunciation of 480 V    Loss of capability to  None: See Remarks   1.Failures of the cooling coil, fan, supply to 480 V Board Fails while      failure; Train B     Board Room 2B HVAC       provide cooling air to                     motor, and filter are enveloped by the Air Handling Unit   Room 2B Battery       running          power failure;       System abnormal for      480 V Board Room                           failure of the AHU.
2B-B for 480 V      Room IV                                Control signal       2-FS-31-476 closed       2B and Battery Board Board Room 2B                                              failure;             on low flow from AHU     Room IV                                    2. The Condenser 2B-B and and Battery Room                                           Temperature          2B-B                                                                Compressor 2B-B are interlocked to IV (Train B)                                               control sensing                                                                          automatically stop or start with the failure at           Indicating lights in     Battery Room IV will                       AHU 2B-B stop or start.
2-TS-31-447A;        MCR                      continue to be low flow control     (2-HS-31-475A).          ventilated. The                            3. Board Room 2A and Battery Room sensing failure at   Motor running light on   pressurizing fan will                      III provide the redundancy.
2-FS-31-476;         MCC.                     supply air to the Operator error                                battery room through                       4. Train A provides cooling to the (handswitch                                   the AHU duct.                              Train A components in the 480V 2-HS-31-475B in                                                                          Board Room 2B.
wrong position)      No indication in MCR Loss of Train A                                5. Operator actions are defined to of a low temperature     equipment located in                       deal with a loss of Train B cooling.
sensing failure other    these rooms.
than indication that the AHU is not running.
9.4-100                                                                                                                                                                                                                                                           WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 5 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                   Method of No. Component            Function         Failure Mode   Potential Cause          Detection           Effect on System       Effect on Plant                  Remarks 5     1-COND-31-290-A Provides refrigerant   Fails to run;   Mechanical         Motor running light on   Loss of cooling to 480 None               1. Failure of the condenser to AHU 1A-A            Stops while     failure; Train A   MCC                      V Board Room 1A                           envelopes failure of its fan, coils and Air Cooled                             running         power failure;                              The Battery Room I                        motor.
Condenser Unit                                         Start signal                                will be ventilated by 1A-A                                                   failure.                                    the air supply from the                   2. The condenser is interlocked to Pressurizing Fan to                       automatically start or stop with the provide Hydrogen                          AHU and compressor start or stop.
ventilation.
: 3. The condenser is interlocked to automatically open 1-FSV-31-290 when running and close it when stopped.
: 4. Board Room 1B and Battery Room II provide the redundancy.
: 5. Actions are defined that deal with a loss of Train A cooling.
: 6. Battery Room I can be exhausted from the pressurizing fan supply air to provide hydrogen ventilation.
Calculations indicate that sufficient cooling is still available to assure the battery rooms remain below the maximum temperature limit.
9.4-101                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 6 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                   Method of No. Component            Function         Failure Mode   Potential Cause          Detection           Effect on System       Effect on Plant                    Remarks 6     1-COND-31-289-B Provides refrigerant   Fails to run;   Mechanical         Motor running light on   Loss of cooling to 480 None (See Remarks)   1. Failure of the condenser to AHU 1B-B            Stops while     failure; Train B   MCC                      V Board Room 1B                             envelopes failure of its fan, coils and Air Cooled                             running         power failure;                              The Battery Room II                         motor.
Condenser Unit                                         Start signal                                will be ventilated by 1B-B                                                   failure.                                    the air supply from the                     2. The condenser is interlocked to Pressurizing Fan to                         automatically start or stop with the provide Hydrogen                            AHU and compressor start or stop.
ventilation.
: 3. The condenser is interlocked to automatically open 1-FSV-31-289 when running and close it when stopped.
: 4. Board Room 1A and Battery Room I provide the redundancy.
: 5. The Train A equipment located in the Board Room 1B is cooled by Train A.
9.4-102                                                                                                                                                                                                                                                       WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 7 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                   Method of No. Component            Function         Failure Mode   Potential Cause          Detection           Effect on System       Effect on Plant                    Remarks 7     2-COND-31-290-A Provides refrigerant   Fails to run;   Mechanical         Motor running light on   Loss of cooling to 480 None (See Remarks)   1. Failure of the condenser to AHU 2A-A            Stops while     failure; Train B   MCC                      V Board Room 2A                             envelopes failure of its fan, coils and Air Cooled                             running         power failure;                              The Battery Room III                        motor.
Condenser Unit                                         Start signal                                will be ventilated by 2A-A                                                   failure.                                    the air supply from the                     2. The condenser is interlocked to Pressurizing Fan to                         automatically start or stop with the provide Hydrogen                            AHU and compressor start or stop.
ventilation.
: 3. The condenser is interlocked to automatically open 2-FSV-31-290 when running and close it when stopped.
: 4. Board Room 2B and Battery Room IV provide the redundancy.
9.4-103                                                                                                                                                                                                                                                       WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 8 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                   Method of No. Component            Function         Failure Mode   Potential Cause          Detection           Effect on System       Effect on Plant                    Remarks 8     2-COND-31-289-B Provides refrigerant   Fails to run;   Mechanical         Motor running light on   Loss of cooling to 480 None (See Remarks)   1. Failure of the condenser to AHU 2B-B            Stops while     failure; Train A   MCC                      V Board Room 2B                             envelopes failure of its fan, coils and Air Cooled                             running         power failure;                              The Battery Room IV                         motor.
Condenser Unit                                         Start signal                                will be ventilated by 2B-B                                                   failure.                                    the air supply from the                     2. The Condenser is interlocked to Pressurizing Fan to                         automatically start or stop with the provide Hydrogen                            AHU and compressor start or stop.
ventilation.
: 3. The condenser is interlocked to automatically open 2-FSV-31-289 when running and close it when stopped.
: 4. Board Room 2A and Battery Room III provide the redundancy.
: 5. The Train A equipment located in the Board Room 2B will be cooled by Train A.
9.4-104                                                                                                                                                                                                                                                       WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 9 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                   Method of No. Component           Function         Failure Mode    Potential Cause          Detection         Effect on System      Effect on Plant                  Remarks 9     1-FCO-31-290     Provides exhaust flow Fails to open   Mechanical failure Indicating lights in   Loss of ability to   None (See Remarks)   1. Interlocked with Condensing Unit path for Condensing (stuck closed)                       MCR (1-ZS-31-290)      exhaust from                              1A-A via 1-FSV-31-290 to Exhaust Damper   Unit 1A-A                                                                       condensing Unit 1A-A                      automatically open on ACU start.
for ACU 1A-A
: 2. A review of the Control Air flow diagrams shows that nonsafety control air is supplied to both 1-FC0-31-290 and 289.
: 3. The exhaust damper is air operated and fails open upon loss of air or Train A power.
: 4. Board Room 1B and Battery Room II provide the redundancy.
9.4-105                                                                                                                                                                                                                                                WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 10 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                   Method of No. Component           Function         Failure Mode    Potential Cause          Detection         Effect on System      Effect on Plant                  Remarks 10     2-FCO-31-290     Provides exhaust flow Fails to open   Mechanical failure Indicating lights in   Loss of ability to   None (See Remarks)   1. Interlocked with Condensing Unit path for Condensing (stuck closed)                       MCR (2-ZS-31-290)      exhaust from                              2A-A via 2-FSV-31-290 to Exhaust Damper   Unit 2A-A                                                                       condensing Unit 2A-A                      automatically open on ACU start.
for AHU 2A-A
: 2. A review of the Control Air flow diagrams shows that nonsafety control air is supplied to both 2-FC0-31-290 and 289.
: 3. The exhaust damper is air operated and fails open upon loss of air or Train A power.
: 4. Board Room 2B and Battery Room IV provide the redundancy.
9.4-106                                                                                                                                                                                                                                                WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 11 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                        Method of No.      Component             Function         Failure Mode     Potential Cause           Detection           Effect on System        Effect on Plant                   Remarks 11     1-FAN-31-462-A   Provides pressurizing Fails to start;     Mechanical           Indicating lights in   Loss of redundancy in None (See Remarks)   1. Fan is controlled by locally air flow to 480 V       Fails while       failure; Train A     MCR                    pressurizing air                             mounted stop-start push button Pressurizing     Board Room 1A           running           power failure;       (1-HS-31-462 A).       supply to 480 V Board                        stations in conjunction with auto-start Supply Fan 1A1-A Battery Room I and                        Control signal       Locally,               Room 1A and Battery                          switches in MCR.
(Train A)        partial makeup air to                     failure; Operator    1-HS-31-462B. ANN      Room I and V the Fifth Vital Battery                   error (handswitch    19-9 low flow from                                                  2. Pressurizing Fan 1A1-A is Room.                                     in wrong position)   Press. Fans            Low flow on                                  interlocked with Battery Board Room 1-FS-31-463-B will                           I Exhaust Fan 1A2-B and 480 V automatically stop                           Room 1A Fan 1A2-B such that when Fan 1A1-A and                                Fan 1A1-A is in auto-standby, low Battery Board Room                           flow on either of the 1A2-B Fans will Exhaust fan 1A1-A                            start 1-FAN-31-462-A and stop 1-and, will automatically                      FAN-31-463-B.
start Fan 1A2-B and Battery Room                                 3. A review of the schematics Exhaust fan 1A2-B.                           establishes the separation and redundancy of the train A and B fans.
(See Remark #2.)                             The loss of nondivisional train associated power supply for the separation relay will not prevent the switchover from a failed pressurizing fan to the standby fan.
Failure to stop   Spurious low flow Indicating lights in Overpressurization of None (See Remarks)        Insignificant increase in air flow to when Train B      signal; Hot short MCR (1-HS-31-462A). 480 V Board Room                                   480 V Board Room 1A and fan starts.       in control wiring;                     1A.                                               Mechanical Equipment Room 1A.
Operator error.                                                                          Battery room I will not be (See 'Remarks')                                   overpressurized without second failure.
9.4-107                                                                                                                                                                                                                                                            WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 12 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                        Method of No.      Component             Function         Failure Mode     Potential Cause           Detection           Effect on System        Effect on Plant                   Remarks 12     1-FAN-31-463-B   Provides pressurizing Fails to start;     Mechanical           Indicating lights in   Loss of redundancy in None (See Remarks)   1. Fan is controlled by locally air flow to 480 V     Fails while         failure; Train B     MCR                    pressurizing air                             mounted stop-start push button Pressurizing     Board Room 1A         running             power failure;       (1-HS-31-463 A).       supply to 480 V Board                        stations in conjunction with auto-start Supply Fan 1A2-B Battery Room I and                        Control signal       Locally,               Room 1A and Battery                          switches in MCR.
(Train B)        partial makeup air to                     failure; Operator    1-HS-31-463B. ANN      Room I and V the FVBR                                  error (handswitch    19-9 low flow from                                                  2. Pressurizing Fan 1A2-B is in wrong position)   Press. Fans            Low flow on                                  interlocked with Battery Board Room 1-FS-31-462-A will                           I Exhaust Fan 1A1-A and 480 V automatically stop                           Room 1A Fan 1A1-A such that when Fan 1A2-B and                                Fan 1A2-B is in auto-standby, low Battery Board Room                           flow of either of the 1A1-A Fans will Exhaust fan 1A2-B                            start 1-FAN-31-463B and stop and, will automatically                      1-FAN-31-462A.
start Fan 1A1-A and Battery Room                                 3. A review of the schematics Exhaust fan 1A1-A.                           establishes the separation and redundancy of the Train A and B (See Remark #2.)                             fans. The loss of nondivisional train associated power supply for the separation relay will not prevent the switchover from a failed pressurizing fan to the standby fan.
Failure to stop   Spurious low flow Indicating lights in Overpressurization of None (See Remarks)        Insignificant increase in air flow to when Train A      signal; Hot short MCR (1-HS-31-463A). 480 V Board Room                                   480 V Board Room 1A and fan starts.       in control wiring;                     1A.                                               Mechanical Equipment Room 1A.
Operator error.                                                                          Battery room I will not be (See 'Remarks')                                   overpressurized without a second failure.
9.4-108                                                                                                                                                                                                                                                            WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 13 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                        Method of No.      Component             Function         Failure Mode     Potential Cause           Detection           Effect on System        Effect on Plant                   Remarks 13     1-FAN-31-478-A   Provides pressurizing Fails to start;     Mechanical           Indicating lights in   Loss of redundancy in None (See Remarks)   1. Fan is controlled by locally air flow to 480 V     Fails while         failure; Train B     MCR (1-HS-31-478A). pressurizing air                             mounted stop-start push button Pressurizing     Board Room 1B         running             power failure;       Locally,               supply to 480 V Board                        stations in conjunction with auto-start Supply Fan 1B1-A Battery Room II and                       Control signal       1-HS-31-478B ANN       Room 1B and Battery                          switches in MCR.
(Train A)        partial makeup air to                     failure; Operator    19-11 low flow from    Room II the FVBR                                  error (handswitch    Press. Fans                                                         2. Pressurizing Fan 1B1-A is in wrong position)                          Low flow on                                  interlocked with Battery Room I 1-FS-31-477-B will                           Exhaust Fan 1B-A and 480 V Room automatically stop                           1B pressurizing Fan 1B2-B such that Fan 1B1-A and                                when Fan 1B1-A is in auto-standby, Battery Board Room                           low flow on either of the 1B2-B Fans Exhaust fan 1B1-A                            will start 1-FAN-31-478-A and stop and, will automatically                      1-FAN-31-477-B.
start Fan 1B2-B and Battery Room                                 3. A review of the schematics Exhaust fan 1B2-B.                           establishes the separation and (See Remark #2.)                             redundancy of the Train A and B fans. The loss of nondivisional train associated power supply for the separation relay will not prevent the switchover from a failed pressurizing fan to the standby fan.
Failure to stop   Spurious low flow Indicating lights in Overpressurization of None (See Remarks)        Insignificant increase in air flow to when Train B      signal; Hot short MCR (1-HS-31-478A). 480 V Board Room                                   480 V Board Room 1B and fan starts.       in control wiring;                     1B.                                               Mechanical Equipment Room 1B.
Operator error.                                                                          Battery room I will not be (See 'Remarks')                                   overpressurized without second failure.
9.4-109                                                                                                                                                                                                                                                            WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 14 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                        Method of No.      Component             Function         Failure Mode     Potential Cause           Detection           Effect on System        Effect on Plant                   Remarks 14     1-FAN-31-477-B   Provides pressurizing Fails to start;     Mechanical           Indicating lights in   Loss of redundancy in None (See 'Remarks')    1. Fan is controlled by locally air flow to 480 V     Fails while         failure; Train B     MCR (1-HS-31-477A). pressurizing air                              mounted stop-start push button Pressurizing     Board Room 1B and running                 power failure;       Locally, HS-31-477B    supply to 480 V Board                         stations in conjunction with auto-start Supply Fan 1B2-B Battery Room II and                       Control signal       ANN 19-11 low flow     Room 1B and Battery                           switches in MCR.
(Train B)        partial makeup air to                     failure; Operator    from Press. Fans       Room II the FVBR                                  error (handswitch                                                                         2. Pressurizing Fan 1B2-B is in wrong position)                          Low flow on                                   interlocked with Battery Room II 1-FS-31-478-A will                            Exhaust Fan 1B2-B and 480 V Room automatically stop                            1B pressurizing Fan 1B1-A such that Fan 1B2-B and                                 when Fan 1B2-B is in auto-standby, Battery Room                                  low flow on either of the 1B1-A Fans Exhaust fan 1B2-B                             will start 1-FAN-31-477-B and stop and, will automatically                       1-FAN-31-478-A.
start Fan 1B1-A and Battery Room                                  3. A review of the schematics Exhaust fan 1B1-A.                            establishes the separation and redundancy of the Train A and B (See Remark #2.)                              fans. The loss of non-divisional train associated power supply for the separation relay will not prevent the switchover from a failed pressurizing fan to the standby fan.
Failure to stop   Spurious low flow Indicating lights in      Overpressurization of None (See 'Remarks') Insignificant increase in air flow to when Train A      signal; Hot short MCR                       480 V Board Room                           480 V Board Room 1B and fan starts.       in control wiring; (1-HS-31-477A-B).        1B.                                        Mechanical Equipment Room 1B.
Operator error.                                                                        Battery room II will not be (See 'Remarks')                            overpressurized without a second failure.
9.4-110                                                                                                                                                                                                                                                             WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 15 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                      Method of No. Component             Function        Failure Mode     Potential Cause           Detection           Effect on System       Effect on Plant                Remarks 15     1-FAN-31-287-A     Exhausts air from   Fails to start;   Mechanical          Local indicating light   Loss of redundancy in None.               1. Interlocked with Pressurizing Fan Battery Room 1 to   Fails while       failure; Train A    for Damper               exhausting Battery                        1A1-A such that the Battery Room Exhaust Fan        prevent hydrogen    running.          power failure;      1-FCO-31-287-A           Room 1.                                   Exhaust Fan starts when the 1A1- A for Battery build-up.                             spurious low flow   closure. Motor                                                     Pressurizing Fan starts and stops Room 1 (Train A).                                        signal.             running light on MCC. On low flow from                          when the Pressurizing Fan stops.
pressurizing or Battery Room                              2. A review of the schematics Exhaust Fan 1A1-A,                        establishes the independence of the the Train B                               Train A and B fans.
Pressurizing Fan 1A2-B and the Battery Room Exhaust Fan 1A2-B will automatically start. Damper 1-FCO-31-288-B will open.
9.4-111                                                                                                                                                                                                                                                     WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 16 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                     Method of No. Component             Function       Failure Mode     Potential Cause           Detection           Effect on System       Effect on Plant                  Remarks 16     1-FAN-31-288-B    Exhausts air from   Fails to start;   Mechanical          Local indicating light   Loss of redundancy in None. (See Remarks) 1. Interlocked with Pressurizing Fan Battery Room 1 to   Fails while       failure; Train B    for damper               exhausting Battery                        1A2-B such that the Battery Room Exhaust Fan 1A2- prevent hydrogen     running.          power failure;      1-FCO-31-288-B           Room 1.                                   Exhaust Fan starts when the B for Battery     build-up.                             spurious low flow   closure. Motor                                                     Pressurizing Fan starts and stops Room 1 (Train B).                                       signal.             running light on MCC. On low flow from                          when the Pressurizing Fan stops.
pressurizing or Battery Room                              2. A review of the schematics Exhaust Fan 1A2-B,                        establishes the independence of the the Train A                               Train A and B fans.
Pressurizing Fan 1A1-A and the Battery Room Exhaust Fan 1A2-B will automatically start. Damper 1-FCO-31-287-A will open.
9.4-112                                                                                                                                                                                                                                                    WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 17 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                     Method of No. Component             Function       Failure Mode     Potential Cause           Detection           Effect on System       Effect on Plant                 Remarks 17     1-FAN-31-285-A   Exhausts air from    Fails to start;   Mechanical          Local indicating light   Loss of redundancy in None.               1. Interlocked with Pressurizing Fan Battery Room II to   Fails while       failure; Train A    for damper               exhausting Battery                        1B1-A such that the Battery Room Exhaust Fan 1B1- prevent hydrogen     running.          power failure;      1-FCO-31-285-A           Room II.                                  Exhaust Fan starts and stops whtn A for Battery II build-up.                              spurious low flow   closure. Motor                                                     the Pressurizing Fan starts.
(Train A)                                               signal.             running light on MCC. One low flow from pressurizing or                           2. A review of the schematics Battery Room                              restablishes the independance of the Exhaust Fan 1B1-A,                        Train A and B fans.
the Train B Pressurizing Fan 1B2-B and the Battery Room Exhaust Fan will automaticaly start.
Damper 1-FCO-31-286-A will open.
9.4-113                                                                                                                                                                                                                                                    WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 18 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                       Method of No.      Component             Function        Failure Mode     Potential Cause           Detection           Effect on System       Effect on Plant                Remarks 18     1-FAN-31-286-B     Exhausts air from    Fails to start;   Mechanical          Local indicating light   Loss of redundancy in None.               1. Interlocked with Pressurizing Fan Battery Room II to   Fails while       failure; Train B    for Damper               exhausting Battery                        1B2-B such that the Battery Room Exhaust Fan 1B2- prevent hydrogen       running.          power failure;      1-FCO-31-286-B           Room II.                                  Exhaust Fan starts when the B for Battery      build-up.                              spurious low flow   closure. Motor                                                     Pressurizing Fan starts and stops Room II (Train B).                                        signal.             running light on MCC. On low flow from                          when the Pressurizing Fan stops.
pressurizing or Battery Room                              2. A review of the schematics Exhaust Fan 1B2-B,                        establishes the independence of the the Train A                               Train A and B fans.
Pressurizing Fan 1B1-A and the Battery Room Exhaust Fan 1B1-A will automatically start. Damper 1-FCO-31-285-B will open.
9.4-114                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 19 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                        Method of No.      Component             Function         Failure Mode     Potential Cause           Detection           Effect on System        Effect on Plant                  Remarks 19     2-FAN-31-462-A   Provides pressurizing Fails to start;     Mechanical           Indicating lights in   Loss of redundancy in None (See Remarks)    1. Fan is controlled by locally air flow to 480 V     Fails while         failure; Train A     MCR                    pressurizing air                            mounted stop-start push button Pressurizing     Board Room 2A and running                 power failure;       (2-HS-31-462-A).       supply to 480 V Board                       stations in conjunction with auto-start Supply Fan 2A1-A Battery Room IV.                          Control signal       Locally,               Room 2A and Battery                         switches in MCR.
(Train A)                                                  failure; Operator    2-HS-31-462B. ANN      Room IV error (handswitch    19-9 low flow from                                                 2. Pressurizing Fan 2A1-A is in wrong position)   Press. Fans            Low flow on                                 interlocked with Battery 2-FS-31-462-A will                          Room IV Exhaust Fan 2A2-B and 480 automatically stop                          V Room 2A Fan 2A2-B such that Fan 2A1-A and                               when Fan 2A1-A is in auto-standby, Battery Room                                low flow on either of the 2A2-B Fans Exhaust fan 2A1-A;                          will start 2-FAN-31-462-A and stop and, will automatically                     2-FAN-31-463-B.
start Fan 2A2-B and Battery Room                                3. A review of the schematics Exhaust fan 2A2-B.                          establishes the separation and redundancy of the Train A and B See Remark #2.                              fans. The loss of non-divisional train associated power supply for the separation relay will not prevent the switchover from a failed pressurizing fan to the standby fan.
Failure to stop   Spurious low flow Indicating lights in Overpressurization of None (See Remarks)         Insignificant increase in air flow to when Train B      signal; Hot short MCR (2-HS-31-462A). 480 V Board Room                                  480 V Board Room 2A and fan starts.       in control wiring;                     2A.                                              Mechanical Equipment Room 2A.
Operator error.                                                                         Battery room IV will not be (See Remarks)                                    overpressurized without a second failure.
9.4-115                                                                                                                                                                                                                                                           WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 20 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                        Method of No.      Component             Function         Failure Mode     Potential Cause           Detection            Effect on System        Effect on Plant                  Remarks 20     2-FAN-31-463-B   Provides pressurizing Fails to start;     Mechanical           Indicating lights in    Loss of redundancy in None (See Remarks)    1. Fan is controlled by locally air flow to 480 V     Fails while         failure; Train B     MCR                     pressurizing air                            mounted stop-start push button Pressurizing     Board Room 2A and running                 power failure;       (2-HS-31-463-A).        supply to 480 V Board                       stations in conjunction with auto-start Supply Fan 2A2-B Battery Room IV.                          Control signal       Locally, 2-HS-31-463B   Room 2A and Battery                         switches in MCR.
(Train B)                                                  failure; Operator    ANN 19-9 low flow       Room IV error (handswitch    from Press. Fans                                                    2. Pressurizing Fan 2A2-B is in wrong position)                           Low flow on                                 interlocked with Battery Board Room 2-FS-31-463-B will                          IV Exhaust Fan 2A1-A and 480 V automatically stop                          Room 2A Fan 2A1-A such that when Fan 2A2-B and                               Fan 2A2-B is in auto-standby, low Battery Room                                flow on either of the 2A1-A Fans will Exhaust fan 2A2-B                           start 2-FAN-31-463-B and stop and, will automatically                      2-FAN-31-462-A.
start Fan 2A1-A and Battery Room                                3. A review of the schematics Exhaust fan 2A1-A.                          establishes the separation and redundancy of the Train A and B See Remark #2.                              fans. The loss of non-divisional train associated power supply for the separation relay will not prevent the switchover from a failed pressurizing fan to the standby fan.
Failure to stop   Spurious low flow Indicating lights in Overpressurization of None(See Remarks)           Insignificant increase in air flow to when Train A      signal; Hot short MCR (2-HS-31-463A). 480 V Board Room                                   480 V Board Room 2A and fan starts.       in control wiring;                     2A.                                               Mechanical Equipment Room 2A.
Operator error.                                                                          Battery room IV will not be (See Remarks)                                     overpressurized without a second failure.
9.4-116                                                                                                                                                                                                                                                            WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 21 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                        Method of No.      Component             Function         Failure Mode     Potential Cause           Detection           Effect on System        Effect on Plant                  Remarks 21     2-FAN-31-478-A   Provides pressurizing Fails to start;     Mechanical           Indicating lights in   Loss of redundancy in None (See Remarks)    1. Fan is controlled by locally air flow to 480 V     Fails while         failure; Train A     MCR                    pressurizing air                            mounted stop-start push button Pressurizing     Board Room 2B and running                 power failure;       (2-HS-31-478-A).       supply to 480 V Board                       stations in conjunction with auto-start Supply Fan 2B1-A Battery Room III.                         Control signal       Locally,               Room 2B and Battery                         switches in MCR.
(Train A)                                                  failure; Operator    2-HS-31-478B. ANN      Room III error (handswitch    19-11 low flow from                                                2. Pressurizing Fan 2B1-A is in wrong position)   Press. Fans            Low flow on                                 interlocked with Battery Board 2-FS-31-478-A will                          Room IV Exhaust Fan 2B2-B and 480 automatically stop                          V Room 2B Fan 2B2-B such that Fan 2B1-A and                               when Fan 2B1-A is in auto-standby, Battery Room                                low flow on either of the 2B2-B Fans Exhaust fan 2B1-A                           will start 2-FAN-31-478-A and, will automatically                     and stop 2-FAN-31-477-B.
start Fan 2B2-B and Battery Room                                3. A review of the schematics Exhaust Fan 2B2-B.                          establishes the separation and redundancy of the train A and B fans.
See Remark #2.                              The loss of non-divisional train associated power supply for the separation relay will not prevent the switchover from a failed pressurizing fan to the standby fan.
Failure to stop   Spurious low flow Indicating lights in Overpressurization of None (See Remarks)         Insignificant increase in air flow to when Train B      signal; Hot short MCR (2-HS-31-478A). 480 V Board Room                                  480 V Board Room 2B and fan starts.       in control wiring;                     2B.                                              Mechanical Equipment Room 2B.
Operator error.                                                                         Battery room III will not be (See Remarks)                                    overpressurized without a second failure.
9.4-117                                                                                                                                                                                                                                                           WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 22 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                        Method of No.      Component             Function         Failure Mode     Potential Cause           Detection           Effect on System        Effect on Plant                  Remarks 22     2-FAN-31-477-B   Provides pressurizing Fails to start;     Mechanical           Indicating lights in   Loss of redundancy in None (See Remarks)    1. Fan is controlled by locally air flow to 480 V     Fails while         failure; Train B     MCR                    pressurizing air                            mounted stop-start push button Pressurizing     Board Room 2B and running                 power failure;       (2-HS-31-477-A).       supply to 480 V Board                       stations in conjunction with auto-start Supply Fan 2B2-B Battery Room III.                         Control signal       Locally,               Room 2B and Battery                         switches in MCR.
(Train B)                                                  failure; Operator    2-HS-31-477-B. ANN     Room III error (handswitch    19-11 low flow from                                                2. Pressurizing Fan 2B2-B is in wrong position)   Press. Fans            Low flow on                                 interlocked with Battery Board Room 2-FS-31-477-B will                          III Exhaust Fan 2B1-A and 480 V automatically stop                          Room 2B Fan 2B1-A such that when Fan 2B2-B and                               Fan 2B2-B is in auto-standby, low Battery Room                                flow on either of the 2B1-A Fans will Exhaust fan 2B2-B                           start 2-FAN-31-477-B and, will automatically                     and stop 2-FAN-31-478-A.
start Fan 2B1-A and Battery Room                                3. A review of the schematics Exhaust fan 2B1-A.                          establishes the separation and redundancy of the train A and B fans.
See Remark #2.                              The loss of non-divisional train associated power supply for the separation relay will not prevent the switchover from a failed pressurizing fan to the standby fan.
Failure to stop   Spurious low flow Indicating lights in Overpressurization of None (See Remarks)         Insignificant increase in air flow to when Train A      signal; Hot short MCR (2-HS-31-477A). 480 V Board Room                                  480 V Board Room 2B and fan starts.       control wiring;                        2A.                                              Mechanical Equipment Room 2B.
Operator error.                                                                         Battery room III will not be (See Remarks)                                    overpressurized without a second failure.
9.4-118                                                                                                                                                                                                                                                           WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 23 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                       Method of No. Component             Function         Failure Mode     Potential Cause           Detection           Effect on System       Effect on Plant                  Remarks 23     2-FAN-31-287-A     Exhausts air from    Fails to start;   Mechanical          Local indicating light   Loss of redundancy in None. (See Remarks) 1. Interlocked with Pressurizing Fan Battery Room IV to   Fails while       failure; Train A    for Damper               exhausting Battery                        2A1-A such that the Exhaust Fan Exhaust Fan        prevent hydrogen     running.          power failure;      2-FCO-31-287-A           Room IV.                                  starts when the Pressurizing Fan 2A1- A for Battery build-up.                              spurious low flow   closure. Motor                                                     starts and stops when the Room IV (Train A).                                        signal.             running light on MCC. On low flow from                          Pressurizing Fan stops.
pressurizing or Battery Room                              2. A review of the schematics Exhaust Fan 2A1-A,                        establishes the independence of the the Train B                               Train A and B fans.
Pressurizing Fan 2A2-B and the Exhaust Fan 2A2-B will automatically start. Damper 2-FCO-31-288-B will open.
9.4-119                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 24 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                        Method of No.      Component              Function         Failure Mode     Potential Cause          Detection            Effect on System       Effect on Plant                  Remarks 24     2-FAN-31-288-B       Exhausts air from    Fails to start;   Mechanical          Local indicating light   Loss of redundancy in None. (See Remarks) 1. Interlocked with Pressurizing Fan Battery Room IV to   Fails while       failure; Train B    for damper               exhausting Battery                        2A2-B such that the Exhaust Fan Exhaust Fan          prevent hydrogen     running.          power failure;      2-FCO-31-288-A           Room IV.                                  starts when the Pressurizing Fan 2A2-B for Battery    build-up.                              spurious low flow   closure. Motor running                                             starts and stops when the Room IV (Train B).                                          signal.             light on MCC.            On low flow from                          Pressurizing Fan stops.
Pressurizing or Battery Room                              2. A review of the schematics Exhaust Fan 2A1-B,                        establishes the independence of the the Train A                               Train A and B fans.
Pressurizing Fan 2A1-A and the Exhaust Fan 2A1-A will automatically start. Damper 2-FCO-31-287-A will open.
9.4-120                                                                                                                                                                                                                                                        WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 25 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                         Method of No.      Component              Function         Failure Mode     Potential Cause           Detection           Effect on System       Effect on Plant                  Remarks 25     2-FAN-31-285-A      Exhausts air from     Fails to start;   Mechanical          Local indicating light   Loss of redundancy in None. (See Remarks) 1. Interlocked with Pressurizing Fan Battery Room III to   Fails while       failure; Train A    for damper               exhausting Battery                        2B1-A such that the Exhaust Fan Exhaust Fan         prevent hydrogen      running.          power failure;      2-FCO-31-285-A           Room III.                                 starts when the Pressurizing Fan 2B1-A for Battery   build-up.                               spurious low flow   closure. Motor                                                     starts and stops when the III (Train A).                                              signal.             running light on MCC. On low flow from                          Pressurizing Fan stops.
Pressurizing or Battery Room                              2. A review of the schematics Exhaust Fan 2B1-A,                        establishes the independence of the the Train B                               Train A and B fans.
Pressurizing Fan 2B2-B and the Exhaust Fan 2B2-B will automatically start. Damper 2-FCO-31-286-A will open.
9.4-121                                                                                                                                                                                                                                                        WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 26 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                            Method of No.      Component                Function         Failure Mode     Potential Cause            Detection           Effect on System       Effect on Plant                  Remarks 26     2-FAN-31-286-B        Exhausts air from     Fails to start;   Mechanical           Local indicating light   Loss of redundancy in None. (See Remarks) 1. Interlocked with Pressurizing Fan Battery Room III to   Fails while       failure; Train B     for Damper               exhausting Battery                        2B2-B such that the Exhaust Fan Exhaust Fan           prevent hydrogen      running.          power failure;       2-FCO-31-286-B           Room III.                                 starts when the Pressurizing Fan 2B2-B for Battery     build-up.                               spurious low flow    closure. Motor                                                     starts and stops when the Room III (Train B).                                           signal.              running light on MCC. On low flow from                          Pressurizing Fan stops.
pressurizing or Battery Room                              2. A review of the schematics Exhaust Fan 2B2-B,                        establishes the independence of the the Train A                               Train A and B fans.
Pressurizing Fan 2B1-A and the Battery Room Exhaust Fan 2B1-A will automatically start.
Damper 2-FCO-31-285-A will open.
27     1-FCO-31-287-A        Provides air flow to Spuriously         Mechanical           Mechanical               Loss of redundancy in None. (See Remarks) Damper is motor operated, and fails Exhaust Fan 1A1-A in closes.            failure; Hot short   Equipment Room           exhausting Battery                        as is. Automatically controlled to Tornado Damper        Battery Room I.                         in control wiring;   damper status lights     Room I.                                   open by Battery Room I Exhaust Fan (Exhaust Fan                                                  Operator error       (1-ZS-31-287B-A).                                                  1A1-A. A review of the schematics 1A1-A.)                                                       (handswitch                                   Low flow from 1A1-A                       establishes the independence of the placed in wrong                               Fans will                                 control of Dampers 1-FCO-31-288-B position).                                    automatically stop the                    and fan from Train A, start                   1-FCO-31-287-A.
Train B Press. Fan 1A2-B and Exhaust Fan 1A2-B which will WBNP-97 open 9.4-122 1-FCO-31-288-B.

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 27 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                      Method of No. Component              Function         Failure Mode   Potential Cause           Detection          Effect on System       Effect on Plant                Remarks 28     1-FCO-31-288-B      Provides air flow to Spuriously      Mechanical           Mechanical             Loss of redundancy in None. (See Remarks) Damper is motor operated, and fails Exhaust Fan 1A2-B in closes.         failure; Hot short   Equipment Room         exhausting Battery                        as is. Automatically controlled to Tornado Damper      Battery Room I.                      in control wiring;   damper status lights   Room I.                                   open by Battery Room I Exhaust Fan (Exhaust Fan 1A2-                                        Operator error       (1-ZS-31-288A-B).                                                1A2-B. A review of the schematics B)                                                       (handswitch                                 Low flow from 1A2-B                       establishes the independence of the placed in wrong                             Fans will                                 control of Dampers position).                                  automatically stop the                    1-FCO-31-287-A and fan from Train B, start                   1-FCO-31-288-B.
Train A Press. Fan 1A1-A and Exhaust Fan 1A1-A which will open 1-FCO-31-287-A.
29     1-FCO-31-285-A      Provides air flow to Spuriously      Mechanical           Mechanical             Loss of redundancy in None. (See Remarks) Damper is motor operated, and fails Exhaust Fan 1B1-A in closes.         failure; Hot short   Equipment Room         exhausting Battery                        as is. Automatically controlled to Tornado Damper      Battery Room II.                     in control wiring;   damper status lights   Room II.                                  open by Battery Room II Exhaust Fan (Exhaust Fan                                             Operator error       (1-ZS-31-285B-A).                                                1B1-A. A review of the schematics 1B1-A)                                                   (handswitch                                 Low flow from 1B1-A                       establishes the independence of the placed in wrong                             Fans                                      control of Dampers position).                                  will automatically stop                   1-FCO-31-285-A and the fan from Train A,                     1-FCO-31-286-B.
start Train B Press.
Fan 1B2-B and Exhaust Fan 1B2-B which will open 1-FCO-31-286-B.
9.4-123                                                                                                                                                                                                                                                   WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 28 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                   Method of No. Component           Function         Failure Mode   Potential Cause           Detection          Effect on System       Effect on Plant                 Remarks 30     1-FCO-31-286-B   Provides air flow to Spuriously      Mechanical           Mechanical             Loss of redundancy in None. (See Remarks) Damper is motor operated, and fails Exhaust Fan 1B2-B in closes.         failure; Hot short   Equipment Room         exhausting Battery                        as is. Automatically controlled to Tornado Damper   Battery Room II.                     in control wiring;   damper status lights   Room II.                                  open by Battery Room II Exhaust Fan (Exhaust Fan                                          Operator error       (1-ZS-31-286A-B).                                                1B2-B. A review of the schematics 1B2-B).                                               (handswitch                                 Low flow from 1B2-B                       establishes the independence of the placed in wrong                             Fans                                      control of Dampers position).                                  will automatically stop                   1-FCO-31-285-A and the fan from Train B,                     1-FCO-31-286-B.
start Train A Press.
Fan 1B1-A and Exhaust Fan 1B1-A which will open 1-FCO-31-285-A.
31     2-FCO-31-287-A   Provides air flow to Spuriously      Mechanical           Mechanical             Loss of redundancy in None. (See Remarks) Damper is motor operated, and fails Exhaust Fan 2A1-A in closes.         failure; Hot short   Equipment Room         exhausting Battery                        as is. Automatically controlled to Tornado Damper   Battery Room IV.                     in control wiring;   damper status lights   Room IV.                                  open by Battery Room IV Exhaust (Exhaust Fan                                          Operator error       (2-ZS-31-287B-A).                                                Fan 2A1-A. A review of the 2A1-A).                                               (handswitch                                 Low flow from 2A1-A                       schematics establishes the placed in wrong                             Fans                                      independence of the control of position).                                  will automatically stop                   Dampers 2-FCO-31-287-A and the fan from Train A,                     2-FCO-31-288-B.
start Train B Press.
Fan 2A2-B and Exhaust Fan 2A2-B which will open 2-FCO-31-288-B.
9.4-124                                                                                                                                                                                                                                                WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 29 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                      Method of No. Component              Function         Failure Mode   Potential Cause           Detection          Effect on System       Effect on Plant                 Remarks 32     2-FC0-31-288-B      Provides air flow to Spuriously      Mechanical           Mechanical             Loss of redundancy in None. (See Remarks) Damper is motor operated, and fails Exhaust Fan 2A2-B in closes.         failure; Hot short   Equipment Room         exhausting Battery                        as is. Automatically controlled to Tornado Damper      Battery Room IV.                     in control wiring;   damper status lights   Room IV.                                  open by Battery Room IV Exhaust (Exhaust Fan                                             Operator error       (2-ZS-31-288A-B).                                                Fan 2A2-B. A review of the 2A2-B.                                                   (handswitch                                 Low flow from 2A2-B                       schematics establishes the placed in wrong                             Fans                                      independence of the control of position).                                  will automatically stop                   Dampers 2-FCO-31-287-A and the fan from Train B,                     2-FCO-31-288-B.
start Train A Press.
Fan 2A1-A and Exhaust Fan 2A1-A which will open 2-FCO-31-287-A.
33     2-FCO-31-285-A      Provides air flow to Spuriously      Mechanical           Mechanical             Loss of redundancy in None. (See Remarks) Damper is motor operated, and fails Exhaust Fan 2B1-A in closes.         failure; Hot short   Equipment Room         exhausting Battery                        as is. Automatically controlled to Tornado Damper      Battery Room III.                    in control wiring;   damper status lights   Room III.                                 open by Battery Room III Exhaust (Exhaust Fan 2B1-                                        Operator error       (2-ZS-31-285B-A).                                                Fan 2B1-A. A review of the A).                                                      (handswitch                                 Low flow from 2B1-A                       schematics establishes the placed in wrong                             fans                                      independence of the control of position).                                  will automatically stop                   Dampers 2-FCO-31-285-A and the fan from Train A,                      2-FCO-31-286-B.
start Train B Press.
Fan 2B2-B and Exhaust Fan 2B2-B which will open 2-FCO-31-286-B.
9.4-125                                                                                                                                                                                                                                                   WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 30 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                         Method of No.      Component                Function        Failure Mode   Potential Cause            Detection         Effect on System       Effect on Plant                 Remarks 34     2-FCO-31-286-B        Provides air flow to Spuriously      Mechanical           Mechanical             Loss of redundancy in None. (See Remarks) Damper is motor operated, and fails Exhaust Fan 2B2-B in closes.         failure; Hot short   Equipment Room         exhausting Battery                        as is. Automatically controlled to Tornado Damper        Battery Room III.                    in control wiring;   damper status lights   Room III.                                 open by Battery Room III Exhaust (Exhaust Fan                                               Operator error       (2-ZS-31-286A-B).                                                Fan 2B2-B. A review of the 2B2-B).                                                    (handswitch                                 Low flow from 2B2-B                       schematics establishes the placed in wrong                             fans                                      independence of the control of position).                                  will automatically stop                   Dampers 2-FCO-31-285-A and the fan from Train B,                     2-FCO-31-286-B.
start Train A Press.
Fan 2B1-A and Exhaust Fan 2B1-A which will open 2-FCO-31-285-A.
35     0-FAN-31-493A-A       N/A                  N/A             N/A                  N/A                    N/A                                        Abandoned in place.
N/A Fifth Vital Battery Supply Fan 1A1-A.
36     0-FC-31-487A                               N/A                                                         N/A                                        Abandoned in place.
N/A                                  N/A                                                              N/A Battery Room V Intake Fan 1A1-A Hydramotor Controller.
37     0-FCO-31-483-A                                                                                         N/A                                        Abandoned in place in closed N/A                  N/A             N/A                  N/A                                         N/A                   position.
Tornado Damper WBNP-97 for intake Fan 9.4-126 1A1-A FVBR.

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 31 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                      Method of No. Component            Function          Failure Mode    Potential Cause           Detection           Effect on System        Effect on Plant                   Remarks 38     0-FAN-31-493B-A   Provides exhaust      Fails to run;    Mechanical          ANN 19-8 for low flow    Loss of redundancy in None. (See            The fifth Vital Battery is housed in its from Battery Room     Fails while      failure; Train A    from intake fan or       exhausting Battery    'Remarks')            own separate room, and functions as FVBR Exhaust                            running.         power failure;      exhaust fan from         Room V.                                     a spare to any of the four vital Fan 1B1-A.                                               Auto-start signal   either train.                                                        batteries during periodic testing and failure.                                     The Train B fan is                          maintenance or cell failure during Motor running light on   available to provide                        operation. The two trains of the MCC.                     exhausting of Battery                       ventilation system are 100%
Room V, and will                            redundant. Upon low flow from automatically start on                      Train A exhaust fan, the opposite low flow sensed in                          train fans will start automatically and Train A s exhaust                           its dampers will open. Auto-start of duct.                                       the standby train is independent of the other train. Schematic diagrams were reviewed and it was determined that control from the opposite train flow element does not violate separation of redundant train.
39     0-FCO-31-485-A    Provides flow path for Fails to open   Mechanical          Local control station    Loss of redundancy in None. The Train B     Damper is solenoid actuated to fail exhaust from Exhaust (stuck closed);   failure; Train A    indicating lights.       providing exhaust     exhaust fan and its   closed upon loss of Train A power.
Tornado Damper    Fan 1B1-A              Spuriously      power failure;                               flowpath.             associated dampers for exhaust Fan                          closes.         Operator error.                                                    are automatically     Interlocked to automatically open 1B1-A FVBR.                                                                                                                 controlled to         upon exhaust Fan 1B1-A start.
start/open upon low flow from the operating exhaust fan.
9.4-127                                                                                                                                                                                                                                                           WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 32 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                              Method of No. Component              Function   Failure Mode   Potential Cause         Detection    Effect on System     Effect on Plant               Remarks 40     0-FAN-31-496A                                                                                                                  Abandoned in place.
N/A              N/A            N/A               N/A               N/A                 N/A FVBR supply Fan 1A2-B.
41     0-FC-31-488A-B                                                                                                                 Abandoned in place.
N/A              N/A            N/A               N/A               N/A                 N/A Battery Room V Intake Fan 1A2-B Hydramotor Controller.
42     0-FCO-31-484-B                                                                         N/A                                     Abandoned in place.
N/A              N/A            N/A               N/A                                   N/A Tornado Damper for Intake Fan 1A2-B FVBR.
9.4-128                                                                                                                                                                                                                   WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 33 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                      Method of No. Component            Function          Failure Mode    Potential Cause           Detection           Effect on System         Effect on Plant                  Remarks 43     0-FAN-31-496B     Provides exhaust      Fails to run;    Mechanical          ANN 19-8 for low flow    Loss of redundancy in None. (See Remarks) The fifth Vital Battery is housed in its form Battery Room V   Fails while      failure; Train B    from intake fan or       exhausting Battery                        own separate room, and functions as FVBR Exhaust      for ventilation.      running.         power failure;      exhaust fan from         Room V.                                   a spare to any of the four vital Fan 1B2-B.                                               Auto-start signal   either train.                                                      batteries during periodic testing and failure.                                     The Train A fan is                        maintenance or cell failure during Motor running light on   available to provide                      operation. The two trains of the MCC.                     exhausting of Battery                     ventilation system are 100%
Room V, and will                          redundant. Upon low flow from automatically start on                    Train B exhaust fan, the opposite low flow sensed in                        train fans will start automatically and Train B exhaust                           its dampers will open. Auto-start of duct.                                     the standby train is independent of the other train. Schematic diagrams were reviewed and it was determined that control from the opposite train flow element does not violate separation of redundant train.
44     0-FCO-31-486-B    Provides flowpath for Fails to open    Mechanical          Local Control Station    Loss of redundancy in None. The Train A      Low flow switch FS-31-492-B turns exhaust from Exhaust (stuck closed);   failure; Train B    indicating lights        providing exhaust     exhaust fan and its    on the redundant fan pair Tornado Damper    Fan 1B2-B.            Spuriously       power failure;                               flowpath.             associated damper is   (supply/exhaust) for exhaust Fan                         closes.          Operator error.                                                    automatically 1B2-B FVBR.                                                                                                                 controlled to start/open upon low flow from the operating exhaust fan.
9.4-129                                                                                                                                                                                                                                                         WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 34 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                Method of No. Component           Function         Failure Mode   Potential Cause        Detection           Effect on System         Effect on Plant                     Remarks 45     1-BKD-31-2502   Prevents flow of air   Fails to       Mechanical        No direct indication of Loss of pressurizing      None. (See Remarks)   1. ANN low flow. Indicating lights of through Pressurizing   backseat.      failure;          dampers closing         air to rooms served by                          Fan 1A2-B running in MCR. Local Back Draft      Supply Fan 1A1-A                                                                the fan. Bypass flow                            indication of damper status resulting Damper          when Fan 1A2-B is                                       See Remark #1.          through the standby                             from potential low flow from fan(s).
running.                                                                        unit is required to start but may fail as a                               2. Operability of dampers is result of motor                                 periodically verified in accordance overload to overcome                            with preventative maintenance the reverse rotation.                           procedures.
This would result in the total loss of the pressurizing fan and its paired Battery Room exhaust fan and damper.
See Remark #2.
9.4-130                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 35 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                Method of No. Component           Function         Failure Mode   Potential Cause        Detection           Effect on System         Effect on Plant                     Remarks 46     1-BKD-31-2503   Prevents flow of air   Fails to       Mechanical        No direct indication of Loss of pressurizing      None. (See Remarks)   1. ANN low flow. Indicating lights of through Pressurizing   backseat.      failure.          dampers closing         air to rooms served by                          Fan 1A1-A running in MCR. Local Back Draft      Supply Fan 1A2-B                                                                the fan. Bypass flow                            indication of damper status resulting Damper          when Fan 1A1-A is                                       See Remark #1.          through the standby                             from potential low flow from fan(s).
running.                                                                        unit is required to start but may fail as a                               2. Operability of dampers is result of motor                                 periodically verified in accordance overload to overcome                            with preventative maintenance the reverse rotation.                           procedures.
This would result in the total loss of the pressurizing fan and its paired Battery Room exhaust fan and damper.
See Remark #2.
9.4-131                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 36 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                Method of No. Component           Function         Failure Mode   Potential Cause        Detection           Effect on System         Effect on Plant                     Remarks 47     2-BKD-31-2502   Prevents flow of air   Fails to       Mechanical        See Remark #1.          Loss of pressurizing      None. (See Remarks)   1. ANN low flow. Indicating lights of through Pressurizing   backseat.      failure.                                  air to rooms served by                          Fan 2A2-B running in MCR. Local Back Draft      Supply Fan 2A1-A                                        No direct indication of the fan. Bypass flow                            indication of damper status resulting Damper          when Fan 2A2-B is                                       dampers closing         through the standby                             from potential low flow from fan(s).
running.                                                                        unit is required to start but may fail as a                               2. Operability of dampers is result of motor                                 periodically verified in accordance overload to overcome                            with preventative maintenance the reverse rotation.                           procedures.
This would result in the total loss of the pressurizing fan and its paired Battery Room exhaust fan and damper.
See Remark #2.
9.4-132                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 37 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                Method of No. Component           Function         Failure Mode   Potential Cause        Detection           Effect on System         Effect on Plant                     Remarks 48     2-BKD-31-2503   Prevents flow of air   Fails to       Mechanical        No direct indication of Loss of pressurizing      None. (See Remarks)   1. ANN low flow. Indicating lights of through Pressurizing   backseat.      failure.          dampers closing         air to rooms served by                          Fan 2A1-A running in MCR. Local Back Draft      Supply Fan 2A2-B                                                                the fan. Bypass flow                            indication of damper status resulting Damper          when Fan 2A1-A is                                       See Remark #1.          through the standby                             from potential low flow from fan(s).
running.                                                                        unit is required to start but may fail as a                               2. Operability of dampers is result of motor                                 periodically verified in accordance overload to overcome                            with preventative maintenance the reverse rotation.                           procedures.
This would result in the total loss of the pressurizing fan and its paired Battery Room exhaust fan and damper.
See Remark #2.
9.4-133                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 38 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                Method of No. Component           Function         Failure Mode   Potential Cause        Detection           Effect on System         Effect on Plant                     Remarks 49     1-BKD-31-2520   Prevents flow of air   Fails to       Mechanical        No direct indication of Loss of pressurizing      None. (See Remarks)   1. ANN low flow. Indicating lights of through Pressurizing   backseat.      failure.          dampers closing         air to rooms served by                          Fan 1B2-B running in MCR. Local Back Draft      Supply Fan 1B1-A                                                                the fan. Bypass flow                            indication of damper status resulting Damper          when Fan 1B2-B is                                       See Remark #1.          through the standby                             from potential low flow from fan(s).
running.                                                                        unit is required to start but may fail as a                               2. Operability of dampers is result of motor                                 periodically verified in accordance overload to overcome                            with preventative maintenance the reverse rotation.                           procedures.
This would result in the total loss of the pressurizing fan and its paired Battery Room exhaust fan and damper.
See Remark #2.
9.4-134                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 39 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                Method of No. Component           Function         Failure Mode   Potential Cause        Detection           Effect on System         Effect on Plant                     Remarks 50     1-BKD-31-2521   Prevents flow of air   Fails to       Mechanical        No direct indication of Loss of pressurizing      None. (See Remarks)   1. ANN low flow. Indicating lights of through Pressurizing   backseat.      failure.          dampers closing         air to rooms served by                          Fan 1B1-A running in MCR. Local Back Draft      Supply Fan 1B2-B                                                                the fan. Bypass flow                            indication of damper status resulting Damper          when Fan 1B1-A is                                       See Remark #1.          through the standby                             from potential low flow from fan(s).
running.                                                                        unit is required to start but may fail as a                               2. Operability of dampers is result of motor                                 periodically verified in accordance overload to overcome                            with preventative maintenance the reverse rotation.                           procedures.
This would result in the total loss of the pressurizing fan and its paired Battery Room exhaust fan and damper.
See Remark #2.
9.4-135                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 40 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                Method of No. Component           Function         Failure Mode   Potential Cause        Detection           Effect on System         Effect on Plant                     Remarks 51     2-BKD-31-2520   Prevents flow of air   Fails to       Mechanical        No direct indication of Loss of pressurizing      None. (See Remarks)   1. ANN low flow. Indicating lights of through Pressurizing   backseat.      failure.          dampers closing         air to rooms served by                          Fan 2B2-B running in MCR. Local Back Draft      Supply Fan 2B1-A                                                                the fan. Bypass flow                            indication of damper status resulting Damper          when Fan 2B2-B is                                       See Remark #1.          through the standby                             from potential low flow from fan(s).
running.                                                                        unit is required to start but may fail as a                               2. Operability of dampers is result of motor                                 periodically verified in accordance overload to overcome                            with preventative maintenance the reverse rotation.                           procedures.
This would result in the total loss of the pressurizing fan and its paired Battery Room exhaust fan and damper.
See Remark #2.
9.4-136                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-5 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR (Sheet 41 of 41)
FAILURE MODES AND EFFECTS ANALYSIS FOR ACTIVE FAILURES SUBSYSTEM: AUXILIARY BOARD ROOMS AIR CONDITIONING SYSTEM Item                                                                                Method of No. Component           Function         Failure Mode   Potential Cause        Detection           Effect on System         Effect on Plant                     Remarks 52     2-BKD-31-2521   Prevents flow of air   Fails to       Mechanical        No direct indication of Loss of pressurizing      None. (See Remarks)   1. ANN low flow. Indicating lights of through Pressurizing   backseat.      failure.          dampers closing         air to rooms served by                          Fan 2B1-A running in MCR. Local Back Draft      Supply Fan 2B2-B                                                                the fan. Bypass flow                            indication of damper status resulting Damper          when Fan 2B1-A is                                       See Remark #1.          through the standby                             from potential low flow from fan(s).
running.                                                                        unit is required to start but may fail as a                               2. Operability of dampers is result of motor                                 periodically verified in accordance overload to overcome                            with preventative maintenance the reverse rotation.                           procedures.
This would result in the total loss of the pressurizing fan and its paired Battery Room exhaust fan and damper.
See Remark #2.
9.4-137                                                                                                                                                                                                                                                      WBNP-97

AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 1 of 18)
EFFECT ITEM     COMPONENT                                  FAILURE            POTENTIAL             METHOD OF        EFFECT ON          ON NO. IDENTIFICATION        FUNCTION                MODE                CAUSE               DETECTION         SYSTEM          PLANT                         REMARKS 1     1-FAN-30-244F-A   Exhausts air from   Fails to run; Fails   Mechanical failure;     Motor running     Loss of one      None. (See 1. The four (4) exhaust fans (3 safety- related) 480V Transformer    while running.        Train A power failure; light on MCC.      safety related   Remarks) in 480V Transformer Room 1A are interlocked Exhaust Fan       Room 1A.                                  Temperature control                       fan.                        to automatically start/stop in staged series by sensing failure;                                                      thermostatic control.
Control signal failure.
: 2. The inlet dampers are interlocked to automatically open when any fan is running.
: 3. Schematics have been reviewed and it was determined that rooms 1A and 1B, containing redundant electrical equipment, are independent of each other.
: 4. Room temperature is indicated on Local Panel L-362.
: 5. Two of the three safety-related fans are sufficient to adequately ventilate each 480V Transformer Room.
1.The single failure condition of a fan continuing None.                        to run, or spuriously running during accident Spuriously runs.      Control signal failure;   Indicating      (See Remarks) None.          conditions concurrent with minimum outside Temperature control       lights on MCC                 (See           design temperature, is analyzed to conclude sensing failure; Hot      for fan motor                 Remarks)       that the space temeratures remain within short in control          running.                                     allowable limits.
wiring.
9.4-138                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 2 of 18)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR EFFECT ITEM     COMPONENT                                     FAILURE           POTENTIAL             METHOD OF        EFFECT ON          ON NO. IDENTIFICATION         FUNCTION                  MODE               CAUSE               DETECTION         SYSTEM          PLANT                        REMARKS 2     1-FAN-30-244G-A   Exhausts air from 480 Fails to run; Fails   Mechanical failure;     Motor running     Loss of one      None. (See 1. The four (4) exhaust fans (3 safety-related)
V Transformer Room while running.           Train A power failure; light on MCC.      safety related   Remarks) in 480 V Transformer Room 1A are interlocked Exhaust Fan       1A.                                         Temperature control                       fan.                        to automatically start/stop in staged series by sensing failure;                                                      thermostatic control.
Control signal failure.
: 2. The inlet dampers are interlocked to automatically open when any fan is running.
: 3. Schematics have been reviewed and it was determined that rooms 1A and 1B, containing redundant electrical equipment, are independent of each other.
: 4. Room temperature is indicated on Local Panel L-362.
: 5. Two of the three safety-related fans are sufficient to adequately ventilate each 480V Transformer Room.
: 1. The single failure condition of a fan None.                        continuing to run, or spuriously running during Spuriously runs. Control signal failure;   Indicating      (See Remarks) None.          accident conditions concurrent with minimum Temperature control       lights on MCC                 (See           outside design temperature, is analyzed to sensing failure; Hot      for fan motor                 Remarks)       conclude that the space temeratures remain short in control          running.                                     within allowable limits.
wiring.
9.4-139                                                                                                                                                                                                                                                     WBNP-97

Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 3 of 18)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR EFFECT ITEM     COMPONENT                                     FAILURE           POTENTIAL             METHOD OF        EFFECT ON          ON NO. IDENTIFICATION         FUNCTION                  MODE               CAUSE               DETECTION         SYSTEM          PLANT                        REMARKS 3     1-FAN-30-244H-A   Exhausts air from 480 Fails to run; Fails   Mechanical failure;    Motor running      Loss of one      None. (See 1. The four (4) exhaust fans (3 safety-related)
V Transformer Room while running.           Train A power failure; light on MCC.      safety related   Remarks) in 480 V Transformer Room 1A are interlocked Exhaust Fan       1A.                                         Temperature control                       fan.                        to automatically start/stop in staged series by sensing failure;                                                      thermostatic control.
Control signal failure
: 2. The inlet dampers are interlocked to automatically open when any fan is running.
: 3. Schematics have been reviewed and it was determined that rooms 1A and 1B, containing redundant electrical equipment, are independent of each other.
: 4. Room Temperature is indicated on Local Panel L-362.
: 5. Two of the three safety-related fans are sufficient to adequately ventilate each 480V Transformer Room.
: 1. Analysis shows that the single failure None. (See                  condition of a fan continuing to run, or Spuriously runs. Control signal failure;   Indicating      Remarks)         None. (See spuriously running during accident conditions Temperature control       lights on MCC                    Remarks) concurrent with minimum outside design sensing failure; Hot      for fan motor                               temperature, is acceptable.
short in control          running.
wiring.
9.4-140                                                                                                                                                                                                                                                    WBNP-97

Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 4 of 18)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR EFFECT ITEM     COMPONENT                                  FAILURE          POTENTIAL             METHOD OF           EFFECT ON      ON NO. IDENTIFICATION        FUNCTION                MODE              CAUSE               DETECTION            SYSTEM      PLANT                        REMARKS 4     1-FAN-30-244J    Exhausts air from 480 Spuriously runs. Control signal failure;   Indicating      None.           None.       1. This fan is electrically separate from the 1E V Transformer Room                       Temperature control       lights on MCC                               circuit for the three safety-related fans.
Exhaust Fan      1A                                       sensing failure; Hot      for fan motor   .               See (Non-safety)                                              short in control          running.                        Remark #2. 2. Analysis shows that the single failure wiring.                                                              condition of a fan continuing to run, or spuriously running during accident conditions concurrent with minimum outside design temperature, is acceptable.
9.4-141                                                                                                                                                                                                                                                 WBNP-97

Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 5 of 18)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR EFFECT ITEM     COMPONENT                                     FAILURE           POTENTIAL             METHOD OF        EFFECT ON          ON NO. IDENTIFICATION         FUNCTION                  MODE               CAUSE               DETECTION         SYSTEM          PLANT                         REMARKS 5     1-FAN-30-248E-B   Exhausts air from 480 Fails to run; Fails   Mechanical failure;     Motor running     Loss of one      None. (See 1. The three (3) exhaust fans V Transformer Room while running.           Train B power failure; light on MCC.      safety related   Remarks) (3 safety-related) in 480 V Transformer Room Exhaust Fan       1B.                                         Temperature control                       fan                         1B are interlocked to automatically start/stop in sensing failure;                                                      staged series by thermostatic control.
Control signal failure.
: 2. The inlet dampers are interlocked to automatically open when any fan is running.
: 3. Schematics have been reviewed and it was determined that rooms 1A and 1B, containing redundant electrical equipment, are independent of each other.
: 4. Room temperature is indicated on Local Panel L-368.
: 5. Two of the three safety-related fans are sufficient to adequately ventilate each 480V Transformer Room.
Spuriously runs. Control signal failure;   Indicating      None.            None.        1. Analysis shows that the single failure Temperature control       lights on MCC                                 condition of a fan continuing to run, or sensing failure; Hot      for fan motor                                 spuriously running during accident conditions short in control          running.                                      concurrent with minimum outside design wiring.                                                                 temperature, is acceptable.
9.4-142                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 6 of 18)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR EFFECT ITEM     COMPONENT                                     FAILURE           POTENTIAL             METHOD OF        EFFECT ON          ON NO. IDENTIFICATION         FUNCTION                  MODE               CAUSE               DETECTION         SYSTEM          PLANT                        REMARKS 6     1-FAN-30-248F-B   Exhausts air from 480 Fails to run; Fails   Mechanical failure;    Motor running      Loss of one      None. (See 1. The three (3) exhaust fans (3 safety-related)
V Transformer Room while running.           Train B power failure; light on MCC.      safety related   Remarks) in 480 V Transformer Room 1B are interlocked Exhaust Fan       1B.                                         Temperature control                       fan.                        to automatically start/stop in staged series by sensing failure;                                                      thermostatic control.
Control signal failure
: 2. The inlet dampers are interlocked to automatically open when any fan is running.
: 3. Schematics have been reviewed and it was determined that rooms 1A and 1B, containing redundant electrical equipment, are independent of each other.
: 4. Room temperature is indicated on Local Panel L-368.
: 5. Two of the three safety-related fans are sufficient to adequately ventilate each 480V Transformer Room.
: 1. Analysis shows that the single failure None. (See                  condition of a fan continuing to run, or Spuriously runs. Control signal failure;   Indicating      Remarks)         None. (See spuriously running during accident conditions Temperature control       lights on MCC                    Remarks) concurrent with minimum outside design sensing failure; Hot      for fan motor                               temperature, is acceptable.
short in control          running wiring.
9.4-143                                                                                                                                                                                                                                                     WBNP-97

Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 7 of 18)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR EFFECT ITEM     COMPONENT                                     FAILURE           POTENTIAL             METHOD OF        EFFECT ON          ON NO. IDENTIFICATION         FUNCTION                  MODE               CAUSE               DETECTION         SYSTEM          PLANT                        REMARKS 7     1-FAN-30-248G-B   Exhausts air from 480 Fails to run; Fails   Mechanical failure;    Motor running      Loss of one      None. (See 1. The three (3) exhaust fans (3 safety-related)
V Transformer Room while running.           Train B power failure; light on MCC.      safety related   Remarks) in 480 V Transformer Room 1B are interlocked Exhaust Fan       1B.                                         Temperature control                       fan.                        to automatically start/stop in staged series by sensing failure;                                                      thermostatic control.
Control signal failure
: 2. The inlet dampers are interlocked to automatically open when any fan is running.
: 3. Schematics have been reviewed and it was determined that rooms 1A and 1B, containing redundant electrical equipment, are independent of each other.
: 4. Room temperature is indicated on Local Panel L-368.
: 5. Two of the three safety-related fans are sufficient to adequately ventilate each 480V Transformer Room.
: 1. Analysis shows that the single failure None. (See                  condition of a fan continuing to run, or Spuriously runs. Control signal failure;   Indicating      Remarks)         None. (See spuriously running during accident conditions Temperature control       lights on MCC                    Remarks) concurrent with minimum outside design sensing failure; Hot      for fan motor                               temperature, is analyzed to conclude that the short in control          running                                     space temperatures remain within allowable wiring.                                                               limits..
9.4-144                                                                                                                                                                                                                                                     WBNP-97

Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 8 of 18)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR EFFECT ITEM     COMPONENT                                   FAILURE            POTENTIAL           METHOD OF          EFFECT ON           ON NO. IDENTIFICATION        FUNCTION                 MODE                CAUSE             DETECTION           SYSTEM           PLANT                         REMARKS 8     1-FCO-30-244A    Permits flow of air    Spuriously closes;   Mechanical failure;     MCR               Loss of           None.      1. Both intake dampers are interlocked to and -244B        supply from air intake Fails to open.       Auto-open signal        indicating        redundancy in                automatically open when any of the four (4) to 480 V Transformer                        failure; Hot short in   lights 1-ZS   intake air        See        exhaust fans are either automatically or Intake Dampers   Room 1A.                                    control wiring.         244A and -        supply. 100%      Remark #3. manually started.
244B).            redundant intake damper                 2. Dampers fail open upon loss of control air or can supply                    Train A power to 1-FSB-30-244A and -244B.
sufficient air.
: 3. 1-FSV-30-244A and -244B and the air pressure regulators, 1-PREG-30-244A and -
244B, that regulate the air pressure to these FSVs are Q-Listed as Quality- related, not safety-related. Failure of the air regulators either by blockage or sticking full open will not impact the capability of the damper to open.
Failure of the solenoid to de-energize to close the damper is included in the mechanical failure mode of the damper.
The nonsafety-related solenoid is properly isolated in the 1E circuit.
9.4-145                                                                                                                                                                                                                                                       WBNP-97

Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 9 of 18)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR EFFECT ITEM     COMPONENT                                    FAILURE            POTENTIAL           METHOD OF        EFFECT ON           ON NO. IDENTIFICATION         FUNCTION                 MODE                CAUSE             DETECTION         SYSTEM           PLANT                         REMARKS 9     1-FCO-30-248A     Permits flow of air    Spuriously closes;   Mechanical failure;     MCR             Loss of           None.      1. Both intake dampers are interlocked to and -248B         supply from air intake Fails to open.       Auto-open signal        indicating      redundancy in                automatically open when any of the three (3) to 480 V Transformer                        failure; Hot short in   lights          intake air        See        exhaust fans are either automatically or Intake Dampers. Room 1B.                                    control wiring.         (1-ZS-30-248A   supply.           Remark #3. manually started.
and -248B).
100%                          2. Dampers fail open upon loss of control air redundant                     loss or Train B power to 1-FSV-30-248A and -
intake damper                 248B.
can supply sufficient air.               3. 1-FSV-30-248A and -248B and the air pressure regulators, 1-PREG-30-248A and -
248B, that regulate the air pressure to these FSVs are Q-Listed as Quality- related, not safety-related. Failure of the air regulators either by blockage or sticking full open will not impact the capability of the damper to open.
Failure of the solenoid to de-energize to close the damper is included in the mechanical failure mode of the damper.
The nonsafety-related solenoid is properly isolated in the 1E circuit.
9.4-146                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 10 of 18)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR EFFECT ITEM     COMPONENT                                     FAILURE           POTENTIAL             METHOD OF        EFFECT ON          ON NO. IDENTIFICATION         FUNCTION                  MODE               CAUSE               DETECTION         SYSTEM          PLANT                        REMARKS 10    2-FAN-30-250E-A   Exhausts air from 480 Fails to run; Fails   Mechanical failure;    Motor running      Loss of one      None. (See 1. The three (3) exhaust fans (3 safety-related)
V Transformer Room while running.           Train A power failure; light on MCC.      safety related   Remarks) in 480 V Transformer Room 2A are interlocked Exhaust Fan       2A.                                         Temperature control                       fan.                        to automatically start/stop in staged series by sensing failure;                                                      thermostatic control.
Control signal failure
: 2. The inlet dampers are interlocked to automatically open when any fan is running.
: 3. Schematics have been reviewed and it was determined that rooms 2A and 2B, containing redundant electrical equipment, are independent of each other.
: 4. Room temperature is indicated on Local Panel L-368.
: 5. Two of the three safety-related fans are sufficient to adequately ventilate each 480V Transformer Room.
: 1. The single failure condition of a fan None. (See                  continuing to run, or spuriously running during Spuriously runs. Control signal failure;   Indicating      Remarks)         None. (See accident conditions concurrent with minimum Temperature control       lights on MCC                    Remarks) outside design temperature, is analyzed to sensing failure; Hot      for fan motor                               conclude that the space temeratures remain short in control          running.                                    within allowable limits.
wiring.
9.4-147                                                                                                                                                                                                                                                     WBNP-97

Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 11 of 18)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR EFFECT ITEM     COMPONENT                                     FAILURE           POTENTIAL             METHOD OF        EFFECT ON          ON NO. IDENTIFICATION         FUNCTION                  MODE               CAUSE               DETECTION         SYSTEM          PLANT                        REMARKS 11    2-FAN-30-250F-A   Exhausts air from 480 Fails to run; Fails   Mechanical failure;    Motor running      Loss of one      None.       1. The three (3) exhaust fans (3 safety-related)
V Transformer Room while running.           Train A power failure; light on MCC.      safety related   (See        in 480 V Transformer Room 2A are interlocked Exhaust Fan       2A.                                         Temperature control                       fan.             Remarks)    to automatically start/stop in staged series by sensing failure;                                                       thermostatic control.
Control signal failure
: 2. The inlet dampers are interlocked to automatically open when any fan is running.
: 3. Schematics have been reviewed and it was determined that rooms 2A and 2B, containing redundant electrical equipment, are independent of each other.
: 4. Room temperature is indicated on Local Panel L-368.
: 5. Two of the three safety-related fans are sufficient to adequately ventilate each 480V Transformer Room.
: 1. The single failure condition of a fan None. (See                  continuing to run, or spuriously running during Spuriously runs. Control signal failure;   Indicating      Remarks)         None. (See accident conditions concurrent with minimum Temperature control       lights on MCC                    Remarks) outside design temperature, is analyzed to sensing failure; Hot      for fan motor                               conclude that the space temeratures remain short in control          running.                                    within allowable limits.
wiring.
9.4-148                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 12 of 18)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR EFFECT ITEM     COMPONENT                                  FAILURE            POTENTIAL             METHOD OF        EFFECT ON          ON NO. IDENTIFICATION        FUNCTION                MODE                CAUSE               DETECTION         SYSTEM          PLANT                        REMARKS 12    2-FAN-30-250G-B   Exhausts are from   Fails to run; Fails   Mechanical Failure; Motor running         Loss of one      None.       1. The three (3) exhaust fans (3 safety-related) 480 V Transformer   while running.        Train A power failure; light on MCC.      safety related   (See        in 480 V Transformer Room 2A are interlocked Exhaust Fan       Room 2A.                                  Temperature control                       fan.             Remarks)    to automatically start/stop in staged series by sensing failure;                                                       thermostatic control.
Control signal failure
: 2. The inlet dampers are interlocked to automatically open when any fan is running.
: 3. Schematics have been reviewed and it was determined that rooms 2A and 2B, containing redundant electrical equipment, are independent of each other.
: 4. Room temperature is indicated on Local Panel L-368.
: 5. Two of the three safety-related fans are sufficient to adequately ventilate each 480V Transformer Room.
: 1. The single failure condition of a fan None. (See                  continuing to run, or spuriously running during Spuriously runs.      Control signal failure;   Indicating      Remarks)         None. (See accident conditions concurrent with minimum Temperature control       lights on MCC                    Remarks) outside design temperature, is analyzed to sensing failure; Hot      for fan motor                               conclude that the space temeratures remain short in control          running.                                    within allowable limits.
wiring.
9.4-149                                                                                                                                                                                                                                                    WBNP-97

Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 13 of 18)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR EFFECT ITEM     COMPONENT                                     FAILURE           POTENTIAL             METHOD OF        EFFECT ON          ON NO. IDENTIFICATION         FUNCTION                  MODE               CAUSE               DETECTION         SYSTEM          PLANT                        REMARKS 13    2-FAN-30-246F-B   Exhausts air from 480 Fails to run; Fails   Mechanical failure;    Motor running      Loss of one      None.       1. The four (4) exhaust fans (3 safety-related)
V Transformer Room while running.           Train B power failure; light on MCC.      safety related   (See        in 480 V Transformer Room 2B are interlocked Exhaust Fan       2B.                                         Temperature control                       fan.             Remarks)    to automatically start/stop in staged series by sensing failure;                                                       thermostatic control.
Control signal failure
: 2. The inlet dampers are interlocked to automatically open when any fan is running.
: 3. Schematics have been reviewed and it was determined that rooms 2A and 2B, containing redundant electrical equipment, are independent of each other.
: 4. Room temperature is indicated on Local Panel L-362.
: 5. Two of the three safety-related fans are sufficient to adequately ventilate each 480V Transformer Room.
: 1. The single failure condition of a fan None. (See                  continuing to run, or spuriously running during Spuriously runs. Control signal failure;   Indicating      Remarks)         None. (See accident conditions concurrent with minimum Temperature control       lights on MCC                    Remarks) outside design temperature, is analyzed to sensing failure; Hot      for fan motor                               conclude that the space temeratures remain short in control wiring   running.                                    within allowable limits.
9.4-150                                                                                                                                                                                                                                                     WBNP-97

Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 14 of 18)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR EFFECT ITEM     COMPONENT                                     FAILURE           POTENTIAL             METHOD OF        EFFECT ON          ON NO. IDENTIFICATION         FUNCTION                  MODE               CAUSE               DETECTION         SYSTEM          PLANT                        REMARKS 14    2-FAN-30-246G-B   Exhausts air from 480 Fails to run; Fails   Mechanical failure;    Motor running      Loss of one      None. (See 1. The four (4) exhaust fans (3 safety-related)
V Transformer Room while running.           Train B power failure; light on MCC.      safety related   Remarks) in 480 V Transformer Room 2B are interlocked Exhaust Fan       2B.                                         Temperature control                       fan.                        to automatically start/stop in staged series by sensing failure;                                                      thermostatic control.
Control signal failure
: 2. The inlet dampers are interlocked to automatically open when any fan is running.
: 3. Schematics have been reviewed and it was determined that rooms 2A and 2B, containing redundant electrical equipment, are independent of each other.
: 4. Room temperature is indicated on Local Panel L-362.
: 5. Two of the three safety-related fans are sufficient to adequately ventilate each 480V Transformer Room.
: 1. The single failure condition of a fan None. (See                  continuing to run, or spuriously running during Spuriously runs. Control signal failure;   Indicating      Remarks)         None. (See accident conditions concurrent with minimum Temperature control       lights on MCC                    Remarks) outside design temperature, is analyzed to sensing failure; Hot      for fan motor                               conclude that the space temeratures remain short in control          running.                                    within allowable limits.
wiring.
9.4-151                                                                                                                                                                                                                                                    WBNP-97

Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 15 of 18)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR EFFECT ITEM     COMPONENT                                     FAILURE           POTENTIAL             METHOD OF        EFFECT ON          ON NO. IDENTIFICATION         FUNCTION                  MODE               CAUSE               DETECTION         SYSTEM          PLANT                        REMARKS 15    2-FAN-30-246H-B   Exhausts air from 480 Fails to run; Fails   Mechanical failure;    Motor running      Loss of one      None. (See 1. The four (4) exhaust fans (3 safety-related)
V Transformer Room while running.           Train B power failure; light on MCC.      safety related   Remarks) in 480 V Transformer Room 2B are interlocked Exhaust Fan       2B.                                         Temperature control                       fan.                        to automatically start/stop in staged series by sensing failure;                                                      thermostatic control.
Control signal failure
: 2. The inlet dampers are interlocked to automatically open when any fan is running.
: 3. Schematics have been reviewed and it was determined that rooms 2A and 2B, containing redundant electrical equipment, are independent of each other.
: 4. Room temperature is indicated on Local Panel L-362.
: 5. Two of the three safety-related fans are sufficient to adequately ventilate each 480V Transformer Room.
: 1. The single failure condition of a fan None. (See                  continuing to run, or spuriously running during Spuriously runs. Control signal failure;   Indicating      Remarks)         None. (See accident conditions concurrent with minimum Temperature control       lights on MCC                    Remarks) outside design temperature, is analyzed to sensing failure; Hot      for fan motor                               conclude that the space temeratures remain short in control          running.                                    within allowable limits.
wiring.
9.4-152                                                                                                                                                                                                                                                    WBNP-97

Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 16 of 18)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR EFFECT ITEM     COMPONENT                                  FAILURE          POTENTIAL             METHOD OF        EFFECT ON      ON NO. IDENTIFICATION        FUNCTION                MODE              CAUSE               DETECTION         SYSTEM      PLANT                        REMARKS 16    2-FAN-30-246J    Exhausts air from 480 Spuriously runs. Control signal failure;   Indicating      None.        None.       1. This fan is electrically separate from the 1E V Transformer Room                       Temperature control       lights on MCC                            circuit for the three safety-related fans.
Exhaust Fan      2B                                       sensing failure; Hot      for fan motor   See Remark   See (Non-safety)                                              short in control          running.        #2.          Remark #2. 2. The single failure condition of a fan wiring.                                                           continuing to run, or spuriously running during accident conditions concurrent with minimum outside design temperature, is analyzed to conclude that the space temeratures remain within allowable limits.
9.4-153                                                                                                                                                                                                                                              WBNP-97

Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 17 of 18)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR EFFECT ITEM     COMPONENT                                   FAILURE            POTENTIAL           METHOD OF        EFFECT ON           ON NO. IDENTIFICATION        FUNCTION                 MODE                CAUSE             DETECTION         SYSTEM           PLANT                         REMARKS 17    2-FCO-30-246A    Permits flow of air    Spuriously closes;   Mechanical failure;     MCR             Loss of           None.      1. Both intake dampers are interlocked to and -246B        supply from air intake Fails to open.       Auto-open signal        indicating      redundancy in                automatically open when any of the four (4) to 480 V Transformer                        failure; Hot short in   lights          intake air        See        exhaust fans are either automatically or Intake Dampers   Room 2B.                                    control wiring.         (2-ZS-30-246A   supply.           Remark #3. manually started.
and -246B).
100%                          2. Dampers fail open upon loss of control air or redundant                     Train B power to 2-FSV-30-246A and -246B.
intake damper can supply                    3. 2-FSV-30-246A and -246B and the air sufficient air.               pressure regulators, 1-PREG-30-246A and
                                                                                                                                                                                                        -246B, that regulate the air pressure to these FSVs are Q-Listed as Quality- related, not safety-related.
Failure of the air regulators either by blockage or sticking full open will not impact the capability of the damper to open.
Failure of the solenoid to de-energize to close the damper is included in the mechanical failure mode of the damper.
The nonsafety-related solenoid is properly isolated in the 1E circuit.
9.4-154                                                                                                                                                                                                                                                        WBNP-97

Table 9.4-6 Failure Modes and Effects Analysis for Active Failures Subsystem: 480 V Shutdown Transformer Room Ventilation (Sheet 18 of 18)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR EFFECT ITEM     COMPONENT                                    FAILURE            POTENTIAL           METHOD OF        EFFECT ON           ON NO. IDENTIFICATION         FUNCTION                 MODE                CAUSE             DETECTION         SYSTEM           PLANT                       REMARKS 18    2-FCO-30-250A     Permits flow of air    Spuriously closes:   Mechanical failure;     MCR             Loss of           None. 1. Both intake dampers are interlocked to and -250B         supply from air intake Fails to open.       Auto-open signal        indicating      redundancy in               automatically open when any of the three (3) to 480V Transformer                         failure; Hot short in   lights          intake air        (See      exhaust fans are either automatically or Intake Dampers. Room 2A.                                    control wiring.         (2-ZS-30-250A   supply.           Remark    manually started.
and -250B).                       #3) 100%                        2. Dampers fail open upon loss of control air or redundant                   Train A power to 1-FSV-30-250A and -250B.
intake damper can supply                  3. 1-FSV-30-250A and -250B and the air sufficient air.             pressure regulators, 1-PREG-30-250A and
                                                                                                                                                                                                        -250B, that regulate the air pressure to these FSVs are Q-Listed as Quality- related, not safety-related.
Failure of the air regulators either by blockage or sticking full open will not impact the capability of the damper to open.
Failure of the solenoid to de-energize to close the damper is included in the mechanical failure mode of the damper.
The nonsafety-related solenoid is properly isolated in the 1E circuit.
9.4-155                                                                                                                                                                                                                                                       WBNP-97

AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 1 of 51)
METHOD OF ITEM   COMPONENT                                     FAILURE         POTENTIAL           FAILURE              EFFECT ON         EFFECT ON NO. IDENTIFICATION           FUNCTION                MODE             CAUSE            DETECTION              SYSTEM             PLANT                      REMARKS 1A   Tornado Damper     Isolation of Train A     Fails to close     -Mechanical   Status indication in Control None. (See   None. (See remarks)   Redundant Train B Tornado 0-FCO-31-32        supply air normal (west) during tornado      failure      Room via Limit Switch        remarks.)                          Damper 0-FCO-31-33 powered intake during tornado    event              -Electrical   ZS-31-32                                                        from Train B and installed in event                                        failure                                                                      series accomplished isolation during tornado event 1B   Tornado Damper     Isolation of Train B     Fails to close     -Mechanical   Status indication in Control None. (See   None. (See remarks)   Redundant Train B Tornado 0-FCO-31-34        supply air normal (west) during tornado      failure      Room on Panel 1-M-9 via remarks.)                               Damper 0-FCO-31-35 powered intake during tornado    event              -Electrical   Limit Switch ZS-31-34.                                          from Train B and installed in event                                        failure                                                                      series accomplished isolation during tornado event Spuriously closes   Mechanical    Status indication in Control None. (See   None. (See remarks)   Operator removes power from failure      Room via Limit Switch        remarks.)                          damper, during non-tornado
                                                                                                                                  -Electrical   ZS-31-32                                                        operation, to prevent spurious failure                                                                      closure.
2A   Tornado Damper     Isolation of Train A     Fails to close     -Mechanical   Status indication in Control None. (See   None. (See remarks)   Redundant Train A Tornado 0-FCO-31-33        supply air normal (west) during tornado      failure      Room on Panel 1-M-9 via remarks.)                               Damper 0-FCO-31-32 powered intake during tornado    event              -Electrical   Limit Switch ZS-31-33                                           from Train A and installed in event                                        failure                                                                      series accomplished isolation during tornado event 2B   Tornado Damper     Isolation of Train B     Fails to close     -Mechanical   Status indication in Control None. (See   None. (See remarks)   Redundant Train A Tornado 0-FCO-31-35        supply air normal (west) during tornado      failure      Room on Panel 1-M-9 via remarks)                                Damper 0-FCO-31-34 powered intake during tornado    event              -Electrical   Limit Switch ZS-31-35                                           from Train A and installed in event                                        failure                                                                      series accomplished isolation during tornado event 3A   Isolation Damper   See remarks             See remarks         See remarks   See remarks                See remarks    See remarks           This isolation damper all controls 0-FCO-31-1                                                                                                                                   are disconnected and the damper is locked in fully open position 3B   Isolation Damper   See remarks             See remarks         See remarks   See remarks                See remarks    See remarks           This isolation damper all controls WBNP-97 0-FCO-31-2                                                                                                                                   are disconnected and the damper 9.4-156 is locked in fully open position

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 2 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                   FAILURE          POTENTIAL           FAILURE              EFFECT ON          EFFECT ON NO. IDENTIFICATION          FUNCTION               MODE              CAUSE            DETECTION              SYSTEM              PLANT                     REMARKS 4A   Flow Control       See remarks            See remarks         See remarks   See remarks               See remarks      See remarks         This flow control damper all Damper                                                                                                                                     controls are disconnected and the 0-FCO-31-1A                                                                                                                                damper is locked in fully open position 4B   Flow Control       See remarks            See remarks         See remarks   See remarks               See remarks      See remarks         This flow control damper all Damper                                                                                                                                     controls are disconnected and the 0-FCO-31-2A                                                                                                                                damper is locked in fully open position 5A   Pressurization     See remarks            See remarks         See remarks   See remarks               See remarks      See remarks         This pressurization fan is Fan A-A                                                                                                                                    disconnected and abandoned in place 5B   Pressurization     See remarks            See remarks         See remarks   See remarks               See remarks      See remarks         This pressurization fan is Fan B-B                                                                                                                                    disconnected and abandoned in place 6A   Backdraft Damper   See remarks            See remarks         See remarks   See remarks               See remarks      See remarks         This backdraft damper is locked in 0-31-2097                                                                                                                                  open position 6B   Backdraft Damper   See remarks            See remarks         See remarks   See remarks               See remarks      See remarks         This backdraft damper is locked in 0-31-2098                                                                                                                                  open position 7   Isolation Valve    Isolates Main Control  Open (during CRI)   -Mechanical   Status indication in Control None          None. See remarks   Redundant safety Train B 0-FCV-31-3         Room Habitability Zone                      failure      Room Panel 1-M-9 via         See Remarks                       Isolation Valve installed in series (MCRHZ) from outside                       -Control      Limit Switch ZS-31-3                                           will close to provide isolation makeup air supply                           failure 8   Isolation Valve    Isolates MCRHZ from    Open (during CRI) -Mechanical     Status indication in Control None          None. See remarks   Redundant safety Train A 0-FCV-31-4         outside makeup air                        failure        Room Panel 1-M-9 via         (See Remarks)                     Isolation Valve installed in series supply                                   -Control        Limit Switch ZS-31-4                                           will close to provide isolation failure 9.4-157                                                                                                                                                                                                                                             WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 3 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                       FAILURE           POTENTIAL              FAILURE      EFFECT ON        EFFECT ON NO. IDENTIFICATION           FUNCTION                  MODE               CAUSE               DETECTION      SYSTEM            PLANT                     REMARKS 9    Fire Damper       To maintain fire barrier   Open during fire     -Mechanical      See remarks        See remarks   See remarks          Single failures of HVAC system 0-ISD-31-3934     integrity between          (see remarks                                                                                need not be postulated as being Mechanical Equip.                                                                                                      concurrent with fire Room Floor El 755.0' and Spreading Room El. 729.0' during fire Fusible link failure --Mechanical     Surveillance and   None (see     None (see remarks)   Fire damper has dual fusible links (see remarks)         (fusible        Maintenance (see   remarks) link failure)   remarks) 10   Isolation Valve   See remarks                See remarks          See remarks      See remarks        See remarks   See remarks          This valve controls are 0-FCV-31-37                                                                                                                              disconnected 11   Isolation Valve   See remarks                See remarks          See remarks      See remarks        See remarks   See remarks          This valve controls are 0-FCV-31-36                                                                                                                              disconnected 11A Isolation Damper    See remarks                See remarks          See remarks      See remarks        See remarks   See remarks          The damper controls are 0-FCO-31-19                                                                                                                                disconnected, and the duct is blanked off 11B Isolation Damper    See remarks                See remarks          See remarks      See remarks        See remarks   See remarks          The damper controls are 0-FCO-31-20                                                                                                                                disconnected, and the duct is blanked off 12   Fire Damper       To maintain fire barrier   Open during fire     -Mechanical      See remarks        See remarks   See remarks          Single failures of HVAC system 0-ISD-31-3938     integrity between          (see remarks)                                                                               need not to be postulated as Spreading Room El.                                                                                                     being concurrent with fire 729.0' & Unit 1 Aux.
Instr. Room El. 708.0' during fire Fusible link failure -Mechanical      Surveillance and   None. (See    None (see remarks)   Additional independent fusible link (see remarks)         (fusible        Maintenance        remarks)                           is to be installed link WBNP-97 failure) 9.4-158

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 4 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                    FAILURE          POTENTIAL           FAILURE              EFFECT ON          EFFECT ON NO. IDENTIFICATION         FUNCTION                 MODE              CAUSE            DETECTION              SYSTEM              PLANT                      REMARKS 12A 0-XS-31-179       To detect smoke in the    Spurious actuation -Electrical    Surveillance               See remarks    None (see remarks)     Upon activation of air intake Control Building          of smoke detector failure                                                                          smoke detectors a CRI is initiated.
Pressurization Fan                                          Annunciation in MCR of                                           Operator action will determine if Intake                                                      CRI signal                                                       the smoke detector activation was spurious and if so return system to Failure to detect   -Electrical   Smoke detectors in         Abandon MCR    None. Use Auxiliary normal operation valid smoke         failure       MCRHZ                                     Control Room 12B 0-XS-31-183       To detect smoke in the    Spurious actuation -Electrical    Surveillance               See remarks    None (see remarks)     Upon activation of air intake Control Building          of smoke detector failure                                                                          smoke detectors a CRI is initiated.
Pressurization Fan                                          Annunciation in MCR of                                           Operator action will determine if Intake                                                      CRI signal                                                       the smoke detector activation was spurious and if so return system to Failure to detect   -Electrical   Smoke detectors in         Abandon MCR    None. Use Auxiliary normal operation valid smoke         failure       MCRHZ                                     Control Room 13   Fire Damper     Maintain fire barrier     Open during fire    See remarks   See remarks                See remarks    None. (See remarks)    Single failures of HVAC system 0-ISD-31-3931   between Control Bldg.     (see remarks                                                                                       need not to be postulated as roof and Main Control                                                                                                        being concurrent with fire Room in case of fire on the roof at the east emergency air intake Closed during CRI   -Mechanical   Loss of Control Room       Loss of Control None. (See remarks)   Control Bldg. Press. Diff. switches (fusible     Press. Diff. Common        Room                                  0-PDS-31-1A, 2A, -3A & -4A start link)        Alarm through switches     pressurization                        redundant Control Bldg.
0-PDS-31-1B, -2B, 3B & -   due to loss of                        emergency press. fan A-A with its 4B in Control Room         emergency                             outdoor air intake (west) press. fan air flow path through east emerg. air intake 9.4-159                                                                                                                                                                                                                                                WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 5 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                    FAILURE         POTENTIAL            FAILURE              EFFECT ON          EFFECT ON NO. IDENTIFICATION          FUNCTION                MODE             CAUSE             DETECTION              SYSTEM              PLANT                     REMARKS 14   Tornado Damper   Isolation of emergency   Fails to close      -Mechanical    Status indication via Limit None. (See   None. (See remarks)   Redundant Train B Tornado 0-FCO-31-21      outdoor air intake for   during Tornado       failure       Switch ZS-31-21             remarks)                           Damper 0-FCO-31-22 powered Emergency Press Fan      Event               -Electrical                                                                   from Train B and installed in B-B during Tornado                            failure                                                                      series accomplishes isolation Event                                                                                                                      during Tornado Event Spuriously closes   -Electrical    Annunciation in MCR on    Momentary loss None. Use redundant   Operator removes power from failure        loss of +1/8 w.g.        of MCRHZ       air intake            damper, during non-tornado pressure                  pressurization                       operation, to prevent spurious closure 15   Tornado Damper   Isolation of east        Fails to close      -Mechanical    Status indication via Limit None. (See   None. (See remarks)   Redundant Train A Tornado 0-FCO-31-22      emergency outdoor air    during Tornado       failure       Switch ZS-31-22             remarks)                           Damper 0-FCO-31-21 powered intake for Emergency     Event               -Electrical                                                                   from Train A and installed in Press Fan B-B during                          failure                                                                      series accomplishes isolation Tornado Event                                                                                                              during Tornado Event 16B Isolation Damper   Isolates Emergency       Closes during       -Mechanical    The Loss of Control      Loss of air flow None (see remarks)   Redundant Train B emerg. press.
0-FCV-31-6         Pressurization Fan A-A Emerg. Press. fan      failure.      Room Press. Diff.        through Emerg.                        Fan B-B starts upon signal from from normal outdoor air A-A operation        -Electrical    Common Alarm through Press. Fan A-A                            the Control Room Press. Diff.
intake (west) supply air                      & aux.        switches 0-PDS-31-1A, -                                        switches 0-PDS-31-1B, -2B, -3B control air   2A, -3A & -4A and status                                       and -4B failure       indication in Control Room on Panel 1-M-9 via Limit Switch ZS-31-6 Fails to close      -Mechanical    The Loss of Control       May reduce the None (see remarks)    Same as above during standby       failure       Room Press. Diff.         outside air operation                          Common Alarm through      supply and switches 0-PDS-31-1A, -   cause loss of 2A, 3A & -4A and status   pressurization indication in Control Room on Panel 1-M-9 via WBNP-97 Limit Switch ZS-31-6 9.4-160

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 6 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                     FAILURE     POTENTIAL           FAILURE               EFFECT ON          EFFECT ON NO. IDENTIFICATION          FUNCTION                 MODE         CAUSE            DETECTION               SYSTEM              PLANT                     REMARKS 16A Isolation Damper   Isolates Emerg.          Closes during   -Mechanical    The Loss of Control      Loss of air flow None (see remarks)     Redundant Train A emerg. press.
0-FCV-31-5         Pressurization Fan B-B Emerg. Press. Fan failure.       Room Press. Diff.        through Emerg.                          Fan A-A starts upon signal from from emerg. outdoor air B-B operation    -Electrical    Common Alarm through Press. Fan B-B                              the Control Room Press. Diff.
intake (east) supply air                  & aux.        switches 0-PDS-31-1B, -                                          switches 0-PDS-31-1A, -2A, -3A control air   2B, -3B & -4B and status                                         and -4A failure       indication in Control Room on Panel 1-M-9 via Limit Switch ZS-31-5 Fails to close   -Mechanical   The Loss of Control        May reduce the None (see remarks)     Same as above during standby    failure      Room Press. Diff.          outside air operation                      Common Alarm through       supply and switches 0-PDS-31-1B, -    cause loss of 2B, 3B & -4B and status    pressurization indication in Control Room via Limit Switch ZS-31-5 17B Control Bldg.      Pressurize Main Control -Fail to start    -Mechanical   The Loss of Control        Loss of Control None. (See remarks)   The Control Room Press. Diff.
Emergency Air      Room Habitability Zone -Stops              failure      Room Press. Diff.          Room                                  Switches 0-PDS-31-1B, -2B, -3B Press. Fan A-A     (MCRHZ) during CRI                        -Electric     Common Alarm through       pressurization                        and -4B start the Control Bldg.
failure      Switches 0-PDS-31-1A, -    due to loss of                        redundant Train B Emergency Air
                                                                                                                               -Control      2A, 3A & -4A in Control    air flow path                         Press. Fan B-B failure      Room                       through Train A 17A Control Bldg.      Pressurize Main Control -Fails to         -Mechanical   The Loss of Control        Loss of Control None. (See remarks)   The Control Room Press. Diff.
Emergency Air      Room Habitability Zone start               failure      Room Press. Diff.          Room                                  Switches 0-PDS-31-1A, -2B, -3A Press. Fan B-B     (MCRHZ) during CRI      -Stops            -Electrical   Common Alarm through       pressurization                        and -4A start the Control Bldg.
failure      switches 0-PDS-31-1B, -    due to loss of                        redundant Train A Emergency Air
                                                                                                                               -Control      2B, 3B and 4B in Control   air flow path                         Press. Fan A-A failure      Room                       through Train B 9.4-161                                                                                                                                                                                                                                         WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 7 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                  FAILURE         POTENTIAL           FAILURE               EFFECT ON             EFFECT ON NO. IDENTIFICATION         FUNCTION               MODE             CAUSE            DETECTION               SYSTEM                 PLANT                        REMARKS 18A Fire Damper       To prevent a fire or    Open during fire    -Mechanical   See remarks                See remarks        See remarks           Single failures of HVAC system 0-ISD-31-4608     smoke from entering the                      failure                                                                          need not be postulated as being Control Bldg.                                                                                                                 concurrent with fire Emergency Air Cleanup Unit A-A Closed during CRI   -Mechanical   Loss of Control Room       Loss of air flow   None. (See remarks)   The Control Room Press. Diff.
failure      Press. Diff. Common        through the                              Switches 0-PDS-31-1B, -2B, -3B (fusible     Alarm through Switches     Train A Air                              and -4B start redundant Train B link)        0-PDS-31-1A, -2A, 3A & -   Cleanup Unit                             Air Cleanup Unit with its Fan B-B.
4A in Control Room         and loss of                              (Existing dual fusible link is left in MCR                                      place) pressurization 18B Fire Damper       To prevent a fire or    Open during fire    -Mechanical   See remarks                See remarks        See remarks           Single failures of HVAC system 0-ISD-31-3958     smoke from entering the                      failure                                                                          need not be postulated as being Control Bldg.                                                                                                                 concurrent with fire Emergency Air Cleanup Unit B-B Closed during CRI   -Mechanical   Loss of Control Room       Loss of air flow   None. (See remarks)   The Control Room Press. Diff.
failure      Press. Diff. Common        through the                              Switches 0-PDS-31-1A, -2A, -3A (fusible     Alarm through Switches     Train B Air                              and -4A start redundant Train A link)        0-PDS-31-1B, -2B, -3B &    Cleanup Unit                             Air Cleanup Unit with its Fan A-A.
                                                                                                                                              -4B                        and loss of                              (Existing dual fusible link is left in MCR                                      place) pressurization 9.4-162                                                                                                                                                                                                                                                    WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 8 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                    FAILURE        POTENTIAL              FAILURE                EFFECT ON             EFFECT ON NO. IDENTIFICATION          FUNCTION                MODE            CAUSE               DETECTION                SYSTEM                 PLANT                      REMARKS 19A Isolation Damper   Isolation of Emergency   Closed during      -Mechanical      In Control Room Loss of     Loss of air flow   None. (See remarks)   The Control Room Press. Diff.
FCO-31-8           Air Cleanup Unit A-A     operation of        failure         Control Room Press. Diff. path for                                 Switches 0-PDS-31-1B, -2B, -3B Emergency Air      -Electrical      Common Alarm through        Emergency Air                            and -4B start redundant Train B Cleanup Unit Fan    & Aux           Switches 0-PDS-31-1A,       Cleanup Unit                             Fan B-B with its emerg. air A-A                 Control         -2A, -3A and -4A and        Fan A-A and                              cleanup unit Air Failure     Damper Status Indication    loss of MCR via Limit Switch ZS-31-8    pressurization Open during        -Mechanical      Damper Status Indication    Air flow path is   None. (See remarks)   Pressurization Air is still standby             failure         via Limit Switch ZS-31-8    open through                             adequately filtered and Control
                                                                                                                                 -Electrical                                  Air Cleanup                              Room Pressurization is still failure                                     Unit during                              maintained standby 19B Isolation Damper   Isolation of Emergency   Closed during      -Mechanical      In Control Room Loss of     Loss of air flow   None (See remarks)    The Control Room Press. Diff.
FCO-31-7           Air Cleanup Unit B-B     operation of        failure.        Control Room Press. Diff. path for                                 Switches 0-PDS-31-1A, -2A, -3A Emergency Air      -Electrical      Common Alarm through        Emergency Air                            and -4A start the Control Bldg.
Cleanup Unit Fan    & Aux           Switches 0-PDS-31-1B,       Cleanup Unit                             redundant Train A Fan A-A with B-B                 Control         -2B, -3B and -4B and        Fan B-B and                              its emerg. air cleanup unit Air Failure     Damper Status Indication    loss of MCR via Limit Switch ZS-31-7    pressurization Open during        -Mechanical      Damper Status Indication    Air flow path is   None (See remarks)    Pressurization Air is still standby             failure         via Limit Switch ZS-31-7    open through                             adequately filtered and Control
                                                                                                                                 -Electrical                                  Air Cleanup                              Room Pressurization is still failure                                     Unit during                              maintained standby 20A Control Bldg.      Filters potentially      Blocked            -Dirty filters   Loss of Control Room        Reduced or no None.                      Control Room Press. Diff.
Emergency Air      contaminated outside                                         Press. Diff. common         air flow through (See Remarks)           Switches 0-PDS-31-1B, -2B, -3B Cleanup Unit A-A   air prior to MCRHZ                                           Alarm through Switches      emergency air                            and -4B start redundant Train B during CRI                                                   0-PDS-31-1A, -2A, -3A,      cleanup unit                             Emerg. Air Cleanup Unit Fan B-B and -4A                     and loss of WBNP-97 MCR 9.4-163 pressurization

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 9 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                      FAILURE     POTENTIAL             FAILURE             EFFECT ON           EFFECT ON NO. IDENTIFICATION          FUNCTION                  MODE         CAUSE              DETECTION             SYSTEM               PLANT                     REMARKS 20B Control Bldg.      Filters potentially         Blocked       -Dirty filters   Loss of Control Room     Reduced or no None. (See remarks)      Control Room Press. Diff.
Emergency Air      contaminated outside                                       Press. Diff. common      air flow through                       Switches 0-PDS-31-1A, -2A, -3A Cleanup Unit B-B   air prior to introducing it                                Alarm through Switches   emergency air                          and -4A start redundant Train A into MCRHZ during CRI                                      0-PDS-31-1B, -2B, -3B,   cleanup unit                           Emerg. Air Cleanup Unit Fan A-A and                      and loss of
                                                                                                                                                -4B                      MCR pressurization 21A Control Bldg.      Draws recirc. and       -Fails to start   -Mechanical      Loss of Control Room     Loss of air flow None. (See remarks)   Control Room Press. Diff.
Emergency Air      outside air through air -Stops             failure         Press. Diff. common      path through                           Switches 0-PDS-31-1B, -2B, -3B Cleanup Unit Fan   cleanup unit during CRI                   -Electrical      Alarm through Switches   Train A and loss                       and -4B start redundant Train B A-A                                                           failure         0-PDS-31-1A, -2A, -3A,   of MCR                                 Emerg. Air Cleanup Unit Fan B-B and                      pressurization
                                                                                                                                                -4A 21B Control Bldg.      Draws recirc. and       -Fails to start   -Mechanical      Loss of Control Room     Loss of air flow None. (See remarks)   Control Room Press. Diff.
Emergency Air      outside air through air -Stops             failure         Press. Diff. common      path through                           Switches 0-PDS-31-1A, -2A, -3A Cleanup Unit Fan   cleanup unit during CRI                   -Electrical      Alarm through Switches   Train B and loss                       and -4A start redundant Train A B-B                                                           failure         0-PDS-31-1B, -2B, -3B,   of MCR                                 Emerg. Air Cleanup Unit Fan A-A and                      pressurization
                                                                                                                                                -4B 9.4-164                                                                                                                                                                                                                                           WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 10 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                   FAILURE         POTENTIAL           FAILURE               EFFECT ON             EFFECT ON NO. IDENTIFICATION         FUNCTION                MODE             CAUSE            DETECTION               SYSTEM                 PLANT                     REMARKS 22A Fire Damper       Fire barrier at the      Open during fire    -Mechanical   See remarks                See remarks        See remarks           Single failure of HVAC system 0-ISD-31-3935     Control Bldg. Emerg. Air                      failure                                                                          need not be postulated as being Cleanup Unit (ACU)                                                                                                             concurrent with fire Fan A-A discharge.
(Prevents fire spreading downstream of the Fan A-A)
Closed during CRI   -Mechanical   The Loss of Control Room   Loss of air flow   None. (See remarks)   The Control Room Press. Diff.
failure. Press. Diff. Common        through the                              Switches 0-PDS-31-1B, -2B, -3B, (fusible     Alarm through Switches     Train A ACU                              and -4B start Redundant Train B link)        0-PDS-31-1A, -2A, -3A,     and loss of                              Emerg. Air Cleanup Unit with its and -4A                    MCR                                      Fan B-B pressurization 22B Fire Damper       Fire barrier at the      Open during fire    -Mechanical   See remarks                See remarks        See remarks           Single failure of HVAC system 0-ISD-31-3936     Control Bldg. Emerg. Air                      failure                                                                          need not be postulated as being Cleanup Unit (ACU)                                                                                                             concurrent with fire Fan B-B discharge.
(Prevents fire spreading downstream of the Fan B-B)
Closed during CRI   -Mechanical   The Loss of Control Room   Loss of air flow   None. (See remarks)   The Control Room Press. Diff.
failure      Press. Diff. Common        through the                              Switches 0-PDS-31-1A, -2A, -3A, (fusible     Alarm through Switches     Train B ACU                              and -4B start Redundant Train A link)        0-PDS-31-1B, -2B,          and loss of Emerg. Air Cleanup Unit with its
                                                                                                                                               -3B, and -4B               MCR Fan A-A pressurization 9.4-165                                                                                                                                                                                                                                               WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 11 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                  FAILURE        POTENTIAL           FAILURE        EFFECT ON         EFFECT ON NO. IDENTIFICATION         FUNCTION               MODE            CAUSE            DETECTION        SYSTEM             PLANT                     REMARKS 23   Fire Damper 0-   Fire barrier between   Open during fire   -Mechanical   See remarks        See remarks    See remarks           Single failures of HVAC system XFD-31-75        Conference Room and                        failure                                                              need not be postulated as being Technical Support                         -Electrical                                                           concurrent with fire Center                                     failure Close during other -ETL Link     Surveillance and   May result in  None (see remarks)    These areas are not essential for modes of operation failure       Maintenance        overheating of                       safe shutdown Technical Support Center 24   Fire Damper 0-   Fire barrier between   Open during fire   -Mechanical   See Remarks        See Remarks    See remarks           Single failures of HVAC system XFD-31-83        Relay Room and Main                        failure                                                              need not be postulated as being Control Room                              -Electrical                                                           concurrent with fire failure Close during other -ETL Link     Surveillance and   None. (See     None. (See remarks)   The transfer opening with fire modes of operation failure       Maintenance        remarks)                             Damper 0-XFD-31-153 provides alternate return air flow path 25   Fire Damper      Fire barrier between   Open during fire   -Mechanical   See Remarks        See Remarks    See remarks           Single failures of HVAC system 0-XFD-31-153     Relay Room and Main                        failure                                                              need not be postulated as being Control Room                              -Electrical                                                           concurrent with fire.
failure Close during other -ETL Link     Surveillance and   None. (See     None. (See remarks)   This fire damper has two ETL modes of operation failure       Maintenance        remarks) 9.4-166                                                                                                                                                                                                                                  WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 12 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                    FAILURE         POTENTIAL            FAILURE              EFFECT ON             EFFECT ON NO. IDENTIFICATION          FUNCTION                MODE             CAUSE             DETECTION              SYSTEM                 PLANT                      REMARKS 26   Fire Damper      To prevent smoke or fire Open during fire.   -Mechanical   See remarks.               See remarks.       See remarks.          Single failure of HVAC system 0-XFD-31-99      from the Shift Eng                            failure                                                                          need not be postulated as being Office and Conference                        -Electrical                                                                       concurrent with fire.
Room from being                               failure introduced into the air recirculation system.
Closed during       -ETL link     Surveillance and           May result in    None. (See remarks). These areas are not essential for other modes of       failure. Maintenance.               overheating of                           safe shutdown.
operation.                                                   Shift Eng Office and Conference Room.
27A Isolation Damper   Isolate Main Control     Close during Air    -Mechanical   Annunciation in MCR of     Loss of air flow   None (see remarks). Redundant AHU B-B starts on 0-FCO-31-12        Room (MCR) Air           Handling Unit A-A    failure      MCR Air Conditioning       path through                             low air flow signal from AHU A-A Handling Unit (AHU) A-   operation.          -Electrical   Safety train switchover,   AHU A-A.                                 via Flow Switch FS-31-84.
A during standby or                           failure      via Switches maintenance.                                               0-PDS-31-161, 0-FS-31-84 &
0-TS-31-88B Open during        -Mechanical                                                  None (see remarks). Backdraft Damper 0-31-2105 standby operation. failure                                                                            prevents backflow.
                                                                                                                                 -Electrical
                                                                                                                                 -Auxiliary Control Air Failure 9.4-167                                                                                                                                                                                                                                                 WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 13 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                    FAILURE         POTENTIAL             FAILURE                 EFFECT ON           EFFECT ON NO. IDENTIFICATION          FUNCTION                MODE             CAUSE              DETECTION                 SYSTEM               PLANT                     REMARKS 27B Isolation Damper   Isolate Main Control     Close during Air    -Mechanical    Annunciation in MCR of      Loss of air flow   None (see remarks). Redundant AHU A-A starts on 0-FCO-31-11        Room (MCR) Air           Handling Unit B-B    failure       MCR Air Conditioning        path through                             low air flow signal from AHU A-A Handling Unit (AHU) B-   operation.          -Electrical    Safety train switchover via AHU B-B.                                 via Flow Switch FS-31-94.
B during standby or                           failure       Switches maintenance.                                                0-PDS-31-186, 0-FS-31-94 &
0-TS-31-89B Open during        -Mechanical                                   None (see        None (see remarks). Backdraft Damper 0-31-2104 standby operation. failure                                       remarks).                              prevents backflow.
                                                                                                                                 -Electrical
                                                                                                                                 -Auxiliary Control Air Failure 28A Modulating         Modulates the air flow   Closed (coil        -Mechanical    Annunciation in MCR of        Air bypasses     None (see remarks). Temp. Switch TS-31-88B starts Damper 0-FCO-      through cooling coil and section).            failure       MCR Air Conditioning          the cooling coil                       the redundant AHU B-B upon 31-82              bypass to maintain the                       -Control Air   Safety train switchover via   and increase of                        high return temp.
temperature at                                failure       Switches                      space thermostat 0-TE-31-82                                       0-PDS-31-161,                 temperature.
setpoint.                                                   0-FS-31-84 &
0-TS-31-88B Spurious            -Control                                     Space            None (see remarks). Temp. Switch TS-31-88B starts modulation.          failure                                     temperature is                         the redundant AHU B-B upon not maintained                         high return temp.
at thermostat setting.
9.4-168                                                                                                                                                                                                                                                  WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 14 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                      FAILURE         POTENTIAL              FAILURE                 EFFECT ON             EFFECT ON NO. IDENTIFICATION            FUNCTION                MODE             CAUSE               DETECTION                 SYSTEM                 PLANT                     REMARKS 28B Modulating          Modulates the air flow   Closed (coil         -Mechanical     Annunciation in MCR of        Air bypasses     None (see remarks). Temp. Switch TS-31-89B starts Damper              through cooling coil and section).             failure        MCR Air Conditioning          the cooling coil                         the redundant AHU A-A upon 0-FC0-31-91         bypass to maintain the                        -Control Air    Safety train switchover via   and increase of                          high return temp.
temperature at                                 failure        Switches                      space thermostat 0-TE-31-91                                         0-PDS-31-186,                 temperature.
setpoint.                                                     0-FS-31-94 &
0-TS-31-89B Spurious            -Control                                      Space              None (see remarks). Temp. Switch TS-31-89B starts modulation.          failure                                      temperature is                           the redundant AHU A-A upon not maintained                           high return temp.
at thermostat setting.
29A Main Control Room Air Handling Unit A-A
                                                                   -Filter            Filters the air           Clogged             -Accumulation   Surveillance (PDI-31-87)      Reduced Air        None. (See Remarks)   Surveillancce (PDI-31-87) &
of dirt         and Maintenance and           flow may result                          Maintenance of filters in Annunciation in MCR Air       in rise of space                         accordance with maintenance Conditioning Safety Train     temperature procedures. Either Temp. Switch Switchover via Switches 0-PDIS-31-161,                                                         0-TS-31-88B or Flow Switch 0-FS-31-84 &                                                           0-FS-31-84 starts redundant Air 0-TS-31-88B                                                            Handling Unit B-B
                                                                   -Cooling Coil      Cools the supply air to   Cooling coil tube   -Mechanical     Annunciation in MCR Air       Temperature        None. (See Remarks)   Redundant AHU B-B starts upon maintain design           break or crack      failure         conditioning Safety Train     increase in the                          signal from AHU A-A high temperature in the                                            Switchover via Switches       MCRHZ                                    temperature switch 0-TS-31-88B MCRHZ                                                         0-PDIS-31-161, 0-FS-31-84 &
0-TS-31-88B 9.4-169                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 15 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                 FAILURE           POTENTIAL            FAILURE             EFFECT ON        EFFECT ON NO. IDENTIFICATION        FUNCTION               MODE               CAUSE             DETECTION             SYSTEM            PLANT                      REMARKS
                                                                   -Humidifier      Provides moisture to   No humidification     -Steam Boiler Moisure Indicator         Decrease of   None. (See Remarks)   Maintenance of the relative maintain the design                          failure        MI-31-176 on Panel L-529 Relative                            humidity is not required for safe relative humidity in                         -Steam Control                          Humidity                            shutdown of plant MCRHZ during normal                          Valve closes operation mode                               -Mechanical failure
                                                                                                                                 -Electrical failure
                                                                                                                                 -Mechanical failure
                                                                                                                                 -Electrical failure Humidification                       Moisture Indicator       None. (See    None. (See Remarks)   MCR moisture level will not Control Valve fails                  MI-31-176 on Panel L-529 Remarks)                            exceed design requirements open 9.4-170                                                                                                                                                                                                                                          WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 16 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                       FAILURE        POTENTIAL              FAILURE               EFFECT ON             EFFECT ON NO. IDENTIFICATION            FUNCTION                 MODE            CAUSE               DETECTION               SYSTEM                 PLANT                     REMARKS 29A -Fan                Circulates the air        -Fails to start     -Mechanical     Annunciation in MCR of      Loss of air flow   None. (See Remarks)   Redundant AHU B-B starts upon Cont                                              -Stops              failure         MCR Air conditioning        through AHU                              signal from AHU A-A Air flow
                                                                                                                                    -Electrical     Safety Train Switchover     A-A                                      Switch FS-31-84 failure         via Switches 0-PDIS-31-161, 0-FS-31-84 &
0-TS-31-88B Fails to stop or,   -Electrical     Annunciation in MCR of      Increased        None. (See Remarks)     When both AHUs are operating starts              failure         MCR Air conditioning        pressure in duct                         the common ductwork static Safety Train Switchover                                              pressure does not exceed 6 via Switches inches wg safety-related duct 0-PDIS-31-161, 0-FS-31-84 &                                                         design pressure 0-TS-31-88B 29B Main Control Room Air Handling Unit B-B
                                                                   -Filter            Filters the air           Clogged             -Accumulation   Surveillance (PDI-31-97)    Reduced Air        None. (See Remarks)   Surveillancce (PDI-31-97) &
of dirt         and Maintenance and         flow may result                          Maintenance of filters in Annunciation in MCR Air     in rise of space                         accordance with maintenance Conditioning Safety Train   temperature procedures. Either Temp. Switch Switchover via Switches 0-PDIS-31-186,                                                       0-TS-31-89B or Flow Switch 0-FS-31-94 &                                                         0-FS-31-94 starts redundant Air 0-TS-31-89B                                                          Handling Unit A-A
                                                                   -Cooling Coil      Cools the supply air to   Cooling coil tube   -Mechanical     Annunciation in MCR Air     Temperature        None. (See Remarks)   Redundant AHU A-A starts upon maintain design           break or crack      failure         conditioning Safety Train   increase in the                          signal from AHU B-B high temperature in the                                            Switchover via Switches     MCRHZ                                    temperature switch 0-TS-31-89B MCRHZ                                                         0-PDIS-31-186, 0-FS-31-94 &
0-TS-31-89B 9.4-171                                                                                                                                                                                                                                                    WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 17 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                     FAILURE          POTENTIAL            FAILURE              EFFECT ON             EFFECT ON NO. IDENTIFICATION         FUNCTION                  MODE              CAUSE             DETECTION              SYSTEM                 PLANT                      REMARKS 29B -Humidifier       Provides moisture to      No humidification     -Steam Boiler Moisure Indicator         Decrease of         None. (See Remarks)   Maintenance of the relative Cont.                 maintain the design                             failure        MI-31-201 on Panel L-530 Relative                                  humidity is not required for safe relative humidity in                            -Steam Control                          Humidity                                  shutdown of plant MCRHZ during normal                             Valve closes operation mode                                  -Mechanical failure
                                                                                                                                    -Electrical failure
                                                                                                                                    -Mechanical failure
                                                                                                                                    -Electrical failure Humidification                       Moisture Indicator       None. (See          None. (See Remarks)   MCR moisture level will not Control Valve fails                  MI-31-201 on Panel L-530 Remarks)                                  exceed design requirements open
                                                                   -Fan             Circulates the air        -Fails to start       -Mechanical    Annunciation in MCR of    Loss of air flow   None. (See Remarks)   Redundant AHU A-A starts upon
                                                                                                              -Stops                failure        MCR Air conditioning      through AHU                              signal from AHU B-B Air flow
                                                                                                                                    -Electrical    Safety Train Switchover   A-A                                      Switch FS-31-94 failure        via Switches 0-PDIS-31-186, 0-FS-31-94 &
0-TS-31-89B Fails to stop or,     -Electrical    Annunciation in MCR of    Increased        None. (See Remarks)     When both AHUs are operating starts                failure        MCR Air conditioning      pressure in duct                         the common ductwork static Safety Train Switchover                                            pressure does not exceed 6 via Switches inches wg safety-related duct 0-PDIS-31-186, design pressure 0-FS-31-94 &
0-TS-31-89B 9.4-172                                                                                                                                                                                                                                                   WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 18 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                   FAILURE      POTENTIAL            FAILURE              EFFECT ON             EFFECT ON NO. IDENTIFICATION         FUNCTION                MODE          CAUSE             DETECTION              SYSTEM                 PLANT                     REMARKS 30A Backdraft Damper   Prevent backflow from   Fails to open    - Mechanical   Annunciation in MCR of    Loss of flow       None (See Remarks)   Redundant AHU B-B start upon 0-BKD-31-2105      AHU B-B through                          Failure        MCR Air Conditioning      through                                 signal from AHU A-A Air Flow AHU A-A when on                                         Safety Train switchover   AHU A-A                                 Switch FS-31-84 standby                                                 via Switches 0-PDIS-31-161, 0-FS-31-84, and 0-TS-31-88B Fails to close   - Mechanical                             None (See          None (See Remarks)   Isolation Damper 0-FCO-31-12 (AHU A-A on      Failure                                  Remarks)                                prevents the backflow Standby) 30B Backdraft Damper   Prevent backflow from   Fails to open    - Mechanical   Annunciation in MCR of    Loss of air flow   None (See Remarks)   Redundant AHU A-A starts upon 0-BKD-31-2104      AHU A-A through                          Failure        MCR Air Conditioning      through                                 signal from AHU B-B Air Flow AHU B-B when on                                         Safety Train switchover   AHU B-B                                 Switch FS-31-94 standby                                                 via Switches 0-PDIS-31-186, 0-FS-31-94, and 0-TS-31-89B Fails to Close   - Mechanical                             None (See          None (See Remarks)   Isolation Damper 0-FCO-31-11 (AHU B-B on      Failure                                  Remarks)                                prevents the backflow Standby) 30C Backdraft Damper   See Remarks             See Remarks      See Remarks    See Remarks               See Remarks        See Remarks          This backdraft damper is not 0-BKD-31-2103                                                                                                                                required and is locked in open position 9.4-173                                                                                                                                                                                                                                         WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 19 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                   FAILURE         POTENTIAL             FAILURE       EFFECT ON           EFFECT ON NO. IDENTIFICATION         FUNCTION                MODE             CAUSE              DETECTION       SYSTEM               PLANT                    REMARKS 31   Fire Damper     To prevent smoke       Open during fire      - Mechanical    See Remarks        See Remarks      See Remarks          Single failures of HVAC system 0-XFD-31-98     spreading to                                 Failure                                                                  need not be postulated as being Conference Room, Shift                       - Electrical                                                             concurrent with fire Eng. Office, Lockers,                        Failure Toilet, and Kitchen Close during other - ETL Link       Surveillance and   None (See        None (See Remarks)   This fire damper has two ETL modes of operation Failure          Maintenance        Remarks)                              links 32   Fire Damper     Fire barrier between     Open during fire    - Mechanical    See Remarks        See Remarks      See Remarks          Single failures of HVAC system 0-XFD-31-86     Relay Room and Main                          Failure                                                                  need not be postulated as being Control Room                                 - Electrical                                                             concurrent with fire Failure Close during other - ETL Link       Surveillance and   None (See        None (See Remarks)   This fire damper has two ETL modes of operation Failure          Maintenance        Remarks)                              Links 33   Fire Damper     Prevent fire spreading   Open during fire    - Mechanical    See Remarks        See Remarks      See Remarks          Single failures of HVAC system 0-ISD-31-4402   to Conference Room                           Failure                                                                  need not be postulated as being concurrent with fire Maintenance of the room design Close during other - Fusible Link   Surveillance and   Loss of supply   None (See Remarks) modes of operation Failure          Maintenance        air to room                           temperature is not essential to the Control Building Safety Function 9.4-174                                                                                                                                                                                                                                     WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 20 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                       FAILURE        POTENTIAL             FAILURE              EFFECT ON            EFFECT ON NO. IDENTIFICATION           FUNCTION                  MODE            CAUSE              DETECTION              SYSTEM                PLANT                    REMARKS 34   Fire Damper       Prevent fire spreading    Open during fire    - Mechanical    See Remarks               See Remarks       See Remarks          Single failures of HVAC system 0-ISD-31-4404     to NRC Office                                 Failure                                                                          need not be postulated as being concurrent with fire Maintenance of the room design Close during other - Fusible Link   Surveillance and          Loss of supply    See Remarks modes of operation Failure          Maintenance               air to room                            temperature is not essential to the Control Building Safety Function 35   Fire Damper       Fire barrier to Technical Open during fire    -Mechanical     See Remarks               See Remarks       See Remarks          Single failures of HVAC system 0-XFD-31-76       Support Center (TSC)                          Failure                                                                          need not be postulated as being concurrent with fire.
Close during other -Fusible Link    Surveillance and          Loss of supply    See Remarks          Maintenance of the room design modes of operation Failure          Maintenance               air to the room                        temperature is not essential to the Control Building Safety Function 36A MCR Water Chiller Cooling of Chilled Water -Fails to              -Mechanical     Annuniciation in MCR of   Increase in       None (See Remarks)   Redundant MCR Air Conditioning A-A                                         start                 Failure         MCR Air Conditioning      chilled water                          Train B is started by any of
                                                                                                             -Stops                 -Electrical     Safety Train Switchover   temperature                            Switches 0-PDIS-31-161, 0-FS-Failure         via Switches 0-PDIS                                                                                                                                                                                                                      31-84 & 0-TS-31-88B 161, 0-FS-31-84 & 0-TS-31-88B 36B MCR Water           Cooling of Chilled Water - Fails to start     - Mechanical    Annunciation in MCR of    Increase in       None (See Remarks)   Redundant MCR Air Conditioning Chiller B-B                                  - Stops              Failure         MCR Air Conditioning      chilled water                          Train A is started by any of
                                                                                                                                    - Electrical    Safety Train switchover   temperature                            Switches 0-PDIS-31-186, Failure         via Switches 0-FS-31-94, and 0-TS-31-89B 0-PDIS-31-186, 0-FS                                                                                                                                                     94 and 0-TS-31-89B 9.4-175                                                                                                                                                                                                                                                WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 21 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                     FAILURE       POTENTIAL            FAILURE              EFFECT ON           EFFECT ON NO. IDENTIFICATION           FUNCTION                MODE           CAUSE             DETECTION              SYSTEM               PLANT                    REMARKS 37A MCR Chilled Water Circulate the chilled     - Fails to start   - Mechanical   Annunciation in MCR of   Loss chilled      None (See Remarks)   Redundant MCR Air Conditioning Circulation       water                     - Stops            Failure        MCR Air Conditioning     water flow                             Train B is started by any of Pump A-A                                                       - Electrical   Safety Train switchover                                         Switches 0-PDIS-31-161, Failure        via Switch 0-PDIS-31-161 0-FS-31-84, and 0-TS-31-88B Leakage through    - Mechanical   Annunciation in MCR of    Decrease of      None (See Remarks)   Redundant MCR Air Conditioning seals              Failure        MCR Air Conditioning      water content in                      Train B is started by any of Safety Train switchover   the system                            Switches 0-PDIS-31-161, via                                                             0-FS-31-84, and 0-TS-31-88B Switches 0-PDIS-31-161, 0-FS-31-84, and 0-TS-31-88B 37B MCR Water           Circulate the chilled   - Fails to start   - Mechanical   Annunciation in MCR of   Loss of chilled   None (See Remarks)   Redundant MCR Air Conditioning Chiller B-B         water                   - Stops            Failure        MCR Air Conditioning     water flow                             Train A is started by any of
                                                                                                                                 - Electrical   Safety Train switchover                                         Switches 0-PDIS-31-186, Failure        via Switch 0-PDIS-31-186 0-FS-31-94, and 0-TS-31-89B Leakage through    - Mechanical   Annunciation in MCR of    Decrease of      None (See Remarks)   Redundant MCR Air Conditioning seals              Failure        MCR Air Conditioning      water content in                      Train A is started by any of Safety Train switchover   the system                            Switches 0-PDIS-31-186, via                                                             0-FS-31-94, and 0-TS-31-89B Switches 0-PDIS-31-186, 0-FS-31-94, and 0-TS-31-89B 9.4-176                                                                                                                                                                                                                                          WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 22 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                  FAILURE         POTENTIAL            FAILURE               EFFECT ON            EFFECT ON NO. IDENTIFICATION         FUNCTION               MODE             CAUSE             DETECTION               SYSTEM                PLANT                    REMARKS 38A Check Valve       Prevents reverse flow   Stuck closed       - Mechanical    Annunciation in MCR of     Loss of chilled   None (See Remarks)   Redundant MCR Air Conditioning 0-CKV-31-2193                                                Failure         MCR Air Conditioning       water flow                             Train B is started by any of Safety Train switchover                                           Switches 0-PDIS-31-161, via 0-FS-31-84, and 0-TS-31-88B Switches 0-PDIS-31-161, 0-FS-31-84, and 0-TS-31-88B Stuck open         - Mechanical                               None (See         None (See Remarks)   The subsystem has only one Failure                                    Remarks)                               pump. Check valve is preventing backflow during maintenance 38B Check Valve       Prevents reverse flow   Stuck closed       - Mechanical    Annunciation in MCR of     Loss of chilled   None (See Remarks)   Redundant MCR Air Conditioning 0-CKV-31-2235                                                Failure         MCR Air Conditioning       water flow                             Train B is started by any of Safety Train Switchover                                           Switches 0-PDIS-31-186, via Switches 0-FS-31-94, and 0-TS-31-89B 0-PDIS-31-186, 0-FS-31-94, and 0-TS-31-89B Stuck open         - Mechanical                               None (See         None (See Remarks)   The subsystem has only one Failure                                    Remarks)                               pump. Check valve is preventing backflow during maintenance 39   Chilled Water   Provide chilled water   Pipe break or crack - Mechanical   Annunciation in MCR of     Decrease of      None (See Remarks)    Redundant MCR air conditioning Piping          system flow path                            Failure        MCR Air Conditioning       water content in                       subsystems are started by any of Safety Train switchover    the system                             the associated switches via Switches 0-PDIS-31-161, 0-FS-31-84, and 0-PDIS-31-161, 0-TS-31-88B for Train A and 0-FS-31-84, and 0-TS-31-88B for Train A                                           0-PDIS-31-186, 0-FS-31-96, and and 0-PDIS-31-186,                                                0-TS-31-89B for Train B 0-FS-31-94, and 0-TS-31-89B for Train B.
9.4-177                                                                                                                                                                                                                                             WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 23 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                      FAILURE       POTENTIAL              FAILURE               EFFECT ON          EFFECT ON NO. IDENTIFICATION           FUNCTION                 MODE           CAUSE               DETECTION               SYSTEM              PLANT                      REMARKS 40   Chilled Water     Provides shut-offs        - Leakage         - Mechanical     Annunciation in MCR of     Decrease of      None (See Remarks)   Redundant MCR air conditioning System Manual                                                 Failure          MCR Air Conditioning       water content in                      subsystems are started by any of Shut-off Valves                                                                Safety Train switchover    the system                            the associated switches via 0-PDIS-31-161, 0-FS-31-84, and Switches 0-PDIS-31-161, 0-TS-31-88B for Train A and 0-FS-31-84, and 0-TS-31-88B for Train A                                          0-PDIS-31-186, 0-FS-31-96, and and 0-PDIS-31-186,                                               0-TS-31-89B for Train B 0-FS-31-94, and 0-TS-31-89B for Train B.
41   Fire Damper       Fire barrier between Open during fire       - Mechanical     See Remarks                See Remarks    See Remarks            Single failures of HVAC system 0-ISD-31-3978     Secondary Alarm                             Failure                                                                           need not be postulated as being Station Room and                                                                                                              concurrent with fire Communications Room Closed during     - Fusible Link   Surveillance and           None (See      None (See Remarks)     Fire damper has dual fusible links other modes of    Failure          Maintenance                Remarks) operation 42   Fire Damper       Fire barrier between Open during fire       - Mechanical     See Remarks                None (See      None (See Remarks)     Single failures of HVAC system 0-ISD-31-2037     Communications Room                         Failure                                     Remarks)                              need not be postulated as being and Mechanical                                                                                                                concurrent with fire Equipment Room 692.0-C10 Closed during     - Fusible Link   Surveillance and           None (See      None (See Remarks)     Fire damper has dual fusible links other modes of    Failure          Maintenance                Remarks) operation 9.4-178                                                                                                                                                                                                                                                  WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 24 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                       FAILURE         POTENTIAL              FAILURE       EFFECT ON        EFFECT ON NO. IDENTIFICATION            FUNCTION                 MODE             CAUSE               DETECTION       SYSTEM            PLANT                      REMARKS 43   Fire Dampers (4)   Fire barrier between      Open during fire    - Mechanical     See Remarks        See Remarks   See Remarks          Single failures of HVAC system 0-ISD-31-2036,     Communication Room                            Failure                                                                need not be postulated as being 0-ISD-31-2038,     and Mechanical                                                                                                       concurrent with fire 0-ISD-31-2039,     Equipment Room and                692.0-C10 and 0-ISD-31-3951      Communication Room and corridor, respectively Closed during       - Fusible Link   Surveillance and   None (See     None (See Remarks)   Fire damper has dual fusible links other modes of      Failure          Maintenance        Remarks) operation 44   Fire Damper (2)    Fire barrier between    Open during fire      - Mechanical     See Remarks        See Remarks   See Remarks          Single failures of HVAC system 0-ISD-31-4617      corridor and Mechanical                       Failure                                                                need not be postulated as being and                Equipment                                                                                                            concurrent with fire 0-ISD-31-3941      Room 692.0-C2 Closed during       - Fusible Link   Surveillance and   None (See     See Remarks          Fire damper has dual fusible links other modes of      Failure          Maintenance        Remarks) operation 45   Fire Damper        Fire barrier and isolation Open during fire   - Mechanical     See Remarks        See Remarks   See Remarks          Single failures of HVAC system 2-ISD-31-2058      between Unit 2 Auxiliary                      Failure                                                                need not be postulated as being Instrument Room and                           - Electrical                                                           concurrent with fire. See Item Computer Room                                 Failure 69B for CO2 system spurious actuation Closed during       - Fusible Link   Surveillance and   None (See     None (See Remarks)   Fire damper has dual fusible links other modes of      Failure          Maintenance        Remarks)
WBNP-97 operation 9.4-179

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 25 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                       FAILURE         POTENTIAL              FAILURE       EFFECT ON        EFFECT ON NO. IDENTIFICATION            FUNCTION                 MODE             CAUSE               DETECTION       SYSTEM            PLANT                        REMARKS 46   Fire Damper        Fire barrier between      Open during fire    - Mechanical     See Remarks        See Remarks   See Remarks          Single failures of HVAC system 0-ISD-31-3968      Computer Room and                             Failure                                                                need not be postulated as being Unit 1 Auxiliary                                                                                                     concurrent with fire Instrument Room Closed during       - Fusible Link   Surveillance and   None (See     None (See Remarks)   Fire damper has two independent other modes of      Failure          Maintenance        Remarks)                           fusible links installed operation 47   Fire Dampers (2)   Fire barrier and isolation Open during fire   - Mechanical     See Remarks        See Remarks   See Remarks          Single failures of HVAC system 0-ISD-31-3956      between Computer                              Failure                                                                need not be postulated as being and                Room and Unit 1                               - Electrical                                                           concurrent with fire. See Item 0-ISD-31-3957      Auxiliary Instrument                          Failure 69B for CO2 system spurious Room (CO2 actuated)                                                                                                                          activation.
Closed during       - Fusible Link   Surveillance and   None (See     None (See Remarks)   Additional independent fusible other modes of      Failure          Maintenance        Remarks)                           link to be installed operation 48   Fire Dampers (3)   Isolation of the Unit 1   Open during fire    - Mechanical     See Remarks        See Remarks   See Remarks          Single failures of HVAC system 1-ISD-31-3958,     Auxiliary Instrument                          Failure                                                                need not be postulated as being 1-ISD-31-3959,     Room                                          - Electrical                                                           concurrent with fire. See Item and 1-ISD-                                                       Failure 69B for CO2 system spurious 31-3961 actuation Closed during       - Fusible Link                      None (See     None (See Remarks)   Additional independent fusible other modes of      Failure                             Remarks)                           link is installed operation 9.4-180                                                                                                                                                                                                                                       WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 26 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                       FAILURE           POTENTIAL              FAILURE       EFFECT ON        EFFECT ON NO. IDENTIFICATION            FUNCTION                 MODE               CAUSE               DETECTION       SYSTEM            PLANT                     REMARKS 49   Fire Damper        Prevent spreading of      Open during fire      - Mechanical     See Remarks        See Remarks   See Remarks          Single failures of HVAC system 0-ISD-31-4297      fire                                            Failure                                                                need not be postulated as being concurrent with fire Closed during         - Fusible Link   Surveillance and   None (See     None (See Remarks)   Fire damper has dual fusible links other modes of        Failure          Maintenance        Remarks) operation 50   Backdraft Damper   See Remarks               See Remarks           See Remarks      See Remarks        See Remarks   See Remarks          This backdraft damper is not 0-BKD-31-2086                                                                                                                             required since the air flow can be controlled by Balancing Damper 0-31-2087 and is locked in open position 51   Fire Damper        To maintain fire barrier Open during fire       - Mechanical     See Remarks        See Remarks   See Remarks          Single failures of HVAC system 0-ISD-31-3971      integrity between Unit 1 (See Remarks)          Failure                                                                need not be postulated as being Auxiliary Instrument                                                                                                   concurrent with fire Room Elev. 708.0 and Mechanical Equipment Room 692.0-C2 Fusible link failure   Mechanical       Surveillance and   None (See     None (See Remarks)   This fire damper has two (See Remarks)          (fusible link    Maintenance        Remarks)                           independent fusible links failure) 9.4-181                                                                                                                                                                                                                                            WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 27 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                     FAILURE         POTENTIAL               FAILURE               EFFECT ON            EFFECT ON NO. IDENTIFICATION          FUNCTION                 MODE             CAUSE                DETECTION               SYSTEM                PLANT                    REMARKS 52A Isolation Damper   Isolate Electrical Board   Close during AHUs - Mechanical       Annunciation in MCR of    Loss of air flow   None (See Remarks)   Redundant Train B AHUs C-B 0-FCO-31-30        Room AHUs A-A and          A-A and B-A       Failure            MCR Air Conditioning      path through                            and D-B start on low air flow B-B while on standby       operation         - Electrical       Safety Train Switchover   AHUs A-A and                            signal from AHUs A-A and B-A Failure            via Switches              B-A Air Flow Switches FS-31-117 or 0-PDIS-31-211, FS-31-123 0-FS-31-117 and -123, and 0-TS-31-150B Open when AHUs    - Mechanical                                 None (See          None (See Remarks)   Backdraft dampers 0-31-2001A are on standby    Failure                                      Remarks)                                and 0-31-2001B prevents
                                                                                                                                  - Electrical and                                                                     backflow Auxiliary Control Air Failure 52B Isolation Damper   Isolate Electrical Board   Close during AHUs - Mechanical       Annunciation in MCR of    Loss of air flow   None (See remarks)   Redundant Train A AHUs A-A 0-FCO-31-31        Room AHUs C-B and          C-B and D-B       Failure            MCR Air Conditioning      path through                            and B-A start on low air flow D-B while on standby       operation         - Electrical       Safety Train Switchover   AHUs C-B and                            signal from AHUs C-B and D-B Failure            via Switches              D-B Air Flow Switches FS-31-126 or 0-PDIS-31-241, FS-31-154 0-FS-31-126 and -154, and 0-TS-31-157B Open when AHUs    - Mechanical                                 None (See          None (See Remarks)   Backdraft Dampers 0-31-3972 are on standby    Failure                                      Remarks)                                and 0-31-3973 prevents backflow
                                                                                                                                  - Electrical and Auxiliary Control Air Failure 9.4-182                                                                                                                                                                                                                                                  WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 28 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                   FAILURE     POTENTIAL             FAILURE               EFFECT ON            EFFECT ON NO. IDENTIFICATION          FUNCTION               MODE         CAUSE              DETECTION               SYSTEM                PLANT                    REMARKS 53A Modulating         Modulates the air flow   Open           - Mechanical    Annunciation in MCR of    Air bypasses       None (See Remarks)   Temperature Switch TS-31-150B Dampers (2)        through cooling coil and                Failure         MCR Air Conditioning      the cooling coil                        starts the redundant AHUs upon 0-FCO-31-335 &     bypass of AHU's A-A &                   - Control Air   Safety Train              and results in                          Temp. Element TE-31-150B 0-FCO-31-336       B-A to maintain the                     Failure         Switchover[1] via         increase of sensing high return air temperature at                                          Switches 0-FS-31-117      space temperature thermostat setpoint                                     and -123, and 0-TS    temperature 0-TE-31-335 and -336                                    150B Spurious       - Control                                 Space is not    None (See Remarks)      Same as above modulation     Failure                                   maintained at set temperature 53B Modulating         Modulates air flow       Open           - Mechanical    Annunciation in MCR of    Air bypasses       None (See Remarks)   Temperature Switch TS-31-157B Dampers (2)        through cooling coil and                Failure         MCR Air Conditioning      the cooling coil                        starts the redundant AHUs upon 0-FCO-31-337 and   bypass of AHUs C-B                      - Control Air   Safety Train Switchover   and results in                          Temp. Element TE-31-157B 0-FCO-31-338       and D-B to maintain the                 Failure         via Switches              increase of sensing high return air temperature at                                          0-FS-31-126 and -154,     space temperature thermostat setpoint                                     and 0-TS-31-157B          temperature 0-TE-31-337 and 0-TE-31-338 Spurious       - Control                                 Space is not    None (See Remarks)      Same as above modulation     Failure                                   maintained at set temperature 9.4-183                                                                                                                                                                                                                                         WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 29 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                   FAILURE         POTENTIAL             FAILURE              EFFECT ON         EFFECT ON NO. IDENTIFICATION            FUNCTION             MODE             CAUSE              DETECTION              SYSTEM             PLANT                      REMARKS 54A Electrical Board Rooms (EBR) Air Handling Units (AHU) A-A and B-A
                                                                   -Filters           Filters the air        Clogged             Accumulation of dirt Surveillance         Reduced air   None. (See Remarks)    Surveillance (PDI-31-120 and PDI-31-120 and       flow
                                                                                                                                                                                                                -121) and maintenance of filters 121, and Maintenance and                                           in accordance with maintenance Annunciation in                                           procedures. Either Temp. Switch MCR of EBR Air                                            0-TS-31-150B or Flow Switches Conditioning Safety                                       0-FS-31-117 and -123 starts Train Switchover via                                      redundant AHUs C-B and D-B Switches 0-FS-31-117 and
                                                                                                                                                      -123, and 0-TS-31-150B
                                                                   -Cooling Coil      Cools the supply air   Cooling coil tube   -Mechanical Failure Annunciation in      Temperature      None (See Remarks)   Redundant AHUs C-B and D-B break or crack                          MCR of EBR Air       increases in the                      starts upon signal from AHUs A-A Conditioning Safety EBR spaces.                            and B-A High Temp Switch Train Switchover via Switches                                                   TS-31-150B 0-PDIS-31-211, 0-FS-31-117 and
                                                                                                                                                     -123, and 0-TS-31-150B
                                                                   -Humidifier        Provides moisture to  No humidification    -Steam Boiler       Moisture Indicator   None (See      None (See Remarks)     Maintenance of the relative maintain the design                        Failure             MI-31-231 on Local   Remarks)                              humidity is not required for safe Relative Humidity in                       -Steam Control      Panel L-523                                                shutdown of plant EBR spaces during                          Valve closes normal operation mode                      -Mechanical Failure
                                                                                                                                 -Electrical Failure 9.4-184                                                                                                                                                                                                                                             WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 30 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                       FAILURE        POTENTIAL              FAILURE                EFFECT ON            EFFECT ON NO. IDENTIFICATION            FUNCTION                 MODE            CAUSE               DETECTION                SYSTEM                PLANT                     REMARKS
                                                                   -Fan               Circulates the air        -Fails to start     -Mechanical Failure Annunciation in      Loss of air flow      None (See Remarks)    Redundant AHUs C-B and D-B
                                                                                                                -Stops              -Electrical Failure MCR of EBR Air       through AHU                                 starts upon signal from AHUs A-A Conditioning Safety                                              and B-A Air Flow Switches Train Switchover via Switches                                                         FS-31-117 or FS-31-123 0-FS-31-117 and
                                                                                                                                                        -123, and 0-TS-31-150B
                                                                                                                -Fails to stop or   Electrical Failure   Annunciation in      Increased        None (See Remarks)        When both AHUs are operating, start                                    MCR of EBR Air       pressure in duct                           the common ductowork static Conditioning Safety                                             pressure does not exceed Train Switchover via 6 inches wg safety-related duct Switches design pressuer 0-FS-31-117 and
                                                                                                                                                         -123, and 0-TS-31-150B 54B Electrical Board Rooms (EBR) Air Handling Units (AHU) C-B and D-B
                                                                   -Filters           Filters the air           Clogged             Accumulation of dirt Surveillance           Reduced air        None. (See Remarks)   Surveillance (PDI-31-125 and PDI-31-125 and         flow may result
                                                                                                                                                                                                                         -152) and maintenance of filters PDI-31-152, and        in rise of space Maintenance and        temperatures                             in accordance with maintenance Annunciation in                                                 procedures. Either Temp. Switch MCR of EBR Air                                                  0-TS-31-157B or Flow Switches Conditioning Safety                                             0-FS-31-126 and -154 starts Train Switchover via                                            redundant AHUs A-A and B-A Switches 0-FS-31-126 and
                                                                                                                                                         -154, and 0-TS-31-157B 9.4-185                                                                                                                                                                                                                                                     WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 31 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                     FAILURE        POTENTIAL             FAILURE               EFFECT ON           EFFECT ON NO. IDENTIFICATION         FUNCTION                  MODE            CAUSE              DETECTION               SYSTEM               PLANT                     REMARKS
                                                                   -Cooling Coil    Cools the supply air      Cooling coil tube   -Mechanical Failure Annunciation in      Temperature      None (See Remarks)     Redundant AHUs A-A and B-A break or crack                          MCR of EBR Air       increases in the                        starts upon signal from AHUs C-B Conditioning Safety EBR spaces.                              and D-B High Temp Switch Train Switchover via Switches                                                     TS-31-157B 0-PDIS-31-241, 0-FS-31-126 and
                                                                                                                                                      -154, and 0-TS-31-157B
                                                                   -Humidifier      Provides moisture to  No humidification       -Steam Boiler       Moisture Indicator    None (See         None (See Remarks)   Maintenance of the relative maintain the design                           Failure             MI-31-261 on Local    Remarks)                               humidity is not required for safe Relative Humidity in                          -Steam Control      Panel L-524                                                  shutdown of plant EBR spaces during                             Valve closes normal operation mode                         -Mechanical Failure
                                                                                                                                  -Electrical Failure 54B -Fan              Circulates the air        -Fails to start     -Mechanical Failure Annunciation in      Loss of air flow   None (See Remarks)   Redundant AHUs A-A and B-B Cont.                                           -Stops              -Electrical Failure MCR of MCR Air       through AHUs                            starts upon signal from AHUs C-B Conditioning Safety C-B and D-B                              and D-B Air Flow Switches Train Switchover via FS-31-126 or FS-31-154 Switches 0-FS-31-126 and
                                                                                                                                                      -154, and 0-TS-31-157B
                                                                                                              -Fails to stop or   Electrical Failure   Annunciation in      Increased        None (See Remarks)    When both AHUs are operating, start                                    MCR of MCR Air       pressure in duct                       the common ductwork static Conditioning Safety                                         pressure does not exceed Train Switchover via 6 inches wg safety-related duct Switches design pressuer 0-FS-31-126 and
                                                                                                                                                       -154, and WBNP-97 0-TS-31-157B 9.4-186

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 32 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                  FAILURE         POTENTIAL              FAILURE                EFFECT ON            EFFECT ON NO. IDENTIFICATION        FUNCTION                MODE             CAUSE               DETECTION                SYSTEM                PLANT                     REMARKS 55A Backdraft         Prevent backflow from   Fails to open       - Mechanical Failure Annunciation in        Loss of air flow   None (See Remarks)   Redundant AHUs C-B and D-B Dampers (2)       Train B AHUs through                                             MCR of EBR Air         through AHUs                            starts upon signal from AHUs A-A 0-BKD-31-2001A    Train A air handling                                             Conditioning Safety    A-A and B-A                             or B-A Air Flow Switches and               units when on standby                                            Train Switchover via FS-31-117 and FS-31-123, 0-BKD-31-2001B                                                                     Switches respectively 0-PDIS-31-211, 0-FS-31-117 and
                                                                                                                                                     -123, and 0-TS-31-150B Fails to close      - Mechanical Failure                        None (See          None (See remarks)   Isolation Damper 0-FCO-31-30 (AHUs A-A and                                                   Remarks)                                prevents the backflow B-A on standby) 55B Backdraft         Prevent backflow from   Fails to open       - Mechanical Failure Annunciation in        Loss of air flow   None (See Remarks)   Redundant AHUs A-A and B-A Dampers (2)       Train A AHUs through                                             MCR of EBR Air         through AHUs                            starts upon signal from AHUs C-B 0-BKD-31-3972     Train B air handling                                             Conditioning Safety    A-A and B-A                             or D-B Air Flow Switches and               units when on standby                                            Train Switchover via FS-31-126 and FS-31-154, 0-BKD-31-3973                                                                      Switches 0-PDIS-respectively 241, 0-FS-31-126 and
                                                                                                                                                     -154, and 0-TS-31-157B Fails to close      - Mechanical Failure                        None (See          None (See Remarks)   Isolation Damper 0-FCO-31-31 (AHUs C-B and                                                   Remarks)                                prevents the backflow D-B on standby) 56   Fire Damper     Fire barrier between    Open during fire    - Mechanical Failure See Remarks            See Remarks        See Remarks          Single failures of HVAC systems 0-ISD-31-3942   Mechanical Equipment                                                                                                            need not be postulated as being Room 692.0-C2 and                                                                                                               concurrent with fire 250V Battery Room #1 WBNP-97 Closed during other - Mechanical Failure Surveillance and       None (See          None (See Remarks)   Fire damper has dual fusible links 9.4-187 modes of operation                       Maintenance            Remarks)

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 33 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                  FAILURE         POTENTIAL              FAILURE            EFFECT ON        EFFECT ON NO. IDENTIFICATION         FUNCTION               MODE             CAUSE               DETECTION            SYSTEM            PLANT                     REMARKS 57   Fire Damper     Fire barrier between   Open during fire    - Mechanical Failure See Remarks          See Remarks   See Remarks          Single failures of HVAC systems 0-ISD-31-3943   250V Battery Room #1                                                                                                    need not be postulated as being and 250V Battery Board                                                                                                  concurrent with fire Room #1 Fire damper has dual fusible links Closed during other - Fusible Link         Surveillance and   None (See     None (See Remarks) modes of operation Failure                 maintenance        Remarks) 58   Fire Damper     Fire barrier between  Open during fire     - Mechanical failure   See Remarks        See Remarks   See Remarks          Single failures of HVAC systems 0-ISD-31-3944   250V Battery Board                                                                                                      need not be postulated as being Room #1 and 250V                                                                                                        concurrent with fire Battery Board Room #2 Fire damper has dual fusible links Closed during other - Fusible Link         Surveillance and   None (See     None (See Remarks) modes of operation Failure                 Maintenance        Remarks) 59   Fire Damper     Fire barrier between   Open during fire    - Mechanical Failure See Remarks          See Remarks   See Remarks          Single failures of HVAC systems 0-ISD-31-3947   250V Battery Board                                                                                                      need not be postulated as being Room #2 and 250V                                                                                                        concurrent with fire Battery Room #2 Fire damper has dual fusible links Closed during other - Mechanical Failure Surveillance and     None (See     See Remarks modes of operation                       Maintenance          Remarks) 60   Fire Damper     Fire barrier between   Open during fire    - Mechanical Failure See Remarks          See Remarks   See Remarks          Single failures of HVAC systems 0-ISD-31-3948   250V Battery Room #2                                                                                                    need not be postulated as being and 24V and 48V                                                                                                         concurrent with fire Battery Room Fire damper has dual fusible links Closed during other - Fusible Link         None (See          None (See     See Remarks modes of operation Failure                 Remarks)           Remarks) 9.4-188                                                                                                                                                                                                                                          WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 34 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                     FAILURE          POTENTIAL            FAILURE            EFFECT ON        EFFECT ON NO. IDENTIFICATION            FUNCTION               MODE              CAUSE             DETECTION            SYSTEM            PLANT                     REMARKS 61   Fire Damper        Fire barrier between Open during fire    - Mechanical Failure See Remarks           See Remarks   See Remarks          Single failures of HVAC systems 0-ISD-31-3949      24V and 48V Battery                                                                                                    need not be postulated as being Room and 24V and 48V                                                                                                   concurrent with fire Battery Board and Charge Room Fire damper has dual fusible links Closed during other - Mechanical Failure Surveillance and      None (See     See Remarks modes of operation                       Maintenance           Remarks) 62   Fire Damper        Fire barrier between    Open during fire    - Mechanical Failure See Remarks        See Remarks   See Remarks          Single failures of HVAC systems 0-ISD-31-3950      24V and 48V Battery                                                                                                    need not to be postulated as Board and Charge                                                                                                       being concurrent with fire Room and Central Alarm Station Room Closed during other - Fusible Link       Surveillance and   None (See     See Remarks          Additional independent fusible modes of operation Failure               Maintenance        Remarks)                           link is installed 63   Fire Dampers (2)   Fire barrier between    Open during fire    - Mechanical Failure See Remarks        See Remarks   See Remarks          Single failures of HVAC systems 0-ISD-31-3976      Central Alarm Station                                                                                                  need not to be postulated as and 0-ISD      Room and                                                                                                               being concurrent with fire 3977               Communication Room Closed during other - Mechanical Failure Surveillance and   None (See     See Remarks          Additional independent fusible modes of operation                       Maintenance        Remarks)                           link is installed 64   Fire Damper        Fire barrier between    Open during fire    - Mechanical Failure See Remarks        See Remarks   See Remarks          Single failures of HVAC systems 0-ISD-31-3970      Unit 1 Auxiliary                                                                                                       need not to be postulated as Instrument Room and                                                                                                    being concurrent with fire the Mechanical Equipment Room 692.0-C2 Closed during other - Mechanical Failure Surveillance and   None (See     None (See Remarks)   This fire damper has two WBNP-87 modes of operation                       Maintenance        Remarks)                           independent fusible links 9.4-189

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 35 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                 FAILURE          POTENTIAL            FAILURE            EFFECT ON        EFFECT ON NO. IDENTIFICATION         FUNCTION              MODE              CAUSE             DETECTION            SYSTEM            PLANT                      REMARKS 65   Fire Damper     Fire barrier between   Open during fire    - Mechanical Failure See Remarks        See Remarks   See Remarks          Single failures of HVAC system 0-ISD-31-3969   Unit 1 Auxiliary                                                                                                      need not to be postulated as Instrument Room and                                                                                                   being concurrent with fire Computer Room Closed during other - Mechanical Failure Surveillance and   None (See     None (See Remarks)   Fire damper has two independent modes of operation                       Maintenance        Remarks)                           fusible links installed 66   Fire Damper     Fire barrier between   Open during fire    - Mechanical Failure See Remarks        See Remarks   See Remarks          Single failures of HVAC system 2-ISD-31-3955   Computer Rooms and                                                                                                    need not be postulated as being Unit 2 Auxiliary                                                                                                      concurrent with fire. See Item Instrument Room 69B for CO2 system spurious actuation Closed during other - Fusible Link       Surveillance and   None (See     None (See Remarks) modes of operation Failure               Maintenance        Remarks)                           Fire damper has dual fusible links 67   Fire Damper     Fire barrier in EBR    Open during fire    - Mechanical Failure See Remarks        See Remarks   See Remarks          Single failures of HVAC system 0-ISD-31-4296   supply to computer                                                                                                    need not be postulated as being room                                                                                                                  concurrent with fire Close during other - Fusible Link        Surveillance and   None (See     None (See Remarks)   Fire damper has dual fusible links modes of operation Failure               Maintenance        Remarks) 9.4-190                                                                                                                                                                                                                                        WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 36 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                    FAILURE         POTENTIAL               FAILURE            EFFECT ON          EFFECT ON NO. IDENTIFICATION         FUNCTION                 MODE             CAUSE                DETECTION            SYSTEM              PLANT                     REMARKS 68   Fire Damper     Fire barrier between     Open during fire     - Mechanical Failure See Remarks          See Remarks    See Remarks           Single failures of HVAC system 0-ISD-31-3956   Unit 1 Auxiliary                                                                                                             need not be postulated as being Instrument Room and                                                                                                          concurrent with fire. See Item Computer Room                                                                                                                69B for CO2 system spurious failure Close during other - Fusible Link           Surveillance and   None (See      None (See Remarks)    Fire damper has dual fusible links modes of operation Failure                  Maintenance        Remarks) 69A Fire Damper       Provide isolation of Unit Open during fire    - Mechanical Failure See Remarks          See Remarks    See Remarks           Single failures of HVAC system 1-ISD-31-3960     1 Auxiliary Instrument                                                                                                       need not be postulated as being Room during CO2 fire                                                                                                         concurrent with fire. See Item extinguishing                                                                                                                69B for CO2 system spurious failure. This fire damper has CO2 actuator without fusible link See Item 69B for CO2 system spurious failure 69B Fire Damper       Provide isolation of     Closed during a      - Electrical Failure   Annunciation in    Loss of cooling None (See Remarks)   Plant can be shut down from 2-ISD-31-2058     Unit #1 and Unit #2      spurious actuation                          MCR following a    in Unit #1 and                       Auxiliary Control Room 2-ISD-31-3955     Auxiliary Instrument     of the CO2 system                           CO2 discharge      Unit #2 Auxiliary 0-ISD-31-3956     Rooms and Computer                                                                      Instrument 0-ISD-31-3657     Room during CO2 fire                                                                    Rooms and 1-ISD-31-3958     extinguishing.                                                                          Computer 1-ISD-31-3959                                                                                             Room 1-ISD-31-3960 1-ISD-31-3961 9.4-191                                                                                                                                                                                                                                               WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 37 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                        FAILURE      POTENTIAL              FAILURE               EFFECT ON          EFFECT ON NO. IDENTIFICATION            FUNCTION                  MODE          CAUSE               DETECTION               SYSTEM              PLANT                    REMARKS 70A EBR Water            Cooling of chilled water - Fails to start   - Mechanical Failure Annunciation in      Increase in       None (See Remarks)   Redundant EBR air conditioning Chiller A-A                                   - Stops            - Electrical Failure MCR of EBR Air       chilled water                          subsystem is started by any of Conditioning Safety temperature                             Switches 0-PDIS-31-211, Train Switchover via                                        0-FS-31-117 and -123, and Switches                                                    0-TS-31-150B 0-PDIS-31-211, 0-FS-31-117 and
                                                                                                                                                        -123, and 0-TS-31-150B 70B EBR Water Chiller Cooling of chilled water - Fails to start      - Mechanical Failure Annunciation in        Increase in     None (See Remarks)   Redundant EBR air conditioning B-B                                        - Stops               - Electrical Failure MCR of EBR air         chilled water                        subsystem is started by any of conditioning safety    temperature                          Switches 0-PDIS-31-241, train switchover via                                        0-FS-31-126 and -156, and Switches                                                    0-TS-31-157B 0-PDIS-31-241, 0-FS-31-126 and
                                                                                                                                                        -154, and 0-TS-31-157B 9.4-192                                                                                                                                                                                                                                              WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 38 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                   FAILURE       POTENTIAL              FAILURE               EFFECT ON            EFFECT ON NO. IDENTIFICATION           FUNCTION              MODE           CAUSE               DETECTION               SYSTEM                PLANT                    REMARKS 71A EBR Chilled Water Circulate the chilled   - Fails to start   - Mechanical Failure Annunciation in        Loss of chilled   None (See Remarks)   Redundant EBR air conditioning Circ. Pump A-A    water                   - Stops            - Electrical Failure MCR of EBR air         water flow                             Train B is started by any of conditioning safety                                           Switches 0-PDIS-31-211, train switchover via                                          0-FS-31-117 and -123, and Switch                                                        0-TS-31-150B 0-PDIS-31-211 Leakage through    - Mechanical Failure Annunciation in        Decrease of      None (See Remarks)    Same as above seals                                   MCR of EBR air         water content in conditioning safety    the system train switchover via Switches 0-PDIS-31-211, 0-FS-31-117 and
                                                                                                                                                    -123, and 0-TS-31-150B 71B EBR Chilled Water Circulate the chilled   - Fails to start   - Mechanical Failure Annunciation in        Loss of chilled   None (See Remarks)   Redundant EBR air conditioning Circ. Pump B-B    water                   - Stops            - Electrical Failure MCR of EBR air         water flow                             Train A is started by any of conditioning safety                                           Switches 0-PDIS-31-241, train switchover via                                          0-FS-31-126 and -154, and Switch                                                        0-TS-31-157B 0-PDIS-31-241 Leakage through    - Mechanical Failure Annunciation in        Decrease of      None (See Remarks)    Same as above seals                                   MCR of EBR air         water content in conditioning safety    the system train switchover via Switches 0-PDIS-31-241, 0-FS-31-126 and
                                                                                                                                                    -154, and 0-TS                                                                                                                                                                                                                                                    WBNP-97 157B 9.4-193

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 39 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                 FAILURE       POTENTIAL              FAILURE               EFFECT ON            EFFECT ON NO. IDENTIFICATION         FUNCTION              MODE           CAUSE               DETECTION               SYSTEM                PLANT                    REMARKS 72A Check Valve       Prevent reverse flow   Stuck closed      - Mechanical Failure Annunciation in        Loss of chilled   None (See Remarks)   Redundant EBR air conditioning 0-CKV-31-2307                                                                   MCR of EBR air         water flow                             Train B is started by any of conditioning safety                                           Switches 0-PDIS-31-211, train switchover via                                          0-FS-31-117 and -123, and Switches                                                      0-TS-31-150B 0-PDIS-31-211, 0-FS-31-117 and
                                                                                                                                                  -123, and Stuck open        - Mechanical Failure 0-TS-31-150B           None (See         None (See Remarks)   The subsystem has only one Remarks)                               pump. Check valve prevents backflow during maintenance 72B Check Valve       Prevent reserve flow   Stuck closed      - Mechanical Failure Annunciation in        Loss of chilled   None (See Remarks)   Redundant EBR air conditioning 0-CKV-31-2364                                                                   MCR of EBR air         water flow                             Train A is started by any of conditioning safety                                           switches 0-PDIS-31-241, train switchover via                                          0-FS-31-126 and -154, and Switches 0-PDIS-                                              0-TS-31-157B.
31-241, 0-PS                                                                                                                                                   126 and -154 and 0-    None (See TS-31-157B             Remarks)
Stuck open        - Mechanical Failure                                          None (See Remarks)   The subsystem has only one pump. Check valve prevents backflow during maintenance.
9.4-194                                                                                                                                                                                                                                          WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 40 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                     FAILURE          POTENTIAL             FAILURE               EFFECT ON          EFFECT ON NO. IDENTIFICATION           FUNCTION                MODE              CAUSE              DETECTION               SYSTEM              PLANT                     REMARKS 73   Chilled Water     Provide chilled water    Pipe break or crack - Mechanical Failure Annunciation in        Decrease of      None (See Remarks)   Redundant EBR air conditioning Piping            system flow path                                                  MCR of EBR air         water content in                      subsystem is started by any of conditioning safety    the system                            Switches 0-PDIS-31-177 and train switchover via                                         -123, 0-TS-31-150B for Train A, Switches                                                     and 0-PDIS-31-241, 0-FS-31-126 0-PDIS-31-211,                                               and -154, and 0-TS-31-157B for 0-FS-31-117 and                                              Train B
                                                                                                                                                        -123, and 0-TS-31-150B for Train A, and 0-PDIS-31-241, 0-FS-31-126 and
                                                                                                                                                        -154, and 0-TS-31-157B for Train B.
74   Chilled Water     Provide Shut-Offs        - Leakage           - Mechanical Failure Annunciation in      Decrease of      None (See Remarks)     Redundant EBR Air Conditioning System manual                                                                       MCR of EBR air       water content in                        Subsystems are started by any of shut-off valves                                                                     conditioning safety the system                               the associated Switches train switchover via                                         0-PDIS-31-211, 0-FS-31-117 and Switches                                                     -123, and 0-TS-31-150B for 0-PDIS-31-211,                                               Train A, and 0-PDIS-31-241, 0-FS-31-117 and                                              0-FS-31-126 and -154, and
                                                                                                                                                        -123, and                                                    0-TS-31-157B for Train B 0-TS-31-150B for Train A, and 0-PDIS-31-241, 0-FS-31-126 and
                                                                                                                                                        -154, 0-TS-31-157B for Train B 9.4-195                                                                                                                                                                                                                                                 WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 41 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                     FAILURE        POTENTIAL            FAILURE            EFFECT ON        EFFECT ON NO. IDENTIFICATION            FUNCTION               MODE            CAUSE             DETECTION            SYSTEM            PLANT                     REMARKS 75   Fire Dampers (3)   Fire barrier between   Open during fire    - Mechanical Failure See Remarks       See Remarks   See Remarks          Single failures of HVAC system 0-ISD-31-2013      Battery Board Rooms                                                                                                  need not be postulated as being 0-ISD-31-2018      and Corridor                                                                                                         concurrent with fire.
0-ISD-31-2029 Close during other - Fusible Link       Surveillance and   None (See     None (See Remarks)   Fire damper has dual fusible links modes of operation Failure              Maintenance        Remarks) 76   Fire Dampers (3)   Fire barrier between   Open during fire    - Mechanical Failure See Remarks       See Remarks   See Remarks          Single failures of HVAC system 0-ISD-31-2010      Battery Rooms and                                                                                                    need not be postulated as being 0-ISD-31-2021      Corridor                                                                                                             concurrent with fire.
0-ISD-31-2028 Close during other - Fusible Link       Surveillance and   None (See     None (See Remarks)   Fire damper has dual fusible links modes of operation Failure              Maintenance        Remarks) 77   Fire Damper        Fire barrier between  Open during fire   - Mechanical Failure See Remarks         See Remarks   See Remarks          Single failures of HVAC system 0-ISD-31-2024      24V and 48V Battery                                                                                                  need not be postulated as being Room and 250V Battery                                                                                                concurrent with fire.
Room #2 Close during other - Fusible Link       Surveillance and    None (See     None (See Remarks)   Fire damper has dual fusible links modes of operation Failure              Maintenance         Remarks) 78   Fire Damper        Fire barrier between   Open during fire    - Mechanical Failure See Remarks       See Remarks   See Remarks          Single failures of HVAC system 0-ISD-31-2019      250V Battery Room #2                                                                                                 need not be postulated as being and 250V Battery Board                                                                                               concurrent with fire.
Room #2 Close during other - Mechanical Failure Surveillance and   None (See     None (See Remarks)   Fire damper has dual fusible links modes of operation                      Maintenance        Remarks) 79   Fire Damper        Fire barrier between  Open during fire   - Mechanical Failure See Remarks         See Remarks   See Remarks          Single failures of HVAC system 0-ISD-31-3945      250V Battery Board                                                                                                   need not be postulated as being Room #2 and 250V                                                                                                     concurrent with fire.
Battery Board Room #1 WBNP-97 Close during other - Fusible Link       Surveillance and    None (See     None (See Remarks)   Fire damper has dual fusible links 9.4-196 modes of operation Failure              Maintenance         Remarks)

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 42 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                     FAILURE        POTENTIAL               FAILURE            EFFECT ON            EFFECT ON NO. IDENTIFICATION          FUNCTION                 MODE            CAUSE                DETECTION            SYSTEM                PLANT                     REMARKS 80   Fire Damper      Fire barrier between     Open during fire    - Mechanical Failure See Remarks          See Remarks       See Remarks          Single failures of HVAC system 0-ISD-31-2012    250V Battery Board                                                                                                            need not be postulated as being Room #1 and 250V                                                                                                              concurrent with fire.
Battery Room #1 Close during other - Fusible Link          Surveillance and   None (See         None (See Remarks)   Fire damper has dual fusible links modes of operation Failure                 Maintenance        Remarks) 81   Fire Damper      Fire barrier between     Open during fire    - Mechanical Failure See Remarks          See Remarks       See Remarks          Single failures of HVAC system 0-ISD-31-2007    Battery Room #1 and                                                                                                           need not be postulated as being Mechanical Equipment                                                                                                          concurrent with fire.
Room 692.0-C2 Close during other - Fusible Link          Surveillance and   None (See         None (See Remarks)   Fire damper has dual fusible links modes of operation Failure                 Maintenance        Remarks) 82A Battery Room       Battery rooms exhaust    - Fails to start    - Mechanical Failure Alarm in MCR via     Loss of battery   None (See Remarks)   Redundant Battery Exhaust Fan Exhaust Fan A-A    to prevent hydrogen      -Stops              - Electrical Failure Airflow Switch       rooms exhaust                          B-B starts on Low Air Flow signal buildup                                                           0-FS-31-402                                                 from Fan A-A Air FLow Switch 0-FS-31-402 82B Battery Room       Battery rooms exhaust    - Fails to start    - Mechanical Failure Alarm in MCR via     Loss of battery   None (See Remarks)   Redundant Battery Exhaust Fan Exhaust Fan B-B    to prevent hydrogen      -Stops              - Electrical Failure Airflow Switch       rooms exhaust                          A-A starts on Low Air Flow signal buildup                                                           0-FS-31-401                                                 from Fan B-B Air Flow Switch 0-FS-31-401 83A Backdraft Damper   Prevents backflow        Fails to open       - Mechanical Failure Alarms in MCR via    Loss of airflow   None (See Remarks)   Redundant Battery Exhaust Fan 0-BKD-31-2163                                                                        Airflow Switch       path through                           B-B starts on Low Air Flow signal 0-FS-31-402          Exhaust Fan                            from Fan A-A Air Flow Switch B-B                                    0-FS-31-402 Fails to close      - Mechanical Failure                      None (See         None (See Remarks)   Isolation Damper 0-FCO-31-28 Remarks)                               prevents backflow 9.4-197                                                                                                                                                                                                                                                 WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 43 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                    FAILURE        POTENTIAL               FAILURE            EFFECT ON            EFFECT ON NO. IDENTIFICATION         FUNCTION                 MODE            CAUSE                DETECTION            SYSTEM                PLANT                     REMARKS 83B Backdraft Damper   Prevents backflow        Fails to open      - Mechanical Failure Alarms in MCR via    Loss of airflow   None (See Remarks)   Redundant Battery Exhaust Fan 0-BKD-31-2162                                                                       Airflow Switch       path through                           A-A starts on Low Air Flow signal 0-FS-31-401          Exhaust Fan                            from Fan B-B Air Flow Switch B-B                                    0-FS-31-401 Fails to close     - Mechanical Failure                      None (See         None (See Remarks)   Isolation Damper 0-FCO-31-29 Remarks)                               prevents backflow 84A Isolation Damper   Isolates Fan A-A when    Close during Fan   - Mechanical Failure Alarm in MCR via     Loss of Airflow   None (See Remarks)   Redundant Battery Exhaust Fan 0-FC0-31-28        on standby               A-A operation      - Electrical Failure Airflow Switch 0-FS- Path through                           B-B starts on Low Air Flow signal 31-402               Exhaust Fan A-                         from Fan A-A Air Flow Switch 0-A                                      FS-31-402.
Open when Fan A- - Mechanical Failure Damper Status          None (See         None (See Remarks)   Backdraft Damper A is on Standby  - Electrical Failure Indication on Panel    Remarks)                               0-BKD-31-2163 will prevent 1-M-9 in MCR via                                              backflow through fan.
Limit Switch ZS                                                                                                                                                     28 84B Isolation Damper   Isolates Fan B-B when    Close during Fan   - Mechanical Failure Alarm in MCR via     Loss of Airflow   None (See Remarks)   Redundant Battery Exhaust Fan 0-FC0-31-29        on standby               B-B operation      - Electrical Failure Airflow Switch 0-FS- Path through                           A-A starts on Low Air Flow signal 31-401               Exhaust Fan A-                         from Fan B-B Air Flow Switch 0-A                                      FS-31-401.
Open when Fan B- - Mechanical Failure Damper Status          None (See         None (See Remarks)   Backdraft Damper 0-BKD                                                                                                               B is on Standby  - Electrical Failure Indication on Panel    Remarks)                               2163 will prevent backflow 1-M-9 in MCR via                                              through fan.
Limit Switch 0-MTR-31-29/BRE-B 9.4-198                                                                                                                                                                                                                                               WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 44 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                    FAILURE         POTENTIAL              FAILURE              EFFECT ON            EFFECT ON NO. IDENTIFICATION          FUNCTION                MODE             CAUSE               DETECTION              SYSTEM                PLANT                     REMARKS 85   Fire Damper      Fire Barrier between     Open during fire    - Mechanical Failure See Remarks           See Remarks       See Remarks          Single failures of HVAC system 0-ISD-31-3940    Mechanical Equipment                                                                                                           need not be postulated as Room 692.0-C2 and                                                                                                              concurrent with fire.
Unit #1 Aux. Instr. Rm 708.0 C1 Close during other - Fusible Link         Surveillance and     None (See         None (See Remarks)   Fire damper has dual fusible links modes of operation Failure                Maintenance          Remarks) 86   Fire Damper      Fire Barrier between     Open during fire    - Mechanical Failure See Remarks           See Remarks       See Remarks          Single failures of HVAC system 0-ISD-31-3939    Unit #1 Aux. Instr.                                                                                                            need not be postulated as Room 708.0 C1 and                                                                                                              concurrent with fire.
Spreading Room Close during other - Fusible Link         Surveillance and     None (See         None (See Remarks)   Fire damper has dual fusible links modes of operation Failure                Maintenance          Remarks) 87   Fire Damper      Fire Barrier between     Open during fire    - Mechanical Failure See Remarks           See Remarks       See Remarks          Single failures of HVAC system 0-ISD-31-3932    Spreading Room and                                                                                                             need not be postulated as MCRHZ                                                                                                                          concurrent with fire.
Close during other - Fusible Link         Surveillance and     None (See         None (See Remarks)   Fire damper has dual fusible links modes of operation Failure                Maintenance          Remarks) 88   Tornado Damper   Isolation during Tornado Fails to close      - Mechanical Failure Status Indication in None (See          None (See Remarks)   Redundant Tornado Damper 0-0-FC0-31-14      Event                    during Tornado      - Electrical Failure Mechanical Equip. Remarks)                                FC0-31-13 powered from Train B Event                                    Rm. via Limit Switch                                         and installed in series ZS-31-14                                                     accomplishes isolation during Tornado Event Isolates exhaust from    Spuriously closes   -Electrical Failure   Loss of Flow Alarm   Loss of           None (See Remarks)   Operator turns on redundant Battery Room Exhaust                                               in MCR, zone         ventilation for                        exhaust fan C-B Fans A-A and B-B                                                   switches ZS-31-13    Battery Rooms WBNP-97 and ZS-31-14 9.4-199

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 45 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                       FAILURE          POTENTIAL                FAILURE              EFFECT ON            EFFECT ON NO. IDENTIFICATION            FUNCTION                 MODE              CAUSE                 DETECTION              SYSTEM                PLANT                      REMARKS 89   Tornado Damper     Isolation during Tornado Fails to close        - Mechanical Failure Status Indication in None (See            None (See Remarks)   Redundant Tornado Damper 0-0-FC0-31-13        Event                    during Tornado        - Electrical Failure Mechanical Equip. Remarks)                                  FC0-31-14 powered from Train A Event                                      Rm. via Limit Switch                                           and installed in series ZS-31-13                                                       accomplishes isolation during Tornado Event Isolates exhaust from     Spuriously closes    -Electrical Failure     Loss of Flow Alarm   Loss of           None (See Remarks)   Operator turns on redundant Battery Room Exhaust                                                   in MCR, zone         ventilation for                        exhaust fan C-B Fans A-A and B-B                                                       switches ZS-31-13    Battery Rooms and ZS-31-14 90   Spreading Room     Supply of Ventilation Air Fails to Stop on     - Electrical Failure                         None (See         None (See Remarks)   Isolation Dampers 0-FC0-31-9 &
Supply Fan         to Spreading Room         CRI signal                                                        Remarks)                               10 are closed during CRI and no air is supplied to Spreading Room 90A Spreading Room       Fan: Supply ventilation   Failure of the        - Mechanical Failure   Surveillance and     None (See         None (See Remarks)   Amount of outleakage generated Non-Safety Supply    air to spreading room     nonsafety related     - Electrical Failure   Maintenance for fan. Remarks)                               by this failure will not increase the Fan and Isolation    dampers: Provide          fan to stop                                  Status indication in                                        total MCRHZ outleakage beyond Damper 0-FC0     isolation of MCRHZ        concurrent with                              MCR on Panel 1-M-                                           the maximum allowable make-up 10 or 0-FC0-31-9     from spreading room       failure of one of the                        9 for dampers.                                              air quantity. Therefore, the two dampers failing                                                                                      positive pressure of 1/8" wg to close on a CRI                                                                                        minimum is maintained even signal                                                                                                   under this failure condition 91   Isolation Damper   Isolation of MCRHZ        Open during CRI      - Mechanical Failure Status Indication in None (See            None (See Remarks)   Redundant Safety Train B 0-FC0-31-10        from Spreading Room                            - Electrical Failure MCR on Panel 1-M- Remarks)                                     Isolation Valve 0-FC0-31-9 9 via Limit Switch                                             installed in series will be closed ZS-31-10                                                       during CRI to provide isolation 92   Isolation Damper   Isolation of MCRHZ        Open during CRI      - Mechanical Failure Status Indication in None (See            None (See Remarks)   Redundant Safety Train A 0-FC0-31-9         from Spreading Room                            - Electrical Failure MCR on Panel 1-M- Remarks)                                     Isolation Valve 0-FC0-31-10 9 via Limit Switch                                             installed in series will be closed ZS-31-9                                                        during CRI to provide isolation 9.4-200                                                                                                                                                                                                                                                           WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 46 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                     FAILURE           POTENTIAL              FAILURE           EFFECT ON        EFFECT ON NO. IDENTIFICATION            FUNCTION               MODE               CAUSE               DETECTION           SYSTEM            PLANT                     REMARKS 93   Fire Damper        Fire barrier between    Open during fire      - Mechanical Failure See Remarks        See Remarks   See Remarks          Single failures of HVAC system 0-ISD-31-3933      Mechanical Equipment                                                                                                     need not be postulated as being Room and Spreading                                                                                                       concurrent with fire Room Close                 - Mechanical Failure Surveillance and   None (See     None (See Remarks)   Spreading Room ventilation is Maintenance        Remarks)                           isolated during CRI 94   Spreading Room     Exhaust of Spreading    Fails to stop during - Electrical Failure                     None (See     None (See Remarks)   Isolation Dampers 0-FC0-31-9 Exhaust Fans (2-   Room                    CRI                                                           Remarks)                           and 0-FC0-31-10 are closed 100%) A-A & B-B                                                                                                                             during CRI 95   Isolation Dampers Isolation of Spreading   Open during CRI      - Mechanical Failure Status Indication in None (See    None (See Remarks)   The fans are stopped during CRI 0-FC0-31-25 for   Room from outside                             - Electrical Failure MCR on Panel 1-M- Remarks)
Fan A-A and 0-                                                                       9 via Limit Switches FCO-31-26 for Fan                                                                    ZS-31-25 & ZS                                                                     B-B                                                                                  26 96   Backdraft Damper   Prevent backflow to     Open during CRI       - Mechanical Failure Surveillance and   None (See     None (See Remarks)   Isolation Dampers 0-FC0-31-25 0-BKD-31-2152      Spreading Room                                                     Maintenance        Remarks)                           and 0-FC0-31-26 are closed during CRI 97   Fire Damper        Fire barrier between    Open during fire      - Mechanical Failure See Remarks        See Remarks   See Remarks          Single failures of HVAC system 0-ISD-31-3953      Spreading Room and                                                                                                       need not be postulated as being Turbine Room                                                                                                             concurrent with fire Closed during other - Mechanical Failure Surveillance and     None (See     None (See Remarks)   Spreading Room ventilation is modes of operation                       Maintenance          Remarks)                           isolated during CRI 9.4-201                                                                                                                                                                                                                                           WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 47 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                    FAILURE           POTENTIAL              FAILURE             EFFECT ON           EFFECT ON NO. IDENTIFICATION           FUNCTION               MODE               CAUSE               DETECTION             SYSTEM               PLANT                      REMARKS 98   Tornado Damper    Isolation during Tornado Fails to close       - Mechanical Failure Status Indication in None (See       None (See Remarks)     Redundant Tornado Damper 0-0-FC0-31-24       Event                    during Tornado       - Electrical Failure Mech Equip Room      Remarks)                               FC0-31-23 powered from Train A (Train B)                                  Event                                     via Limit Switch ZS-                                        and installed in series 31-24                                                       accomplishes isolation during Tornado Event Isolates Battery Room   Closes spuriously     -Electrical Failure   Loss of flow alarm in Loss of         None (See Remarks)   Spreading Room ventilation is not exhaust fans C-B and                                                MCR, zone switches ventilation for                         essential and Battery Rm Exhaust spreading room                                                      ZS-31-23, -24         spreading room                       Fan C-B does not normally run.
exhausts                                                                                  (Battery Rm fan C-B is idle) 99   Tornado Damper    Isolation during Tornado Fails to close       - Mechanical Failure Status Indication in None (See       None (See Remarks)     Redundant Tornado Damper 0-0-FC0-31-23       Event                    during Tornado       - Electrical Failure Mech Equip Room      Remarks)                               FC0-31-24 powered from Train B (Train A)                                  Event                                     via Limit Switch ZS-                                        and installed in series 31-23                                                       accomplishes isolation during Tornado Event Isolates Battery Room   Closes spuriously     -Electrical Failure   Loss of flow alarm in Loss of         None (See Remarks)   Spreading Room ventilation is not exhaust fans C-B and                                                MCR, zone switches ventilation for                         essential and Battery Rm Exhaust spreading room                                                      ZS-31-23, -24         spreading room                       Fan C-B does not normally run.
exhausts                                                                                  (Battery Rm fan C-B is idle) 100   Toilet & Locker   Provide exhaust of      Fails to stop during - Electrical Failure   Surveillance and    None (See       None (See Remarks)     Isolation Dampers 0-FC0-31-16 Room Exhaust      toilets and lockers     CRI                                         Maintenance         Remarks)                               and -17 will close during CRI and Fan                                                                                                                                              prevent exhaust air flow during CRI 9.4-202                                                                                                                                                                                                                                                  WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 48 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                       FAILURE          POTENTIAL                FAILURE             EFFECT ON       EFFECT ON NO. IDENTIFICATION            FUNCTION                 MODE              CAUSE                 DETECTION             SYSTEM           PLANT                       REMARKS 100A Toilet & Locker     Fan: Provides exhaust     Failure of the        - Mechanical Failure   Maintenance for fan. None (See   None                  Amount of outleakage generated Room Non-Safety     of toilets & lockers. nonsafety related     - Electrical Failure   Status indication in Remarks)                          by this failure will not increase the Exhaust Fan &       Dampers: Provide          fan to stop                                  MCR on Panel 1-M-                                      total MCRHZ outleakage beyond Isolation Damper    isolation of MCRHZ        concurrent with                              9 for dampers                                          the maximum allowable make-up 0-FCO-31-17 or 0-   from outside during CRI   failure of one of the                                                                               air quantity. Therefore, the FCO-31-16                                     two dampers failing                                                                                 positive pressure of 1/8" wg to close on a CRI                                                                                   minimum is maintained even signal                                                                                              under this failure condition 101   Isolation Damper   Isolation of MCRHZ      Open during CRI        - Mechanical Failure Status Indication in   None (See    None (See Remarks)    Redundant Safety Train B 0- FCO-31-17       during CRI from outside                        - Electrical Failure Control Room on        Remarks)                           Isolation Damper 0-FCO-31-16 Panel 1-M-9 via                                           will be closed during CRI Limit Switch ZS                                                                                                                                                            17 102   Tornado Damper     Isolation of MCRHZ      Open during CRI        - Mechanical Failure Status Indication in   None (See    None (See Remarks)    Redundant Safety Train A 0-FCO-31-16        during CRI from outside                        - Electrical Failure Control Room on        Remarks)                           Isolation Damper 0-FCO-31-17 Panel 1-M-9 via                                           will be closed during CRI Limit Switch ZS                                                                                                                                                            16 103   Tornado Damper     Isolation of MCRHZ        Fails to close       - Mechanical Failure Status Indication via None (See     None (See Remarks)    Redundant Tornado Damper 0-FCO-31-18        during Tornado Event      during Tornado       - Electrical Failure Limit Switch ZS Remarks)                              0-FCO-31-15 powered from (Train B)                                    Event                                     18                                                        Train A and installed in series accomplishes isolation during Tornado Event 104   Tornado Damper     Isolation of MCRHZ        Fails to close       - Mechanical Failure Status Indication via None (See     None. (See Remarks)   Redundant Tornado Damper 0-FCO-31-15        during Tornado Event      during Tornado       - Electrical Failure Limit Switch ZS Remarks)                              0-FCO-31-18 powered from (Train A)                                    Event                                     15                                                        Train B and installed in series accomplishes isolation during Tornado Event 9.4-203                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 49 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                     FAILURE          POTENTIAL             FAILURE              EFFECT ON         EFFECT ON NO. IDENTIFICATION            FUNCTION               MODE              CAUSE              DETECTION              SYSTEM             PLANT                     REMARKS 105A Emergency Power Provide power to the        Power Train A fails - Mechanical Failure Alarm/indication in   Loss of Train A None (See Remarks)   Redundant Train B Control to Train A      Control Building HVAC                             (Diesel Generator MCR                    Control Building                     Building HVAC System with its System Train A                                    Failure)                                 HVAC Systems                         Train B electrical power is
                                                                                                                                   - Electrical Failure                                                            available 105B Emergency Power Provide power to the        Power Train B fails - Mechanical Failure Alarm/indication in   Loss of Train B None (See Remarks)   Redundant Train A Control to Train B      Control Building HVAC                             (Diesel Generator MCR                    Control Building                     Building HVAC System with its System Train B                                    Failure)                                 HVAC Systems                         Train A electrical power is
                                                                                                                                   - Electrical Failure                                                            available 106A Auxiliary Control  Provide safety related   Loss of Auxiliary  - Mechanical Failure Alarm/indication in    Loss of Train A None (See Remarks)   Redundant Train B Control Air System Train A control air to Train A   Air System Train A - Electrical Failure MCR                    Control Building                     Building HVAC System with Train valves, dampers and                                                                     HVAC Systems                         B Aux. Control Air System is instruments                                                                                                                  available 106B Auxiliary Control  Provide safety related   Loss of Auxiliary  - Mechanical Failure Alarm/indication in    Loss of Train B None (See Remarks)   Redundant Train A Control Air System Train B control air to Train B   Air System Train B - Electrical Failure MCR                    Control Building                     Building HVAC System with Train valves, dampers and                                                                     HVAC Systems                         A Aux. Control Air System is instruments                                                                                                                  available 9.4-204                                                                                                                                                                                                                                              WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 50 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                     FAILURE          POTENTIAL       FAILURE            EFFECT ON        EFFECT ON NO. IDENTIFICATION            FUNCTION               MODE              CAUSE        DETECTION            SYSTEM            PLANT                REMARKS 107   Roof ventilators 1- Provide Turbine        - Loss of power to   - Electrical   Surveillance and   None (See     None            Loss of power to Board 1A stops FAN-30-912, -913, Building El 755'         Board 1A                            maintenance        Remarks)                      five roof ventilators and north
                                                                    -916, -917 & -918 ventilation                                                                                                   supply Fan 1, and results in on Board 1A                                                                                                                     operation of 15 roof ventilators @
28,500 cfm each and north supply 1-FAN-30-909, -                                                                                                                 Fan 2 @ 68,000 cfm and 2 south 910, -911, -914 &                                                                                                               supply fans @ 35,000 cfm each
                                                                    -915 on Board 1B                                                                                                                resulting in lower than atmospheric pressure (68,000 +
2-FAN-30-912, -                                                                                                                 2x35,000 - 15X28,500 = -289,500 913, -916, -917 & -                                                                                                             cfm) 918 on Board 2A 2-FAN-30-909, -
910, -911, -914, & -
915 on Board 2B North El 755                               - Loss of power to                  Surveillance and   None (See     None            Loss of power to Board 1B stops Supply Fan 1, 1-                           Board 1B                            maintenance        Remarks)                      five roof ventilators and south FAN-30-924 on                                                                                                                   supply Fan 1, and results in Board 1A                                                                                                                        operation of 15 roof ventilators @
28,500 cfm each and 2 north South El 755                                                                                                                    supply fan @ 68,000 cfm each Supply Fan 1, 1-                                                                                                                and one South supply fan @
FAN-30-921 on                                                                                                                   35,000 cfm resulting in lower than Board 1B                                                                                                                        atmospheric pressure (2x68,000 cfm + 35,000 - 15X28,500 cfm = -
North El 755                                                                                                                    256,500 cfm)
Supply Fan 2, 2-FAN-30-924 on Board 2A 9.4-205                                                                                                                                                                                                                                  WBNP-97

Table 9.4-7 Failure Modes and Effects Analysis Control Building HVAC (Sheet 51 of 51)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR METHOD OF ITEM   COMPONENT                                      FAILURE          POTENTIAL       FAILURE            EFFECT ON        EFFECT ON NO. IDENTIFICATION             FUNCTION               MODE              CAUSE        DETECTION            SYSTEM            PLANT                REMARKS 107 South El 755                                  - Loss of power to                  Surveillance and   None (See     None            Loss of power to Boards 1B and Cont. Supply Fan 2, 2-                            Boards 1B and 2B                    maintenance        Remarks)                      2B stops 10 roof vents and 2 FAN-30-921 on                                                                                                                    south supply fans and results in Board 2B                                                                                                                         operation of 10 roof vents @
28,500 cfm each and 2 north supply fans @ 35,000 cfm each resulting in lower than atmospheric pressure (2x68,000 cfm 28,500 = -149,000 cfm)
Note:
: 1. Refer to TVA Calculation No. TI-639.
9.4-206                                                                                                                                                                                                                                 WBNP-97

AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Table 9.4-8 Failure Modes and Effects Analysis for Active Failures Subsystem: Auxiliary Building General Ventilation (Sheet 1 of 11)
Item     Component                                                                            Method of                                      Effect on No. Identification       Function         Failure Mode         Potential Cause            Detection            Effect on System            Plant                      Remarks 1     1-FAN-30-103    Fan to stop and       Fan fails to stop   Fan: Spurious           Indicating lights in   Increased in-leakage        None. See    1.Supply fan is not safety- related but is remain stopped        and one damper      operation, ABI or       MCR for Fan 1A         within the ABSCE.           Remarks. required to stop running during a DBE.
Aux. Bldg.      during DBE's.         fails to close      RAD detection high      running indicating General Supply  Dampers to close      during an ABI       temperature signal      lights in MCR for      Potential loss of the                    2.The fan and isolation dampers Fan 1A-A and    and remain closed     emergency.          failure, hot short in   damper.                required negative                        separately receive independently trained associated      during DBE's to                           control wiring.                                pressure level within the                ABI or RAD detection signals.
isolation       prevent flow of                           Operator error                                 ABSCE. Potential loss of Dampers 1-FCO- supply air to the                          (handswitch placed                             duct/damper pressure                     3.If the additional in-leakage through the 30-86,          Aux. Bldg. after an                       in wrong position).                            integrity.                               fan/damper disturbs the system to a point
                                                                     -87, -106 and - ABI signal.                                                                                                                       that one ABGTS filtration unit cannot 107.                                                      Damper:                                                                                 maintain the design negative pressure Mechanical failure,                                                                     level, the standby ABGTS filtration unit control wiring or                                                                       will start in order to handle the additional contact failures.                                                                       in-leakage and to maintain the required Handswitch failure to                                                                   negative pressure level.
spring return from open to A-Auto.                                                                         4.Pressure differential across the duct/damper assembly is acceptable.
: 5. The spurious operation of the supply fans and failure of one damper will not affect the safe shutdown of the plant, in accordance with analyses and test results.
Fan fails to stop   Same as above, plus Same as above.             AB air intake room          None. (See   An analysis has shown that the low with one safety-    the non-safety                                 temperature may reach       Remarks). temperature condition inside the AB air related isolation   building heating                               the minimum outside                      intake room would have no adverse damper failed       system is not                                  design temperature of                    impact on the ability of the plant to cope open during the     operating.                                     13&deg;F                                     with an accident situation.
minimum outside design WBNP-97 conditions.
9.4-207

Table 9.4-8 Failure Modes and Effects Analysis for Active Failures Subsystem: Auxiliary Building General Ventilation (Sheet 2 of 11)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item     Component                                                                                Method of                                      Effect on No. Identification       Function          Failure Mode            Potential Cause            Detection            Effect on System            Plant                     Remarks 2     1-FAN-30-103      Supply fan to stop   Supply fan fails       For Supply Fan:         Indicating lights in   Increase in in-leakage      None. See    1.Supply fan is not safety- related but is and to remain        to stop;               spurious operation,     the MCR.               within the ABSCE.           Remarks. required to stop running during a DBE.
Aux. Bldg.        stopped during       spuriously             ABI or RAD                                                                              Therefore, the only failure having a General Supply    DBE's. To prevent    operates. One          detection high                                 Potential loss of the                    potential effect on the safety functions of Fan 1A-A and      flow of supply air   ABGTS fan fails        temperature signal                             required negative                        the Aux. Bldg. HVAC system is spurious ABGTS Exhaust     to the Aux. Bldg. to start or fails to   failure, hot short in                          pressure level within the                operation or failure to stop.
Fan A-A or B-B    by stopping on an    run.                   control wiring.                                ABSCE. Loss of ABI signal.                                 Operator error                                 redundancy in the                        2.Supply fan failure concurrent with an ABGTS Fan                                   (handswitch placed                             ABGTS.                                   ABGTS failure during a LOCA and FHA operates to                                 in wrong position).                                                                     has been determined not to be credible.
maintain a                                                                                                                          In addition, an analysis has shown that negative pressure                           For ABGTS Fan:                                                                          ABGTS safety functions will not be in the ABSCE                                Mechanical failure,                                                                     impeded by failures in ABI signals or relative to the                             train power failure,                                                                    spurious actuation of AB general supply outside                                     train signal failure.                                                                   fans..
environment.
9.4-208                                                                                                                                                                                                                                                                  WBNP-97

Table 9.4-8 Failure Modes and Effects Analysis for Active Failures Subsystem: Auxiliary Building General Ventilation (Sheet 3 of 11)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item     Component                                                                              Method of                                      Effect on No. Identification       Function           Failure Mode         Potential Cause            Detection            Effect on System            Plant                      Remarks 3     2-FAN-30-105      Fan to stop and       Fan fails to stop   Fan: Spurious           Indicating lights in   Increased in-leakage        None. See    1.Supply fan is not safety- related but is remain stopped        and one damper      operation, ABI or       MCR for Fan 2B         within the ABSCE.           Remarks. required to stop running during a DBE.
Aux. Bldg.        during DBE's.         fails to close      RAD detection high      running indicating General Supply    Dampers to close      during an ABI       temperature signal      lights in MCR for      Potential loss of the                    2.The fan and isolation dampers Fan 2B-B and      and remain closed     emergency.          failure, hot short in   damper.                required negative                        separately receive independently trained associated        during DBE's to                           control wiring.                                pressure level within the                ABI or RAD detection signals.
isolation         prevent flow of                           Operator error                                 ABSCE. Potential loss of Dampers           supply air to the                         (handswitch placed                             duct/damper pressure                     3.If the additional in-leakage through the 2-FCO-30-21, -    Aux. Bldg. after an                       in wrong position).                            integrity.                               fan/damper disturbs the system to a point 22, -108,         ABI signal.                                                                                                                       that one ABGTS filtration unit cannot
                                                                     -109.                                                       Damper:                                                                                 maintain the design negative pressure Mechanical failure,                                                                     level, the standby ABGTS filtration unit control wiring or                                                                       will start in order to handle the additional contact failures.                                                                       in-leakage and to maintain the required Handswitch failure to                                                                   negative pressure level.
spring return from open to A-Auto.                                                                         4.Pressure differential across the duct/damper assembly is acceptable.
: 5. The spurious operation of the supply fans and failure of one damper will not affect the safe shutdown of the plant, in accordance with analyses and test results.
Fan fails to stop   Same as above, plus Same as above.             AB air intake room          None. (See   An analysis has shown that the low with one safety-    the non-safety                                 temperature may reach       Remarks). temperature condition inside the AB air related isolation   building heating                               the minimum outside                      intake room would have no adverse damper failed       system is not                                  design temperature of                    impact on the ability of the plant to cope open during the     operating.                                     13&deg;F                                     with an accident situation.
minimum outside design conditions 9.4-209                                                                                                                                                                                                                                                                 WBNP-97

Table 9.4-8 Failure Modes and Effects Analysis for Active Failures Subsystem: Auxiliary Building General Ventilation (Sheet 4 of 11)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item     Component                                                                                Method of                                      Effect on No. Identification       Function          Failure Mode            Potential Cause            Detection            Effect on System            Plant                     Remarks 4     2-FAN-30-105      Supply fan to stop   Supply fan fails       For Supply Fan:         Indicating lights in   Increase in in-leakage      None. See    1.Supply fan is not safety- related but is and to remain        to stop;               spurious operation. the MCR.               within the ABSCE.           Remarks. required to stop running during a DBE.
Aux. Bldg.        stopped during       spuriously             ABI or RAD                                                                              Therefore, the only failure having a General Supply    DBE's. To prevent    operates. One          detection high                                 Potential loss of the                    potential effect on the safety functions of Fan 2B-B and      flow of supply air   ABGTS fan fails        temperature signal                             required negative                        the Aux. Bldg. HVAC system is spurious ABGTS Exhaust     to the Aux. Bldg. to start or fails to   failure, hot short in                          pressure level within the                operation or failure to stop.
Fan A-A or B-B    by stopping on an    run.                   control wiring.                                ABSCE. Loss of ABI signal.                                 Operator error                                 redundancy in the                        2.Supply fan failure concurrent with an ABGTS Fan                                   (handswitch placed                             ABGTS.                                   ABGTS failure during a LOCA or FHA operates to                                 in wrong position).                                                                     has been determined not to be credible.
maintain a                                                                                                                          Also, see remark No. 2 for Item 2.
negative pressure                           For ABGTS Fan:
in the ABSCE                                Mechanical failure, relative to the                             train power failure, outside                                     train signal failure.
environment.
9.4-210                                                                                                                                                                                                                                                                  WBNP-97

Table 9.4-8 Failure Modes and Effects Analysis for Active Failures Subsystem: Auxiliary Building General Ventilation (Sheet 5 of 11)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item     Component                                                                              Method of                                      Effect on No. Identification        Function          Failure Mode         Potential Cause            Detection            Effect on System            Plant                      Remarks 5     1-FAN-30-102      Fan to stop and       Fan fails to stop   Fan: Spurious           Indicating lights in   Increased in-leakage        None. See    1.Supply fan is not safety- related but is remain stopped        and one damper      operation, ABI or       MCR for Fan 1B         within the ABSCE.           Remarks. required to stop running during a DBE.
Aux. Bldg.        during DBE's.         fails to close      RAD detection high      running indicating General Supply    Dampers to close      during an ABI       temperature signal      lights in MCR for      Potential loss of the                    2.The fan and isolation dampers Fan 1B-B and      and remain closed     emergency.          failure, hot short in   damper.                required negative                        separately receive independently trained associated        during DBE's to                           control wiring.                                pressure level within the                ABI or RAD detection signals.
isolation         prevent flow of                           Operator error                                 ABSCE. Potential loss of Dampers           supply air to the                         (handswitch placed                             duct/damper pressure                     3.If the additional in-leakage through the 1-FCO-30-86, -    Aux. Bldg. after an                       in wrong position).                            integrity.                               fan/damper disturbs the system to a point 87, -106 and -107 ABI signal.                                                                                                                       that one ABGTS filtration unit cannot Damper:                                                                                 maintain the design negative pressure Mechanical failure,                                                                     level, the standby ABGTS filtration unit control wiring or                                                                       will start in order to handle the additional contact failures.                                                                       in-leakage and to maintain the required Handswitch failure to                                                                   negative pressure level.
spring return from open to A-Auto.                                                                         4.Pressure differential across the duct/damper assembly is acceptable.
: 5. The spurious operation of the supply fans and failure of one damper will not affect the safe shutdown of the plant, in accordance with analyses and test results.
Fan fails to stop   Same as above, plus Same as above.             AB air intake room          None. (See   An analysis has shown that the low with one safety-    the non-safety                                 temperature may reach       Remarks). temperature condition inside the AB air related isolation   building heating                               the minimum outside                      intake room would have no adverse damper failed       system is not                                  design temperature of                    impact on the ability of the plant to cope open during the     operating.                                     13&deg;F                                     with an accident situation.
minimum outside design conditions 9.4-211                                                                                                                                                                                                                                                                 WBNP-97

Table 9.4-8 Failure Modes and Effects Analysis for Active Failures Subsystem: Auxiliary Building General Ventilation (Sheet 6 of 11)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item     Component                                                                                Method of                                      Effect on No. Identification       Function          Failure Mode            Potential Cause            Detection            Effect on System            Plant                     Remarks 6     1-FAN-30-102      Supply fan to stop   Supply fan fails       For Supply Fan:         Indicating lights in   Increase in in-leakage      None. See    1.Supply fan is not safety- related but is and to remain        to stop;               spurious operation. the MCR.               within the ABSCE.           Remarks. required to stop running during a DBE.
Aux. Bldg.        stopped during       spuriously             ABI or RAD                                                                              Therefore, the only failure having a General Supply    DBE's. To prevent    operates. One          detection high                                 Potential loss of the                    potential effect on the safety functions of Fan 1B-B and      flow of supply air   ABGTS fan fails        temperature signal                             required negative                        the Aux. Bldg. HVAC system is spurious ABGTS Exhaust     to the Aux. Bldg. to start or fails to   failure, hot short in                          pressure level within the                operation or failure to stop.
Fan A-A or B-B    by stopping on an    run.                   control wiring.                                ABSCE. Loss of ABI signal.                                 Operator error                                 redundancy in the                        2.Supply fan failure concurrent with an ABGTS Fan                                   (handswitch placed                             ABGTS.                                   ABGTS failure during a LOCA or FHA operates to                                 in wrong position).                                                                     has been determined not to be credible.
maintain a                                                                                                                          Also, see remark No. 2 for Item 2.
negative pressure                           For ABGTS Fan:
in the ABSCE                                Mechanical failure, relative to the                             train power failure, outside                                     train signal failure.
environment.
9.4-212                                                                                                                                                                                                                                                                  WBNP-97

Table 9.4-8 Failure Modes and Effects Analysis for Active Failures Subsystem: Auxiliary Building General Ventilation (Sheet 7 of 11)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item     Component                                                                              Method of                                      Effect on No. Identification        Function          Failure Mode         Potential Cause            Detection            Effect on System            Plant                      Remarks 7     2-FAN-30-104      Fan to stop and       Fan fails to stop   Fan: Spurious           Indicating lights in   Increased in-leakage        None. See    1.Supply fan is not safety- related but is remain stopped        and one damper      operation, ABI or       MCR for Fan 2A-A       within the ABSCE.           Remarks. required to stop running during a DBE.
Aux. Bldg.        during DBE's.         fails to close      RAD detection high      running indicating General Supply    Dampers to close      during an ABI       temperature signal      lights in MCR for      Potential loss of the                    2.The fan and isolation dampers Fan 2A-A and      and remain closed     emergency.          failure, hot short in   damper.                required negative                        separately receive independently trained associated        during DBE's to                           control wiring.                                pressure level within the                ABI or RAD detection signals.
isolation         prevent flow of                           Operator error                                 ABSCE. Potential loss of Dampers           supply air to the                         (handswitch placed                             duct/damper pressure                     3.If the additional in-leakage through the 2-FCO-30-21, -    Aux. Bldg. after an                       in wrong position).                            integrity.                               fan/damper disturbs the system to a point 22, -108 and -109 ABI signal.                                                                                                                       that one ABGTS filtration unit cannot Damper:                                                                                 maintain the design negative pressure Mechanical failure,                                                                     level, the standby ABGTS filtration unit control wiring or                                                                       will start in order to handle the additional contact failures.                                                                       in-leakage and to maintain the required Handswitch failure to                                                                   negative pressure level.
spring return from open to A-Auto.                                                                         4.Pressure differential across the duct/damper assembly is acceptable.
: 5. The spurious operation of the supply fans and failure of one damper will not affect the safe shutdown of the plant, in accordance with analyses and test results.
Fan fails to stop   Same as above, plus Same as above.             AB air intake room          None. (See   An analysis has shown that the low with one safety-    the non-safety                                 temperature may reach       Remarks). temperature condition inside the AB air related isolation   building heating                               the minimum outside                      intake room would have no adverse damper failed       system is not                                  design temperature of                    impact on the ability of the plant to cope open during the     operating.                                     13&deg;F                                     with an accident situation.
minimum outside design conditions 9.4-213                                                                                                                                                                                                                                                                 WBNP-97

Table 9.4-8 Failure Modes and Effects Analysis for Active Failures Subsystem: Auxiliary Building General Ventilation (Sheet 8 of 11)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item     Component                                                                                Method of                                      Effect on No. Identification       Function          Failure Mode            Potential Cause            Detection            Effect on System            Plant                     Remarks 8     2-FAN-30-104      Supply fan to stop   Supply fan fails       For Supply Fan:         Indicating lights in   Increase in in-leakage      None. See    1.Supply fan is not safety- related but is and to remain        to stop;               spurious operation. the MCR.               within the ABSCE.           Remarks. required to stop running during a DBE.
Aux. Bldg.        stopped during       spuriously             ABI or RAD                                                                              Therefore, the only failure having a General Supply    DBE's. To prevent    operates. One          detection high                                 Potential loss of the                    potential effect on the safety functions of Fan 2A-A and      flow of supply air   ABGTS fan fails        temperature signal                             required negative                        the Aux. Bldg. HVAC system is spurious ABGTS Exhaust     to the Aux. Bldg. to start or fails to   failure, hot short in                          pressure level within the                operation or failure to stop.
Fan A-A or B-B    by stopping on an    run.                   control wiring.                                ABSCE. Loss of ABI signal.                                 Operator error                                 redundancy in the                        2.Supply fan failure concurrent with an ABGTS Fan                                   (handswitch placed                             ABGTS.                                   ABGTS failure during a LOCA or FHA operates to                                 in wrong position).                                                                     has been determined not to be credible.
maintain a                                                                                                                          Also, see remark No. 2 for Item 2.
negative pressure                           For ABGTS Fan:
in the ABSCE                                Mechanical failure, relative to the                             train power failure, outside                                     train signal failure.
environment.
9     1-FAN-30-159    Fan to stop and        One damper             Damper:               Indicating lights in     None. See remarks.          None. See    1.Exhaust fan is not safety- related but is remain stopped         fails to close         Mechanical failure,   MCR for dampers.                                     Remarks. required to stop runnin during a DBE.
Aux. Bldg.      during DBE's.          during an ABI          control wiring or                                                                       Fan motor is equipped with safety-related General Exhaust Dampers to close       emergency.             contact failures.                                                                       redundant breakers.
Fan 1A-A and    and remain closed      (exhaust fan is        Handswitch failure to associated      during DBE's to        shutdown see           spring return from                                                                      2.The fan and isolation dampers isolation       prevent flow of        remark 1).             open to A-Auto.                                                                         separately receive independently trained Dampers         unfiltered exhaust                                                                                                                    ABI or RAD detection signals.
1-FCO-30-160,- air from Aux. Bldg.
161             to outside, after an                                                                                                                  3. Ventilation space maintained below ABI signal.                                                                                                                           outside pressure. Reverse flow through operable (closed) damper prevents release by fan flow path.
9.4-214                                                                                                                                                                                                                                                                  WBNP-97

Table 9.4-8 Failure Modes and Effects Analysis for Active Failures Subsystem: Auxiliary Building General Ventilation (Sheet 9 of 11)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item     Component                                                                        Method of                               Effect on No. Identification      Function         Failure Mode       Potential Cause           Detection           Effect on System      Plant                     Remarks 10     2-FAN-30-274    Fan to stop and      One damper        Damper:               Indicating lights in   None. See remarks. None. See    1.Exhaust fan is not safety- related but is remain stopped       fails to close    Mechanical failure,   MCR for dampers.                             Remarks. required to stop running during a DBE.
Aux. Bldg.      during DBE's.        during an ABI     control wiring or                                                               Fan motor is equipped with safety-related General Exhaust Dampers to close     emergency.        contact failures.                                                               redundant breakers.
Fan 2A and      and remain closed    (Exhaust fan is   Handswitch failure to associated      during DBE's to      shutdown see      spring return from                                                              2.The fan and isolation dampers dampers         prevent flow of      remark 1).        open to A-Auto.                                                                 separately receive independently trained 2-FCO-30-271, - unfiltered exhaust                                                                                                     ABI or RAD detection signals.
272             air from the Aux.
Bldg. to outside,                                                                                                       3. Venitilation space maintained below after an ABI                                                                                                           outside pressure. Reverse flow through signal.                                                                                                                operable (closed) damper prevents relaease by fan flow path.
11     1-FAN-30-162    Fan to stop and      One damper        Damper:               Indicating lights in   None. See remarks. None. See    1.Exhaust fan is not safety- related but is remain stopped       fails to close    Mechanical failure,   MCR for damper.                              Remarks. required to stop running during a DBE.
Aux. Bldg.      during DBE's.        during an ABI     control wiring or                                                               Fan motor is equipped with safety-related General Exhaust Dampers to close     emergency.        contact failures.                                                               redundant breakers.
Fan 1B and      and remain closed    (Exhaust fan is   Handswitch failure to associated      during DBE's to      shutdown see      spring return from                                                              2.The fan and isolation dampers dampers         prevent flow of      remarks).         open to A-Auto.                                                                 separately receive independently trained 1-FCO-30-166, - unfiltered exhaust                                                                                                     ABI or RAD detection signals.
167             air from the Aux.
Bldg. to outside,                                                                                                      3. Ventilation space maintained below after an ABI                                                                                                           outside pressure. Reverse flow through signal.                                                                                                                operable (closed) damper prevents release by fan flow path.
9.4-215                                                                                                                                                                                                                                                   WBNP-97

Table 9.4-8 Failure Modes and Effects Analysis for Active Failures Subsystem: Auxiliary Building General Ventilation (Sheet 10 of 11)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item     Component                                                                        Method of                               Effect on No. Identification      Function         Failure Mode       Potential Cause           Detection           Effect on System      Plant                     Remarks 12     2-FAN-30-278    Fan to stop and      One damper        Damper:               Indicating lights in   None. See remarks. None. See    1.Exhaust fan is not safety- related but is remain stopped       fails to close    Mechanical failure,   the MCR.                                     Remarks. required to stop running during a DBE.
Aux. Bldg.      during DBE's.        during an ABI     control wiring or                                                               Fan motor is equipped with safety-related General Exhaust Dampers to close     emergency.        contact failures.                                                               redundant breakers.
Fan 2B and      and remain closed    (Exhaust fan is   Handswitch failure to associated      during DBE's to      shutdown see      spring return from                                                              2.The fan and isolation dampers dampers         prevent flow of      remark 1).        open to A-Auto.                                                                 separately receive independently trained 2-FCO-30-275, - unfiltered exhaust                                                                                                     ABI or RAD detection signals.
276             air from the Aux.
Bldg. to outside,                                                                                                      3. Ventilation space maintained below after an ABI                                                                                                           outside pressure. Reverse flow through signal.                                                                                                                operable (closed) damper prevents release by fan flow path.
13     0-FAN-30-136   Fan to stop and       One damper        Damper:               Indicating lights in   None. See remarks. None. See    1.Exhaust fan is not safety- related but is remain stopped        fails to close    Mechanical failure,   the MCR.                                     Remarks. required to stop running during a DBE.
Fuel Handling  during DBE's.         during an ABI     control wiring or                                                               Fan motor is equipped with safety-related Area Exhaust   Dampers to close      emergency.        contact failures.                                                               redundant breakers.
Fan A-A and    and remain closed     (Exhaust fan is   Handswitch failure to associated     during DBE's to       shutdown see      spring return from                                                              2.The fan and isolation dampers dampers 0-FCO- prevent flow of       remark 1).        open to A-Auto.                                                                 separately receive independently trained 30-137, -138   unfiltered exhaust                                                                                                      ABI or RAD detection signals.
air from the Aux.
Bldg. to outside,                                                                                                       3. Ventilation space maintained below after an ABI                                                                                                            outside pressure. Reverse flow through signal.                                                                                                                 operable (closed) damper prevents release by fan flow path.
9.4-216                                                                                                                                                                                                                                                   WBNP-97

Table 9.4-8 Failure Modes and Effects Analysis for Active Failures Subsystem: Auxiliary Building General Ventilation (Sheet 11 of 11)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item     Component                                                                    Method of                               Effect on No. Identification      Function        Failure Mode      Potential Cause         Detection           Effect on System      Plant                     Remarks 14     0-FAN-30-139   Fan to stop and      One damper        Damper:               Indicating lights in None. See remarks. None. See    1.Exhaust fan is not safety- related but is remain stopped       fails to close    Mechanical failure,   the MCR for damper.                       Remarks. required to stop running during a DBE.
Fuel Handling  during DBE's.        during an ABI     control wiring or                                                            Fan motor is equipped with safety-related Area Exhaust   Dampers to close     emergency.        contact failures.                                                            redundant breakers.
Fan B-B and    and remain closed    (Exhaust fan is   Handswitch failure to associated     during DBE's to      shutdown see      spring return from                                                           2.The fan and isolation dampers dampers 0-FCO- prevent flow of      Remark 1).        open to A-Auto.                                                              separately receive independently trained 30-140, -141   unfiltered exhaust                                                                                                  ABI or RAD detection signals.
air from the Aux.
Bldg. to outside,                                                                                                   3. Ventilation space maintained below after an ABI                                                                                                        outside pressure. Reverse flow through signal.                                                                                                             operable (closed) damper prevents release by fan flow path.
9.4-217                                                                                                                                                                                                                                               WBNP-97

AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Table 9.4-8A Failure Modes And Effects Analysis for Active Failures for Components Common to the Aux Bldg Hvac Subsystem (Sheet 1 of 2)
Method of Item No. Component             Function          Failure Mode      Potential Cause           Detection          Effect on System        Effect on Plant                Remarks 1       Auxiliary Building Deenergizes          Signal fails.      Train A vital ac bus   MCR indiation of     Loss of redundancy in None. (See Remarks)     Train A and Train B ABI Isolation (ABI)    solenoid valves to                      failure; Relay VKA     only one train of    ABSCE isolation and                           initiating signals are derived signal Train A. close associated                        1 failure; Train A     ABGTS fan starting   ESF coolers actuation.                        from independent (train dampers; stops AB                       initiating signal      and one train of                                                   separated) qualified devices.
general ventilation                     (Phase A               ABSCE dampers fans; starts various                    containment            closing.                                                           Either train signal will stop all ESF room coolers.                       isolation, high rad                                                                       general supply and exhaust in refueling area)                                                                        fans, and fuel handling area failure.                                                                                  exhaust fans. An analysis has shown that the failure of an Operator error,                              Unnecessary isolation                         ABI signal will not have an Spurious signal. spurious initiating     None.                of ABSCE, initiation of None. (See Remarks)   adverse effect on the ABGTS signal (initiating                           ESF coolers and                               safety function.
signals listed                               startup of ABGTS.
above.)
2       Auxiliary Building Deenergizes          Signal fails.      Train B vital ac bus   MCR indiation of     Loss of redundancy in None. (See Remarks)     Train A and Train B ABI Isolation (ABI)    solenoid valves to                      failure; Relay         only one train of    ABSCE isolation and                           initiating signals are derived signal Train B. close associated                        VKB1 failure; Train    ABGTS fan starting   ESF coolers actuation.                        from independent (train dampers; stops AB                       B initiating signal    and one train of                                                   separated) qualified devices.
general ventilation                     (Phase A               ABSCE dampers fans; starts various                    containment            closing.                                                           Either train signal will stop all ESF room coolers.                       isolation, high rad                                                                       general supply and exhaust in refueling area)                                                                        fans, and fuel handling area failure.                                                                                  exhaust fans. An analysis has shown that the failure of an Operator error,                              Unnecessary isolation                         ABI signal will not have an Spurious signal. spurious initiating     None.                of ABSCE, initiation of None. (See Remarks)   adverse effect on the ABGTS signal (initiating                           ESF coolers and                               safety function.
WBNP-97 signals listed                               startup of ABGTS.
9.4-218 above.)

Table 9.4-8A Failure Modes And Effects Analysis for Active Failures for Components Common to the Aux Bldg Hvac Subsystem (Sheet 2 of 2)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Method of Item No. Component       Function       Failure Mode    Potential Cause       Detection         Effect on System        Effect on Plant              Remarks 3       Train A       Provides Class 1E Loss of or      Diesel generator    Alarm and indication Loss of redundancy in None. (See Remarks)   Redundant Train B HVAC Emergency     diesel-backed     inadequate      failure; bus fault  in MCR.              safety-related HVAC                         system available.
Power.        power supply to   voltage.        (Train A); Operator                      system.
active components                 error.
of Train A of AB HVAC subsystems.
4       Train B       Provides Class 1E Loss of or      Diesel generator    Alarm and indication Loss of redundancy in None. (See Remarks)   Redundant Train AHVAC Emergency     diesel-backed     inadequate      failure; bus fault  in MCR.              safety-related HVAC                         system available.
Power.        power supply to   voltage         (Train B); Operator                      system.
active components                 error.
of Train B of AB HVAC subsystems.
9.4-219                                                                                                                                                                                                                                WBNP-97

AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Table 9.4-8B Failure Modes and Effects Analysis for Auxiliary Building HVAC Subsystem Passive Failures (Sheet 1 of 2)
Method of Item No. Component             Function          Failure Mode     Potential Cause         Detection          Effect on System           Effect on Plant              Remarks 1       Intake opening      Provides air supply Blockage          Mechanical         -----------------      Loss of Redundancy       None. (See Remarks)   Redundant intake opening will (one for each of    intake to 480V                        Failure. Foreign                          in providing air supply.                       supply sufficient air to the room two dampers in      Transformer Room                      Object.
each Transformer    1A, 1B, 2A, and                                                                 Redundant intake Room).              2B.                                                                             opening will supply sufficient air to the room.
2       Refrigerant         Provides flowpath Leakage             Cracks             No direct indication   Loss of effectiveness    None. (See Remarks)   Redundant Chillers and AHUs Piping and Valves   for refrigerant from                                     of leakage.            of one Chiller and                             are provided.
for Chiller or      Chiller to AHU and                                                              associated AHUs Condensing Unit     back to Chiller.                                                                redundant loop.
Opposite Train Chiller and AHUs are independent and remain available.
3                           Close in the event   Spuriously       See Remarks        See Remarks            None. (See Remarks) None. (See Remark #2.) 1Double fusible links will of fire.             closes.                                                                                               prevent spurious closure..
Fire Dampers 2.An analysis has shown that fire dampers have no identifiable realistic failure mechanisms as passive components.
3.Single active failure is not postulated per WB-DC-40-64 Design Basis Events Design Criteria.
Fails to close   See Remarks        See Remarks            None. (See Remarks) None. (See Remarks)        Fire Protection Report postulates no failures other WBNP-97 than those directly attributable 9.4-220 to the fire.

Table 9.4-8B Failure Modes and Effects Analysis for Auxiliary Building HVAC Subsystem Passive Failures (Sheet 2 of 2)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Method of Item No. Component              Function        Failure Mode   Potential Cause        Detection             Effect on System            Effect on Plant              Remarks 4       Ductwork in the      Provides            Leakage        Cracks            --------------------------- Minimal localized       None                 Only small cracks are Auxiliary Building   containment for air                                                              reduction of negative                        postulated due to seismic Gen. Vent and        flow path and                                                                    pressure and                                 qualification of ductwork. Most A/C subsystems       controlled                                                                       minimized effect on                          of air leaking from flow path distribution and                                                                 temperature of areas.                        will enter the areas for which it exhausting of                                                                                                                 is intended.
cooling/ventilating air.                                                                                                                          Loss of fluid (air) is not a concern since the system is in the same fluid.
9.4-221                                                                                                                                                                                                                                                         WBNP-97

AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 1 of 26)
Item No.        Component           Function       Failure Mode        Potential Cause       Method of Detection Effect on System    Effect on Plant                  Remarks 1     0-CHR-31-36/2-A       Provides        Fails to start; Fails Mechanical failure;   Annunciator of       (See Remarks)     None               1.Equipment includes CW pump and chilled water   while running.        Train A power         Shutdown Board                                            motor and compressor and motor.
Chilled Water         to Train A                            failure; Control      Room HVAC System                       (See Remarks)
Package A-A (Train A) AHUs.                                 signal failure from   A-A Abnormal.                                             2.Control of the CWCP, 0-PMP                                                                                                                                  0-PDIS-31-101-A;      Indicating lights in                                      36/1-A, and AHUs A-A and B-A is 0-FS-31-43-A;         MCR (0-HS-31-400A).                                       interlocked with Chiller A-A.
0-FS-31-38-A;         Compressor running                                        3.The system design intent is such 0-TS-31-40B-A; and    light on MCC.                                             that loss of one chiller results only in O-TS-31-48B-A.                                                                  the loss of redundancy in providing chilled water for cooling Unit 1 and Unit 2 Shutdown Board Rooms. The redundant train chiller serves AHUs C-B and D-B. Chiller A-A will stop automatically and Chiller B-B will start automatically on:
Low DP at Circulating Water Cooling Pump for Chiller A-A.
T > Setpoint at air inlet to Train A AHUs.
Low air flow at AHU A-A or B-A.
4.The switchover to the standby chiller uses separation relays in a non-divisional Train A associated power supply.
9.4-222                                                                                                                                                                                                                                                     WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 2 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.         Component           Function       Failure Mode        Potential Cause       Method of Detection Effect on System          Effect on Plant                  Remarks 1     0-CHR-31-36/2-A                       Reduction of         Loss of refrigerant;   Inlet temperature        Loss of             None, (See (cont                                         cooling capacity     Chiller freeze up;     indication on L-551 or   redundancy in       remarks)
Chilled Water                                              Control signal         L-538 for AHU air        cooling air flow.
Package A-A                                                failure.               intake in 6.9 kV (Train A) (cont'd)                                                                Shutdown Board           See remark #3.
Room.
See remark #1.
2      0-CHR-31-49/2-B       Provides        Fails to start; Fails Mechanical failure;   Annunciation of          Loss of             None, See remark   1.Equipment includes CW pump &
chilled water   while running         Train B power         Shutdown Board           Redundancy          #3                 motor and compressor & motor.
Chilled Water Package to Train B                            failure; Control      Room Hvac System                                                2.Control of the CWCP, 0-PMP                                                                       B-B (Train B)         AHUs.                                 signal failure from   B-B Abnormal.                                                   49/1-B, and AHUs C-B and D-B is 0-PDIS-31-131-B,      Indicating lights in                                            interlocked with Chiller B-B.
0-FS-31-51-B,         MCR (0-HS-31-49A).                                              3.The system design intent is such 0-FS-31-57-B,         Compressor running                                              that loss of one chiller results only in 0-TS-31-60B-B,        light on MCC.                                                   the loww of redundancy in providing 0-TS-31-52B-B.                                                                        chilled water for cooling Unit 1 and Unit 2 Shutdown Board Rooms. The redundant train dchiller seves AHUs A-A and B-A. Chiller B-B will stop automatically and Chiller A-A will start automatically on:
Low DP at Circulating Water Cooling Pump for Chiller B-B.
T > Setpoint at air inlet to Train B AHUs.
Low air flow at AHU C-B or D-B.
4.The switchover to the standby chiller uses separation relays in a non-divisional Train A associated WBNP-97 power supply.
9.4-223

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 3 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.         Component           Function     Failure Mode       Potential Cause       Method of Detection Effect on System        Effect on Plant   Remarks 2     0-CHR-31-49/2-B                     Reduction of        Loss of refrigerant;   Inlet temperature      Loss of             None, (See (cont                                       cooling capacity. chiller freeze up;     indication on L-540 or redundancy in       remarks)
Chilled Water Package                                   Control signal         L-537 for AHU air      cooling air flow.
B-B (Train B) (cont'd)                                  failure.               intake in 6.9 kV Shutdown Board Room.
9.4-224                                                                                                                                                                                                                      WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 4 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.        Component            Function         Failure Mode         Potential Cause      Method of Detection Effect on System           Effect on Plant                     Remarks 3     0-AHU-31-45             Provides       Fails to start; Fails   Mechanical Failure;   Annunciation of        Loss of               None. Redundant         Review of the schematics cooling air to while running.          Train A power         Shutdown Board         redundancy in         Train B Chiller B-B     establishes that the AHUs A-A and Air Handling Unit A-A   maintain                               failure. Control      Room HVAC System       cooling air to Unit   and AHU C-B on          C-B (on Unit 1 side) are (Train A)               required                               signal failure;       A-A Abnormal.          1 side Shutdown       Unit 1 side will        independent.
temperatures                           sensing failure for   Indicating lights in   Board rooms.          automatically start for Shutdown                           0-TS-31-40A or        MCR (0-HS-31-400A-                           on:                     AHU A-A is interlocked to Board Rooms                            0-TS-31-48A           A). AHU A-A running                                                  automatically start on Chiller A-A safety-related                                               light on MCC.                                    Low DP at          start.
equipment on                                                                                                   Circulating the Unit 1                                                                                                     Chilled Water      Either train of AHUs (Train A AHUs side.                                                                                                          Pump.              A-A and B-A or Train B AHUs C-B Low Air flow at    and D-B) is capable of providing cooling air to the Aux. Control Room.
AHU A-A or T > Setpoint at inlet to Train A AHU.
Fails to stop or     Electrical Failure      Annunciation in the    Increased          None (See                  When both Air Handling Units are starts while unit C-                         MCR.                   pressure in supply Remarks)                   operating the common ductwork B is operating.                                                     duct.                                         static pressure does not exceed 6 in. wg. duct design pressure.
9.4-225                                                                                                                                                                                                                                                                WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 5 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.        Component            Function         Failure Mode         Potential Cause      Method of Detection Effect on System           Effect on Plant                     Remarks 4     0-AHU-31-44             Provides       Fails to start; Fails   Mechanical Failure;   Annunciation of        Loss of               None.                   Review of the schematics cooling air to while running.          Train A power         Shutdown Board         redundancy in         Redundant Train B       establishes that the AHUs B-A and Air Handling Unit B-A   maintain                               failure; control      Room HVAC System       cooling air to Unit   Chiller B-B and         D-B (on Unit 2 side) are (Train A)               required                               signal failure;       A-A Abnormal.          2 side Shutdown       AHU D-B on Unit 2       independent.
temperatures                           sensing failure for   Indicating lights in   Board rooms.          side will for Shutdown                           0-TS-31-40A or        MCR (0-HS-31-400A-                           automatically start     AHU B-A is interlocked to Board Rooms                            0-TS-31-48A.          A). AHU B-A running                          on:                     automatically start on Chiller A-A Safety-related                                               light on MCC.                                                        start.
equipment on                                                                                                  Low DP at the Unit 2                                                                                                     Circulating        Either train of AHUs (Train A AHUs side.                                                                                                          Chilled Water      A-A and B-A or Train B AHUs C-B Pump.              and D-B) is capable of providing Low Air flow at    cooling air to the Aux. Control Room.
AHU B-A or T > Setpoint at inlet to Train A AHU.
Fails to stop or     Electrical Failure      Annunciation in the    Increased          None (See                  When both Air Handling Units are starts while unit D-                         MCR.                   pressure in supply Remarks)                   operating, the common ductwork B is operating.                                                     duct.                                         static pressure does not exceed 6 in. wg. duct design pressure.
9.4-226                                                                                                                                                                                                                                                                WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 6 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.        Component            Function         Failure Mode         Potential Cause      Method of Detection Effect on System           Effect on Plant                     Remarks 5     0-AHU-31-55             Provides       Fails to start; Fails   Mechanical Failure;   Annunciation of        Loss of               None.                   Review of the schematics cooling air to while running.          Train B power         Shutdown Board         redundancy in         Redundant Train A       establishes that the AHUs A-A and Air Handling Unit C-B   maintain                               failure. Control      Room HVAC System       cooling air to Unit   Chiller A-A and         C-B (on Unit 1 side) are (Train B)               required                               signal failure;       B-B Abnormal.          1 side Shutdown       AHU A-A on Unit 1       independent.
temperatures                           sensing failure for   Indicating lights on   Board rooms.          side will for Shutdown                           0-TS-31-52A or        MCR (0-HS-31-49A-                            automatically start     AHU C-B is interlocked to Board Rooms                            0-TS-31-60A           B). AHU C-B running                          on:                     automatically start on Chiller B-B safety-related                                               light on MCC.                                                        start.
equipment on                                                                                                  Low DP at the Unit 1                                                                                                     Circulating        Either train of AHUs (Train A AHUs side.                                                                                                          Chilled Water      A-A and B-A or Train B AHUs C-B Pump.              and D-B) is capable of providing Low Air flow at    cooling air to the Aux. Control Room.
AHU C-B or T > Setpoint at inlet to Train B AHU.
Fails to stop or     Electrical Failure      Annunciation in the    Increased          None (See                  When both Air Handling Units are starts while unit A-                         MCR.                   pressure in supply Remarks)                   operating, the common ductwork A is operating.                                                     duct.                                         static pressure does not exceed 6 in. wg. duct design pressure.
9.4-227                                                                                                                                                                                                                                                                WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 7 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.        Component            Function         Failure Mode         Potential Cause      Method of Detection Effect on System           Effect on Plant                     Remarks 6     0-AHU-31-61             Provides       Fails to start; Fails   Mechanical Failure;   Annunciation of        Loss of               None.                   Review of the schematics cooling air to while running.          Train B power         Shutdown Board         redundancy in         Redundant Train A       establishes that the AHUs B-A and Air Handling Unit D-B   maintain                               failure; control      Room HVAC System       cooling air to Unit   Chiller A-A and         D-B (on Unit 2 side) are (Train B)               required                               signal failure;       B-B Abnormal.          2 side Shutdown       AHU A-A on Unit 2       independent.
temperatures                           sensing failure for   Indicating lights in   Board rooms and       side will for Shutdown                           0-TS-31-52A or        MCR (0-HS-31-49A-      480V Shutdown         automatically start     AHU D-B is interlocked to Board Rooms                            0-TS-31-60A           B). AHU D-B running    Board Room Unit       on:                     automatically start on Chiller B-B safety-related                                               light on MCC.          2 side.                                       start.
equipment on                                                                                                  Low DP at the Unit 2                                                                                                     Circulating        Either train of AHUs (Train A AHUs side.                                                                                                          Chilled Water      A-A and B-A or Train B AHUs C-B Pump.              and D-B) is capable of providing Low Air flow at    cooling air to the Aux. Control Room.
AHU D-B or T > Setpoint at inlet to Train B AHU.
Fails to stop or       Electrical Failure    Annunciation in the    Increased          None (See                  When both Air Handling Units are starts while unit                            MCR.                   pressure in supply Remarks)                   operating, the common ductwork A-A is operating.                                                   duct.                                         static pressure does not exceed 6 in. wg. duct design pressure.
9.4-228                                                                                                                                                                                                                                                                WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 8 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.        Component           Function       Failure Mode         Potential Cause        Method of Detection Effect on System             Effect on Plant                    Remarks 7     0-PMP-31-36/1-A       Provides        Fails to start; Fails Mechanical failure;     Annunciator 2-113 for      Loss of             None.                 Control of 0-PMP-31-36/1-A is water to the    while running.        Train A power           0-PDIS-31-101-A.           redundancy in       Redundant Train B     interlocked with Chiller A-A to Chilled Water Package Water Chiller                         failure; Control        Indicating lights for 0-   supplying cooling   Chiller B-B will      automatically start after chiller start.
A-A                   A-A loop.                             signal failure; start   HS-31-400A in MCR.         air to the          automatically start   Review of the control and schematic Cooling Water                                               signal failure;                                    Shutdown Board      on Lo DP at the       diagrams establishes the Circulating Pump                                            operator error          Chilled water              Rooms of both       pump and will         redundancy and independence of (handswitch placed      Temperature and            units.              provide cooling       the Train A and Train B pumps.
in wrong position). Pressure indication on                         water to AHUs C-B L-541.                                         and D-B.
8     0-PMP-31-49/1-B       Provides        Fails to start; Fails Mechanical failure;     Annunciator 2-120 for      Loss of             None.                 0-PMP-31-49/1-B is interlocked to water for to    while running.        Train B power           0-PDIS-31-131-B.           redundancy in       Redundant Train A     automatically start after Chiller B-B Chilled Water Package the Water                             failure; Control        Indicator lights for 0-    supplying cooling   Chiller A-A will      start. Review of the control and B-B Cooling Water     Chiller B-B                           signal failure; start   HS-31-49A in MCR.          air to the          automatically start   schematic diagrams establishes the Circulating Pump      loop.                                 signal failure;                                    Shutdown Board      on Lo DP at the       redundancy and independence of operator error          Chilled Water              Rooms of both       pump and will         the Train A and Train B pumps.
(handswitch placed      Temperature and            units.              provide cooling in wrong position). Pressure indication on                         water to AHUs A-A L-542.                                         and B-A.
9.4-229                                                                                                                                                                                                                                                                  WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 9 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.       Component           Function       Failure Mode        Potential Cause     Method of Detection Effect on System        Effect on Plant                   Remarks 9     TCV-31-112            Provides        Spuriously bypass Mechanical failure;    See Remark #1.      Potential loss of     None.                 1.Local indication on L-551 of inlet control of      too much flow. Control Air failure;                       redundancy of         Redundant Train B     air temperature to AHU A-A.
Temperature Control   water                             Sensor failure.                            Train A Chiller A-A   Chiller B-B and Valve for AHU A-A. temperature                                                                  and AHU A-A           associated AHUs       2.Temp. rise in Shutdown rooms >
to AHU A-A                                                                   resulting in air      C-B and D-B can       Setpoint will automatically cause from Chiller A-                                                              temperature rise in   provide cooling air   Train A Chiller with AHUs A-A and B-A by                                                                         Shutdown Board        supply.               A to stop, and Train B with AHUs C-regulating the                                                               Room.                                       B and D-B to start.
flow of chilled                                                                                    See Remark #2.
water to AHU.                                                                                                            3.The temperature control valves for the AHUs are served by the Aux. Air Supply. The trains are separate.
Provides        Spuriously bypass Mechanical failure;    See Remark #1.      Potential loss of     None.                 1.Local indication on L-538 of inlet 10     0-TCV-31-108 control of      too much flow. Control Air failure;                       redundancy of         Redundant Train B     air temperature to AHU B-A.
water                             Sensor failure.                            Train A Chiller A-A   Chiller B-B and Temperature Control   temperature                                                                  and AHU B-A           associated AHUs       2.Temp. rise in Shutdown rooms >
Valve for AHU B-A. to AHU B-A                                                                   resulting in air      C-B and D-B can       Setpoint will automatically cause from Chiller A-                                                              temperature rise in   provide cooling air   Train A Chiller with AHUs A-A and B-A by                                                                         Shutdown Board        supply.               A to stop, and Train B with AHUs C-regulating the                                                               Room.                                       B and D-B to start.
flow of chilled                                                                                    See Remark #2.
water to AHU.                                                                                                            3.The temperature control valves for the AHUs are served by the Aux. Air Supply. The trains are separate.
9.4-230                                                                                                                                                                                                                                                    WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 10 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.       Component           Function       Failure Mode        Potential Cause     Method of Detection Effect on System        Effect on Plant                   Remarks 11     0-TCV-31-142          Provides        Spuriously bypass Mechanical failure;    See Remark #1.      Potential loss of     None.                 1.Local indication on L-537 of inlet control of      too much flow. Control Air failure;                       redundancy of         Redundant Train A     air temperature to AHU C-B.
Temperature Control   water                             Sensor failure.                            Train B Chiller B-B   Chiller A-A and Valve for AHU C-B. temperature                                                                  and AHU C-B           associated AHUs       2.Temp. rise in Shutdown rooms >
to AHU C-B                                                                   resulting in air      A-A and B-A can       Setpoint will automatically cause from Chiller B-                                                              temperature rise in   provide cooling air   Train B Chiller with AHUs C-B and B by                                                                         Shutdown Board        supply.               D-B to stop and Train A with AHUs regulating the                                                               Room.                                       A-A and B-A to start.
flow of chilled                                                                                    See Remark #2.
water to AHU.                                                                                                            3.The temperature control valves for the AHUs are served by the Aux. Air Supply. The trains are separate.
12     0-TCV-31-138          Provides        Spuriously bypass Mechanical failure;    See Remark #1.      Potential loss of     None.                 1.Local indication on L-540 of inlet control of      too much flow. Control Air failure;                       redundancy of         Redundant Train A     air temperatures to AHU D-B.
Temperature Control   water                             Sensor failure.                            Train B Chiller B-B   Chiller A-A and Valve for AHU D-B. temperature                                                                  and AHU D-B           associated AHUs       2.Temp. rise in Shutdown rooms >
to AHU D-B                                                                   resulting in air      A-A and B-A can       Setpoint will automatically cause from Chiller B-                                                              temperature rise in   provide cooling air   Train B Chiller with AHUs C-B and B by                                                                         Shutdown Board        supply.               D-B to stop and Train A with AHUs regulating the                                                               Room.                                       A-A and B-A to start.
flow of chilled                                                                                    See Remark #2.
water to AHU.                                                                                                            3.The temperature control valves for the AHUs are served by the Aux. Air Supply. The trains are separate.
9.4-231                                                                                                                                                                                                                                                    WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 11 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.       Component         Function        Failure Mode       Potential Cause      Method of Detection Effect on System            Effect on Plant                  Remarks 13     0-BKD-31-2706       Prevents        Fails to backseat   Mechanical failure. See Remarks             A) Loss of cooling None. (See              1.Indirect indication of functional backflow of                                                                       air to room served Remarks)                failure of AHU; MCR indication of Backdraft Damper    cooling air                                               Local position          by the AHU                                 AHU A-A and B-A motors running; through                                                   indicators on the                                                  local indication on L-551 of high inlet standby AHU                                               damper will indicate if B) Bypass flow                             temp. to AHU A-A.
C-B when                                                  damper is stuck open. through the AHU A-A is                                                                        standby unit can                           2.Operability of the dampers is running.                                                                          cause standby fan                          periodically verified.
to rotate in reverse. Due to loss of cooling to room. Standby unit is required to start but may fail as a result of motor overload to overcome the reverse rotation.
C) This would result in the total loss of cooling air                        1.Normally opens when AHU is in the Shutdown                            running.
Board Rooms See Remark #2.                                                   2.Indirect indication of functional Provides flow   Fails to open       Mechanical failure.                           Loss of               None.              failure of AHU; local indication on path for air    (Stuck closed)                                                    redundancy in         Low flow from AHU L-537 of inlet temperature to flow from       when AHU C-B is                                                   cooling air flow      will automatically AHU C-B.
AHU.            running (Train B)                                                 from Shutdown         initiate Train "A" Board Room.           chiller and AHUs.
9.4-232                                                                                                                                                                                                                                                         WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 12 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.       Component         Function       Failure Mode        Potential Cause      Method of Detection Effect on System              Effect on Plant                   Remarks 14     0-BKD-31-2761       Prevents       Fails to backseat. Mechanical failure. See Remark #1.            A) Loss of cooling None. (See               1.Indirect indication of functional backflow of                                               Local position            air to room served Remarks)                 failure of AHU; MCR indication of Backdraft Damper    cooling air                                               indicators on the         by the AHU.                                 AHU B-A and A-A motors running; through                                                   damper will indicate if                                               local indication on L-538 of high inlet standby AHU                                               damper is stuck open      B) Bypass flow                              temperature to AHU B-A.
D-B when                                                  when the fan is idle. through the AHU B-A is                                                                          standby unit can                            2.Operability of the dampers is running.                                                                            cause standby fan                           periodically verified..
to rotate in reverse. Due to loss of cooling to room, Standby unit is required to start but may fail as a result of motor overload to overcome the reverse rotation.
C) This would result in the total loss of cooling air in the Shutdown Board Rooms.                                1.Normally opens when AHU is running.
2.Indirect indication of functional Provide flow   Fails to open        Mechanical failure    See Remark #2.            Loss of                None.                failure of AHU; local indication on path for air   (Stuck closed)                                                       redundancy in                               L-540 of inlet temp. to AHU D-B.
flow from      when AHU D-B is                                                      cooling air flow       Low flow from AHU AHU.           running (Train B)                                                    from Shutdown          will automatically board Room.            initiate Train "A" WBNP-97 Chiller and AHUs.
9.4-233

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 13 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.       Component         Function       Failure Mode        Potential Cause      Method of Detection Effect on System               Effect on Plant                 Remarks 15     0-BKD-31-2705       Prevents       Fails to backseat. Mechanical failure. See Remark #1.            A) Loss of cooling None. (See               1.Indirect indication of functional backflow of                                               Local position            air to room served Remarks)                 failure of AHU; MCR indication of Backdraft Damper    cooling air                                               indicators on the         by the AHU.                                 AHU C-B and D-B motors running; through                                                   damper will indicate if                                               local indication on L-537 of inlet standby AHU                                               damper is stuck open. B) Bypass flow                              temperature to AHU C-B.
A-A when                                                                            through the AHU C-B is                                                                          standby unit can                            2.Operability of the dampers is running.                                                                            cause standby fan                           periodically verified..
to rotate in reverse. Due to loss of cooling to room, Standby unit is required to start but may fail as a result of motor overload to overcome the reverse rotation.
C) This would result in the total loss of cooling air in the Shutdown Board Rooms.                                1.Normally opens when AHU is running.
2.Indirect indication of functional Provide flow   Fails to open        Mechanical failure. See Remark #2.            Loss of                None.              failure of AHU; local indication on path for air   (Stuck closed)                                                       redundancy in                             L-551 of inlet temperature to flow from      when AHU A-A is                                                      cooling air flow       (Low flow from AHU AHU A-A.
AHU.           running.                                                             from Shutdown          will automatically Board Room.            initiate Train B WBNP-97 Chiller and AHUs.)
9.4-234

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 14 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.       Component         Function       Failure Mode        Potential Cause      Method of Detection Effect on System               Effect on Plant                 Remarks 16     0-BKD-31-2760       Prevents       Fails to backseat. Mechanical failure. See Remark #1.            A) Loss of cooling None. (See               1.Indirect indication of functional backflow of                                               Local position            air to room served Remarks)                 failure of AHU; MCR indication of Backdraft Damper    cooling air                                               indicators on the         by the AHU.                                 AHU D-B and C-B motors running; through                                                   damper will indicate if                                               local indication on L-540 of inlet standby AHU                                               damper is stuck open. B) Bypass flow                              temperature to AHU D-B.
B-A when                                                                            through the AHU D-B is                                                                          standby unit can                            2.Operability of the dampers is running.                                                                            cause standby fan                           periodically verified..
to rotate in reverse. Due to loss of cooling to room, Standby unit is required to start but may fail as a result of motor overload to overcome the reverse rotation.
C) This would result in the total loss of cooling air in the Shutdown Board Rooms.                                1.Normally opens when AHU is running.
2.Indirect indication of functional Provide flow   Fails to open        Mechanical failure. See Remark #2.            Loss of                None.              failure of AHU; local indication on path for air   (Stuck closed)                                                       redundancy in          (Low flow from AHU L-538 of inlet temperature to flow from      when AHU B-A is                                                      cooling air flow       will automatically AHU B-A.
AHU.           running.                                                             from Shutdown          initiate Train "B" Board Room.            chiller and AHUs).
9.4-235                                                                                                                                                                                                                                                        WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 15 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.        Component            Function        Failure Mode           Potential Cause       Method of Detection Effect on System         Effect on Plant                 Remarks 17     0-FAN-31-62-A           Provides        Fails to start, fails   Mechanical failure;    Indicating lights in   Loss of             None.               1.The pressurizing fans are not pressur-        while running.          Train A power          MCR (1-HS-31-64A)      redundancy in                           required to mitigate the effects of a Pressurizing Air Supply ization to                              failure; Control       and CISP indicating    providing                               DBE.
(After trip due to lo Fan A-A                 maintain                                signal failure.        lights in MCR          pressurization to   suction flow to Fan 6.9kV                                                          (1-HS-31-64A).         6.9 kV Shutdown     A-A, the redundant 2.Fans can be restarted after reset Shutdown                                                                              Board Room.         Train B Fan C-B will after Phase A CIS from Unit 1.
Board Room                                                                                                automatically start.) Review of the schematics at slightly                                                                           See Remark #1.                            establishes the separation and positive                                                                                                                        independence of the Train A and pressure with                                                                                                                   Train B fans.
respect to atmosphere.
Indicating lights in                       None Fails to stop.          Mechanical failure;    MCR and CISP           See Remark #2.      (See Remark #3). 1.Fans can be stopped via Hot short in control   indicating lights in                                           HS-31-64 A or B.
wiring; Control        MCR signal failure; CIS    (1-HS-31-64A).                                                 2.Over pressurization of 6.9 kV Phase A Control                                                                       Shutdown Board Room A with signal failure.                                                                       respect to MCR.
Alarm is MCR when CRI Control Room       P between MCRHZ                                               3.)Differential pressure switches will Isolation signal -     and ABSDBR is                                                  alarm if the P is not adequate and Train A fails.         <1/8- inch w.g.                                                start standby C-B emergency pressurizing fan during CRI mode to restore MCR P with respect to Shutdown Bd. Rooms.
9.4-236                                                                                                                                                                                                                                                             WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 16 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.        Component            Function        Failure Mode           Potential Cause       Method of Detection Effect on System           Effect on Plant                 Remarks 18     0-FAN-31-67-B           Provides        Fails to start, fails   Mechanical failure;    Indicating lights in     Loss of             None.               1.The pressurizing fans are not pressuri-       while running.          Train B power          MCR                      redundancy in                           required to mitigate the effects of a Pressurizing Air Supply zation to                               failure; Control       (1-HS-31-64A) and        providing                               DBE.
(After trip due to lo Fan C-B                 maintain 6.9                            signal failure.        CISP indicating lights   pressurization to   suction flow to Fan kV Shutdown                                                    in MCR                   6.9 kV Shutdown     C-B, the redundant 2.Fan can be restarted after reset Board Room                                                     (1-HS-31-64A).           Board Room.         Train A Fan A-A will after Phase A CIS from Unit 1.
at slightly                                                                                                 automatically start.) Review of the schematics positive                                                                                See Remark #1.                            establishes the separation and pressure with                                                                                                                     independence of the Train A and respect to                                                                                                                        Train B fans.
atmosphere.
Fails to stop.          Mechanical failure;    Indicating lights in     See Remark #2.      None                1.Fans can be stopped via HS-31-67 Hot short in control   MCR and CISP                                 (See Remark #2.)    A or B.
wiring; Control        indicating lights in signal failure; CIS    MCR                                                              2.Differential pressure switches will Phase A Control        (1-HS-31-64A).                                                   alarm if the P is not adequate and signal failure.                                                                         start standby CB emergency pressurizing fan during CRI mode to CRI Control Room       Alarm in MCR when        Over                                    restore MCR P with respect to Isolation signal -     P between MCRHZ         pressurization of                       Shutdown Bd. Rooms.
Train A fails.         and ABSDBR is            6.9 kV Shutdown
                                                                                                                                                            <1/8 inch w.g.           Board Room A.
9.4-237                                                                                                                                                                                                                                                              WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 17 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.        Component            Function        Failure Mode           Potential Cause       Method of Detection Effect on System         Effect on Plant                 Remarks 19     0-FAN-31-64-A           Provides        Fails to start, fails   Mechanical failure;    Indicating lights in   Loss of             None.               1.The pressurizing fans are not pressuri-       while running.          Train A power          MCR and CISP           redundancy in                           required to mitigate the effects of a Pressurizing Air Supply zation to                               failure; Control       indicating lights in   providing                               DBE.
(After trip due to lo Fan B-A                 maintain 6.9                            signal failure.        MCR                    pressurization to   suction flow to Fan kV Shutdown                                                    (1-HS-31-62A).         6.9 kV Shutdown     B-A, the redundant 2.Fan can be restarted after reset Board Room                                                                            Board Room.         Train B Fan D-B will after Phase A CIS from Unit 1.
at slightly                                                                                               automatically start.) Review of the schematics positive                                                                              See Remark #1.                            establishes the separation and pressure with                                                                                                                   independence of the Train A and respect to                                                                                                                      Train B fans.
atmosphere.
None Fails to stop.          Mechanical failure;    Indicating lights in   See Remark #2.      (See Remark #2.)    1.Fans can be stopped via Hot short in control   MCR and CISP                                                   HS-31-62 A or B.
wiring; Control        indicating lights in signal failure; CIS    MCR                                                            2.Differential pressure switches will Phase A Control        (1-HS-31-62A).                                                 alarm if the P is not adequate and signal failure.                                                                       start standby C-B emergency pressurizing fan during CRI mode to restore MCR P with respect to CRI Control Room       Alarm in MCR when      Over                                    Shutdown Bd. rooms.
Isolation signal -     P between MCRHZ       pressurization of Train A fails.         and ABSDBR is          6.9 kV Shutdown
                                                                                                                                                            <1/8 inch w.g.         Board Room A.
9.4-238                                                                                                                                                                                                                                                            WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 18 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.        Component            Function        Failure Mode           Potential Cause       Method of Detection Effect on System         Effect on Plant                 Remarks 20     0-FAN-31-68-B           Provides        Fails to start, fails   Mechanical failure;    Indicating lights in   Loss of             None.               1.The pressurizing fans are not pressur-        while running.          Train B power          MCR and CISP           redundancy in                           required to mitigate the effects of a Pressurizing Air Supply ization to                              failure; Control       indicating lights in   providing                               DBE.
(After trip due to lo Fan D-B                 maintain 6.9                            signal failure.        MCR (1-HS-31-68A). pressurization to   suction flow to Fan kV Shutdown                                                                           6.9 kV Shutdown     D-B, the redundant 2.Fan can be restarted after reset Board Room                                                                            Board Room.         Train A Fan B-A will after Phase A CIS from Unit 1.
at slightly                                                                                               automatically start.) Review of the schematics positive                                                                              See Remark #1.                            establishes the separation and pressure with                                                                                                                   independence of the Train A and respect to                                                                                                                      Train B fans.
atmosphere.
Fails to stop.          Mechanical failure;    Indicating lights in   See Remark #2.      None                1.Fans can be stopped via HS-31-68 Hot short in control   MCR and CISP                               (See Remark #2.)    A or B.
wiring; Control        indicating lights in signal failure; CIS    MCR (1-HS-31-68A).                                             2.Differential pressure switches will Phase A Control                                                                       alarm if the P is not adequate and signal failure.                                                                       start standby C-B emergency pressurizing fan during CRI mode to restore MCR P with respect to CRI Control Room       Alarm in MCR when      Over                                    Shutdown Bd. rooms.
Isolation signal -     P between MCRHZ       pressurization of Train A fails.         and ABSDBR is          6.9 kV Shutdown
                                                                                                                                                            <1/8 inch w.g.         Board Room B.
9.4-239                                                                                                                                                                                                                                                            WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 19 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.       Component         Function       Failure Mode       Potential Cause      Method of Detection Effect on System           Effect on Plant                  Remarks 21     0-BKD-31-2756       Permits        Fails to open       Mechanical failure. See Remark #1.        No air flow to fan     None.                1.Indicating lights of Fan C-B Backdraft Damper    airflow to     (when Fan C-B is                          Local position        C-B. Loss of                                powered and running (HS-31-67A) in Pressurizing   running).                                 indicators on damper. redundancy in          Train A Fan A-A will MCR and CISP.
Fan C-B.                                                                       providing              supply the pressurizing air       pressurizing air. 2.The functioning of the Pressurizing flow to Shutdown                            Fans is not required for mitigating Board Rooms.                                the effects of a DBE.
Lo flow at FS                                                                                                                                                                          66 will be detected and automatically start fan A-A.
See Remark #2.
Mechanical failure. See Remark #1.        Loss of                None.                1.MCR and CISP indication of Fan Isolates idle Fails to backseat.                         Local position        pressurizing air to                         A-A powered and running (HS                                                                                          Fan C-B from                                             indicators on damper. room served by         See Remarks #2.      64A).
running Fan                                                                    the fan.
A-A.                                                                                                                       2.The functioning of the Pressurizing Fans is not required for mitigating the effects of a DBE.
3.Operability of dampers is periodically verified.
9.4-240                                                                                                                                                                                                                                                     WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 20 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.       Component         Function        Failure Mode        Potential Cause      Method of Detection Effect on System          Effect on Plant                 Remarks 22     0-BKD-31-2755       Permits         Fails to open        Mechanical failure. See Remark #1.        No air flow to fan    None.                1.Indicating lights of Fan A-A airflow to      (When Fan A-A is                           Local position        A-A. Loss of                               powered and running (HS-31-64A) in Backdraft Damper    Pressurizing    running).                                  indicators on damper. redundancy in         (Train B Fan C-B     MCR and CISP.
Fan A-A.                                                                         providing             will supply the pressurizing air      pressurizing air.)   2.The functioning of the Pressurizing flow to Shutdown                           Fans is not required for mitigating Board Rooms. Lo                            the effects of a DBE.
flow at FS-31-65 will be detected and automatically start fan C-B.
See Remark #2.
Isolates idle   Fails to backseat. Mechanical failure. See Remark #1.        Loss of               None.                1.MCR and CISP indication of Fan Fan A-A from                                               Local position        pressurizing air to                        C-B powered and running (HS                                                                                          running Fan                                                indicators on damper. room served by        (See Remark #2.)     67A).
C-B.                                                                             the fan.
2.The functioning of the Pressurizing Fans is not required for mitigating the effects of a DBE.
9.4-241                                                                                                                                                                                                                                                      WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 21 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.       Component         Function        Failure Mode        Potential Cause      Method of Detection Effect on System         Effect on Plant                Remarks 23     0-BKD-31-2812       Permits         Fails to open        Mechanical failure. See Remark #1.         No air flow to fan None.                1.Indicating lights of Fan B-A airflow to      (When Fan B-A is                           (Local position        B-A. Loss of                            powered and running (HS-31-62A) in Backdraft Damper    Pressurizing    running).                                  indicators on          redundancy in      (See Remark #2.)     MCR and CISP.
Fan B-A.                                                   damper.)               providing pressurizing air                        2.The functioning of the Pressurizing flow to Shutdown                        Fans is not required for mitigating Board Rooms. Lo                         the effects of a DBE.
flow on FS-31-63 will be detected and automatically start Fan D-B.
(See Remark #2.)
Isolates idle   Fails to backseat. Mechanical failure. See Remark #1.                              None.              1.MCR and CISP indication of Fan Fan B-A from                                               Local position        Loss of                                  C-B powered and running (HS                                                                                          running Fan                                                indicators on damper. pressurizing air to   (See Remark #2.)   67A).
D-B.                                                                             room served by the Fan.                                 2.The functioning of the Pressurizing Fans is not required for mitigating the effects of a DBE.
9.4-242                                                                                                                                                                                                                                                    WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 22 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.       Component         Function       Failure Mode       Potential Cause      Method of Detection Effect on System       Effect on Plant                 Remarks 24     0-BKD-31-2811       Permits        Fails to open       Mechanical failure. See Remark #1. No air flow to fan    None.                1.Indicating lights of Fan D-B airflow to     (when Fan D-B is                          (Local position    D-B. Loss of                               powered and running (HS-31-68A) in Backdraft Damper    Pressurizing   running).                                 indicators on      redundancy in         (Train A Fan B-A     MCR and CISP.
Fan D-B.                                                 damper.)           providing             will supply the pressurizing air      pressurizing air.)   2.The functioning of the Pressurizing flow to Shutdown                           Fans is not required for mitigating Board Room. Lo                             the effects of a DBE.
flow at FS-31-69 will be detected and automatically start fan B-A.
See Remark #2.
Isolates idle Fails to backseat. Mechanical failure. See Remark #1. Loss of               None.                1.MCR and CISP indication of Fan Fan D-B from                                             (Local position    pressurizing air to                        B-A powered and running (HS                                                                                          running Fan                                              indicators on      room served by        (See Remark #2.)     62A).
B-A.                                                     damper.)           the Fan.
2.The functioning of the Pressurizing Fans is not required for mitigating the effects of DBE.
9.4-243                                                                                                                                                                                                                                                 WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 23 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.       Component          Function      Failure Mode         Potential Cause      Method of Detection Effect on System          Effect on Plant                  Remarks 25     0-FCO-31-276-A       Provides     Spuriously Closes      Mechanical failure;   Indicating light in    Loss of suction to   None.                1.Fails as is. Normally open.
suction flow (no tornado)           Hot short in          MCR (0-HS-31-34-A). Shutdown Board Tornado Damper Train path for the                        electrical supply. Mechanical             Room Press. fans     (See Remark #2.)     2.Pressurizing fans are not required A                    6.9kV/480V                                                Equipment Room         on Unit 1 side.                           to mitigate the effects of a DBE.
shutdown                                                  indication. Locally,   Loss of board room                                                0-ZS-31-276A-A         pressurization       There is no effect pressurizing                                              status indication. function to 6.9 kV   on the plant with the Fans A-A and                                                                     Shutdown Board       failure of the C-B.                                                      Indicating lights in   Room A.              damper to close.
MCR (0-HS-31-34).                           Redundant Mechanical failure,   Mechanical             Loss of tornado      isoloation Fails to close when   electrical            equipment room         isolation            components are required for          failure,Operator      indication. Locally,   redundancy.          installed which Tornado               error (hand switch    0-ZS-31-276A-A                              prevent the           Pressurizing fans are not required protection.           placed in wrong       status indication.                          pressure differential during a tornado event.
position).                                                        from affecting the components downstream of this device.
9.4-244                                                                                                                                                                                                                                                     WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 24 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.       Component          Function      Failure Mode         Potential Cause      Method of Detection Effect on System        Effect on Plant                  Remarks 26     0-FCO-31-275-B       Provides     Spuriously Closes      Mechanical failure;   Indicating lights in   Loss of suction     None.               1.Fails as is. Normally open. Motor suction flow (no tornado).          Hot short in          MCR (0-HS-31-35-B). due to Shutdown                         operated valve.
Tornado Damper Train path for the                        electrical supply. Mechanical             Board Room          (See Remark #2.)
B                    6.9kV/480V                                                Equipment Room         Press. fans on Unit                     2.Pressurizing fans are not required Shutdown                                                  indication. Locally,   1 side. Loss of                         to mitigate the effects of a DBE.
Board Rooms                                               0-ZS-31-275 status     pressurization Pressurizing                                              indication.            function to 6.9 kV Fans A-A and                                                                     Shutdown Board C-B.                                                                             Room A.
Fails to close when   Mechanical failure,   Indicating lights in   Loss of tornado    There is no effect    Pressurizing fans are not required required for          electrical failure,   MCR (0-HS-31-35).      isolation          on the plant with the during a tornado event.
Tornado               Operator error        Mechanical             redundancy.        failure of the protection.           (hand switch placed   Equipment Room                            damper to close.
in wrong position). indication. Locally,                      Redundant isolation 0-ZS-31-275A-B                            components are status indication.                        installed which would prevent the pressure differential from affecting the components downstream of this.
9.4-245                                                                                                                                                                                                                                                   WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 25 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.       Component        Function      Failure Mode       Potential Cause      Method of Detection Effect on System       Effect on Plant                  Remarks 27     0-FCO-31-278-A     Provides      Spuriously Closes   Mechanical failure;   Indicating lights in   Loss of suction    None.               1.Fails as is. Normally open.
suction flow  (no tornado)        Hot short in          MCR 0-(HS-31-32-A). due to Shutdown Tornado Damper     path for the                      electrical supply. Mechanical             Board Room         (See Remark #2.)    2.Pressurizing fans are not required Train A            6.9kV/480V                                              Equipment Room         Press. fans on                         to mitigate the effects of a DBE.
Shutdown                                                indication. Locally,   Unit 2 side. Loss Board Rooms                                             0-ZS-31-278 status     of pressurization Pressurizing                                            indication.            function 60 6.9 kV Fans B-A and                                                                   Shutdown Board D-B (Unit 2).                                                                  Room B.
Fails to close      Mechanical failure,   Indicating lights in   Loss of tornado   There is no effect    Pressurizing fans are not required when required for   electrical failure,   MCR (0-HS-31-32).      isolation         on the plant with the during a tornado event.
Tornado             Operator error        Mechanical             redundancy.       failure of the protection.         (hand switch placed   Equipment Room                           damper to close.
in wrong position). indication. Locally,                     Redundant isolation 0-ZS-31-275A-A                           components are status indication                        installed which would prevent the pressure differential from affecting the components downstream of this.
9.4-246                                                                                                                                                                                                                                              WBNP-97

Table 9.4-9 Failure Modes and Effects Analysis Subsystem: Shutdown Board Room Air Conditioning and Ventilation (Sheet 26 of 26)
AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Item No.       Component           Function      Failure Mode      Potential Cause      Method of Detection Effect on System          Effect on Plant                  Remarks 28     0-FCO-31-277-B       Provides      Spuriously Closes   Mechanical failure;   Indicating lights in   Loss of suction      None.                1.Fails as is. Normally open.
suction flow  (no tornado)        Hot short in          MCR (0-HS-31-33-B). due to Shutdown Tornado Damper Train path for the                      electrical supply. Mechanical             Board Room           (See Remark #2.)     2.Pressurizing fans are not required B                    6.9kV/480V                                              Equipment Room         Pressurization                            to mitigate the effects of a DBE.
Shutdown                                                indication. Locally,   fans on Unit 2 Board Rooms                                             0-ZS-31-277 status     side. Loss of Pressurizing                                            indication.            pressurization Fans B-A and                                                                   function to 6.9 kV D-B (Unit 2).                                                                  Shutdown Board Room B.
Fails to close      Mechanical failure,   Indicating lights in   Loss of tornado      There is no effect    Pressurizing fans are not required when required for   electrical failure,   MCR (0-HS-31-33).      isolation            on the plant with the during a tornado event.
Tornado             Operator error        Mechanical             redundancy.          failure of the protection.         (hand switch placed   Equipment Room                              damper to close.
in wrong position). indication. Locally,                        Redundant isolation 0-ZS-31-277A-B                              components are status indication                           installed which would prevent the pressure differential from affecting the components downstream of this.
9.4-247                                                                                                                                                                                                                                                   WBNP-97

AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Table 9.4-10 Failure Modes and Effects Analysis for Active Failures Subsystem: Main Steam Valve Vault Ventilation System (Sheet 1 of 1)
Item No.       Component           Function          Failure Mode          Potential Cause         Method of Detection Effect on System    Effect on Plant                Remarks 1     1-FAN-30-26 and       Provides          Continues to run       Electrical control       No direct detection     None, (See     None, (See         System Description and Freeze 1-FAN-30-302          outside air for   after shutdown         failure, operator        method for the fan;     Remarks)       Remarks)           protection procedure require that cooling of the    command is given       error (switch left in    the indicating lights                                     door and ventilation covers be South Steam       or spuriously starts   incorrect position). and hand switch are                                       installed on both the north and south Valve Vault.      after shutdown.                                 local devices.                                            main steam valve vaults should the This failure is of                                                                                        outside temperature drop below concern during                                                                                            35&deg;F. With the covers installed there periods when the                                                                                          would be little if any air flow ambient                                                                                                   produced as a result of the fans temperature is at                                                                                         continuing to run. Therefore this the design                                                                                                failure would have no adverse minimum.                                                                                                  impact on the plant.
2     1-FAN-30-25 and 301   Provides          Continues to run        Electrical control      No direct detection     None, (See     None, (See         System Description and Freeze outside air for   after shutdown          failure, operator       method for the fan;     Remarks)       Remarks)           protection procedure require that cooling of the    command is given                                the indicating lights                                     door and ventilation covers be error (switch left in North Steam       or spuriously starts                            and hand switch are                                       installed on both the north and south Valve Vault.      after shutdown.         incorrect position). local devices.                                            main steam valve vaults should the This failure is of                                                                                        outside temperature drop below concern during                                                                                            35&deg;F. With the covers installed there periods when the                                                                                          would be little if any air flow ambient                                                                                                   produced as a result of the fans temperature is at                                                                                         continuing to run. Therefore this the design                                                                                                failure would have no adverse minimum.                                                                                                  impact on the plant.
9.4-248                                                                                                                                                                                                                                                        WBNP-97

AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS WATTS BAR Table 9.4-10A Failure Modes and Effects Analysis for Active Failures Subsystem: Post Accident Sampling System (Sheet 1 of 1)
Item No.       Component        Function          Failure Mode          Potential Cause        Method of Detection Effect on System    Effect on Plant                Remarks 1     1-FAN-31-18A1      Provides          Continues to run       Electrical control      No direct detection     None, (See     None, (See         1. An anaylsis was performed to heated (if        after shutdown         failure, operator       method for the fan;     Remarks)       Remarks)              show that the space temperatures required)         command is given       error (switch left in   the indicating lights                                        would remain within allowable outside air to    or spuriously starts   incorrect position). and hand switch are                                          limits.
the post          after shutdown.                                local devices.
accident          One of the                                                                                               2. Post accident, this system is sampling          redundant                                                                                                   manually energized. Post facility during   isolation dampers                                                                                           accident sampling ventilation is periods of        fails open                                                                                                  controlled by procedures. These times that a      (1-FCO-31-350 or                                                                                            procedures control operation of post accident     365). Heater                                                                                                this system and require the sample is         (1-HTR-31-479)                                                                                              ventilation system be shut down required.         fails off. Outside                                                                                          after sampling is complete.
temperature at minimum design value.
9.4-249                                                                                                                                                                                                                                                  WBNP-97

WATTS BAR                                                    WBNP-97 9.4-250   AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR                                                         WBNP-63 Table 9.4-10 Deleted by Amendment 56 AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS         9.4-251

WATTS BAR                                                                WBNP-63 Table 9.4-11 Deleted by Amendment 56 9.4-252               AIR CONDITIONING, HEATING, COOLING, AND VENTILATION SYSTEMS

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-1 Powerhouse, Control Building Units 1 & 2 Flow Diagram for Heating, Ventilating, and Air Conditioning Air Flow 9.4-253

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-2 Powerhouse Units 1 & 2 Flow Diagram for Air Conditioning Chilled Water 9.4-254

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-3 Powerhouse, Control Building Units 1 & 2 Flow Diagram for Air Conditioning Chilled Water 9.4-255

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-4 Powerhouse, Control Building Units 1 & 2 Electrical Control Diagram Air Conditioning 9.4-256

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-4a Control Building Units 1 & 2 Electrical Air Conditioning Control Diagram - Chilled Water 9.4-257

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-5 Control Building units 1 & 2 Electrical Air Conditioning Control Diagram - Chilled Water 9.4-258

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-6 Control Building Units 1 & 2 Electrical Logic Diagram Air Conditioning System 9.4-259

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-7 Control Building Units 1 & 2 Electrical Logic Diagram Ventilation System 9.4-260

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-8 Powerhouse Units 1 & 2 Auxiliary Building Flow Diagram, Heating, and Ventilating Air Flow 9.4-261

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-9 Auxiliary Building Units 1 & 2 Electrical Logic Diagram for Ventilation System 9.4-262

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-10 Auxiliary Building Units 1 & 2 Electrical Logic Diagram for Ventilation System 9.4-263

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS Figure 9.4-11 Powerhouse Units 1 & 2 for Containment Ventilation Sytem Control Diagram WBNP-91 9.4-264

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-89 Figure 9.4-12 Powerhouse Units 1 & 2 Electrical Control Diagram for Radiation Monitoring System 9.4-265

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-13 Powerhouse Units 1 & 2 Auxiliary Building Flow Diagram for Heating, Cooling, and Ventilating Air Flow 9.4-266

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS Figure 9.4-14 Auxiliary Building Units 1 & 2 Flow Diagram for Heating, Cooling, and Ventilating Air Flow WBNP-91 9.4-267

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-92 Figure 9.4-15 Powerhouse Units 1 & 2 Auxiliary Building Flow Diagram for Heating, Ventilation and Air Conditioning Air Flow 9.4-268

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS Figure 9.4-16 Powerhouse Units 1 & 2 Auxiliary Building & Additional Eqpt Bldg Flow Diagram for Heating, Cooling & Ventilating Air Flow WBNP-91 9.4-269

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-17 Powerhouse Units 1 & 2 Electrical Control Diagram for Containment Ventilating System 9.4-270

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-18 Turbine Building Units 1 & 2 and Control Flow Diagram for Heating and Ventilating Air Flow 9.4-271

WATTS BAR                                                                          WBNP-89 Figure 9.4-19 Powerhouse Units 1 & 2 Flow Diagram Building Heating AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS                                                                        9.4-272

WATTS BAR                                                    WBNP-89 Figure 9.4-20 Powerhouse Unit 2 Flow Diagram Building Heating AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS                                                                   9.4-273

Security-Related Information - Withheld Under 10CFR2.390 WATTS BAR                                                                                                                       WBNP-91 Figure 9.4-21 Pumping Stations Units 1 & 2 Mechanical Heating and Ventilating AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS                                                                                                                             9.4-274

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS Figure 9.4-22 Diesel Generator Building Units 1 & 2 Flow and Control Diagram for Heating, Ventilating Air Flow WBNP-91 9.4-275

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-22a Additional Diesel Generator Building Units 1 & 2 Flow and Control Diagram for Heating and Ventilating Air Flow 9.4-276

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-89 Figure 9.4-22b Additional Diesel Generator Building Units 1 & 2 Electrical Logic Diagram for 5th Diesel Generator Ventilator System 9.4-277

Security-Related Information - Withheld Under 10CFR2.390 WATTS BAR                                                                                                                                                                                       WBNP-91 Figure 9.4-22c Additional Diesel Generator Building Mechanical Heating and Ventilating AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS                                                                                                                                         9.4-278

Security-Related Information - Withheld Under 10CFR2.390 WATTS BAR                                                                                              WBNP-91 Figure 9.4-23 Diesel Generator Building Mechanical Heating and Ventilating AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS                                                                                                                          9.4-279

Security-Related Information - Withheld Under 10CFR2.390 WATTS BAR                                                                                              WBNP-91 Figure 9.4-24 Diesel Generator Building Mechanical Heating and Ventilating AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS                                                                                                                          9.4-280

WATTS BAR                                                    WBNP-91 Figure 9.4-24a Diesel Generator Building Mechanical Heating and Ventilation AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS                             9.4-281

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-25 Diesel Building Units 1 & 2 Electrical Logic Diagram for Ventilation System 9.4-282

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-26 Powerhouse Unit 1 Electrical Control Diagram for Containment Ventilation System 9.4-283

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-27 Powerhouse Unit 1 Electrical Control Diagram for Containment Ventilation System 9.4-284

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-28 Reactor Building Units 1 & 2 Flow Diagram for Heating and Ventilation Air Flow 9.4-285

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-89 Figure 9.4-28a Powerhouse Reactor Building Unit 2 Flow Diagram Heating & Ventilation Air Flow 9.4-286

WATTS BAR                                                    WBNP-91 Figure 9.4-29 Powerhouse Unit 1 Electrical Logic Diagram for Ventilation System AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS                               9.4-287

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-30 Powerhouse Unit 1 Electrical Control Diagram for Containment Ventilating System 9.4-288

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-89 Figure 9.4-30 Powerhouse Unit 2 Electrical Control Diagram Containment Ventilating System (Sheet A) 9.4-289

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-89 Figure 9.4-30 Powerhouse Unit 1 Electrical Control Diagram Containment Ventilating System (Sheet B) 9.4-290

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-31 Powerhouse Unit 1 Electrical Control Diagram for Containment Ventilating System 9.4-291

WATTS BAR                                                               WBNP-91 Figure 9.4-32 Powerhouse Unit 1 Logic Diagram for Ventilation System AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS                                                                          9.4-292

WATTS BAR                                                    WBNP-91 Figure 9.4-33 Powerhouse Unit 1 Electrical Logic Diagram for Ventilation System AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS                                                                           9.4-293

WATTS BAR                                                    WBNP-91 Figure 9.4-34 Powerhouse Unit 1 Electrical Logic Diagram for Ventilation System AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS                                                                                     9.4-294

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-35 Powerhouse Post-Accident Sampling System Unit 1 Flow Diagram for Heating, Ventilating and Air Conditioning Air Flow 9.4-295

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS Figure 9.4-36 Auxiliary Building Units 1 & 2 Electrical Post-Accident Sampling System Logic Diagram WBNP-91 9.4-296

WATTS BAR AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS WBNP-91 Figure 9.4-37 Auxiliary Building Units 1 & 2 Electrical Post-Accident Sampling Control Diagram 9.4-297

WATTS BAR                                                                           WBNP-91 THIS PAGE INTENTIONALLY BLANK AIR CONDITIONING, HEATING, COOLING AND VENTILATION SYSTEMS                             9.4-298

WATTS BAR                                                                                   WBNP-92 9.5 OTHER AUXILIARY SYSTEMS 9.5.1 Fire Protection System The WBN Fire Protection Program is described in the WBN Fire Protection Report.[2][3][4][5] For interface with a auxiliary feedwater system, see Section 10.4.9.
9.5.1.1 Deleted by Amendment 87 9.5.1.2 Deleted by Amendment 87 9.5.1.3 Deleted by Amendment 87 9.5.1.4 Deleted by Amendment 87 9.5.1.5 Deleted by Amendment 87 9.5.2 Plant Communications System 9.5.2.1 Design Bases Interplant and/or Offsite Systems The design basis for interplant and/or offsite communications is to provide dependable systems to ensure reliable service during normal plant operation and emergency conditions.
The primary interplant offsite communications systems are microwave radio, fiber optics circuits, telephone systems and radio systems.See Section 9.5.2.3 for a general description of each system.
Intraplant Communications The design basis for the intraplant communications is to provide sufficient equipment of various types such that the plant has adequate communications to start up, continue safe operation, or shutdown safely.
The primary intraplant communications systems are the TSS telephone system, intercoms, sound powered telephones, two-way VHF cellular radios, VHF radio paging, codes (code call is not used), alarms (accountability/evacuation and fire/medical), and paging.
See Section 9.5.2.2 for a general description of each system.
9.5.2.2 General Description Intraplant Communications The plant communications systems are installed and maintained by TVA with the exception of the cellular radio system which is maintained by the cell radio provider.
The following paragraphs describe the basic functions of the intraplant communications systems.
OTHER AUXILIARY SYSTEMS                                                                         9.5-1

WATTS BAR                                                                                WBNP-92 Telephone System Telephone Switching System (TSS) - A TSS is installed to provide primary 2-way voice communications and data transmission throughout the Watts Bar Nuclear Plant as well as access to offsite circuits.
The Node 1 and Node 2 TSSs are powered from separate 48V dc systems. Each 48V system consists of battery chargers, a regulating power board, and a 48V battery.
Each battery charger is capable of assuming the total load for its respective Node. The selected charger provides 48V dc to its TSS with the battery available as needed. Each battery is sized to carry the load at full capacity for 3 hours without the chargers. The Node 1 chargers are powered by dual ac voltage sources supplied from train A and train B diesel-backed boards. The Node 2 chargers are powered by dual ac voltage sources. The main source is the construction sub-station, and the other is from the telephone diesel generator unit.
Sound-Powered Telephone Systems Plant Operation Systems - The primary purpose of these systems is to provide communications for maintenance and operations personnel. There are 7 separate systems provided for each unit.
Backup Control Center System - The primary purpose of this sound powered system is to provide alternative communications between the auxiliary control room and other stations which must be manned to shutdown the reactor if the MCR is abandoned.
This system consists of two completely redundant subsystems. Each subsystem is wired directly and independently of all other communications systems. Wiring routes avoid the spreading room, unit control rooms, and auxiliary instrument rooms.
Sound-powered equipment and circuits are provided in the Diesel Generator Buildings, the 480V ac shutdown board rooms, the 6.9 kV ac shutdown board rooms, and the auxiliary control room.
Health Physics System - The primary purpose of this sound powered telephone system is to provide an alternate communications link between the health physics office and the MCR. A direct dedicated circuit is provided between the health physics office and the Unit control room (physically on the electrical control area desk).
Diesel Building to Main Control Room - The primary purpose of this sound powered telephone system is to provide an alternate communications link between the Diesel Generator Building and main control room. A direct dedicated circuit is provided between the shielded waiting room in the Diesel Generator Building and the MCR at the diesel generator control panel.
9.5-2                                                                    OTHER AUXILIARY SYSTEMS

WATTS BAR                                                                                   WBNP-92 Closed-Circuit Television Portable closed circuit television systems are provided, when necessary, for remotely viewing radwaste packaging operation, refueling operations, area and equipment surveillance, and maintenance activities.
Codes, Alarms, and Paging System The codes, alarms, and paging (CAP) system is one system that combines assembly and accountability alarm, fire and medical emergency alarm, and paging. Control logic, tone generation, and power and signal distribution equipment is located in the communications room with speakers with solid-state amplifier as end devices located throughout the plant.
All alarms are controlled from the MCR. The assembly/accountability and paging alarms are also controllable from the auxiliary control room.
Paging may be accessed from selected TSS telephones. Paging may also be accessed by paging handsets in the main and auxiliary control room.
The CAP system operational priority sequence is fixed by relay logic as follows:
(1)   Site Assembly alarm (2)   Fire and medical emergency alarm (3)   Paging Paging can be advanced to a higher priority in emergencies by using the evacuation alarm control unit cancel push button.
Design consideration has been given to increase system reliability with the following features provided:
(1)   Redundant operating centers.
(2)   Three separate tone generator units.
(3)   Two physically separate power distribution networks with approximately half of the amplifier-speaker units in each area of the plant fed from each fuse panel via alarm-type fuses.
(4)   Redundant chargers are used and can be switched into service as required.
(5)   DC supervision of each individual audio pair.
(6)   Isolation of evacuation alarm actuating devices.
(7)   Electrical separation of amplified-speakers in each area into two circuits such that adequate coverage can be maintained in the event of one circuit failure.
OTHER AUXILIARY SYSTEMS                                                                          9.5-3

WATTS BAR                                                                                  WBNP-92 Radio System Onsite Radio Paging System - The primary purpose of this system is to provide onsite paging of key plant personnel. This system, is accessible from the TSS telephone system.
Inplant VHF Radio System - The primary purpose of this system is to provide voice communications throughout the plant for plant operations and maintenance personnel.
This system consists of several repeaters, numerous remote control units, and portable VHF radios. One or more repeaters may be used by the fire brigade for communications during a fire emergency. Nuclear Security personnel also have access to these repeaters as an alternative to the Nuclear Security Radio System.
Inplant Cellular Radio System - The primary purpose of this system is to provide voice communications throughout the plant and owner controlled property for use by operations and maintenance personnel. The system consists of a cell site, remote interface unit (to interface with the inplant distributed antenna system), and cell radio/phones. Nuclear Security and Fire Operations also have access to this system.
9.5.2.3 General Description Interplant System Microwave Radio Microwave circuit provides access to the power system control center (PSCC).
Redundant 24V dc-dc converters supplied from the 48V dc telephone power system are installed for the exclusive use of this microwave circuit.
Fiber Optic Circuit The fiber optic circuit provides high speed digital communication connecting major communication centers and administrative offices through TVA. This fiber optic circuit is integrated into the 161kV insulated shield wire. Electro-optical interface and channel equipment are located in Telecommunications Node 2 Building.
Telephone System Commercial Telephone Service - Public telephone service is provided to all TSS telephones with proper class of service, to pay telephones, and to dedicated data circuits.
Emergency Notification System (ENS) - The primary purpose of this telephone circuit is to provide a direct circuit from Watts Bar Nuclear Plant to the NRC in the event of a serious emergency as well as ongoing information on plant system, status and parameters at the nuclear plant reactor. A dedicated telephone line that is independent of the public telephone switching network is provided for the NRC.
Health Physics Network (HPN) - The primary function of this telephone circuit is to report directly to the NRC on radiological and meteorological conditions as well as assessment of trends and the need for protective measures on-site and off-site. A 9.5-4                                                                      OTHER AUXILIARY SYSTEMS

WATTS BAR                                                                                   WBNP-92 dedicated telephone line that is independent of public telephone switching network is provided for the NRC.
Transmission & Power Supply - The primary purpose of this system is to provide communications for Transmission & Power Supply engineers, but it may also be used by plant operations personnel during emergencies. This system is capable of contacting local mobile units and other TVA power generating facilities.
Nuclear Security Radio - The primary purpose of this system is to provide effective communications between all Nuclear Security officers.
Emergency Radio Communication System - This system is integrated with inplant repeater system for coordination with field monitoring teams and other personnel.
Sheriffs' Radio - The primary purpose of this system is to provide communications between Nuclear Security officers and the Meigs and Rhea County sheriffs.
9.5.2.4 Evaluation The following evaluation is intended to establish adequacy and redundancy of the plant communications systems design.
Interplant Systems There are four basic types of plant-to-offsite communications: microwave radio, fiber optics circuits, radio, and telephone systems. The availability of these systems during or after an emergency is enhanced by the fact that each enters the plant via different means.
The redundancy of the communications systems is of further significance. The microwave and fiber optics equipment design employs redundancy both in the channelizing and in the RF circuitry. The microwave system is powered from a battery-battery charger system through parallel-connected, redundant dc-dc converters. Each charger is fed from two separate ac sources, and each battery is capable of operating its system for a minimum of three hours without chargers.
The major electronic portions of the microwave are housed in the communications room which is located in the Control Building (Node 1). This building is a Seismic Category I structure.
The commercial telephone lines are terminated in Bell Hut and extend to Node 1 and 2 and from there to instruments located throughout the plant via the TSS. Local central office lines are available in the control room in the event of the loss of the TSS.
The Transmission & Power Supply radio have no components in the communications room and, therefore, would not be affected by the total destruction of this room. The Nuclear Security and Sheriffs RCUs in the Secondary Alarm Station (SAS) would be affected by the total destruction of the communication room and would be inoperable.
Hand held radios would still be available to communicate from the SAS. The OTHER AUXILIARY SYSTEMS                                                                        9.5-5

WATTS BAR                                                                                 WBNP-92 emergency radio communications system, however, depends on equipment in the communications room and would be inoperative.
All of the VHF radio systems are powered by battery- and/or diesel-backed ac sources and would remain operative following loss of offsite power.
Refer to Figure 9.5-19 for availability of interplant communications during various postulated conditions.
Intraplant System The automatic telephone equipment is one of the primary systems is designed so that failures in individual switches or lines do not interrupt service. However, such failures are annunciated and repairs are made promptly. The main (Node 1) switching equipment for this system is located in the communications room which is in a Seismic Category I building. Communication between TSS phones within seismic Category I buildings is through Node 1. In times of emergency, the TSS can be programmed to limit access only to key people to ensure that they will always have telephone service.
The codes, alarms (assembly/accountability) and paging system is designed for survivability with the following features:
(1)   Duplicate operating locations: one in the main control room and the other in the auxiliary control room. Isolation of the duplicate controls is provided in the communications room.
(2)   Three tone generator consoles powered from two separate sources:
(a)   The operating console is normally aligned to the A source.
(b)   A standby console which automatically is inserted upon power failure of the operating console. The standby console is normally aligned to the B source. It may also be manually switched at any time.
(c)   A third console which may be manually substituted for either of the other consoles.
(3)   Plug-in features:
(a)   The tone generators are solid-state plug-in devices.
(b)   The amplifier in the speaker unit is solid-state, easily unplugged and replaced.
(4)   The power-leads to each speaker-amplifier are fused and annunciated.
(5)   The signal-leads to each speaker-amplifier are supervised with dc while idle.
Any occurrence which causes a short of the signal-leads will cause the fuse to blow and annunciate. The rest of the units will function normally with single or multiple open-circuited signal-leads to individual speaker-amplifiers.
9.5-6                                                                     OTHER AUXILIARY SYSTEMS

WATTS BAR                                                                                    WBNP-92 (6)  There are two sources of 24V dc power distributed to the speaker- amplifiers and approximately half in each area of the plant are supplied from each source. Each source is quite reliable since it is supplied from chargers which are backed up by batteries capable of supplying the load for three hours.
The failure of the TSS equipment will not impair the use of the paging equipment from the local stations located at the unit operator's desk or the auxiliary control room.
The sound-powered telephone systems are completely independent of power, each other, and all other systems provided. As long as a complete metallic path exists between instruments, communications can be maintained since the instruments supplied with these systems are very rugged and will successfully withstand high shocks, negligence, and abuse. If permanently installed wires are rendered unusable for any reason, a temporary pair of wires can be used with the sound-powered instruments.
Neither the Inplant VHF Radio System nor the Inplant Cellular Radio System have any components in the communications room and, therefore, would not be affected by the total destruction of this room. The Onsite Radio Paging System, however, depends on equipment located in the communications room and would be inoperative.
The Inplant VHF Radio System, the Cellular Radio System, and the Onsite Radio Paging System are powered by battery- and/or diesel-backed ac sources and would remain operative following loss of offsite power.
Refer to Figure 9.5-19 for availability of intraplant communications during various postulated conditions.
9.5.2.5 Inspection and Tests The two communication systems are covered by Special Performance Tests (SPT-251-02 and SPT-252-02):
(1)  The sound-powered telephone systems provided for the backup control center, health physics office, and Diesel Building shielded room; (2)  The codes, alarms, and paging system.
All systems are carefully installed and checked for proper operation initially by construction forces. Routine maintenance is performed by operating personnel on a regular basis and includes such items as checking for proper switch operation, checking for proper operating levels, visual inspection, etc.
The most comprehensive testing, however, results from the heavy daily usage of the equipment and the subsequent reports of any of the users. Individual power failures in the equipment are annunciated.
OTHER AUXILIARY SYSTEMS                                                                          9.5-7

WATTS BAR                                                                                   WBNP-92 9.5.3 Lighting Systems 9.5.3.1 Design Bases There are three basic lighting systems in the plant designated as follows: normal, standby, and emergency. These systems are designed in accordance with TVA design guides and standards which use the recommendations of the Illuminating Engineering Society of North America as their basis, and good engineering practice to provide the required illumination necessary for safe conduct of plant operations and under normal conditions to make the plant personnel as comfortable as possible.
The normal lighting system is designed to economically provide the amount and quality of illumination to meet normal plant operations and maintenance requirements.
The standby lighting system upon loss of the normal lighting system, provides adequate illumination for the safe shutdown of the reactor and the evacuation of personnel from vital areas of the plant if the need should occur. It forms an integral part of the normal lighting requirements but is fed from an entirely independent source.
The emergency lighting system is composed of two separate systems: (1) The 125V dc lighting system, which is designed to provide immediately the minimum illumination level in areas vital to the safe shutdown of the reactor for the period required for diesel loading or upon loss of ac auxiliary power for the duration of capacity of the 125V vital dc batteries and (2) an individual eight-hour battery pack network, which is used to supplement the 125V dc emergency lighting to provide emergency lighting in areas that must be manned for safe shutdown; and for access and egress to and from fire areas, which meet the requirements of 10CFR50, Appendix R, III.J. Other battery pack units are provided for building egress for personnel safety purposes.
9.5.3.2 Description of the Plant Lighting System All plant lighting systems have the following features in common: adequate capacity and rating for the operation of the loads connected to the systems, independent wiring and power supply, overcurrent protection for conductor and equipment using nonadjustable inverse time circuit breakers, copper conductor with 600-volt insulation run in metal raceways.
The insulated cable used inside the primary containment areas is resistant to nuclear radiation and chemical environmental conditions in this area.
The plant lighting system consists of three basic schemes, the first of which is the normal lighting. This system is for general lighting of the plant: the major power supply is through two alternate feeders from the 6.9kV common boards A and B to selective and interrupter switch and 3-phase 6900-120/208-volt ac transformers, feeding a lighting board. These lighting boards are located in the Turbine and Auxiliary Buildings of the main plant. Other lighting boards in the Service Building, Office Buildings, gatehouse, etc., are fed from 480V boards through 3-phase 480-120/208V ac transformers. These lighting boards feed the normal lighting cabinets, designated by the prefix LC___, distributed throughout the main plant. In the MCR, alternate rows of fixtures or alternate fixtures are fed from different lighting boards to prevent total 9.5-8                                                                       OTHER AUXILIARY SYSTEMS

WATTS BAR                                                                                    WBNP-89 blackout in a particular area in case of failure of one of the other lighting boards or cabinets.
The second system is the standby lighting, which forms a part of the normal lighting requirements and is normally energized at all times. This system is fed from 480V Reactor MOV boards 1A2-A, 1B2-B, 2A2-A, and 2B2-B to 3-phase 480-120/208V ac transformers to each standby lighting cabinet, designated by the prefix LS___ . The Reactor MOV boards have a normal and alternate ac power supply and in event of their failure are fed from the standby diesel generators. The cable feeders to the standby cabinets located in the Seismic Category I structure are routed in redundant raceways and the fixtures are dispersed among the normal lighting fixtures.
The third lighting system is referred to as the emergency system. It consists of two systems as described in Section 9.5.3.1. The 125V dc emergency lighting system is electrically held in the off position until a power failure occurs on the associated standby lighting systems. Then the emergency lighting cabinets, designated by the prefix LD___, are automatically energized from the 125V dc vital battery boards. This system is an essential supporting auxiliary system for the ESF, and the cable feeders to the LD cabinets are routed on the redundant ESF cable tray system or in conduit.
The fixtures are incandescent type and are dispersed among the normal and standby fixtures with alternate emergency fixtures being fed from redundant power trained LD cabinets.
The individual eight-hour battery pack emergency lighting system is automatically held in the de-energized state until loss of the normal ac supply. A charger monitors battery voltage and charges on fast rate when necessary. Solid-state circuits continually monitor both ac and dc current. The transfer switch circuit instantly connects lamps to battery on ac failure and disconnects them when normal power is restored. In some cases, the lamp heads are mounted remote from the units to obtain adequate light distribution.
9.5.3.3 Diesel Generator Building Lighting System The Diesel Generator Building lighting cabinets are fed through 480-208/120V 3-phase local lighting transformers, which in turn are fed from the diesel 480V auxiliary boards respectively. Each of these auxiliary boards has dual feeders from the 480V shutdown boards during normal operation. In the event of an ac power failure to the 480V shutdown boards, the diesel should start within the prescribed time to provide the 480V ac power requirements for the safe shutdown of the plant through the standby feeders to the 480V shutdown boards, thus supplying power again to the Diesel Generator Building lighting transformers. Each diesel generator unit has a lighting cabinet which supplies the normal lighting for that unit. Low-level lighting required for maintenance or operating procedures and ingress/egress in the event of loss of normal lighting is supplied from fixtures with a self-contained battery and inverter charger and also individual eight-hour battery pack lighting units.
OTHER AUXILIARY SYSTEMS                                                                          9.5-9

WATTS BAR                                                                                      WBNP-95 9.5.3.4 Safety Related Functions of the Lighting Systems The lighting system is adequate for the operation and evacuation of the plant to the extent that the supports for the components of the system, that are located in areas of Seismic Category I structures containing safety-related equipment are qualified to prevent failure that could impair the functioning of any safety-related plant feature.
Lighting systems are classified as non-safety related. However, due to their functions, standby and emergency lighting systems shall be of a high reliability design so as to ensure necessary illumination in areas of the plant needed for operation of safe shutdown equipment and in access and egress routes thereto.
9.5.3.5 Inspection and Testing Requirements Following the complete installation of a lighting system, it will be tested and inspected and short circuits, grounding of potential conductors, other faults, etc. will be eliminated and damaged or nonoperable fixtures replaced or repaired. The operation of the lighting system shall be observed during the initial and periodic testing of the normal and alternate feeder systems and during the 125V dc emergency power tests to the various boards from which these emergency lighting systems are fed. Maintenance and relamping of the normal and standby lighting systems shall be according to routine plant operating procedures.
The 125V dc emergency lighting system shall be tested periodically by tripping the holding coil circuit fed from the LS standby cabinet, thus closing the feeder circuit to the LD emergency cabinet. A written record of dates and results of these tests shall be maintained by plant personnel responsible for these tests.
The individual eight-hour battery pack lighting units will be tested periodically to ensure that the lamps are operational in according with routine plant procedures.
9.5.4 Diesel Generator Fuel Oil Storage and Transfer System 9.5.4.1 Design Basis The diesel generator fuel oil system provides independent storage and transfer capacity to supply the four diesel generator units operating at continuous ratings with No. 2 Fuel Oil for a period of seven days without replacement.
The buildings are Seismic Category I structures and will withstand the affects of tornadoes, credible missiles, floods, rain, snow, or ice, as defined in Chapter 3, Section 3.3, 3.4, and 3.5.
The design code requirements for the system are as follows:
(1)   Diesel Generator Building 7-day fuel oil storage tanks - Code for Unfired Pressure Vessels, ASME Section VIII. Division I.
(2)   Piping from the 7-day fuel oil storage tanks to the interface with the skid-mounted diesel generator unit fuel oil piping - Boiler and Pressure Vessel Code, ASME Section III, Class 3 (Per NFPA Code 30-1973).
9.5-10                                                                       OTHER AUXILIARY SYSTEMS

WATTS BAR                                                                                     WBNP-92 Skid mounted piping and components for the fuel oil system were designed, manufactured and installed in accordance with ANSI B31.1. This subsystem performs a primary safety function and is supported to Seismic Category I requirements. The scope of this work was done to meet 10CFR50, Appendix B quality assurance requirements. Future modifications performed on this subsystem piping are required to meet the intent of ASME Section III, Class 3.
(3)   Remaining piping, valves, pumps, and associated equipment - Power Piping Code, ANSI B31.1-1973.
The 7-day diesel fuel oil storage tanks are designed for embedment within the Diesel Generator Building foundation. The fuel oil day tanks are skid-mounted on the diesel generator units.
The diesel fuel oil system for the diesel generator units meets the single failure criterion. That portion of the system from the 7-day storage tanks to the diesel generator units meets Seismic Category I requirements. The remainder of the system within the Diesel Generator Building meets Seismic Category I (L) requirements.
9.5.4.2 System Description The flow diagram of the diesel generator fuel oil system is shown in Figure 9.5-20. The control and logic diagrams are shown in Figures 9.5-21 and 9.5-22, respectively.
The diesel generator fuel oil system consists of four 7-day embedded storage tank assemblies, one assembly for each diesel generator unit, with their associated day tanks, pumps, valves, and piping. The 7-day tanks are embedded in the Diesel Generator Building substructure and have a capacity of approximately 70,248 gallons of fuel for each diesel generator unit. The fuel day tanks (one per diesel engine) are mounted to the diesel engine skid and were supplied by the diesel generator vendor.
These tanks have a capacity of approximately 550 gallons.
Level transmitters are provided on the 7-day storage tank assemblies to provide the following functions:
(1)   Provide local fuel level indication.
(2)   Annunciate an alarm in the MCR when the fuel level approaches a seven-day supply.
(3)   Annunciate an alarm in the MCR on high level above the pump shut-off setting.
(4)   Provide an interlock with the outside transfer pump at the yard storage tanks to shut off the pump automatically on high level of any of the four 7-day tanks which is being filled. Provide a high level interlock with the DG transfer pump in the DG Building when transferring fuel to fill any of the 7-day tanks from another 7-day tank within that building. Interlocks are not provided when using the DG transfer pump to transfer fuel to any other tanks.
OTHER AUXILIARY SYSTEMS                                                                           9.5-11

WATTS BAR                                                                                   WBNP-92 A truck fill connection, condensate sump suction connection, and inspection dipstick gauge manholes are provided for each 7-day storage tank assembly. The vents to the atmosphere on all tank assemblies, with the exception of the skid-mounted day tanks, are provided with double fire screens to prevent an outside spark from entering the assemblies and igniting the gases within. The National Fire Code (NFC) does not require flame arrestors for Class 2 combustible liquid storage tank vents. Therefore, in order to facilitate the installation of missile protection devices, the skid mounted fuel oil day tank vent lines are not flame-proofed. However, the open vent lines are shielded from the atmosphere and equipped with bird screens. All tank connections and vents are above maximum flood elevation. That portion of the 7-day fuel oil tank vent above the roof level is encased in reinforced concrete for missile protection.
Two skid-mounted, electric motor driven, 15 gpm fuel oil transfer pumps, powered from the 480V diesel auxiliary boards (See Figure 8.3-32), are provided for each generating unit to transfer fuel from the 7-day storage tank assembly to the two skid-mounted day tanks of each generating unit. Each of these pumps supplies fuel to both day tanks.
Two sets of level switches are provided for each day tank and associated transfer pumps to maintain day tank level. An additional set of level switches provide both Main Control Room (MCR) and Auxiliary Control Room (ACR) alarms to indicate high and low fuel oil level in the day tanks.
From each day tank, fuel is supplied to the diesel injectors by a diesel engine driven pump. An electric motor-driven fuel pump is provided as a backup for the engine driven fuel pump. Separate suction and discharge lines serve each pump. Each pump has a suction strainer and dual element fuel filters are provided at each pump discharge. Additional filters at the inlet and outlet of each fuel injector protect the working parts of the injector. Pressure gauges are provided on both sides of the dual element fuel filters to provide a means of determining filter pressure drop. Pressure switches are provided between the fuel pumps and the dual element filters and between the final filters and the fuel injectors. The pressure switches provide ACR and MCR alarms on low pressure. Maintenance procedures call for periodic changing of filters and surveillance test runs verify the cleanliness of these filters.
Screens are provided in the suction lines of the Diesel Generator Building transfer pumps which transfer the fuel from the yard storage tank to the 7-day storage tanks.
The 7-day tanks are sloped to collect water and sediment at the low end and can be "dip leg" pumped as necessary. The fuel storage and transfer system is protected against the entry of rain water, and the day tanks and 7-day tanks are not harmed by flood waters.
Each shipment of No. 2 diesel fuel oil can be sampled prior to pumping to the yard tanks. Samples collected may be used for analyses to verify site specific criteria prior to offloading the tanker and to ensure contractual requirements are met if necessary.
Shipments of diesel fuel can be held in the yard tanks until the specified criteria are met and the fuel oil is transferred to one of the 7-day storage tanks or the fuel is burned in the auxiliary boilers. If necessary the fuel is discarded. Sampling and analyses of fuel 9.5-12                                                                      OTHER AUXILIARY SYSTEMS

WATTS BAR                                                                                       WBNP-92 oil that is transferred to or stored in the 7-day storage tanks is completed in accordance with Technical Specifications.
The 7-day storage tanks are inspected in accordance with the Technical Specifications.
The methods for maintaining acceptable levels of fuel quality for the standby diesel generators at Watts Bar Nuclear Plant meet the guidelines set forth by NRC Regulatory Guide 1.137, Revision 1, except for pressure testing required by Section C1.e which was accepted by SER Supplement 5, Section 9.5.4.1 and exceptions to C2, given as follows:
(a)   C2.a the reference year of ASTM D 975 used is 1990 or later revision instead of the year 1977 which is specified in the Regulatory Guide.
(b)   C2.b methods for water and particle detection in fuel oil prior to transferring fuel oil to supply tank is specified in the Technical Specifications.
(c)   C2.b analytical results to be completed after transfer of fuel to supply tanks are completed within time frames given in the Technical Specifications instead of the listed 2 weeks.
(d)   C2.c fuel oil samples are collected using applicable ASTM method specified in the Technical Specifications instead of the listed ASTM D 270.
A transfer pump located adjacent to the yard fuel oil storage tanks provides the following functions:
(1)    Transfer fuel oil from a tank truck to either of two yard fuel oil storage tanks.
(2)    Transfer fuel oil from either yard fuel oil storage tank to the other.
(3)    Transfer fuel oil from either yard fuel oil tank to any of the four7-day fuel oil storage tank assemblies.
(4)    Reject fuel oil from either yard fuel oil tank through a reject connection in the yard.
Seismically qualified fuel oil transfer pumps are also located in the Diesel Generator Building.
The Diesel Generator Building fuel oil transfer pump allows fuel oil to be transferred from any one of the 7-day fuel oil storage tanks in the Diesel Generator Building to any other 7-day fuel oil storage tanks in the Diesel Generator Building or either yard storage tank.
OTHER AUXILIARY SYSTEMS                                                                             9.5-13

WATTS BAR                                                                                      WBNP-92 9.5.4.3 Safety Evaluation With a 7-day supply of diesel fuel in each tank assembly, and each assembly embedded in the concrete substructure of a Seismic Category I building and separated by 18 inches of concrete, the diesel generator units are assured of a sufficient fuel supply for any of the conditions discussed in Section 9.5.4.1. The diesel generator fuel oil tank assemblies, piping, and pumps are so arranged that malfunction or failure of either an active or passive component associated with the source of supply for any one diesel generator unit does not impair the ability of the other sources to supply fuel oil to the other units. Each diesel generator is aligned so as to be able to supply power to its own auxiliaries so that a single failure can not result in loss of more than one diesel generator unit. The system thus meets the requirements of the single failure criterion.
Automatic carbon dioxide fire protection is provided in the Diesel Building fuel oil transfer pump room and the four rooms housing the diesel generator units.
A corrosion allowance is provided in the design wall thickness for the Diesel Generator Building 7-day fuel oil storage tanks. The interiors of the tanks were coated for added corrosion protection. The fuel oil piping and fittings within the Diesel Generator Building have ample corrosion allowance, having been designed per the codes noted in Section 9.5.4.1, and will operate at a pressure considerably below the maximum allowable for the schedule of pipe and fittings used.
It is expected that additional fuel oil beyond that stored onsite can be procured and delivered to the plant site within a reasonable period of time since:
(1)   The plant site is served by a railroad spur owned by TVA. The yard transfer pump is provided for transferring fuel oil from a tank car to either of the two fuel oil tanks in the yard, or directly to the diesel fuel oil storage tank assemblies.
(2)   State Route 68 provides vehicle access to the site and intersects: State Route 58 and Interstate 75 (I-75) east of the site and State Route 29 (US 27) west of the site. State Routes 29 (US 27) and 58 pass within 10 miles of the site and I-75 within 30 miles of the site. These thoroughfares provide year round access (extreme weather conditions could interrupt traffic flow for short periods of time) to both Chattanooga and Knoxville. With access to both of these major cities it would be very unlikely that tanker truck deliveries would be interrupted for any significant period of time, even in periods of extreme weather conditions.
(3)   If rail or road transportation is unavailable, barge or tanker delivery can be accepted at the dock area on the west bank of the Tennessee River near the plant site.
A failure modes and effects analysis for the diesel generator fuel oil storage and transfer subsystem is presented in Table 9.5-2.
9.5-14                                                                         OTHER AUXILIARY SYSTEMS

WATTS BAR                                                                                       WBNP-92 9.5.4.4 Tests and Inspections The engine-mounted, motor and engine-driven fuel oil transfer pumps and day tanks were functionally tested in the vendor's shop in accordance with the manufacturer's standards to verify the performance of the diesel generator units and accessories. The fuel oil transfer pumps in the yard and Diesel Generator Building were tested in the manufacturer's factory to verify their performance. The 7-day fuel oil storage tanks were tested with compressed air to 20 psig prior to shipment to the plant site.
The entire diesel fuel oil system is flushed with oil and is functionally tested at the plant site in accordance with Chapter 14.0. The diesel fuel oil system will be periodically tested to satisfy the Technical Specifications.
9.5.5 Diesel Generator Cooling Water System 9.5.5.1 Design Bases A closed-loop circulating water cooling system is furnished for each engine of the four tandem diesel generator units housed within the Diesel Generator Building. The system maintains the temperature of the diesel engine within a safe operating range, under all load conditions, and maintains the coolant pre-heat during stand-by conditions. The heat sink for this system is the ERCW system which, flows through the tube side of the skid-mounted heat exchangers. See Section 9.2.1 for discussion of the ERCW system.
The diesel generator skid-mounted cooling water piping and components between the skid interface connection and the engine interface are vendor supplied, safety-related, ANSI B31.1, Seismic Category I with the exception of the cooling water heat exchangers which are ASME Section III, Class 3. All modifications to the skid-mounted diesel generator cooling water system piping are performed to meet the intent of ASME Section III, Class 3 (TVA Class C).
These buildings are designed to Seismic Category I requirements, and are designed to withstand the effects of tornadoes, credible missiles, hurricanes, floods, rain, snow, or ice as defined in Chapter 3 (Sections 3.3, 3.4, and 3.5).
9.5.5.2 System Description Each cooling system includes a pump, heat exchanger expansion tank, and all accessories required for a cooling loop. (See Figure 9.5-23.)
To preclude long term corrosion or organic fouling the engine cooling water system requires de-ionized water with a corrosion inhibitor. The water chemistry is maintained in conformance with the engine manufacturer's recommendations, Electromotive Division of Generel Motors Corporation MI 1748. The closed-loop engine cooling water is circulated through the shell side of each skid-mounted heat exchanger by two diesel-engine shaft-driven pumps. Jacket water immersion heaters are provided for each engine to maintain the jacket water within the vendor recommended temperature range in order to reduce thermal stresses and assure the fast starting and load OTHER AUXILIARY SYSTEMS                                                                             9.5-15

WATTS BAR                                                                                    WBNP-92 accepting capability of the diesel generator units in performing their required safety function.
Temperature switches are used to control the immersion heater and to annunciate on high or low jacket water temperature. For temperature switch set points, see Figure 9.5-23.
Jacket water flows through the lubrication oil cooler by thermosyphon action when the diesel generators are idle. An electric motor driven lubrication oil circulation pump, powered from the 480V diesel auxiliary board, is also provided for each engine to circulate the lubrication oil through the lubrication oil cooler, which is warmed by the engine jacket water, and return the oil to the engine sump. The jacket water immersion heaters are controlled by thermostats, and the lubrication oil circulation pumps run continuously when the engine is not running. This recirculation ensures the lube-oil temperature is maintained at 85&deg;F (minimum) during the standby mode. (See Figures 8.3-33, -33A, -33B, -33C, and -35.)
Each diesel generator unit is provided with two closed engine cooling water loops (one for each engine), for which the heat sink is provided by the ERCW system. (Refer to Section 9.2.1). The ERCW flows through the tube side of the skid-mounted heat exchangers.
9.5.5.3 Safety Evaluation The cooling water is supplied to the heat exchangers of each diesel generator unit through redundant headers of the ERCW system. The system isolation valves are so arranged as to provide the capability to isolate either cooling source in the event of a component malfunction or excessive leakage from the system. Refer to Figures 9.2-1 and 9.2-4A. These valves are powered from the 480V diesel auxiliary board and closure signals for these valves are manually initiated (See Figures 8.3-33, -33A, -33B,
          -33C, and -35.) Therefore a malfunction (single failure of a component) or loss of one cooling water source can not jeopardize the function of a diesel generator unit. Both the non-skid-mounted air-start piping and fire protection piping located in the vicinity of the diesel generator cooling water system are designed to Seismic Category I(L) to ensure that no seismic event will degrade the functional capability of the diesel generator cooling water system. A failure modes and effects analysis for the diesel generator cooling water system is presented in Table 9.5-2.
9.5.5.4 Tests and Inspections The ERCW system within the Diesel Generator Building is hydrostatically tested in accordance with the requirements of ASME Section III and is functionally tested in accordance with Chapter 14.0. System components are accessible for periodic inspections during operation.
The skid-mounted diesel generator cooling water system components are inspected and serviced as specified in the scheduled maintenance program for the Watts Bar Nuclear Plant diesel generator units.
9.5-16                                                                       OTHER AUXILIARY SYSTEMS

WATTS BAR                                                                                    WBNP-92 9.5.6 Diesel Generator Starting System 9.5.6.1 Design Bases Each diesel engine is equipped with an independent pneumatic starting system to provide reliable, automatic starting of the engines. See Figure 9.5-24. The diesel starting air system components are housed with their respective diesel generator units within the diesel generator rooms in the Diesel Generator Building.
The supply headers from each air compressor to the isolation check valve on its skid-mounted accumulator are designed to Seismic Category I(L) requirements. The supply headers from each loadless start device to the isolation check valve and the normally closed bypass valve at the skid-mounted accumulator are designed to Seismic Category I requirements.
The diesel generator skid-mounted starting air system piping and components are vendor supplied, safety-related, ANSI B31.1, Seismic Category I. All modifications to the skid-mounted starting air system piping are required to be performed to meet the intent of ASME Section III, Class 3 (TVA Class C).
9.5.6.2 System Description Each diesel engine has two pairs of air starting motor units (hence, there are four pairs per diesel generator unit). A minimum of two pairs of air start motors are needed to start the diesel generator unit. A set of two skid-mounted air accumulators is provided for each diesel engine; four accumulators per diesel generator unit.
The accumulators are designed in accordance with the ASME Boiler and Pressure Vessel Code, Section VIII. Each set of accumulators is sized for a compressed air storage capacity sufficient to start the diesel generator unit five times without recharging. Each set of accumulators is equipped with pressure gauges, drains, shutoff valves, safety relief valves, check valves, instrumentation, and controls.
Two 480V ac motor-driven compressors supply compressed air to each of the two sets of accumulators for each diesel generator unit. Controls for the compressors have been designed for automatic start-stop operation. Manual test-start selector switches are also provided for each compressor. Pressure switches are provided on each air starting system for actuating low air pressure alarms both in the MCR and ACR (see Figure 9.5-25A, -25B, and -25C).
To prevent moisture and rust accumulation in the air starting system, a fully automatic heatless air dryer has been installed between the air compressor and the accumulators. The air dryer unit contains dual desiccant drying chambers which are alternately cycled through drying and regeneration cycles, a forced air after cooler, and associated cycle and fan controls. One chamber of the desiccant dryers is on stream at all times. Moisture traps are also located downstream of the dryers to collect any residual moisture. The two air storage systems for each diesel generator unit provide redundancy so that a single failure will not jeopardize the design starting capacity of the system.
OTHER AUXILIARY SYSTEMS                                                                         9.5-17

WATTS BAR                                                                                      WBNP-92 9.5.6.3 Safety Evaluation All equipment necessary to start the diesels upon receipt of a start signal is Seismic Category I.
The diesel air start system is classified as quality group D. Section B of Regulatory Guide 1.26 discusses quality groups A through D and generally the types of equipment falling in each group. Section B also discusses systems and components not covered by groups A-D. Examples of these non-covered items are provided in Regulatory Guide 1.26 and include instrument and service air systems, auxiliary support systems and diesel engines. Part NA-1130, Section III of the ASME code states that drive system and other accessories are not part of the code. Regulatory Guide 1.26 states that non-covered items should be designed, fabricated, erected, and tested to quality standards commensurate with the safety functions performed. As a quality group D system, it is considered to meet quality standards commensurate with the safety function performed.
The piping for the air start system is designed to minimize rust accumulation in the system. Moisture is accumulated at the low points in the system and removed by administrative blowdown procedures. ASME Section III, Class 3 soft-seated check valves are provided downstream of the air accumulators. A strainer is also provided in the air start piping system upstream of the air start motors which prevents carry over of oil or rust, etc., to the motors. An oil mist type lubricator located in the air start system piping downstream of the line strainer and before the air start motors, provides lubrication for the motors. The typical arrangement for each engine is a strainer and lubricator for each pair of air start motors. The diesel starting air system is shown in Figures 9.5-25A, 25B, and 25C. A failure modes and effects analysis for the diesel generator starting air system is presented in Table 9.5-2.
9.5.6.4 Tests and Inspections The entire diesel generator starting system is functionally tested in accordance with Chapter 14.0. The system is periodically tested to verify its ability to function as part of the diesel generator unit to satisfy the Technical Specification requirements. Under normal standby conditions, the diesel generator starting system is maintained and inspected at intervals as prescribed in the plant maintenance instructions for the diesel generator units.
9.5.7 Diesel Engine Lubrication System 9.5.7.1 Design Bases The diesel engine lubrication system for each diesel engine shown in Figure 9.5-26 (this figure depicts the diesel lube oil system for Diesel Generator 1A-A which is representative of the other three diesel generator sets), is a combination of four subsystems: the main lubricating subsystem, the piston cooling subsystem, and the scavenging oil subsystem and the motor-driven circulating pump, and soak back pump system.
9.5-18                                                                        OTHER AUXILIARY SYSTEMS

WATTS BAR                                                                                   WBNP-92 The main lubricating subsystem supplies oil under pressure to the various moving parts of the diesel engine. The piston cooling subsystem supplies oil for piston cooling and lubrication of the piston pin bearing surfaces. The scavenging oil subsystem supplies the other systems with cooled and filtered oil. Oil is drawn from the engine sump by the scavenging pump through a strainer in the strainer housing located on the front side of the engine. From the strainer the oil is pumped through oil filters and a cooler. The filters are located on the accessory racks of the engines. The oil is cooled in the lubricating oil cooler (as shown in Figure 9.5-27) by the closed circuit cooling water system in order to maintain proper oil temperature during engine operation.
During standby, the lube-oil temperature is maintained at 85&deg;F or greater by the closed cooling-water system.
The required quality of oil is maintained by scheduled maintenance of strainers, separators, and filters and by oil changes in accordance with the engine manufacturer's owners group recommendation.
A crankcase pressure detector assembly is provided to cause the engine to shut down in case the normal negative crankcase pressure changes to a positive pressure. This is accomplished by relieving the oil pressure to the engine governor. The crankcase pressure detector shutdown device is operative only during diesel generator testing; see Section 8.3.1.1 under the heading, "Standby Diesel Generator Operation."
An overspeed mechanism is provided to shut down the engine by stopping the injection of fuel into the cylinders should the engine speed become excessive.
The piping and components for the skid-mounted diesel engine lubrication system are vendor supplied, safety-related, ANSI B31.1, Seismic Category I. All modifications to the skid-mounted diesel engine lubrication system are performed to meet the intent of ASME Section III, Class 3 (TVA Class C).
9.5.7.2 System Description The system is a combination of four separate systems. The four systems are the main lube oil system, piston cooling system, scavenging oil system, and the motor-driven circulating pump and soak-back pump system. Each system has its own pump. The main lube oil pump and piston cooling oil pump, although individual pumps, are both contained in one housing and are driven from a common shaft and are the helical gear type. The main lubricating, piston cooling, and scavenging oil pumps are driven from the accessory gear train at the front of the engine. The auxiliary system has a circulating oil pump and a soak-back oil pump driven from electric motors mounted on the side of engine base. All pumps are mounted on the engines, skid, or Diesel Generator Building floor.
The main lube oil system supplies oil under pressure to the majority of the engine moving parts. The piston cooling system supplies oil for piston cooling lubrication of the piston pin bearing. The scavenging oil system supplies the other systems with cooled, filtered oil.
OTHER AUXILIARY SYSTEMS                                                                         9.5-19

WATTS BAR                                                                                     WBNP-92 In the operation of these systems, oil is drawn from the engine sump by the scavenging oil pump through a strainer in the strainer housing. From the strainer, the oil is pumped through the oil filter and the lube oil cooler. The cooler absorbs heat from the jacket water to maintain proper operating temperature during standby operation. The oil then flows to the strainer housing to supply the main lubricating and piston cooling pumps.
After being pumped through the engine, the oil returns to the engine sump to be recirculated.
To enhance the reliability of and to minimize wear due to automatic fast starting, each DG has an auxiliary lube oil system driven by two electric motors. The motors drive two pumps, each of which has a separate function. A soak-back pump draws oil from the engine sump and pumps it through the accessory rack-mounted auxiliary turbocharger lube oil filter and through the head of the engine-mounted turbocharger oil filter into the turbocharger bearing area. The auxiliary turbocharger oil filter purifies the oil supplied to the turbocharger. A relief valve allows oil to be bypassed to the circulating pump system when the outlet pressure exceeds 75 psig.
The soak-back system has a two-fold job. It prelubes the turbocharger bearing area so that the bearing will be fully lubricated when the engine receives a start signal requiring rated speed and application of rated load within a matter of seconds. It also removes residual heat from the turbocharger bearing area upon engine shutdown.
The lube oil circulating pump draws oil from the engine sump and pumps it through a check valve, in-line wye strainer, main lube oil filter, lube oil cooler, and returns it to the engine sump through the strainer housing.
This system also serves to continuously prelube the lower portion of the engine. The main engine oil galley stays full and the camshaft area is supplied through a separate exterior line. The pump operates continuously.
The water jacket immersion heater heats the engine cooling water which circulates through the lube oil cooler. As the oil is circulated through the cooler (operating as a heater) it is warmed.
A backup DC lube oil pump provides lube oil to the turbocharger in case the AC pump fails.
Low lube oil pressure alarms are located in the MCR and in the ACR. Lube oil low alarm pressure varies with engine operating conditions.At rated speed, the engine shuts down if lube oil pressure drops below setpoint during non-accident conditions.
There are no other interlocks on this system.
9.5.7.3 Safety Evaluation Each engine crankcase sump contains a sufficient volume of lubricating oil, ample for at least 7 days of diesel generator unit full' load operation without requiring replenishment. The established oil consumption rate is 0.83 gallons per hour. An additional standby oil reserve is stored within the plant's power stores to replenish the engines for longer periods of operation and to "top off" the engines after their periodic 9.5-20                                                                        OTHER AUXILIARY SYSTEMS

WATTS BAR                                                                                        WBNP-94 test operations as specified in the Technical Specifications. A failure modes and effects analysis for the diesel generator lube oil system is presented in Table 9.5-2.
9.5.7.4 Test and Inspections As identified in Chapter 14.0, pre-operational testing for Watts Bar Unit 1 included functional testing of the diesel generator lubricating oil system. Any additional required testing of the diesel generator lubricating oil system for Watts Bar Unit 2 pre-operational testing is also identified in Chapter 14.0. The diesel generator lubricating oil system components are inspected and serviced as specified in the scheduled maintenance program for the Watts Bar diesel generator units. The inspection and service of the lubricating oil systems include visual checking for, and the correction of, oil leakage. This program sets overall standards and testing instructions to qualify the lubricating oil for use in the diesel generator engines.
9.5.8 Diesel Generator Combustion Air Intake and Exhaust System 9.5.8.1 Design Bases Each diesel engine associated with each of the tandem diesel generator units is equipped with an independent combustion air intake and exhaust subsystem. The four subsystems for the plant are housed in physically separated rooms within the Diesel Generator Building. Each of the four diesel generator subsystems has a dedicated air intake and exhaust system.The Diesel Generator Building is designed to Seismic Category I requirements, and is designed to withstand the effects of tornadoes, credible missiles, hurricanes, floods, rain, snow, and ice as defined in Sections 3.3, 3.4, and 3.5. The combustion air intake and exhaust piping, filters, and silencers are so arranged in the individual rooms for each diesel generator unit that a malfunction or failure of any system component associated with any single unit will not impair the operation of the remaining three units. The air intake and exhaust systems thus meets the requirements of the single failure criterion. The piping and components for the diesel generator combustion air intake and exhaust system are designed in accordance with ANSI B31.1, Seismic Category I.
9.5.8.2 System Descriptions The general arrangement of the diesel generator combustion air intake and exhaust systems is shown in Figure 8.3-1. The flow diagrams are shown in Figures 9.5-29 and 9.5-30. Each diesel generator combustion intake and exhaust subsystem includes but not limited to an air intake filter, air intake silencers, and piping of the air intake subsystem from the air intake to its connection to the engine; and an exhaust silencer and piping of the exhaust subsystem from its connection to the engine to a point just above the Diesel Generator Building roof level where the exhaust exits to the atmosphere. As shown in Figure 8.3-1, the major components of the diesel generator combustion air and exhaust system are housed within the Diesel Generator Building which provides protection from missiles, snow, and ice. That portion of the exhaust subsystems exposed above the roof level is short and below the parapet level to reduce the vulnerability to tornado missiles. Drain holes are provided at appropriate points to expel any rainfall that enters the exhaust piping.
OTHER AUXILIARY SYSTEMS                                                                            9.5-21

WATTS BAR                                                                                      WBNP-94 9.5.8.3 Safety Evaluation The diesel generator combustion air intake and exhaust systems are designed to function before, during, and after a SSE, to ensure that a seismic event will not degrade the combustion air intake and exhaust systems to the point that the function of a diesel generator unit is jeopardized.
An analysis of diesel generator exhaust recirculation utilizing a model developed by Halitsky[1] for transverse jet plumes, established that the exhaust plume will be carried well above the level of the air intakes and thus will not degrade the intake air. The diesel generator units can withstand a concentration of 20% carbon dioxide (by volume) in the intake air stream and continue to function at rated, full-load power. The redundancy and separation of the four intake and exhaust subsystems are discussed in Section 9.5.8.1. The protection against missiles, snow, rainfall, and ice are discussed in Section 9.5.8.2.
A failure modes and effects analysis for the Diesel Generator Building ventilation intake and exhaust subsystems is presented in Table 9.4-4. A failure modes and effects analysis for the diesel generator combustion air intake and exhaust systems is presented in Table 9.5-2.
9.5.8.4 Tests and Inspection As identified in Chapter 14.0, pre-operational testing for Watts Bar Unit 1 included functional testing of the entire installed diesel generator combustion air intake and exhaust system. Any additional required testing of that system for Watts Bar Unit 2 pre-operational testing is also identified in Chapter 14.0.
Each diesel generator combustion air intake and exhaust subsystem is periodically tested to verify its ability to function as part of the diesel generator unit testing in accordance with Technical Specifications.
Under normal standby conditions, the diesel generator combustion air intake subsystem is inspected at intervals as prescribed in the plant maintenance instructions for the diesel generator units. These inspections include the air intake filter oil level, oil viscosity, and sludge accumulation.
The diesel generator combustion air exhaust silencer has a continuous drain to remove any water which may accumulate due to condensation or rain.
REFERENCE (1)  James Halitzky, 'A Method for Estimating Concentrations in Transverse Jet Plunes.' Air and Water Pollution Int. J., Pergamon Press. 1966, Vol. 10, pp.
821-843 (2)  Letter to NRC dated February 5, 1992, "Watts Bar Nuclear Plant (WBN) -
Submittal of TVA Fire Protection Report."
9.5-22                                                                        OTHER AUXILIARY SYSTEMS

WATTS BAR                                                                            WBNP-91 (3)  Letter to NRC dated June 15, 1995, "Watts Bar Nuclear Plant (WBN) - Fire Protection Report (FPR) Revision (TAC M63648)."
(4)  Letter to NRC dated September 28, 1995, "Watts Bar Nuclear Plant (WBN) -
Submittal of Fire Protection Report (FPR) Revision 4 (TAC M63648)."
(5)  Letter to NRC dated October 1995, "Watts Bar Nuclear Plant (WBN) -
Submittal of Fire Protection Report (FPR) Revision 5 (TAC M63648)"
OTHER AUXILIARY SYSTEMS                                                                 9.5-23

WATTS BAR                                                     WBNP-91 Table 9.5-1 Deleted by Amendment 52 9.5-24                                        OTHER AUXILIARY SYSTEMS

OTHER AUXILIARY SYSTEMS WATTS BAR Table 9.5-2 Failure Modes and Effects Analysis of the Standby Diesel Generator Auxiliary Systems (Sheet 1 of 4)
METHOD OF ITEM     COMPONENT                                         FAILURE              POTENTIAL              FAILURE            EFFECT ON       EFFECT NO. IDENTIFICATION            FUNCTION                   MODE                  CAUSE               DETECTION            SYSTEM        ON PLANT                    REMARKS 1     Fuel oil system      Forward fuel to         Delivers insufficient   Passive failures such    Control room        None:           None       1. Fuel oil systems of each diesel generator from 7-day tank      injectors of respective quantity of fuel to     as tank ruptures or      indication of       Remaining                  set are completely independent of each forward to engine    engines.                engines.                piping leaks, clogging   failure of diesel   three diesel               other.
on any one of four                                                   of strainers or          generator set to    generators diesel generator                                                     injectors. See Note 2    start or shuts      furnish 100%               2. Due to redundant pumps and valving sets in standby                                                      in Remarks.              down.               standby power              arrangements within each DG FO system, service.                                                                                                          required by                single active failures that disable the system Also, failure of                             plant.                     are not credible.
instrumentation to provide proper signal to pumps and controls.
9.5-25                                                                                                                                                                                                                         WBNP-87

Table 9.5-2 Failure Modes and Effects Analysis of the Standby Diesel Generator Auxiliary Systems (Sheet 2 of 4)
OTHER AUXILIARY SYSTEMS WATTS BAR METHOD OF ITEM     COMPONENT                                         FAILURE                POTENTIAL               FAILURE            EFFECT ON       EFFECT NO. IDENTIFICATION             FUNCTION                  MODE                    CAUSE                DETECTION            SYSTEM        ON PLANT                  REMARKS 2     Starting air system   Crank engine to start   Either one of two sets Active failure of any       Control room        None;            None      Each one of two engines in a diesel from diesel           diesel generator set. of cranking systems     one pneumatic valve        indication of       Duplicate air              generator set includes a cranking system generator skid-                               fails to crank engines. or air start motor that    failure of diesel   start system on            independent of its mate or of the other mounted air                                                           would prevent all four     generator to        other engine in            diesel generator sets.
accumulator inlet                                                     air motors of one of       start.              the diesel check valve                                                           two engines to                                 generator set is forward to the air                                                    engage and crank                               capable of starting motors on                                                    diesel generator set,                          providing 100%
any one of eight                                                      or passive failure due                         cranking power engines in standby                                                    to leakage of air from                         for both service.                                                              the accumulator or                             engines in the piping in one of the                           diesel two cranking                                   generator set.
systems.
Also, failure of instrumentation to provide start signal or failure providing a false signal.
9.5-26                                                                                                                                                                                                                      WBNP-87

Table 9.5-2 Failure Modes and Effects Analysis of the Standby Diesel Generator Auxiliary Systems (Sheet 3 of 4)
OTHER AUXILIARY SYSTEMS WATTS BAR METHOD OF ITEM     COMPONENT                                      FAILURE                POTENTIAL            FAILURE           EFFECT ON     EFFECT NO. IDENTIFICATION            FUNCTION                MODE                    CAUSE             DETECTION           SYSTEM      ON PLANT                   REMARKS 3     Lube oil system of   Lubricate engine      Insufficient lube oil    Failure of any one     Control room       None;          None      Lube oil system of each individual engine is any one of eight     wearing surfaces and flow or oil temperature   pump or passive        indication of      Remaining                separate and independent of all others.
engines in standby   maintain proper       exceeds limits.          failure such as        shutdown of        three diesel service.             piston temperature of                          system leakage or      affected diesel    generator sets respective engine.                             filter clogging.       generator set. are capable of furnishing 100% of the required plant standby power.
None; Remaining Provide cooling for                                                   Control room       three diesel Jacket cooling       lube oil coolers,     Fails to maintain        Active failure of      indication of      generator sets           Jacket cooling water system of each water system and     cylinder liner and    correct engine           either pump,           high engine        are capable of None      individual engine is separate and 4     heat exchanger of    heads and             temperature.             thermostatic control   coolant            furnishing               independent of all others.
any one of eight     turbocharger                                   valve or immersion     temperature in     100% standby engines in standby   aftercoolers of                                water heater, or       affected engine    power required service.             respective engine.                             passive failure of     requiring          by plant.
piping or heat         shutdown of exchanger pressure     diesel generator boundary.              set.
9.5-27                                                                                                                                                                                                                 WBNP-87

Table 9.5-2 Failure Modes and Effects Analysis of the Standby Diesel Generator Auxiliary Systems (Sheet 4 of 4)
OTHER AUXILIARY SYSTEMS WATTS BAR METHOD OF ITEM      COMPONENT                                          FAILURE                POTENTIAL                FAILURE         EFFECT ON        EFFECT NO. IDENTIFICATION             FUNCTION                   MODE                    CAUSE                 DETECTION         SYSTEM         ON PLANT                   REMARKS 5     Combustion air        Direct filtered air to   Insufficient or          Passive failure of          Control room     None;            None       Combustion air intake system of each intake system from turbocharger.               unfiltered air flow to   either filter silencer or   indication of    Remaining                   individual engine is separate and intake filter through                          respective engine.       flexible connection         engine           three diesel                independent of all others.
silencer and flexible                                                   that would either           misfunction or   generator sets connection up to                                                        restrict air flow or        shut down.       are capable of turbocharger inlet                                                      induct unfiltered air                        furnishing on any one of eight                                                     into engine.                                 100% of engines in standby                                                                                                   standby power service.                                                                                                             required by plant.
Exhaust system from turbocharger                                                       Passive failure of                           None; through expansion                              Restricts flow.          silencer.                                    Remaining joint and silencer  Provide path for                                                                Control room     three diesel on any one of eight exhaust.                                                                        indication of    generator sets   None       Exhaust system on each individual engine is 6     engines in service.                                                                                 engine           are capable of              separate and independent of all others.
malfunction or   furnishing shut down.       100% of standby power required by plant.
9.5-28                                                                                                                                                                                                                          WBNP-87

WATTS BAR                                                    WBNP-87 Figure 9.5-1 Deleted by Amendment 87 Other Auxiliary Systems                                         9.5-29

WATTS BAR                                                    WBNP-87 Figure 9.5-2 Deleted by Amendment 87 Other Auxiliary Systems                                         9.5-30

WATTS BAR                                                    WBNP-87 Figure 9.5-3 Deleted by Amendment 87 Other Auxiliary Systems                                         9.5-31

WATTS BAR                                                    WBNP-87 Figure 9.5-4 Deleted by Amendment 87 Other Auxiliary Systems                                         9.5-32

WATTS BAR                                                    WBNP-87 Figure 9.5-5 Deleted by Amendment 87 Other Auxiliary Systems                                         9.5-33

WATTS BAR                                                    WBNP-87 Figure 9.5-6 Deleted by Amendment 87 Other Auxiliary Systems                                         9.5-34

WATTS BAR                                                    WBNP-87 Figure 9.5-7 Deleted by Amendment 87 Other Auxiliary Systems                                         9.5-35

WATTS BAR                                                    WBNP-87 Figure 9.5-8 Deleted by Amendment 87 Other Auxiliary Systems                                         9.5-36

WATTS BAR                                                    WBNP-87 Figure 9.5-9 Deleted by Amendment 87 Other Auxiliary Systems                                         9.5-37

WATTS BAR                                                     WBNP-87 Figure 9.5-10 Deleted by Amendment 87 Other Auxiliary Systems                                          9.5-38

WATTS BAR                                                     WBNP-87 Figure 9.5-11 Deleted by Amendment 87 Other Auxiliary Systems                                          9.5-39

WATTS BAR                                                     WBNP-87 Figure 9.5-12 Deleted by Amendment 87 Other Auxiliary Systems                                          9.5-40

WATTS BAR                                                     WBNP-87 Figure 9.5-13 Deleted by Amendment 87 Other Auxiliary Systems                                          9.5-41

WATTS BAR                                                     WBNP-87 Figure 9.5-14 Deleted by Amendment 87 Other Auxiliary Systems                                          9.5-42

WATTS BAR                                                     WBNP-87 Figure 9.5-15 Deleted by Amendment 87 Other Auxiliary Systems                                          9.5-43

Security-Related Information - Withheld Under 10CFR2.390 WATTS BAR                                                                            WBNP-95 Figure 9.5-16 Deleted by Amendment 95 Other Auxiliary Systems                                                                                         9.5-44

Security-Related Information - Withheld Under 10CFR2.390 WATTS BAR                                                                            WBNP-95 Figure 9.5-17 Deleted by Amendment 95 D
Other Auxiliary Systems                                                                                         9.5-45

WATTS BAR                                                     WBNP-90 Figure 9.5-18 Deleted by Amendment 90 Other Auxiliary Systems                                          9.5-46

WATTS BAR Other Auxiliary Systems WBNP-63 Figure 9.5-19 Watts Bar Nuclear Plant-Communications Equipment Availability 9.5-47

WATTS BAR Other Auxiliary Systems WBNP-89 Figure 9.5-20 Yard, Powerhouse, and Diesel Generator Building Units 1 & 2 Flow Diagram Fuel Oil Atomizing Air & Steam 9.5-48

WATTS BAR Other Auxiliary Systems WBNP-89 Figure 9.5-20a Additional Dsl Gen Bldg Units 1 & 2 Flow Diagram Fuel Oil Atomizing Air & Steam 9.5-49

WATTS BAR Other Auxiliary Systems WBNP-89 Figure 9.5-20b Diesel Generator Building Unit 2 Flow Diagram Fuel Oil Atomizing Air & Steam 9.5-50

WATTS BAR Other Auxiliary Systems WBNP-89 Figure 9.5-21 Powerhouse Units 1 & 2 Electrical Control Diagram for Fuel Oil System 9.5-51

WATTS BAR Other Auxiliary Systems WBNP-89 Figure 9.5-22 Powerhouse Units 1 & 2 Electrical Logic Diagram for Fuel Oil System 9.5-52

WATTS BAR Other Auxiliary Systems WBNP-70 Figure 9.5-23 Schematic Diagram -Jacket Water System With Heat Exchanger 9.5-53

WATTS BAR Other Auxiliary Systems WBNP-89 Figure 9.5-24 Diesel Generator Building Unit 1 Flow Diagram for Diesel Starting Air System 9.5-54

WATTS BAR Other Auxiliary Systems WBNP-89 Figure 9.5-24a Additional Diesel Gen Bldg Unit 1 & 2 Flow Diagram Diesel Starting Air System 9.5-55

WATTS BAR                                                     WBNP-88 Figure 9.5-25 Deleted by Amendment 88 Other Auxiliary Systems                                          9.5-56

WATTS BAR Other Auxiliary Systems WBNP-88 Figure 9.5-25a Diesel Generator Building Unit 1 Electrical Control Diagram Dsl Stg Air Sys DG 1B-B 9.5-57

WATTS BAR Other Auxiliary Systems WBNP-88 Figure 9.5-25b Diesel Generator Building Unit 1 Electrical Control Diagram Dsl Stg Air Sys DG 2A-A 9.5-58

WATTS BAR Other Auxiliary Systems WBNP-88 Figure 9.5-25c Diesel Generator Building Unit 1 Electrical Control Diagram Dsl Stg Air Sys DG 2B-B 9.5-59

WATTS BAR Other Auxiliary Systems WBNP-88 Figure 9.5-25d Diesel Generator Building Unit 1 Electrical Control Diagram Dsl Stg Air Sys DG OC-S 9.5-60

WATTS BAR Other Auxiliary Systems WBNP-57 Figure 9.5-26 Schematic Diagram Lube Oil System 9.5-61

WATTS BAR Other Auxiliary Systems WBNP-57 Figure 9.5-27 Diesel Engine Lubrication System 9.5-62

WATTS BAR                                                     WBNP-41 Figure 9.5-28 Deleted by Amendment 41 Other Auxiliary Systems                                          9.5-63

WATTS BAR Other Auxiliary Systems   ENG   EXHAUST SINLENCER 1A1       SILN-82-101 1A2       SILN-82-102 1B1       SILN-82-103 1B2       SILN-82-104 2A1       SILN-82-201 2A2       SILN-82-202 2B1       SILN-82-203 2B2       SILN-82-204 WBNP-94 Figure 9.5-29 Diesel Air Intake Piping Schematic 9.5-64

WATTS BAR Other Auxiliary Systems ENG   EXHAUST SINLENCER 1A1       SILN-82-101 1A2       SILN-82-102 1B1       SILN-82-103 1B2       SILN-82-104 2A1       SILN-82-201 2A2       SILN-82-202 2B1       SILN-82-203 2B2       SILN-82-204 WBNP-94 9.5-65                                              Figure 9.5-30 Diesel Exhaust System Piping Schematic

WATTS BAR                                                                          WBNP-87 Figure 9.5-31 Deleted by Amendment 87 Watts Bar FSAR Section 9.0 Auxiliary Systems Other Auxiliary Systems                                                               9.5-66}}