ML16256A279

Revision 309 to Final Safety Analysis Report, Chapter 6, Engineered Safety Features, Section 6.4

ML16256A279
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Site:	Waterford
Issue date:	08/25/2016
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WSES-FSAR-UNIT-3 6.4-1 Revision 14 (12/05)6.4 HABITABILITY SYSTEMSThe main control room habitability systems include radiation shielding, air filtration and ventilation equipment, instruments, monitors, controls, missile protection, emergency lighting, food, water, kitchen, sleeping, sanitary facilities, fire protection equipment and, administrative emergency procedures. (DRN 04-705, R14) Habitability systems are provided to assure that the operators can remain in the main control room and take effective actions to operate Waterford 3 safely under normal conditions and maintain a safe condition post accident, as required by General Design Criterion 19 of Appendix A to 10CFR50 and

10CFR50.67.(DRN 04-705, R14) The Control Room Air Conditioning System is discussed in this section and in Subsection 9.4.1. This section addresses emergency operation of the system, while Subsection 9.4.1 is directed toward normal and emergency operation. Emergency lighting is described in Subsection 9.5.3. Protection of the main control room from wind and tornado effects is covered in Section 3.3. Flood design is discussed in Section 3.4. Missile protection is described in Section 3.5. Protection against dynamic effects associated with pipe break is described in Section 3.6. Environmental design conditions are given in Section 3.11.

Fire protection is discussed in Subsection 9.5.1. 6.4.1 DESIGN BASES The functional design of the habitability systems and the provisions for occupancy are based on the following:a) A control room envelope, as defined in Subsection 6.4.2.1, is provided.

b) The main control room environment is suitable for continuous occupancy during normal operation and extended occupancy throughout the duration of any one of the postulated accidents

discussed in Chapter 15. c) Sufficient food, water, medical supplies and sanitary facilities are provided for at least five persons for a five day period following a design basis accident (LOCA). (DRN 04-705, R14) d) The radiation exposure to main control room personnel, throughout the duration of any one of the postulated accidents discussed in Chapter 15, does not exceed the limits of General Design

Criterion 19 of Appendix A to 10CFR50 and 10CFR50.67. (DRN 04-705, R14) e) The habitability systems provide the capability to detect and protect the main control room personnel from smoke and toxic gases. f) Respiratory protection is provided for emergency use within the control room envelope. (DRN 04-705, R14) g) The control room air condition system is capable of automatic transfer from its normal operating mode to the recirculation or isolation mode and manually transferred to the pressurized mode as

necessary.(DRN 04-705, R14)

WSES-FSAR-UNIT-36.4-2Revision 10 (10/99)h)Emergency monitors detectors and control equipment are provided at plant locations, asnecessary, to ensure the ability to meet design bases b, d, e and g.i)The control room envelope and the Control Room Air Conditioning System are designed to remainfunctional (e.g. maintain room temperature within limits acceptable to personnel, instruments and equipment) during and after a safe shutdown earthquake.j)The habitability systems are capable of performing their functions assuming a single activecomponent failure coincident with a loss of offsite power.k)Additional design bases for the normal operation of the Control Room Air Conditioning System aregiven in Subsection 9.4.1.1.6.4.2SYSTEM DESIGN 6.4.2.1Definition of Control Room EnvelopeThe control room envelope is defined to include the main control room, computer room, computer roomair conditioning equipment room, control room HVAC equipment room, emergency living quarters, emergency food and water storage rooms, toilets, locker rooms, kitchen, kitchenette, supervisors office,corridors, conference room and vault (critical document reference file).Control room operators will require access to the above areas immediately after and during anemergency.The entire envelope floor is at elevation +46 ft. MSL inside the Reactor Auxiliary Building.Drawing G134 is a layout drawing showing the control room envelope, and the placement of equipment.6.4.2.2Control Room Air Conditioning System DesignSubsection 9.4.1 contains an overall description of the Control Room Air Conditioning System and asystem airflow diagram is shown on Figure 9.4-1.Air flow diagram shown on Figures 6.4-1, 6.4-2 and 6.4-3 illustrate the normal, high radiation and toxicchemical operating modes respectively. Instrument schematics and logic diagrams number LOU1564 B-431 sheet 260S, 261S, 264S, 265S, 266S, and 267S concerning the Control Room Ventilation System, are submitted under a separate cover (See Section 1.7). Table 6.4-3 shows damper and isolation valve positions for all operating modes.The type of system provided for Waterford 3 is zone isolation, with filtered recirculated air, widelyseparated, dual air inlets, and provisions for positive pressure (0.125 in. WG). Makeup air for pressurization is filtered before entering the control room envelope. During a toxic gas or radiologicalemergency, the modes of operation of the Control Room Air Conditioning System are, respectively:

WSES-FSAR-UNIT-3 6.4-3 Revision 301 (09/07) a) Automatic isolation with automatic recirculation.

b) Automatic isolation with provisions for manual in itiation of filtered pressu rization, recirculation and partial filtration.

(EC-5000081471, R301)

The volume of the control room envelope serviced by the Control Room Air-Conditioning System is approximately 220,000 cubic ft. (A minimum volume of 168,500 ft 3 is assumed in dose calculations where appropriate.)

(EC-5000081471, R301)

The Control Room air-conditioning System consists of two full capacity redundant air handling units, designated AH-12 (3A-SA) and AH-12 (3B-SB), two toilet exhaust fans each with 100 percent capacity designated E-34 (3A-SA) and E-34 (3B-SB) and a conference room and kitchen exhaust fan designated

E-42 (3).

Two full capacity, redundant Engineered Safety Features (ESF) air filtration units S-8 (3A-SA) and S-8 (3B-SB) provide continuous filtrati on following a design basis accident.

The action of all the "nonessential" f ans is described in Subsection 9.4.1.

Design data for the Control Room Air Conditioning System components is given in Table 9.4-2.

The control room envelope penetrations of the emer gency outside air intakes each contain one normally open and one normally closed fail-as-is butterfly valve in series. Each series valve is powered from a different emergency power source. In this manner an electrical fault precludes neither the ability to open the intake for control room pressurization nor clos e the intake for control room isolation. Redundant, normally open, air operated, fail closed butterfly va lves are provided at the control room envelope penetration for the normal outside air intake. Redundant isolation butterfly valves on the normal exhausts are arranged as a channel A valve in series with a c hannel B valve so that an electrical fault does not jeopardize the safety function of the system.

(DRN 01-663, R11-A)

Leakage characteristics of the isolation valves are giv en in Table 6.4-1. The closure time for the normal outdoor air isolation valves is two seconds or less. (DRN 01-663, R11-A)

The seismic classification of com ponents, instrumentation and duct work is indicated in Table 3.2-1.

The system is located within the Reactor Auxiliary Building which is designed to withstand the effects of tornado generated missiles. All outside air intakes are protected from entry of tornado generated missiles. Internally-generated missiles resulting from fan blades would be stopped by the fan casing as

described in Section 3.5.

Figure 1.2-1 is a plot plan showing the plant layou t, including the location of onsite potential radiological and toxic gas release points with respect to the main c ontrol room air intakes. The elevations of release points and intakes are also indicated on Figure 1.2-

1. Elevation and plan drawings showing building dimensions are given in Section 1.2. Potential source s of toxic gas release are identified in section 2.2.

WSES-FSAR-UNIT-3 6.4-4 Revision 14 (12/05)A description of system controls and instrumentation is given in Subsection 9.4.1. CP18 is the HVAC control panel inside the main control room. Redundant radiation monitors are located at both the normal and emergency outside air intakes. These Class 1E radiation monitors are discussed in Subsection

12.3.4.(DRN 04-705, R14) The main control room will be immediately isolated upon receipt of a Safety Injection Actuation Signal, or normal outside air intake high radiation signal. Control room isolation dampers are designed to ensure that the main control room is isolated prior to any unfiltered (and potentially contaminated) air reaching

the control room atmosphere. (DRN 04-705, R14) Five ionization smoke detector zones are located within the control room envelope. The main control room, the control room HVAC equipment room, and the emergency living quarters, each have one detector zone. The computer room has two detector zones, one above and one below the floor. The smoke removal mode of the Control Room Air-Conditioning System following postulated fires is

discussed in Subsection 9.4.1.2.2.

Based on the evaluation of potential accidents in Subsection 2.2.3, redundant chlorine and broad range detectors are provided at the normal outside air intake. Analyses on other toxic chemicals are also

provided in Subsection 2.2.3. Design data for the HEPA and charcoal filter trains are given in Table 9.4-2. The degree to which the recommendations of Regulatory Guide 1.52 (673) are followed is indicated in Subsection 6.5.1. The redundant air conditioning units are served by redundant loops of the Essential Services Chilled Water System (see Subsection 9.2.9) so that loss of one loop of the Essential Services Chilled Water System does not affect ability of the Control Room Air-Conditioning System to control the thermal

environment in the control room envelope. The redundant equipment which is essential for the safety functions are powered from divisions A and B of the Plant Electric Power Distribution System so that loss of one division does not prevent the Control

Room Air-Conditioning System from fulfilling its safety functions. 6.4.2.3 Leak Tightness(DRN 04-705, R14)

The amount of unfiltered air inleakage was measured to address NRC Generic Letter (GL) 2003-01, "Control Room Habitability." Specifically, testing was performed in accordance with ASTM Standard E2029-99, "Standard Test Method for Volumetric and Mass Flow Rate Measurement Using Tracer Gas Dilution," and ASTM Standard E741-00, "Standard Test Method for Determining Air Change Rate in a Single Zone by Means of Tracer Gas Dilution." This testing is the preferred method of testing by the NRC. The results of the tests are presented in Table 6.4-1. These results were conservatively modeled in the various Chapter 15 dose consequence analyses for postulated design basis accidents. (DRN 04-705, R14)

WSES-FSAR-UNIT-3 6.4-5 Revision 14 (12/05)(DRN 04-705, R14)

Gross leakage will be verified by periodic testing as described in Regulatory Guide 1.95 (2/75). Test procedures are summarized in Subsection 6.4.5. (DRN 04-705, R14) An acceptance test will be performed to verify the adequacy of the air makeup rate to maintain a positive pressure inside the control room envelope of at least +0.125 in. WG. 6.4.2.4 Interaction With Other Zones and Pressure-Containing Equipment(DRN 04-705, R14) The ventilation zones adjacent to the envelope are below or at atmospheric pressure, i.e., always negative with respect to the envelope. No other area is served by the Control Room Air Conditioning

System. The closest postulated main steam line break is at least 30 ft. away from any one of the main control room outside air intakes, and the steam jets resulting from a postulated main steam line break (see

Section 3.6) are vertical and are not directed toward the intakes. The east main steam Atmospheric Dump Valve (ADV) is located in close proximity to the east control room air intake (approximately 6.5 meters). Therefore, this combination of ADV and intake could result in fairly significant control room doses for events involving steaming releases. (DRN 04-705, R14) (DRN 00-998, R11) The quantity of Halon in hand portable fire extinguishers inside the control room envelope is insignificant.(DRN 00-998, R11) 6.4.2.5 Shielding DesignShielding design of the control room and the post-accident dose levels that may exist there is discussed in FSAR Section 12.3A. 6.4.3 SYSTEM OPERATIONAL PROCEDURES 6.4.3.1 StartupThe control room operator starts the system, selecting either SA or SB channels, and verifies open the main control room normal outside air intake and exhaust isolation valves. The emergency outside air intake trains are closed and remain closed in the normal mode. The air conditioning unit supply air

temperature controller is set at the design set point. 6.4.3.2 Normal Operation After the air conditioning unit and exhaust fans are started, the Control Room Air Conditioning System is controlled automatically to maintain the desired Control Room temperature. Both trains of the Control Room Air Conditioning System and the interfacing systems are operated alternately to equalize their service times and to exercise them into the state of readiness.

Subsection 9.4.1.2.1 describes the normal operation of the system.

WSES-FSAR-UNIT-3 6.4-6 Revision 301 (09/07) 6.4.3.3 Emergency Operation There are two modes of emergency operation, pressurized and isolated. Isolated emergency operation is

initiated automatically following receipt of a Safety Injection Actuation Signal (SIAS), toxic gas emergency or a high radiation signal at the normal outside air intake.

(DRN 04-705, R14)

During a radiological emergency, Figure 6.4-2 represent s the operator action to manually initiate filtered pressurization, recirculation, and parti al filtration. After the receipt of an SIAS, or a high radiation signal, the following automatic actions will occur to change t he Control Room Air Conditioning System from its normal operating mode to this emergency mode. Refe r to Table 6.4-3 for valve and damper position. (DRN 04-705, R14) a) Close normal outside air isolation valves V-13 and V-14, close exhaust isolation valves V-9, V-10, V-11 and V-12 to isolate these air flow pat hs into and out of the control room areas.

b) Stop operating exhaust fans E-42 end E-34.

c) Open both pairs of recirculation dampers D-18 and D-19 associated with the operating air handling unit AH-12 to automatically recirculate a ll air supplied to all the control room areas.

(DRN 04-705, R14; EC-5000081471, R301) d) Start both Emergency Filtration Units S-8 to pr ovide filtration and adsorpt ion of all outside air and unit recirculation air at a flow rate of 3800 cfm for each filtration unit. Accident analyses assume a maximum filtered pressurization flow rate of 225 cfm of outside air into the control room envelope for the duration of the event.

Class 1E controls are provided in the control room to allow the operator to open any intake and to select the intake which is admitting air with the lowest concent ration of radioactivity (refer to Subsection 12.3.4).

Manual selection of the more favorable air intake is credited in design basis accident dose analyses. In accident analyses 100 cfm of unfiltered inleakage is assumed for the duration of the event. (DRN 04-705, R14; EC-5000081471, R301)

During a toxic gas emergency, the control room air c onditioning system is automatically transferred to the emergency operation mode; however, such a transfe r involving only toxic gas detection does not constitute an ESF actuation. Figure 6.4-3 shows t he control room air conditioning system during a toxic gas emergency. Upon receipt of a toxic chemical signal, the following automatic actions will place the control room envelope in isol ation and recirculation mode:

a) Close normal outside air isolation valves V-13 and V-14, close exhaust isolat ion valves V-9, V-10, V-11 and V-12 to isolate all air flow paths into and out of the control room areas.

b) Open both pairs of recirculation dampers D-18 and D-19 associated with the operating air handling unit AH-12 to automatically recirculate all air supplied to all control room areas.

c) Stop operating exhaust fans E-42 and E-34. The control room air conditioning system is operated in the isolated m ode and provides recirculation.

WSES-FSAR-UNIT-3 6.4-7 Revision 301 (09/07)

In the event that a toxic gas signal is generated s ubsequent to a SIAS or high radiation signal, the toxic gas signal will override the previous signal and close all outside air intakes.

No outside air is drawn into the control room envelope during the toxic chemical emergency.

Manual initiation of emergency operation can occur whenever the control room operator desires.

Radiological protection and toxic gas protection ar e discussed in Subsections 6.4.4.1 and 6.4.4.2, respectively.

6.4.4 DESIGN EVALUATION

6.4.4.1 Radiological Protection (DRN 04-705, R14)

The evaluation of the radiological ex posure to the control room operators is presented in the main control room accident dose analysis given in Chapter 15.

Subsection 15.6.3.3 shows the doses following the design basis accident (LOCA) and demonstrates compliance with GDC 19 and 10CFR50.67. (DRN 04-705, R14)

Table 6.4-2 is a summary sheet of the Control Room Air Conditioning System parameters used in the

main control room dose analysis.

6.4.4.2 Toxic Gas Protection

a) Protection from Chlorine

Redundant chlorine detectors are provided near the Control Room Air Conditioning System normal outside air intake. The chlorine detectors use diffusion-type el ectrochemical probes.

Upon detection of chlorine, the control room envelope is automatically placed in the isolated mode as described in Subsection 6.4.3.3 and the RAB Normal Ventilation System is shut down as described in Subsection 9.4.3.1.2. The chlo rine detectors are provided with outputs to sound an alarm in the main control room. The chlorine concentration readout is available from the plant monitoring computer and appears on a digital display panel in the control room. (DRN M 99001091; EC-5000082258, R301) The response time of the chlorine detectors is a function of the instantaneous chlorine concentration. An analysis of the concentration buildup following a postulated worst-case release from a stationary chlorine storage tank indicates t hat the isolation time (the time interval from when the chlorine concentration at the isolat ion dampers reaches 5 ppm to when the dampers

are completely closed) is less than or equal to 4 seconds. This is based on a chlorine sensor time constant of 12 seconds, a travel time in the duct between the sensors and the isolation damper of 4.76 seconds, and a isolation damper clos ure time of 2 seconds. Since the calculated isolation time is within 4 seconds, the Waterfor d 3 control room meets the RG 1.95 requirements for a Type II control room for stationary chlo rine sources. Mobile sources are treated probabilistically, as described in Subsection 2.2.3.3.3. (DRN M 99001091; EC-5000082258, R301)

WSES-FSAR-UNIT-3 6.4-8 Revision 301 (09/07)

(EC-5000082258, R301)

The Chlorine Detection System, although orig inally purchased as non-seismic equipment, has been seismically qualified by laboratory testing in order to meet the Regulatory Guide1.95 requirements. In addition, the chlorine detec tion equipment has been installed in seismically qualified structures. The plant specific se ismic response spectra as experienced by the equipment and the as-built installation were considered in the testing. (EC-5000082258, R301)

Redundant chlorine detectors are powered from independent nonsafety-related uninterruptible power supplies which in turn draw power from safety-related buses. The loss of power to a detector is annunciated in the control room. (DRN M9901096 There are no onsite Circulating Water System chlorination facilities. (DRN M 9901096) b) Protection from Anhydrous Ammonia

The Broad Range Gas Detection System detects ammonia. The operation of the Broad Range Gas Detection System is descr ibed in Subsection 6.4.4.2c.

Upon detection of ammonia, the control room envelope is automatically placed in the isolated mode as described in Subsection 6.4.3.3 and the RAB Normal Ventilation System is shut down as described in Subsection 9.4.3.1.2..

Redundant broad range detectors are pow ered from independent nonsafety-related uninterruptible power supplies which in turn draw power from safety-related buses. The loss of power to a detector is annuncia ted in the control room.

c) Broad Range Detectors

A Broad Range Gas Detection System which continuously monitors incoming control room air for the presence of a large variety of toxic gases is installed on the Control Room air intake duct. If toxic gas concentration equals or exceeds the hi gh setting, the detector system sounds an alarm and automatically isolates the control room before toxic or IDLH levels can be reached.

The maximum detector response time is 17 seconds or less for gases listed in Table 6.4-4.

Alarms are also actuated by a loss of power.

As a safeguard against detection system failure, a backup Broad Range Gas Detection installation is provided.

Each Broad Range Detection system consists of an analyzer panel that utilizes continuous scan Fourier Transform Infrared (FTIR) sensing technology. The monitor samples the air and automatically analyzes for the pr esense of gases and vapors of chem icals for which the computer has been programmed.

WSES-FSAR-UNIT-3 6.4-9 Revision 302 (12/08)

The broad range gas detectors are designed to be very sensitive to numerous gases and are programmed to respond to the gases listed in Table 6.4-4. The control room will be isolated when

the gases concentrations exceed the designated set point. A display of the specific gases and their concentrations is provided in the control room.

d) Industry Hot Line

Waterford 3 is a participant in the St. Char les Parish Emergency Preparedness/Industrial Hot Line System. This is a dedicated communication network between St. Charles Parish Emergency Operations Center (EOC) and industries in St. Char les Parish. In the event of an emergency, the affected industry would promptly notify the EOC of the class of emergency, the type of incident and the recommended actions. The EOC will then notify affected neighboring industries.

e) Carbon Dioxide Generation and Oxygen Depletion (DRN M 99001091; EC-5435, R302) Carbon dioxide production was calculated to demons trate the capacity of the control room in terms of the number of people it can accommodat e for an extended period of time and not exceed a CO 2 concentration of 1 percent when in isolate mode. Results show that the control room can accommodate 13 people for greater t han 6 days without ventilating with fresh air. A oxygen level of 17 percent would be reached for 13 people afte r 19 days. The above results are based on the assumption that the control room envelope will be comp letely isolated. During periods of time the control room is isolated, acce ss does not have to be limited if CO 2 levels are monitored and maintained below an administrative limit. When the CO 2 level reaches an administrative alert limit, administrative controls would be implemented to ensure CO 2 levels remain acceptable during a toxic chemical event. Due to wind speed, dispersion, etc., calculations show the duration the control room would have to remain isolated for a toxic chemical event is no greater than 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. Therefore, control room staff limits, for a toxic chemical event, are based on a 30 hour3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> duration. (DRN M 99001091; EC-5435, R302) f) Emergency Air Supply System

(EC-5000082258, R301)

(EC-5000082258, R301)

An Emergency Air Supply System for the Main Control Room (MCR) is provided to ensure a minimum six hour supply of air for control room and security personnel. The system WSES-FSAR-UNIT-36.4-10Revision 11 (05/01)(DRN M9901028)is designed to provide Grade D breathable air (as defined by the Compressed Gas Associationstandards) at a rate of 6 scfm for each of 17 individuals. An air storage system with a capacity of 45,000 scf at 1800 psig is provided to maintain a supply of air for use upon demand. Figure 6.4-4 is a flow diagram of the system.(DRN M9901028A breathable air compressor is manually operated to fill the storage tanks. This manual operationprevents accidental chemical contamination of the stored air. The air which leaves the tanks is reduced in pressure to approximately 100 psig prior to entering the control room. Air manifolds are located at strategic locations throughout the MCR envelope for easy personnel access. Air hoses, which will be stored in the MCR envelope, will be utilized to connect the user's breathing apparatus to the air manifold.The tanks, support structures and piping to and in the control room which are required to operatefollowing an earthquake are nonsafety, seismic Category I. The compressor and tank fill piping are not required for successful system operation and therefore, seismic considerations are notapplicable. The tank system is located in the East Cooling Tower area which is part of the Nuclear Plant Island structure. It is protected from the effects of tornado generated missiles andis designed to withstand the loadings associated with tornado and hurricane force winds. Since it is possible that system operation would be required coincident with a loss of power (offsite or onsite), the system will perform its functions without relying on external power sources.In addition, any postulated rupture of the pressurized tanks will not create high velocity missiles.The rupturing vessel will tend to "tear" instead of explosively shattering.Instrumentation is provided to signal low pressure in the control room. Sampling of stored air willbe performed on a periodic basis to ensure that stored air is maintained at Grade D levels.Practice drills are conducted in accordance with Section 8 of the Waterford 3 Emergency Plan.g)Other ProvisionsWritten emergency procedures to be initiated in the event of a toxic chemical release within ornear Waterford 3 are provided. Procedures covering the evacuation of nonessential personnel are also provided.A potable water supply of more than 1.0 gallon per man per day is provided in a number of plasticcontainers stored in the control room envelope. The total amount of potable water stored is at least 25 gallons. One gallon per day per man is the total recommended allowance for drinking,food preparation, personal hygiene and medical requirements.A supply of food is stored in the control room envelope which is sufficient to maintain habitabilityfor at least five men for five days. The main control room contains portable fire extinguishing equipment to permit the timely extinguishing of

)

WSES-FSAR-UNIT-3 6.4-11 Revision 301 (09/07) fires inside the envelope. Hoses from outside the envelope can reach all portions of the control room envelope.

6.4.5 TESTING AND INSPECTION (DRN M 9901096) Preoperational testing and inspection of the Control Room Air Conditioning System are described in Subsections 6.5.1.4 and 9.4.1.4.

Automatic and manual operations import ant to the control room HVAC safety functions are tested periodically to ensure system operation as required by the plant Technical

Specifications. The main control room air conditioning is normally operating and consequently under observation. (DRN M 9901096) Periodic testing of main control room emergency filtration units is described in the Technical Specifications.

Operability of the emergency filtration units is verifi ed by test operation for at least 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> each month with the heaters on. The control room envelope is designed as a minimum leakage structure. During operational testing, a survey will be made by qualifi ed personnel to insure that leakage barriers are in place and properly installed.

Periodic leak rate testing will be conducted every 18 m onths and after any major alteration that may affect the main control room leakage. The gross leakage characteristic of the control room envelope will be determined by pressurizing to +0.125 in. WG and determining the pressurization flow rate.

6.4.6 INSTRUMENTATION REQUIREMENTS

The Control Room Air Conditioning System is described in Subsection 9.4.1. The instruments for this system are designed to maintain habitability conditions in the main control room automatically, with the minimum attention from the operator. The instru mentation and alarms on the CP-18 associated with these systems provide the operator with the information concerni ng the status of the system, and to enable him to take the proper course of action.

The CP-18 is designed to Class 1E requirements.

Valve or damper position and equipment status indicati ons allow the operator to continuously monitor and test the operation of the system and confirm all automatic or m anual actions taken. All abnormal conditions are annunciated.

6.4.6.1 Control Room Air Handling Units (EC-5000081434, R301)

A temperature of 75 F in summer, and a temperature of 70 F in winter can be maintained in the main control room by either air handling unit. Operators can also adjust temperatures as necessary. The following safety-related alarms (a,b,e) and nonsafety-related alarms (c,d,f) are provided for operator use: (EC-5000081434, R301) a) Fan failure (low differential pressure across air handling unit casing).

b) High temperature of air entering main control room (the operator can manually start the standby unit if so desired).

c) Low temperature of air entering the cooling co il (normal intake dampers are closed automatically and air is recirculated).

WSES-FSAR-UNIT-36.4-12d)Low-low temperature of air entering the cooling coil (the air handling unit is tripped automatically).e)High alarm for differential pressure across air handling unit casing to indicate clogged filters.f)High differential pressure across air handling unit filter bank.

In the highly unlikely event of a fire in a computer room the supply and exhaust dampers to the computerroom are closed automatically, preventing the spread of smoke into the main control room. Also an alarmsounds.6.4.6.2Air Filtration UnitsTwo redundant trains of emergency air filtration units are started automatically by the following signals:

a)Safety Injection Actuation Signal (SIAS) b)High radiation signal at the normal outside air intake A SIAS or high radiation signal automatically closes the normal air intake and starts the emergencyfiltration units. Pressurization of the control room occurs by remote manually opening the "good" emergency outside air intake. Control room instrumentation indicates the radioactivity of each emergency outside air intake. A high toxic chemical signal will override operator action that has opened the emergency outside air intakes and the main control room will remain isolated.A high radiation signal is detected by redundant radiation monitors, two pairs per each intake. Theradiation monitors are Class 1E and diversified power is supplied by safety-related channels SA and SB.The instrumentation provided in the main control room will enable the operator to determine:

a)Which side has higher radiation levels.

b)When normal or emergency air intake valves can be opened.

c)Radiation level at outside air intakes.

d)Status of filter train.

e)Amount of air from outside air intakes.

The following safety-related alarms are provided for the operator's use:

a)High radiation levels of outside air intakes b)High toxic chemical levels (nonsafety-related)

WSES-FSAR-UNIT-36.4-13Revision 14 (12/05) c) Status of filter train (high differential pressure) d) Fan Failure (low differential pressure) e) Electric heating coil failure (low differential temperature) f) High temperature of charcoal adsorber.

The control room envelope is considered to be habitable at all times during and after any type of accident except for a fire in the main control room itself.

Design details and logic of the instrumentation is discussed in Sections 7.3 end 7.5. (DRN 04-705, R14) SECTION 6.4: REFERENCES 1. S. Humphreys et. al., "RADTRAD: A Simplified Model for Radionuclide Transport and Removal and Dose Estimation," NUREG/CR-6604, June, 1997 (including supplements 1, 2, and 3). (DRN 04-705, R14)

WSES-FSAR-UNIT-3 TABLE 6.4-1 Revision 301 (09/07) (DRN 04-705, R14)

SUMMARY

OF MAIN CONTROL R OOM LEAK RATE CALCULATIONS (1)(5) (DRN 04-705, R14)

PATH NO.

COMPONENT

UNIT NUMBER OF UNITS NUMBER OF (1) REFERENCE DETAIL LEAKAGE COEFFICIENT

A B LEAKAGE PER UNIT AP + BP 1/2 TOTAL COMPONENT

LEAKAGE (CFM)

1. Hollow Metal Door with Gasketed Interlocking Weather Stripping (Fig. III-A-2) Door Opening Out 3'-0"x7'-0" 1 III-A-2 p.IV-305 5.0 27 10.171 10.171 2. Double Door (Fig. III-A-2) Door Opening Out 6'-0"x7'-0" 2 III-A-2 p.IV-305 5.0 27 16.78215 33.5643 3. Door Frames Ft. 72 I-A-7 p.IV 1.3x10-4 0 0.1625 x 10-4 0.0011 4. Slab (3 ft. and 1 ft. thick) Ft. 2 Ft. 2 1,458 13,461 5.56 x 10-7 0 1.67 x 10-6 0 0.695 x 10

-7 0.20875 x 10

-6 0.0001 0.0028 5. Wall: 1 Ft. thick 2 Ft. thick 2.5 Ft. thick 3 Ft. thick 4 Ft. thick Ft. 2 Ft. 2 Ft. 2 Ft. 2 Ft. 2 1,247 5,290 965 1,482 554 1.67 x 10-6 0 8.33 x 10-7 0 6.67 x 10-7 0 5.56 x 10-7 0 4.17 x 10-7 0 0.20875 x 10

-6 0.041 x 10

-7 0.8337 x 10

-7 0.695 x 10

-7 1.5212 x 10

-7 0.0003 0.0005 0.0001 0.0001 0.00003 6. Roof: 3 Ft. thick 2 Ft. thick Ft. 2 Ft. 2 4,835 10,113 5.13 x 10-7 0 7.41 x 10-7 0 0.6412 x 10

-7 0.9262 x 10

-7 0.00031 0.00094 7. Construction Joints Ft. 1,754 I-A-9 2.4 x 10-4 0 0.3 x 10

-4 0.0526 8. Penetrations for Electrical Cable 4" Conduit 1,100 (Assumed)

A-3(2) 2 x 10-5 1 x 10

-9 0.25 x 10

-5 0.00275 9. Penetrations for HVAC Ducts In. of Seal 800 ADS III-D-1 Case 2 1 x 10-6 0 0.125 x 10

-6 0.0001 10. Isolation Butterfly Valves To Outdoor Air (2) 12" Dia. 5 A-2 p. III-105 - - 2 x 10

-5 0.0001 11. Penetration for Normal Exhaust Louver 2'-0"x4'-0" (Ft. of Frame) 12 Ft. I-A-7 4 x 10-6 0 0.5 x 10

-6 Negligible

12.

Pipe Penetrations In. of Seal 192 490 III-D-1 Detail 2 III-D-1 Detail 1 7 x 10-6 0

3.3 x 10-7 0 0.875 x 10

-5 0.4152 x 10

-7 0.00168

0.00002 TOTAL 43.799 (4)

(1) Based on AEC R & D Report NAA-SR-10100 (2) Leakage rate of 0.02 ft.

3 day assumed. (3) Leakage estimate based on P=0.125 in. wg.

(DRN 04-705, R14; EC-5000081471, R301) (4) This value represents the original theoretical leakage. Actual design pressurization flow is 225 cfm (max). (EC-5000081471, R301)

(5) Initial tracer gas test results from April 2004 of 79 CF M (Recirculation Mode) and 36 CFM (Pressurized Mode) support the analysis assumptions of 100 CFM fo r Recirculation mode and 65 CFM for Pressurized Mode. (DRN 04-705, R14)

WSES-FSAR-UNIT-3 TABLE 6.4-2 Revision 301 (09/07)

SUMMARY

SHEET FOR MAIN CONTROL ROOM AIR CONDITIONING SYSTEM (DRN99-2461, R11) 1. ESF Filter Efficiency (Accident Analysis = 99% Iodine Removal) (DRN99-2461, R11) (DRN 04-705, R14; EC-5000081471, R301) 2. Emergency Outside Air Makeup = 225 cfm Rate (DRN 04-705, R14; EC-5000081471, R301)

3. Normal Outside Air Makeup = 2,200 cfm (nom.)

Rate

4. Filtered Recirculation = 3800 to 7600 cfm

Rate

5. Selection of Intake = Manual

(EC-5000081471, R301)

6. Net Free Volume of Envelope = 220,000 ft.

3 Maximum 168,500 ft 3 Minimum (EC-5000081471, R301)

7. Elevation of Intakes

a) Normal Outside Air Intake = + 73 ft. MSL (Northeast)

b) Emergency Outside Air Intake = + 73 ft. MSL (Northeast) and + 71 ft. MSL (Southwest)

WSES-FSAR-UNIT-3TABLE 6.4-3 (Sheet 1 of 2)CONTROL ROOM AIR CONDITIONING SYSTEM DAMPER AND ISOLATION VALVE POSITIONSVALVENO. ACTUAL VALVE OR DAMPER TAG NO.

TRAIN "A" ACTUAL VALVE OR DAMPER TAG NO.

TRAIN "B"VALVE OR DAMPER FUNCTION VALVE OR DAMPER POSITION FOR EACH OPERATING MODENORMAL ACCIDENT ACCIDENT SMOKE MODE (HIGH RADIATION) (TOXIC CHEMICAL) PURGEV- 13 HV - B196Emergency Outside Air IsolationCLOSED OPEN (3) CLOSED CLOSED V- 23 HV - B199Emergency Outside Air Isolation OPEN OPEN CLOSED OPEN V- 33 HV - B197Emergency Outside Air IsolationCLOSED OPEN (3) CLOSED CLOSED V- 43 HV - B198Emergency Outside Air Isolation OPEN OPEN CLOSED OPEN V- 53 HV - B201Emergency Outside Air IsolationCLOSED OPEN (3) CLOSED CLOSED V- 63 HV - B202Emergency Outside Air Isolation OPEN OPEN CLOSED OPEN V- 73 HV - B200Emergency Outside Air IsolationCLOSED OPEN (3) CLOSED CLOSED V- 83 HV - B203Emergency Outside Air Isolation OPEN OPEN CLOSED OPEN V- 93 HV - B172Conference Room & Kitchen OPEN CLOSED CLOSED OPEN V-103 HV - B171Exhaust Isolation OPEN CLOSED CLOSED OPEN V-113 HV - B178Toilet Exhaust Isolation OPEN CLOSED CLOSED OPEN V-123 HV - B177Toilet Exhaust Isolation OPEN CLOSED CLOSED OPEN V-133 HV - B169Normal Outside Air Isolation OPEN CLOSED CLOSED OPEN V-143 HV - B170Normal Outside Air Isolation OPEN CLOSED CLOSED OPENDAMPERD - 17 (SA)Filtration Unit Inlet DamperCLOSED OPEN CLOSED CLOSEDNO.D - 17 (SB)Filtration Unit Inlet DamperCLOSED CLOSED CLOSED CLOSEDD - 18 (SA)Toilet Recirculation AirCLOSED OPEN OPEN CLOSEDD - 18 (SB)Toilet Recirculation AirCLOSED OPEN OPEN CLOSEDD - 39 (SA)A.H. Unit Recirculation Damper OPEN OPEN OPEN OPEND - 39 (SB)A.H. Unit Recirculation DamperCLOSED CLOSED CLOSED CLOSEDD - 40 (SA)A.H. Unit Outside Air Damper OPEN CLOSED CLOSED OPEND - 40 (SB)A.H. Unit Outside Air DamperCLOSED CLOSED CLOSED CLOSEDD - 41 (SA)Filtration Unit Recirc. DamperCLOSED OPEN CLOSED CLOSEDD - 41 (SB)Filtration Unit Recirc. DamperCLOSED CLOSED CLOSED CLOSEDD - 19 (SA)Conference Room & Kitchen AirCLOSED OPEN OPEN CLOSEDD - 19 (SB)Recirculation DampersCLOSED OPEN OPEN CLOSEDD-43Main Control Room PurgeCLOSED CLOSED CLOSED OPEN (1)

D-44Conference Room Exhaust Damper OPEN OPEN OPEN CLOSED D-45Main Control Room PurgeCLOSED CLOSED CLOSED OPEN D-46Emergency Living Exhaust Air Damper OPEN OPEN OPEN CLOSED WSES-FSAR-UNIT-3TABLE 6.4-3 (Sheet 2 of 2)CONTROL ROOM AIR CONDITIONING SYSTEM DAMPER AND ISOLATION VALVE POSITIONSVALVENO. ACTUAL VALVE OR DAMPER TAG NO.

TRAIN "A" ACTUAL VALVE OR DAMPER TAG NO.

TRAIN "B"VALVE OR DAMPER FUNCTION VALVE OR DAMPER POSITION FOR EACH OPERATING MODENORMAL ACCIDENT ACCIDENT SMOKE MODE (HIGH RADIATION) (TOXIC CHEMICAL) PURGED-62Computer Room Supply Air Damper OPEN OPEN OPEN CLOSED D-63Computer Room Return Air Damper OPEN OPEN OPEN CLOSED D-64Computer Room Plenum Purge DamperCLOSED CLOSED CLOSED CLOSED (2)

D-67Kitchen Exhaust Damper OPEN OPEN OPEN CLOSED D-68Toilets Exhaust Damper OPEN OPEN OPEN CLOSEDNOTES:(1) DAMPER D-43 IS OPEN WHEN PURGING MAIN CONTROL ROOM AND CLOSED WHEN PURGING COMPUTER ROOM RAISED FLOOR PLENUM.(2) DAMPER D-64 IS CLOSED WHEN PURGING MAIN CONTROL ROOM AND IS OPEN WHEN PURGING COMPUTER ROOM. RAISED FLOOR PLENUM.

REFER TO FIGURES 6.4-1, 2 AND 3 RESPECTIVELY FOR NORMAL, HIGH RADIATION AND TOXIC CHEMICAL OPERATING MODES.

(3) MANUAL OPERATION - ONLY ONE OF THE FOUR VALVES (V-1, V-3, AND V-7) WILL BE OPENED BY THE OPERATOR DURING THE PRESSURIZATION MODE OF THE ACCIDENT (HIGH RADIATION).

WSES-FSAR-UNIT-3(DRN 02-1386; R13)TABLE 6.4-4Revision 13 (04/04)GASES AND VAPORS DETECTABLE BY BROAD RANGE GAS DETECTION SYSTEMChemicalChemicalAcetaldehydeHydrogen CyanideAcetic AcidHydrogen Fluoride Anhydrous AcetonitrileIsobutaraldehyde AcroleinIsobutyronitrile AcrylonitrileIsopropyl Alc oholAllyl ChlorideIsopropylamine AmmoniaMethoxydihydropyran Benzene2-Methoxyethanol 1, 3-ButadieneMethylamine 2-Butanone (MEK)Methyl Bromide ButaraldehydeMethyl Chloride tert-Butyl AlcoholMethyl Mercaptan Carbon DisulfidePhosphorus Trichloride Carbon Tetrachloride1-Propanol ChloroformPropylene Dichloride 1,2- DichloropropanePropylene Oxide cis- 1, 3-DichlorpropeneSulfur Dichloride DimethylamineSulfur Dioxide DipropylamineSulfur Monochloride EpichlorohydrinSulfuric Acid Ethyl Acrylate1,1,1,2- Tetrafluroet haneEthylamineToluene Ethylene DichlorideTotal Hydrocarbon Ethylene OxideTriethylamine FormaldehydeTrimethylamine Formic AcidVinyl Acetate HydrazineVinyl Chloride Hydrogen ChlorideVinylidene Chloride(DRN 02-1386; R13)

WSES-FSAR-UNIT-3TABLE 6.4 INTENTIONALLY DELETED Revision 10 (10/99)