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Page 1 of 16 DSAR-9.10 Auxiliary Systems Heating, Ventilating and Air Conditioning System Rev 2 Safety Classification: Usage Level:
Safety Information Change No.: EC 70000 Reason for Change: Revision 2 removes information associated with implementing PDTS.
Preparer: J. Carlson Fort Calhoun Station
DSAR-9.10 Information Use Page 2 of 16 Heating, Ventilating and Rev. 2 Air Conditioning System Table of Contents 9.10 Heating, Ventilating and Air Conditioning Systems ................................................... 5 9.10.1 Design Bases .............................................................................................. 5 9.10.2 System Description ..................................................................................... 6 9.10.3 System Components ................................................................................. 10 9.10.4 System Operation ...................................................................................... 13 9.10.5 Design Evaluation ..................................................................................... 14 9.10.6 Availability and Reliability .......................................................................... 14 9.10.7 Tests and Inspections ............................................................................... 15 9.10.8 Specific References .................................................................................. 15 9.10.9 General References .................................................................................. 16
DSAR-9.10 Information Use Page 3 of 16 Heating, Ventilating and Rev. 2 Air Conditioning System List of Tables Table 9.10.1 - Design Space Temperatures 5 Table 9.10 Deleted ............................................................................................................ 8 Table 9.10 Auxiliary Building Fan Data ............................................................................ 11 Table 9.10 Radioactive Waste Processing Building Fan Data ......................................... 12 Table 9.10 CARP Building-Fan Data................................................................................ 13
DSAR-9.10 Information Use Page 4 of 16 Heating, Ventilating and Rev. 2 Air Conditioning System List of Figures None
DSAR-9.10 Information Use Page 5 of 16 Heating, Ventilating and Rev. 2 Air Conditioning System 9.10 Heating, Ventilating and Air Conditioning Systems 9.10.1 Design Bases The heating, ventilating and air-conditioning systems are designed to maintain a suitable environment for equipment and personnel and to protect personnel and the public from airborne radioactivity. In the discussions which follow, uncontrolled access areas are defined as those to which operating personnel have unlimited access and controlled access areas are defined as those areas subject to potential release of radioactivity. The controlled access area systems (serving the containment and part of the auxiliary building) are designed to handle airborne contaminants so that offsite concentrations and in-plant doses (which are controlled by administrative procedures) are within 10 CFR Part 20 limits. The control room ventilation system is also designed to limit the intake of airborne activity.
The systems are designed on the basis of outside ambient air temperatures of -11°F in winter and 95°F in summer.
Table 9.10 Design Space Temperatures Winter (°F) Summer (°F)
Auxiliary Building Controlled Access Area 40 110 The auxiliary building and control room ventilation systems for outside normal airflow are designed and constructed to Seismic Class I standards (see Appendix F).
Auxiliary Building Ventilation System The auxiliary building ventilation system is non-safety related. The auxiliary building is ventilated and cooled with ambient outside air.
It is divided into two zones for ventilation purposes, the controlled access area and the uncontrolled access area.
The electronic equipment within the Auxiliary Building used for plant components are not credited to mitigate defueled accidents.
The temperature limits are required for radiation monitors credited in the ODCM. The ODCM is part of the license basis defined in the Technical Specifications (Administrative Controls),
Radioactive Effluent Controls Program (Reference 9.10.8-1).
DSAR-9.10 Information Use Page 6 of 16 Heating, Ventilating and Rev. 2 Air Conditioning System 9.10.1.1.1 Deleted 9.10.1.1.2 Deleted Auxiliary Building - Control Room Air Conditioning System The main control room air-conditioning system consists of two non-safety related refrigeration and air handling units. Either unit can be selected for automatic operation if the running unit should fail.
The electronic equipment within the control room used for plant components are not credited to mitigate defueled accidents.
Therefore the temperature limits are no longer applicable for design basis events and the control room does not require mechanical cooling.
The control room uses the following criteria:
- Portions of the control room inlet ductwork for normal outside airflow is credited in the control room dose analysis (Reference 9.10.8-2).
- In accordance with 10 CFR 50.67, doses to an individual in the control room do not exceed 5 rem Total Effective Dose Equivalent (TEDE) for any postulated design basis accident.
Deleted 9.10.2 System Description Auxiliary Building Ventilation System The auxiliary building is ventilated and cooled with ambient outside air. It is divided into two zones for ventilation purposes, the controlled access area and the uncontrolled access area.
Both systems are of the once-through, non-recirculating type using supply and exhaust fans.
DSAR-9.10 Information Use Page 7 of 16 Heating, Ventilating and Rev. 2 Air Conditioning System Controlled Access Area System The controlled access area ventilation supply system consists of an air handling unit, containing roughing filters and preheat and reheat steam coil banks, two 50 percent capacity vane axial fans and distribution ductwork. Steam is supplied from the plant auxiliary boiler. The exhaust system consists of three 33-1/3 percent capacity vane axial fans drawing air through return ducts from each ventilated space to a common filtering unit containing high efficiency particulate air (HEPA) filters. The exhaust air is continuously monitored for radioactive contamination at the ventilation discharge duct before discharge to atmosphere. The total air throughput is 72,500 CFM and its distribution is shown on P&ID 11405-M-2.
Air is supplied to the ventilated spaces through multi-blade dampers and exhausted through ducts equipped with butterfly dampers. These dampers are pneumatically operated with remote-manual control. Each separately ventilated compartment can be isolated.
The supply/exhaust duct work distribution system was designed and balanced so that the zones of highest potential radioactive contamination are at a negative pressure, relative to adjacent areas, in order to prevent outflow of air. Automatic controls provide overall Auxiliary Building negative pressure control, relative to the atmosphere, by adjusting the speed of the supply fans. Under abnormal conditions, the overall negative pressure is maintained by the alignment of the supply/exhaust fans which are manually started and stopped in the Control Room.
In the event of a fault resulting in a low preheat coil exit temperature the controls protect the coils from condensate freezing by tripping the fans.
Uncontrolled Access Area System The uncontrolled access area system is similar to that in the controlled access area, except that shut-off dampers are not installed, the exhaust is not filtered, and a single roof mounted centrifugal exhaust fan is employed. The total air throughput is 22,500 CFM; its distribution is shown on P&ID 11405-M-2.
DSAR-9.10 Information Use Page 8 of 16 Heating, Ventilating and Rev. 2 Air Conditioning System 9.10.2.1.1 Switchgear Rooms Ventilation Non-safety related normal air conditioning (VA-87/89 and VA-88/90) was added to the switchgear rooms after initial plant startup to supplement uncontrolled access area system ventilation (VA-41 and VA-45A/B). The two separate HVAC systems for the switchgear rooms can be cross-tied to allow cooling to both switchgears rooms if one of the units is out of service.
9.10.2.1.2 Counting Room Air-Conditioning Non-safety related air conditioning equipment has been installed in the Counting Room area, due to the addition of temperature sensitive equipment.
Turbine Building Ventilation System The turbine building ventilation system is non-safety related and is used for habitability and to maintain a suitable environment for systems and equipment required post defueling.
Deleted Table 9.10 Deleted Control Room Air Conditioning System The control room air conditioning system is used for habitability post defueling.
The normal outside air duct and airflow measuring station will allow a maximum of 500 CFM of outside airflow with the outside air dampers 100% open (Reference 9.10.8-2). No failure condition of the air-conditioning unit fans and the outlet/inlet dampers can increase the negative pressure in the duct to increase the outside air flow above 1138 CFM used as a design basis value for accidents. The outside inlet ductwork from the outside air inlet to the control room penetration is the only safety related portion of the control room system. The emergency filtration system is isolated.
Two filter assemblies (VA-64A and VA-64B), with separate booster fans (VA-63A and VA-63B)are isolated with valves. These assemblies are no longer credited in accident analysis. The HEPA filters and charcoal filters are removed and heaters isolated.
DSAR-9.10 Information Use Page 9 of 16 Heating, Ventilating and Rev. 2 Air Conditioning System Containment Building HVAC This system is non-safety related and is used to maintain airflow for personnel habitability and to maintain a suitable environment to support decommissioning.
Radioactive Waste Processing Building HVAC The Radioactive Waste Processing Building Heating and Ventilation System consists of two 50% capacity supply air handling units, one 100% exhaust filter package, two 50%
capacity exhaust fans, associated dampers, accessories and controls. Each of the supply air handling units consists of a fan, filters and a supply heating coil. The ductwork on the downstream side of each air handling unit and fan has a backdraft damper.
There is a pneumatic operated isolation damper upstream of each air handling unit, each exhaust fan, and the HEPA filter package.
The exhaust air filter package can be isolated by the isolation dampers upstream of the Filter package and the two isolation dampers downstream of the package, upstream of the exhaust Fans.
The system supplies filtered heating and ventilation to limit the summer building temperature to 110°F maximum and the winter building temperature to 40°F minimum. The temperature limits are required for radiation monitors identified in the ODCM.
Controls for the system are pneumatic and electric.
The supply and exhaust fans are controlled by hand switches on the local HVAC control panel. In addition to automatic trip on motor overload, the fans are interlocked such that each exhaust fan always leads its respective supply fan on start-up and lags the supply fan on shutdown. Therefore, if an exhaust fan trips, the associated supply fan will also trip, to prevent pressurization of the building. Exhaust from the building passes through HEPA filters and a radiation monitor samples the exhaust before discharge to the atmosphere.
DSAR-9.10 Information Use Page 10 of 16 Heating, Ventilating and Rev. 2 Air Conditioning System Chemistry and Radiation Protection (CARP) Building HVAC Systems The CARP Building HVAC Systems are designed to maintain a suitable environment for habitability.
The Laboratory Area HVAC System consists of a commercial quality, penthouse, multizone, air handling unit with a remote condenser for supply air, and a Regulatory Guide 1.140 HEPA Filter Package for exhaust air. The Laboratory exhaust ties into the Radioactive Waste Processing Building exhaust where it is monitored prior to release to the atmosphere. The Chemistry Counting Room supply is filtered through a HEPA Filter Package.
The areas served by the Laboratory HVAC system are maintained at a negative pressure with respect to adjacent areas in the CARP Building. The Chemistry Counting Room and the Computer Room are maintained at a positive pressure with respect to adjacent areas served by the Laboratory HVAC System.
Deleted 9.10.3 System Components Auxiliary Building Ventilation System The air handling supply units in the controlled and uncontrolled access area systems are of similar design. The steam heating coils, supplied from the plant auxiliary boiler, are commercial finned tube units and the roughing filters are the automatically advanced roll type. This equipment is installed in galvanized steel housings with appropriate access provisions.
The supply and exhaust fan data are shown in Table 9.10-4.
DSAR-9.10 Information Use Page 11 of 16 Heating, Ventilating and Rev. 2 Air Conditioning System Table 9.10 Auxiliary Building Fan Data Controlled Controlled Uncontrolled Uncontrolled Access Area Access Area Access Area Access Area Supply Exhaust Supply Exhaust Item No's, VA- 35A and 35B 40A, 40B and 40C 45A and 45B 41 Number 2 3 2 1 Installed Design Air 36,250 24,200 13,000 20,000 Flow, CFM per fan Motor Rating, 60 60 10 20 HP per fan The controlled access area exhaust filter unit consists of a leak-tight galvanized steel housing containing three HEPA filter compartments each of which can be isolated and is separately accessible. The exhaust filter uses replaceable prefilter elements ahead of the HEPA elements.
The controlled access area exhaust ductwork is welded and flanged and is leak tight. All other ductwork is of conventional design and fabrication. The controlled access area supply dampers are multi-blade design with blade seals for tight shut off.
The exhaust system butterfly valves provide "bubble-tight" shut-off to effect complete compartment exhaust isolation.
Deleted Deleted Deleted Radioactive Waste Processing Building HVAC Systems The make-up air handling units are of the central station packaged type consisting of fan, heater, and filter sections mounted together in a common housing on a common base frame. The exhaust fans are centrifugal type with radial blade wheels mounted on a fan/motor isolation base. The exhaust filter package is designed to the requirements of ANSI N-509, 1980 and provides HEPA Filtration of the building exhaust air flow, which is also monitored.
DSAR-9.10 Information Use Page 12 of 16 Heating, Ventilating and Rev. 2 Air Conditioning System Table 9.10 Radioactive Waste Processing Building Fan Data Make-up Air Process Exhaust Handling Units Fans Item Number VA 600A, 600B 30A, 30B Number Installed 2 2 Design Air Flow Rate Per Fan (CFM) 7375 8350 Design Total Pressure Rise (Inches H20) 4.0 16.8 Chemistry and Radiation Protection (CARP) Building HVAC Systems The Laboratory Area HVAC Supply System consists of one 100%
multi-zone air handling unit, nine electric heating coils mounted in the zone supply ducts, two 50% packaged electronic humidifiers, and a HEPA filter package located in the Chemistry Counting Room supply duct. The air handler consists of a supply fan, filter section, electric heating coil, direct expansion cooling coil, outdoor air intake damper and multi-zone dampers. The condensing unit consists of two 50% compressors, condensing coils and condenser fans.
The Laboratory Area exhaust system consists of one 100% Regulatory Guide 1.140 filter package, an exhaust fan, inlet and outlet isolation dampers, and welded stainless steel ductwork.
The filter package consists of prefilters and HEPA filters.
DSAR-9.10 Information Use Page 13 of 16 Heating, Ventilating and Rev. 2 Air Conditioning System Table 9.10 CARP Building-Fan Data Laboratory Process Air Handling Unit Exhaust Fan Item Number VA 652 651 Number Installed 1 1 Design Air Flowrate (action) 9800 12000 Design Total Pressure Rise (in. H20) 5 13 Fan HP 20 40 Item Number VA 629 630 Number Installed 1 1 Design Air Flowrate 1300 640 Fan HP 1/2 1/4 Deleted 9.10.4 System Operation Auxiliary Building Ventilation System Auxiliary Building Controlled Access Area System The system operates continuously and once started, normally requires minimal supervision. If high discharge radiation activity is alarmed several options are open to the operator:
- If the compartment containing the source of activity is known, then this compartment can be individually isolated by closing the dampers;
- Compartments and areas can be isolated and the dampers sequentially opened to identify the activity source; Auxiliary Building Uncontrolled Access Area System The system operates continuously and requires minimal supervision. There are no special operating procedures either during normal operation or in any abnormal situation.
Deleted Deleted
DSAR-9.10 Information Use Page 14 of 16 Heating, Ventilating and Rev. 2 Air Conditioning System Deleted
- a. Deleted
- b. Deleted Radioactive Waste Processing Building HVAC Systems This system operates continuously and requires minimal supervision. Control system design provides interlocking to prevent operation of building supply system without associated exhaust fans on. The system is designed to allow operation at 50% capacity to allow for energy savings during periods of low building use.
Chemistry and Radiation Protection (CARP) Building HVAC Systems The CARP Building HVAC Systems operate continuously and require minimal supervision. Controls for the systems are electric/
electronic.
Deleted 9.10.5 Design Evaluation The heating, ventilation and air-conditioning systems provide a suitable environment for equipment and personnel over a design range of ambient outside temperatures from -11°F to 95°F (dry bulb). In those areas where airborne radioactivity could constitute a hazard, the reduction of this activity is the prime design consideration. Administrative procedures ensure that doses to personnel in these areas are within 10 CFR Part 20 limits during normal plant maintenance. The systems have the capability of limiting off-site release of airborne contaminants to concentrations below those specified in 10 CFR Part 20 by filtration, dilution and, if necessary, isolation (Reference 9.10.8-1).
9.10.6 Availability and Reliability The auxiliary building systems have multiple fans so that in the event of fan failure, the systems can still function but at reduced capacity.
DSAR-9.10 Information Use Page 15 of 16 Heating, Ventilating and Rev. 2 Air Conditioning System The auxiliary building systems are shut down during the short and infrequent periods when the intake filter rolls are replaced. The arrangement of the auxiliary building controlled access area exhaust HEPA filters permits one-third of the filtration capacity to be replaced without disturbing the remainder. The system operates at slightly reduced capacity during filter replacement.
The Radioactive Waste Processing Building Heating and Ventilating System has two 50% capacity exhaust fans and two 50% capacity supply fans so that the system can still operate at reduced capacity in the event of a fan failure.
9.10.7 Tests and Inspections All leak-tight ductwork and equipment housings were pressure tested with air at 0.5 psig after installation and all joints were examined for leaks using soap solution.
After installation the system was tested with regard to flow paths, flow capacities, heating and cooling capabilities, mechanical operability and filtration efficiency. Dampers and the pumps and valves of associated systems were tested for operation at the proper setpoints. Controls, instruments and alarms were checked for operability and adequacy of limits.
9.10.8 Specific References 9.10.8-1 NRC 18-011, NRC Amendment to Permanently Defueled Technical Specifications March 6, 2018.
9.10.8-2 FC08557, Fuel Handling Accident in the Spent Fuel Pool Site Boundary and Control Room Dose, Revision 1, dated 5/29/2018.
DSAR-9.10 Information Use Page 16 of 16 Heating, Ventilating and Rev. 2 Air Conditioning System 9.10.9 General References 9.10.9-1 Deleted 9.10.9-2 Deleted 9.10.9-3 Deleted 9.10.9-4 Deleted 9.10.9-5 Deleted 9.10.9-6 Deleted 9.10.9-7 Deleted 9.10.9-8 Deleted 9.10.9-9 Deleted