ML18068A691
| ML18068A691 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 03/09/2018 |
| From: | Ameren Missouri, Union Electric Co |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML18068A685 | List: |
| References | |
| ULNRC-06401, CAC MF8118, CAC MF8119 | |
| Download: ML18068A691 (6) | |
Text
Attachment 5 ULNRC-0640 I Page 1 o16 ATTACHMENT V PROPOSED TS BASES CHANGES (for information only)
Attachment Class 1 E Electrical Equipment Air-Conditioning (NC) System ULNRC-06401 B 3.7.20 Page 2 oI6 B3.7 PLANT SYSTEMS B 3.7.20 Class I E Electrical Equipment Air Conditioning (A/C) System BASES BACKGROUND The Class 1E electrical equipment air conditioning (A/C) trains provide a suitable environment for the Class I F electrical equipment. These air conditioning trains provide temperature control for the Engineered Safety Features (ESF) switchgear room components. DC switchboard room components. and NK battery room components. The specific rooms supplied by the Class I E electrical eqtlipment A/C trains are:
SGKO5A SGKO5B SWBD RM No. I (340$) SWBD RM No. 4 (3404)
SWBD RM No. 3 (3414) SWBD RM No. 2 (3410)
Battery RM No. 1 (3407) Battery RM No. 4 (3405)
Battery RM No.3 (3413) Battery RM No.2 (3411)
ESF SWGR RM No. 1 (3301) ESF SWGR RM No.2 (3302)
The Class I F electrical equipment A/C system consists of two independent trains such that each train provides cooling of recirctilated air in the rooms normally dedicated to that train. Each train consists of a piefilter. self contained refrigeration unit (using normal service water or essential service water (ESW) as a heat sink), centrifugal fans, instrumentation, and controls to provide for electrical eq ii ipment room temperature control.
The Class I E electrical equipment A/C trains have emergency operation functions and also operate during normal unit operation. Each train is normally aligned to cool only the equipment associated with its emergency load grotip. The Class I F electrical equipment A/C trains are operated in a continuous recirculation mode to maintain the ESF switchgear rooms, the battery rooms, and the DC switchboard rooms to a temperature of 90°F (Ref. 1).
Additional recirctilation capability is provided via standby fans and dampers that may be actuated via operator action. With one Class I E electrical equipment A/C train inoperable, the additional recirculation capability may be utilized in conjunction with the remaining Class I E electrical equipment A/C train to provide adequate area cooling for both trains of Class I E electrical equipment during normal and accident conditions.
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Attachment 5 Class 1 E Electrical Equipment Air-Conditioning (A/C) System ULNRC-06401 B 3 7 20 Page 3 of 6 BASES APPLICABLE The design basis of the Class 1 E Electrical Equipment A/C System is to SAFETY ANALYSES maintain temperatures in the Class I E electrical equipment rooms within limits to assure OPERABILITY of the associated electrical equipment. This Support function for the Class I E electrical equipment in turn supports the Engineered Safety Feature (ESF) systems that are reqttired to be OPERABLE consistent with the assumptions and initial conditions of the designbasis accident (DBA) and transient analyses in the FSAR (Chapters 6 and 15).
including the unavailability of offite power. as applicable. The Class 1E Electrical Equipment A/C System is designed so that the single failure ofan active component coincident with a design basis accident (DBA) cannot impair the ability of the supported systems powered by the electrical equipment to fulfill their safety functions.
During normal operations each Class I E electrical equipment A/C train maintains the teniperature in its associated electrical equipment rooms at a temperature 90°F. For DBA conditions, a Class I E electrical equipment A/C train is required to maintain the associated electrical equipment room temperatures 104°F. The Class I E electrical equipment A!C trains are designed in accordance with Seismic Category I req uirements.
The Class I E Electrical Equipment A/C System satisfies Criterion 3 of 10 CER 50.36(c)(2)( ii).
LCO Two independent Class I E electrical eqtlipment A/C trains are required to be OPERABLE to ensure adequate cooling to their associated electrical equipment rooms during normal operation. Each Class I E electrical equipment A/C train is considered to be OPERABLE when the individual components necessary to maintain associated electrical equipment room temperatures within acceptable limits are OPERABLE. These components include (for each train) the refrigeration compressor, heat exchanger, cooling coils. ESW or normal service water flow, fans and associated temperature control instrumentation. In addition each Class I E electrical equipment A/C train must be OPERABLE to the extent that air circulation can be maintained.
APPLICABILITY In MODES 1,2, 3, and 4. the Class IE Electrical Equipment A/C System is a normally operating system with both trains in operation. Both trains must be OPERABLE to ensure that temperattire in the protected rooms will not exceed equipment design limits.
Although the LCO for the Class I E Electrical Equipment A/C System is not Callaway Plant Revision XX
Attachment 5 Class 1 E Electrical Equipment Air-Conditioning (NC) System ULNRC-06401 B 3.7.20 Page 4 of 6 applicable in MODES 5 and 6. the capability of the Class IE Electrical Equipment A/C System to perform its necessary related support functions may be required for OPERABILITY of supported systems.
BASES ACTIONS Al. A.2. and A.3 With one Class IE electrical equipment A/C train inoperable, acceptable room temperatures for both trains of electrical equipment can be maintained if action is initiated immediately to implement mitigating actions. The mitigating actions include utilizing the additional recirculation capability that may be initiated via operator action. This mitigating action (i.e.. action taken to offset the effects of an inoperable Class I E electrical equipment A/C train) should he preplanned and/or procednialized for implementation upon entry into the condition. regardless of whether entry is intentional or unintentional.
The room area temperature limit of 90°F is based on the normal operating maximum steadystate environmental condition and a plant specific calculation for a single Class 1 E electrical equipment A/C train maintaining both Class I E electrical equipment train rooms at a temperature of 101°F during design basis accident conditions. The plant specific calculation assumes the affected room area temperatures are < 90°F at the onset of the design basis accident.
With one Class I E electrical equipment AJC train inoperable, the overall reliability of the cooling function is reduced. However, the remaining OPERABLE train can provide the required cooling function if mitigating actions are taken. The specified mitigating actions assume that the OPERABLE Class IE electrical equipment A/C train is capable of operating at hill capacity.
Verifying the room area temperatures within I hour and every 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> thereafter is adeqtiate to ensure temperatures remain below 90°F. The 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> Completion Time is reasonable based on the minimal increase in room temperatures expected during this time period, with the mitigating actions in place.
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Attachment Class 1 E Electrical Equipment Air-Conditioning (NC) System ULNRC-06401 B 3.7.20 Pace 5 of 6 BASES ACTIONS A. 1, Al and A.3 (continued)
The inoperable Class I E electrical equipment A/C train must be restored to OPERABLE stattis within 30 days. The 30 day Completion Time is based on the capability of the remaining OPERABLE Class I E electrical equipment A/C train to provide adequate area cooling for both trains of electrical equipment during normal and accident conditions (with mitigating actions implemented).
If the room area temperatures are not verified to be within limits as required once per 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, or if the inoperable Class I E electrical equipment A/C train cannot be restored to OPERABLE status within 30 days. Condition B must be entered.
B.l andB.2 When the Required Actions of Condition A cannot be completed within the required Completion Times, the unit must be placed in a MODE that minimizes accident risk. To achieve this stattis. the unit must be placed in MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are reasonable. based on operating experience, to teach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.
C.l If both Class I E electrical equipment A/C trains are inoperable in MODE 1. 2, 3 or 4. the capability to maintain acceptable temperatures for the Class I E electrical equipment is significantly degraded. Therefore. LCO 3.0.3 must be entered immediately.
SURVEILLANCE SR 3.7.20.1 REQU I RMENTS This SR verifies that each Class I E electrical equipment A/C train stails and operates on an actual or simulated actuation signal. The actuation sigiials include the control room ventilation isolation signal (CRVIS) and actuations driven by the LOCA and shutdown sequencers. A CRVIS is generated by the inputs discussed in the Bases for LCO 3.3.7. CREVS Actuation I nstruimentation. The Surveillance frequency is based on industry operating experience, equipment reliability and plant risk, and is controlled under the Surveillance Frequency Control Program.
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Attachment 5 Class 1 E Electrical Equipment Air-Conditioning (NC) System ULNRC-06101 B 3.7 20 Page 6 of 6 BASES SURVEILLANCE SR 3.7.20.2 REQUIRMENTS (continued) This SR verifies that the heat removal capabi I tV of the air conditioning units is adequate to remove the heat load assumed in the control room during design basis accidents. Since testing of the Class I E Electrical Equipment Air Conditioning (A/C) System condenser heat exchangers under design conditions is impractical. this SR consists of verifying the heat removal capability of the condenser heat exchanger (either through performance testing or inspection), ensuring the proper operation of major components in the refrigeration cycle, verification of unit air flow capacity. and water flow measurement. This SR is performed in the same manner as SR 3.7.11 .1 (Reference 2).
The Stirveillance Frequency is based on operating experience (which shows that significant degradation of the Class I E Electrical Equipment A/C typically occurs gradually and in a self-revealing manner.) The surveillance frequency is controlled under the Surveillance Frequenc) Control Program.
REFERENCES
- 1. FSAR. Section 9.4. I
- 2. Letter from C.F Lyon. USNRC, to F. Diya. Union Electric Company. Callaway Plant.
Unit I Interpretation of Technical Specification Surveillance Requirement 3.7.11.1.
Veri Each CRACS Train I-las The Capability to Remove The Assumed Heat Load (TAC NO. MF3665). May 28, 2014.
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