ML063490404
| ML063490404 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 12/14/2006 |
| From: | Weerakkody S D NRC/NRR/ADRA/DRA/AFPB |
| To: | Marshall M L NRC/NRR/ADRO/DORL/LPLII-2 |
| Dinh T Q, NRR/DRA, 415-2149 | |
| References | |
| TAC MD1460 | |
| Download: ML063490404 (3) | |
Text
December 14, 2006MEMORANDUM TO:Michael L. Marshall, ChiefPlant Licensing Branch II-2Division of Operating Reactor LicensingOffice of Nuclear Reactor RegulationFROM: Sunil D. Weerakkody, Chief
/RA/Fire Protection BranchDivision of Risk AssessmentOffice of Nuclear Reactor Regulation
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION REGARDINGWATTS BAR NUCLEAR PLANT - UNIT 1 LICENSINGAMENDMENT FOR INCREASING THE MAXIMUM ULTIMATEHEAT SINK TEMPERATURE TO 88 oF (TAC NO. MD1460)The Fire Protection Branch reviewed the "Ultimate Heat Sink - 88 oF Maximum OperatingTemperature Evaluation" submitted by Watts Bar Nuclear Plant, Unit 1. The analysiswas reviewed in accordance with the fire protection program requirements of Title 10 ofthe Code of Federal Regulation, Part 50, Section 48 (10 CFR 50.48), "Fire Protection,"and General Design Criteria (GDC) 3, "Fire Protection." As the result of the review, we identified several areas where additional information is needed in order to determine the acceptability of the proposed change.
Enclosed is therequest for additional information (RAI).Our effort on this task (TAC No. MD1460) is being continued. If you have any questionsregarding the RAI, please contact us.
Enclosure:
As statedCONTACT: Thinh Dinh, AFPB/DRA/NRR (301) 415-2149
ML063490404 NRR-106OFFICEAFPB/DRA/NRRBC: AFPB/DRA/NRR NAMETDinhSWeerakkody DATE12/13/0612/14/06 ENCLOSUREREQUEST FOR ADDITIONAL INFORMATIONWATTS BAR NUCLEAR PLANT - UNIT 1 LICENSE AMENDMENT,"ULTIMATE HEAT SINK - 88 oF MAXIMUM OPERATING TEMPERATUREEVALUATION," (TAC NO. MD1460)The ultimate heat sink (UHS) is the water source for the essential raw cooling watersystem, which provide cooling water to various components/systems, includingcomponents required for achieving and maintaining post-fire safe shutdown. Althoughthe expected water temperature increase from 85 oF to 88 oF has no direct physicalimpact on any safe-shutdown components/systems, the rise in cooling watertemperature may adversely impact the performance characteristics of thesecomponents/systems.To evaluate the impact of the proposed license amendment, if any, on the fire protectionprogram at Watts Bar Nuclear Plant, Unit 1, the Fire Protection Branch requests that thefollowing additional information are provided:1.Section 3.7, "Fire Protection," of the license amendment report onlydiscussed the effect of the proposed UHS maximum temperature increase onthe high-pressure fire suppression system. The impact on safe-shutdowncomponents/systems and their ability to achieve and maintain post-fire safeshutdown, which is part of the Fire Protection Program should also bediscussed in this section.2.Note 9 to Table 2 indicated that emergency diesel generator load shedding isperformed to reduce the el ectrical loading to 100%. Will this load sheddingbe accomplished as part of a permanent design change or as post-firemanual actions?