ML14027A663

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G20140013/LTR-13-0976 - Response Letter to K. Vale: Karen Vale, Cape Cod Bay Watch Et Al, Ltr. January 2-3, 2014 Storm and Simultaneous Astronomical High Tides at Pilgrim Nuclear Power Station
ML14027A663
Person / Time
Site: Pilgrim
Issue date: 01/27/2014
From: Raymond Mckinley
NRC/RGN-I/DRP/PB5
To: Vale K
Cape Cod Bay Watch
McKinley R
References
G20140013, LTR-13-0976, RegionI-2014-0002
Download: ML14027A663 (3)


Text

UNITED STATES NUCLEAR REGULATORY COMMISSION REGION I 2100 RENAISSANCE BOULEVARD, SUITE 100 KING OF PRUSSIA, PENNSYLVANIA 19406-2713 January 27, 2014 Ms. Karen Vale Cape Cod Bay Watch 58C Main Street Plymouth, MA 02360

Dear Ms. Vale:

On behalf of the U.S. Nuclear Regulatory Commission (NRC), I am responding to your December 30, 2013, email and attached letter which referred to a winter storm which had the potential to impact Pilgrim Nuclear Power Station (Pilgrim) on January 2-3, 2014. Specifically, you expressed concerns about storm conditions and tide levels.

In preparation for the winter storm, the NRC resident inspectors at Pilgrim performed Inspection Procedure 71111.01, Adverse Weather. This inspection procedure requires the inspectors to perform a site walk down to identify any potential deficiencies or discrepancies not previously identified by Entergy. In addition, the inspectors review and verify that cold weather protection features, such as heat tracing, space heaters, and weatherized enclosures are monitored sufficiently to ensure they support operability of the system, structure, or component they protect. Our resident inspectors and regional staff monitor approaching storms and assess plant impacts both during and after storm passage.

During the winter storm, the highest observed still water tide level along with wave action did not approach Design Basis storm conditions or flooding levels at Pilgrim. Specifically, forecasts predicted a maximum still water high tide of 12 to 13 ft above Mean Lower Low Water level (MLLW) in the vicinity of Pilgrim. This MLLW tide value equates to approximately 7 to 8 ft above Mean Sea Level (MSL). Pilgrims design and Emergency Classifications for flood levels are referenced to MSL. The Notice of Unusual Event (NOUE) Emergency Action Level for still water tide level for Pilgrim is 13.5 ft above MSL as measured in the circulating water intake bay.

The NOUE threshold of 13.5 ft above MSL is also the Design Basis maximum storm level. The highest levels measured in the circulating water bay during the storm occurred coincident with high tide on Friday afternoon on January 3, 2014. The observed readings were consistent with the predicted still water value of 7 to 8 ft above MSL with momentary maximum peaks to 11.7 ft MSL due to wave action. So, this particular storm, while significant in terms of its intensity and coincidence with high tide, did not approach the Design Basis maximum storm level. There was no impact on the equipment in the circulating water bay and there was no observable damage to the jetties. The NRC staff independently concluded that, throughout this event, Entergy operated the plant safely and in accordance with the conditions in the plants license and technical specifications.

K. Vale 2 Finally, you questioned the licensees description as a dry site and you also challenged the validity and application of several established datum standards. A dry site means that a plant is built above the Design Basis maximum storm level, so Pilgrim is a dry site as defined by Nuclear Energy Institute guidance. Pilgrim was designed and licensed using generally accepted national geodetic survey vertical datum standards and maps. In addition, Pilgrim is required to reevaluate site specific flooding hazards and submit a report to the NRC before March 12, 2015.

Thank you for your continued interest in these matters.

Sincerely,

/RA/

Raymond R. McKinley, Chief Reactor Projects Branch 5 Division of Reactor Projects

ML14027A663 Non-Sensitive Publicly Available SUNSI Review Sensitive Non-Publicly Available OFFICE RI/DRP RI/DRP NAME JDeBoer/JPD RMcKinley/RRM DATE 1/23/14 1/27/14