ML13296A338

NRC Response to 9/23/2013 Email from Betty Shank Regarding Limerick'S Potential Inability to Safely Shutdown

ML13296A338
Person / Time
Site:	Limerick
Issue date:	10/23/2013
From:	Fred Bower Reactor Projects Region 1 Branch 4
To:	Shank B - No Known Affiliation
BOWER, FRED
References
Download: ML13296A338 (1)

Text

From: Bower, Fred Sent: Wednesday, October 23, 2013 10:06 AM To: BettyShank@comcast.net Cc: Barber, Scott; Thompson, Margaret; Screnci, Diane; Sheehan, Neil; McNamara, Nancy; Tifft, Doug; Gray, Mel; Pinkham, Laurie

Subject:

Response to 9/23/2013 Email from Betty Shank Regarding Limerick's Potential Inability to Safely Shutdown (EDATS RI-2013-0294)

Dear Ms. Shank,

My name is Fred Bower and I am writing to you in response to an email that you sent Mr. Mel Gray on September 23, 2013. In this email, you reiterated questions from your August 5, 2013, email that Mr. Gray answered in an email dated September 4, 2013.

I understand your questions to be related to actions that Limerick took in response to a generic issue reported by the reactor vendor (GE Hitachi Nuclear Energy) in NRC Event Report Number 46230 (ADAMS Accession # ML12040A283). Specifically, GE Hitachi (GEH) reported that they had determined that the scram capability of the control rod drive mechanism in BWR/2-5 plants may not be sufficient to ensure the control rod will fully insert in a cell with channel-control rod friction at or below the friction limits specified in MFN 08-420 with a concurrent Safe Shutdown Earthquake (SSE). As you can see in the 9/27/11 update to the event report, GE Hitachi recommended to their customers that testing with new allowable friction limits that will ensure control rods fully insert at low reactor pressure concurrent with an SSE (for Mark I containment plants) and SSE with concurrent LOCA (for Mark II containment plants), such as Limerick. Exelon refers to the recommended testing as "distortion testing." You may find additional information on the recommended testing in ADAMS Package ML120380362; however, you will find that many details of this testing are proprietary and have been redacted. To perform our regulatory function, the NRC may view this information, but it cannot be released to the public.

As was mentioned in Mr. Gray's September 4, 2013, email, our inspectors reviewed this information, observed testing and noted acceptable results.

In summary, I believe that Mr. Gray's email dated September 4, 2013, fully answered all the questions you asked in your August 5 and September 23 emails. Hopefully, the information above provides additional clarification.

Please call me at the phone number listed below if you would like to discuss this issue further.

Sincerely,

Fred Bower Chief l Projects Branch 4 l Division of Reactor Projects l Region I l U.S. NRC 2100 Renaissance Boulevard, STE 100, King of Prussia, PA 19406 l : (610) 337-5200 l BB: (610) 731-1920 l : Fred.Bower@nrc.gov