ML12044A300

Email from M. Khanna, NRR to Y. Li, NRR 1 Pager for Chairman Jaczko on North Anna Earthquake Issues

ML12044A300
Person / Time
Site:	North Anna
Issue date:	09/01/2011
From:	Meena Khanna Office of Nuclear Reactor Regulation
To:	Yueh-Li Li Office of Nuclear Reactor Regulation
References
FOIA/PA-2011-0357
Download: ML12044A300 (2)

Text

DE FOIA Resource From: Khanna, Meena Sent: Thursday, September 01, 2011 8:05 AM To: Li, Yong

Subject:

Re: 1 Pager for Chairman Jaczko on North Anna Earthquake Issue Ok thx so much, I will discuss w kamal. Thx From: Li, Yong \QU~~-

To: Khanna, Mgeeena Cc: Manoly, Kamal Sent: Thu Sep 01 08:03:24 2011

Subject:

RE: 1 Pager for Chairman Jaczko on North Anna Earthquake Issue Short description on what we discussed last night.

Based on response spectra* recorded by the seismometers with three components recorded at various levels in both containment building (Unit 1) and in auxiliary building, the corresponding design response spectra at the same levels were all exceeded at different frequency bands, sensitive to a SSC of the reactors. In order to restart of the nuclear power plant, the licensee has to re-evaluate their seismic hazard and provide new GMRS for the site. Under this circumstance, the licensee has to do either and SMA or an SPRA with extensive walkdowns, in combination with other analytical and computation tools to demonstrate that all safety related SSCs have enough seismic margins to resist the new hazard input motion. This process can be extensive and can be risky too because seismic margin is not unlimited.

• Although the spectra obtained from different instruments show some inconsistencies, for example, scratch plates and triaxial accelerometers demonstrate quite different spectrum in both g values and in frequencies at the two horizontal components.

This is just my thinking and I have had a chance to talk to Kamal.

He might disagree.

From: Khanna, Meena Sent: Thursday, September 01, 2011 8:02 AM To: Li, Yong

Subject:

Re: 1 Pager for Chairman Jaczko on North Anna Earthquake Issue Thx From: Li, Yong To: Khanna, Meena Sent: Thu Sep 01 07:59:49 2011

Subject:

RE: 1 Pager for Chairman Jaczko on North Anna Earthquake Issue

Meena, I commented on it a little but I have to go for briefing.

/

Iong From: Khanna, Meena Sent: Wednesday, August 31, 2011 8:46 PM To: Li, Yong; Manoly, Kamal; Munson, Clifford; Benner, Eric Cc: Wilson, George; Karas, Rebecca

Subject:

1 Pager for Chairman Jaczko on North Anna Earthquake Issue Importance: High Pls. update the attached one pager and send to all for comment. George needs to send this to the Chairman by noon, so pls provide any updates by 10 am on Thursday, Sept. 1, if possible. I think the only additional info that we have is the scratch plate results. We really appreciate all of the help.

Do you think we should add a paragraph on the ISFSI stuff?

Thanks, Meena 2