ML14058A040

Email from A. Zoulis, NRR to J. Mitman, NRR Comments on the NRR Draft Memo: Supplement to Tech Basis for Allowing ONS to Remain in Operation

ML14058A040
Person / Time
Site:	Oconee
Issue date:	04/22/2010
From:	Antonios Zoulis Office of Nuclear Reactor Regulation
To:	Jeffrey Mitman Office of Nuclear Reactor Regulation
Shared Package
ML14055A421	List: ML090570117 ML090680737 ML091620669 ML092020480 ML092940769 ML100280954 ML101750619 ML101890803 ML102990064 ML103410042 ML12268A404 ML14055A410 ML14055A411 ML14055A474 ML14058A015 ML14058A016 ML14058A017 ML14058A018 ML14058A019 ML14058A020 ML14058A021 ML14058A022 ML14058A023 ML14058A024 ML14058A025 ML14058A026 ML14058A027 ML14058A028 ML14058A029 ML14058A030 ML14058A031 ML14058A032 ML14058A033 ML14058A034 ML14058A035 ML14058A036 ML14058A037 ML14058A038 ML14058A039 ML14058A040 ML14058A042 ML14058A043 ML14058A044 ML14058A045 ML14058A046 ML14058A047 ML14058A048 ML14058A049 ML14058A050 ML14058A051 ... further results
References
FOIA/PA-2012-0325
Download: ML14058A040 (3)

Text

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Mitman, Jeffrey From: Zoulis, Antonios \(' (Li, Sent: Thursday, April 22, 2010 11:14 AM To: Mitman, Jeffrey Cc: Cunningham, Mark; Ferrante, Fernando; James, Lois; Galloway, Melanie

Subject:

RE: Comments on the NRR Draft Memo: "Supplement to Tech Basis for Allowing ONS to Remain in Operation Jeff, Your comments seem to indicate that the original memo was not appropriate and that Oconee should not have been allowed to continue to operate. My understanding is the second evaluation was conducted to determine the validity of the original memo. If you believe the original evaluation is invalid then Oconee should not be allowed to continue to operate and this second memo should document those reasons.

If you do not believe that, then I suggest the second memo re-affirm the first and allow the site to operate until November 2010 eliminating the extraneous information and lengthy discussion. Currently the memo is 3 pages long and regurgitates many of the same points with inappropriate twists. It would be more appropriate to simplify the second memo since re-hashing the details and word "smithing" is not productive and does not add any value to the Oconee evaluation.

Regards, Antonios From: Mitman, Jeffrey j\U. -

Sent: Thursday, April 22, 2010 10:58 AM To: Galloway, Melanie Cc: Cunningham, Mark; Ferrante, Fernando; James, Lois

Subject:

RE: Comments on the NRR Draft Memo: "Supplement to Tech Basis for Allowing ONS to Remain in Operation Importance: High Melanie, I don't have a copy of the memo at this point. I had only a hard copy and I gave that back to Meena.

My answers are based on my notes and recollections.

In response to the first question: The memo does not quantify the risk increase, it simply makes this qualitative statement "... the staffs assessment to allow a slight increased risk until Duke's implementation schedule i. .in-place ." I don't know what the basis for this qualification is M)y assessment is that the internal events CDF is

'about 1-E-6 p5ryear ana that the CCDF from a .uQca-see Dam failure is about 2E-4 per year. In my opinion this is not a "slight" contribution to the total risk per year.

Second: This new draft memo reaffirms the decision that was made back in 2008 (and documented in Memo ML090570117 from Cunningham, Hiland and Giitter to Evans, McCree and Boger dated August 12, 2009) allowing continued operation for two years through November 2010. This new draft memo does not extend the date beyond 11/2010.

To your final point: The basis for the new memo, and I assume the old, is twofold. The risk increase is acceptable and there is adequate defense in depth. Based on the criterion of LIC-504 the risk increase is acceptable. However, ONS has limited defense for core damage and containment failure given a dam failure which inundates the SSF. The limited defense is a single draft "mitigation strategy" writen to prevent core damage which in my opinion will not work. This mitigation strategy does not address containment failure. This does not meet the basic principles of defense in depth quoted below from RG 1.174.

Thus the problem with the draft memo is not one of wording. The draft memo as written does not make the case to allow continued operations.

Jeff Mitman From RG 1.174: Consistency with the defense-in-depth philosophy is maintained if:

" A reasonable balance is preserved among prevention of core damage, prevention of containment failure, and consequence mitigation.

" Over-reliance on programmatic activities to compensate for weaknesses in plant design is avoided.

" System redundancy, independence, and diversity are preserved commensurate with the expected frequency, consequences of challenges to the system, and uncertainties (e.g., no risk outliers).

" Defenses against potential common cause failures are preserved, and the potential for the introduction of new common cause failure mechanisms is assessed.

• Independence of barriers is not degraded.

• Defenses against human errors are preserved.

• The intent of the General Design Criteria in Appendix A to 10 CFR Part 50 is maintained.

From: Galloway, Melanie vlý ý (,--

Sent: Thursday, April 22, 2010 9:42 AM To: Mitman, Jeffrey; James, Lois Cc: Cunningham, Mark; Ferrante, Fernando

Subject:

RE: Comments on the NRR Draft Memo: "Supplement to Tech Basis for Allowing ONS to Remain in Operation

Jeff, In conversation with Mark this morning on this, he raised the question of whether your reference to the increased in core damage frequency was based on incremental risk (per year). And also whether the memo indicated a timeframe to which it would now apply. Your clarification of these points this morning would be appreciated.

Note that I did pass your summary comments onto Dave Skeen and note that you were working with Meena.

He seemed to suggest that ifissues were not presented correctly itwould be a simple matter to change the wording (suggestions welcome) or delete it.

Melanie From: Mitman, Jeffrey Sent: Wednesday, April 21, 2010 6:14 PM To: Galloway, Melanie; James, Lois Cc: Cunningham, Mark; Khanna, Meena; Ferrante, Fernando

Subject:

RE: Comments on the NRR Draft Memo: "Supplement to Tech Basis for Allowing ONS to Remain in Operation Melanie and Lois, I talked with Meena today about my concerns with the memo as written. She is planning to take these back to her management to discuss and will probably be setting up a discussion with DRA management. My comments are documented in the attached document.

Jeff From: Galloway, Melanie Sent: Tuesday, April 13, 2010 9:38 AM To: Mitman, Jeffrey

Subject:

RE: Comments on the NRR Draft Memo: "Supplement to Tech Basis for Allowing ONS to Remain in Operation Yes.

Mark and I also need further info on the Oconee Risk comparison. Mark was out yesterday, I didn't think what you provided yesterday fit the bill, I talked with him regarding what I thought he/we needed and have just 2

conveyed that to JCircle, who will convey to you. That's a task for today so hopefully you'll have time for the JCO also today or tomorrow.

From: Mitman, Jeffrey Sent: Tuesday, April 13, 2010 9:27 AM To: Galloway, Melanie

Subject:

RE: Comments on the NRR Draft Memo: "Supplement to Tech Basis for Allowing ONS to Remain in Operation Melanie, Meena is asking for input into the subject memo. Do I have permission to share with her my comments and work with her to resolve them?

Jeff 3