ML14058A056

Email from G. Wilson, NRR to J. Mitman, NRR Questions on Ofi

ML14058A056
Person / Time
Site:	Oconee
Issue date:	01/08/2010
From:	George Wilson Japan Lessons-Learned Division
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: ML14058A056 (1)

Text

Mitman, Jeffrey From:

Sent:

Wilson, George A Friday, January 8, 2010 3:47 AM To: Mitman, Jeffrey

Subject:

Re: Questions on OFI We are asking specifically for the hydro procedures associated with item 3 Sent from nrc blackbe (b)(6)

From: Mitman, Jeffrey,~Q To: Wilson, George Cc: Khanna, Meena; James, Lois Sent: Thu Jan 07 18:00:04 2010

Subject:

Questions on OFI George, in our discussion today we talked about additional questions that may be appropriate to ask Duke if they have not already been asked. Below are some to consider. I may have more after thinking more about the existing list.

Thanks.

Jeff

• In addition to the final flood height at the SSF and around the ONS another parameter of interest coming out of the final 2D analysis is the water velocity. The mitigation strategies (or what you have called interim compensatory measures - I assume they are the same) will depend on what equipment remains usable once the flood waters recede. The velocity of the flood water and what the flood waters strike could significantly erode and/or damage systems, structures and components (SSC) that may be useful in event mitigation. When we go to evaluate the mitigation strategies and the credit given in risk space for those strategies we will need to know what forces the SSC experienced. I bring this up now because this is an output of the 2D hydrology work and it would be good to put Duke on notice while they are performing the hydrology analysis that we will be needing this information.

" Likewise, as we have discussed, the 2D analysis results that I've seen to date indicates that at the end of the analysis about a foot of water remains on the site at the SSF. I recognize that the graphs Duke presented to us is only of limited duration. However, if and/or when the water level recedes to below ground elevation after the flood waters pass, will significantly impact/complicate recovery. For example, ifwater continues to flow across the site after flood water recede, it appears that pumping the basement floor elevation of the turbine building and possibly the aux. buildings may be impossible.

Likewise, as we discussed, a constant flow across the site will impede access to SSC that may be relied upon for mitigation.

" In your question 10 you indicate that we are requesting copies of the procedure which Duke would use for decision making in the event of an impending storm and possible PMF. It is unclear to me whether we are requesting ONS procedures that would govern decision making at the nuclear site or whether we are requesting procedures that govern the operation of the Jocassee Dam. In my opinion it would be good to have both. Likewise, as it appears that operation of the entire watershed prior to a dam failure or PMF could affect the water levels at Oconee, I believe it would be prudent to have any procedures that Duke "hydro" might use during these conditions. For example procedures that might direct personnel to drop the Keowee Reservoir level, etc.

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