ML102870984

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Request for Additional Information for the Review of the Columbia Generating Station License Renewal Application-Sama Review
ML102870984
Person / Time
Site: Columbia Energy Northwest icon.png
Issue date: 11/10/2010
From: Dan Doyle
License Renewal Projects Branch 1
To: Gambhir S
Energy Northwest
Doyle D, NRR/DLR, 415-3748
References
TAC ME3121
Download: ML102870984 (5)


Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. S. K. Gambhir , Vice President , Techn i cal Services Columbia Generat i ng Station Energy Northwest MD PE04 P. O. Box 968 Rich l and, WA 99352 November 10 , 2010

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE COLUMBIA GENERATING STATION LICENSE RENEWAL APPLICATION

-SAMA REVIEW (TAC NO. ME3121)

Dear Mr. Gambhir:

By letter dated January 19, 2010, Energy Northwest submitted an application to the U.S. Nuclear Regulatory Commission (NRC) to renew operating license NPF-21 for Columb i a Generating Station pursuant to Title 10 of the Code of Federal Regulations Part 54. T h e NRC staff is r eviewing the information contained in the license renewal application and the associated Environmenta l Report. The staff has identified, in the enclosure , areas where add i t i onal i nformation i s needed to complete the Severe Accident Mitigation Alternatives (SAMA) review. Further requests for addit i onal information may be issued in the future. I tems i n the enclosure were d i scussed with Mr. Abbas Mostala. A mutually agreeable date for the response is within 60 days from the date of this letter. If you have any questions , please contact me at 301-415-3748 or bye-mail at daniel.doyle@

nr c.gov. Docket No. 50-397

Enclosure:

As stated cc w/encl: Distr i but i on v i a Listserv Sincerely , Daniel Doyle, Project Manager Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation Request for Additional Information Regarding the Analysis of Severe Accident Mitigation Alternatives for the Columbia Generating Station License Renewal Review

Background:

The NRC issued a previous request for additional information (RAI) related to the Severe Accident Mitigation Analysis (SAMA) review to Energy Northwest by l etter dated July 1 , 2010 (ADAMS Accession Number ML101760421).

Ene r gy Northwest provided a partial r esponse to the RAls by letter dated September 17, 2010 (ADAMS Accession Number ML102660151).

The purpose of this request for additional information is to prov i de clarification on Energy Northwest's partial response (referred to in this document as "th e r esponse") dated September 17,2010. RAI 3.d(i)-1 The response states th at the " electronic database used to select and locate cables does not includ e all conduit location s," and that "m ost, but not all" of the multi p l e spurious equipment operations (MSOs) that may need to be modeled have been captured and that, for thos e not captured, the response to RAI 6.j will account for the incompleteness.

The response continues to the conclusion that "model incompleteness is judged to be encompassed by the provided sensitiv ity analysis ," which includes the use of a 95th percentile uncertainty band on the base fir e core damage frequency (CDF). (The response to RAI 6.j further cites sens itivity analysis via th e 95th percentile approach.) As Columbia estimates a fire CDF using an analysis that goes beyond the typical fire individual plant examination

-external events (lPEEE), enhancements to r educe potential conservatisms, as well as enhancements to remove potential conservatisms, that might exist in an IPEEE-like estimate of fire CDF shou ld be present. For example, sou rce-target-specific fire scenarios should have been used in lieu of more conservative assumptions of total room burn-up; and hot short probabilities typically of at least 0.3 shou ld have been assumed in lieu of potentially non-conservative lower values. Please describe the se enhancements, including those used with regard to compensat ing for any incompl eteness in the cable lo cation database and modeling of MSOs as cited in the response .. ENCLOSURE RAI6.j-1 i. The uncertainty analysis presented in response to this RAI did not re-evaluate the Phase 1 SAMAs using the maximum uncertainty benefit (from eliminating all int erna l and external ri sk) from applying the uncertainty factors provided in Table 6.j-1. Specifically , the maximum baseline benefit in the ER is reported to be $1.9M , while applying the Tab l e 6.j-1 uncertainty factors would increase the maximum benefit to $5.6M (NRC staff est imate). Provide an assessment of each Phase 1 SAMA eliminated using Screening Criterion 0 and E to determine whether any Phase 1 SAMAs originally screened should have a Phase 2 cost-benefit evaluation performed.

Provide a Phase 2 cost-benefit evaluation for any SAMA not screened.

Mr. S. K. Gambhir , Vice President, Technical Services Columbia Generating Station Energy Northwest MD PE04 P. O. Box 968 R i ch l and , WA 99352 November 10, 2010

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE COLUMBIA GENERATING STATION LICENSE RENEWAL APPLICATION

-SAM A REVIEW (TAC NO. ME3121)

Dear Mr. Gambhir:

By l etter dated January 19 , 2010, Energy Northwest submitted an application to the U.S. Nuclear Regulatory Commission (NRC) to renew operating license NPF-21 for Co l umbia Generat i ng Stat i on pursuant to Title 10 of the Code of Federal Regulations Part 54. The NRC staff is review i ng the information contained in the license renewal application and the associated Environmental Report. The staff has identified, in the enclosure , areas where additional information is needed to complete the Severe Accident Mitigation Alternatives (SAMA) review. Further requests for additional informat i on may be issued in the future. I tems in the enclosure were discussed with Mr. Abbas Mostala. A mutually agreeable date for the response i s within 60 days from the date of this letter. If you have any quest i ons , please contact me at 301-415-3748 or bye-mail at danie l.doyle@nrc.gov. Docket No. 50-397

Enclosure:

As stated cc w/encl: Distribution via Listserv Sincerely , IRA! Daniel Doyle , Project Manager Projects Branch 1 Division of License Renewa l Office of Nuclear Reactor Regulation ADAMS Accession No. ML102870984 OFFICE PM:RPB1 : DLR LADLR BC:RPB1 :DLR PM:RPB1 : DLR NAME DDoyle YEdmonds BPham DDoyle DATE 11/05/10 10/25/10 11/05/1 0 11/10/10 OFFICIAL RECORD COPY Letter to S. Gambhir from D. Doyle dated November 10, 2010

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE COLUMBIA GENERATING STATION LICENSE RENEWAL APPLICATION

-SAMA REVIEW (TAC NO. ME3121) DISTRIBUTION:

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