ML101400092

Request for Additional Information Related to Adoption of TSTF-425, Revision 3

ML101400092
Person / Time
Site:	LaSalle
Issue date:	05/26/2010
From:	Goodwin C Plant Licensing Branch III
To:	Pardee C Exelon Nuclear
Goodwin, Cameron S, NRR/DORL, 415-3719
References
TAC ME3363, TAC ME3364
Download: ML101400092 (4)

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Ii: May 26, 2010 Mr. Charles G. Pardee President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

LASALLE COUNTY STATION, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO ADOPTION OF TSTF-425, REVISION 3 (TAC NOS. ME3363 AND ME3364)

Dear Mr. Pardee:

By letter to the Nuclear Regulatory Commission (NRC) dated February 15, 2010 (Agencywide Documents Access and Management System Accession No. ML100480009), Exelon Generation Company, LLC submitted a request to mOdify the Technical Specifications by relocating specific surveillance frequencies to a licensee-controlled program with the implementation of Nuclear Energy Institute 04-10 "Risk-informed Technical SpeCifications Initiative 5b, Risk-Informed Method for Control at Surveillance Frequencies", for the LaSalle County Station, Units 1 and 2.

The NRC staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is addressed in the enclosure to this letter. During a discussion with your staff on May 18, 2010, it was agreed that you would provide a response 30 days from the date of this letter.

The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for staff review and contribute toward the NRC's goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-3154.

Sincerely, IW, (;

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Cameron S. Goodwin, Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-373 and 50-374

Enclosure:

Request for Additional Information cc w/encl: Distribution via Listserv

REQUEST FOR ADDITIONAL INFORMATION LASALLE COUNTY STATION, UNITS 1 AND 2 DOCKET NOS. 50-373 AND 50-374 In reviewing the Exelon Generation Company's (Exelon's) submittal dated February 15,2010 (Agencywide Documents Access and Management System Accession No. ML100480009),

related to the adoption of Technical Specification Task Force Traveler 425, Revision 3, for the LaSalle County Station (LSCS), Units 1 and 2, the Nuclear Regulatory Commission staff has determined that the following information is needed in order to complete its review:

1. In Table A.2-1 "LaSalle PRA 2008 Peer Review Results," of Attachment 2 "Documentation of Probabilistic Risk Assessment Technical Adequacy," of the submittal, supporting requirement IE-A7 is identified as being Capability Category I in that no review for initiating event precursors was performed. The disposition of this item states that it is only documentation; however, neither the description of the gap or its impact on the base model states that a precursor review was actually performed for the LSCS probabilistic risk assessment (PRA) model. In fact, the disposition states that no additional initiating event categories "would be" identified, which indicates that a precursor review was not performed. The licensee needs to clarify that a precursor review was performed and simply not documented, or else disposition why not having performed a precursor review is acceptable for this application when capability category II is the requirement per Nuclear Energy Institute (NEI) 04-10 "Risk-informed Technical Specifications Initiative 5b, Risk-Informed Method Fix Control of Surveillance Frequencies."

2. In Table A.2-1 of Attachment 2 of the submittal, supporting requirement SC-B5 is identified as being not met in that the success criteria were checked for reasonableness and acceptability by cross comparisons or other methods. While the peer review finding speCifically acknowledged some code cross comparison, it still found the requirement to be not met. The disposition of this finding states that it is a documentation concern, indicating that additional checks of the success criteria, consistent with the methods identified in the standard, have been done but simply were not documented. This is inconsistent with the peer review team finding. The licensee needs to clarify that the success criteria checks required by the standard have been performed, but simply are undocumented, or else disposition why not having performed such reviews is acceptable for this application.

3. In Table A.2-1 of Attachment 2 of the submittal, supporting requirements HR-A1 and HR-A2 are identified as being not met, and HR-B1 are identified as being met at Capability Category I. These requirements address the need to review plant procedures and operational practices to identify potential alignment and miscalibration opportunities, and to apply specific screening criteria. The disposition of these items states that it is a documentation concern, but the basis provided is only that the peer review team did not identify any missing basic events in the PRA model. The licensee needs to clarify that the review of procedures and screening of identified events was in fact done, or should otherwise disposition why not having performed these reviews is acceptable for this application.

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4. In Table A.2-1 of Attachment 2 of the submittal, supporting requirement DA-C8 is identified as meeting only Capability Category I based on estimating the time components are in standby status, rather than evaluating plant operational records. The disposition of this deficiency states that it has a non-significant impact, but no basis is provided for this conclusion. (The disposition also restates the peer review team's observation that some standby times are based appropriately on operational records, but then states that the team " ... desired that all configuration probabilities used in the PRA be based on plant-speciHc data." The staff notes that basing all standby times on operational records is the requirement of the standard for Capability Category II, and is not simply a peer review team preference.) The licensee needs to identify its basis for concluding that estimates of standby times in lieu of plant operational records has a non significant impact on the PRA results for this application.

5. In Table A.2-1 of Attachment 2 of the submittal, supporting requirement DA-C1 0 is identified as meeting only Capability Category I. For this supporting requirement, the additional requirements for Capability Category II require a review of surveillance tests for different component failure modes to assure proper statistical counting of demands and failures, if such a decomposition of failure modes is made. The licensee disposition of this item only states that any impact is "expected" to be non-significant, but does not address how this expectation has been reached. The licensee needs to identify its basis for this deficiency being non-significant for this application.

ML101400092 NRR-088 OFFICE LPL3-2/PM LPL3-2/LA LPL3-2/BC NAME MDavid for THarris SCampbell CGoodwin DATE 5/26/10 05/21/10 5126110