ML101060475

TSTF-425, Revision 3, Relocate Surveillance Frequencies to Licensee Control - RITSTF Initiative 5B.

ML101060475
Person / Time
Site:	Clinton
Issue date:	04/16/2010
From:	Nicholas Difrancesco Plant Licensing Branch III
To:	Hansen J, Mathews M Exelon Corp
Di Francesco N, NRR/DORL/LPL3-2, 415-111
References
Download: ML101060475 (2)

Text

From: DiFrancesco, Nicholas Sent: Friday, April 16, 2010 11:45 AM To: Mitchel.Mathews@exeloncorp.com; jeff.hansen@exeloncorp.com

Subject:

Draft NRC RAI Set II Re: Clinton Power Station License Amendment Request Mr. Mathews, By letter dated February 15, 2010 (Agencywide Documents and Management System (ADAMS)

Accession No. ML100470787), Exelon Generation Company, LLC (EGC), the licensee for the Clinton Power Station (CPS), Unit No. 1, submitted a license amendment request (LAR) to amend Technical Specifications (TS) by proposing a new TS Section 5.5.16 Program and relocating specific TS Surveillance Frequencies to a licensee-controlled program consistent with approved Technical Specification Task Force (TSTF)-425, Revision 3.

The Probabilistic Risk Assessment Licensing Branch has reviewed the information provided and determined that in order to complete its evaluation, additional information may be required. The draft RAI related to the staff review is provided below.

After reviewing the draft RAI, please contact me at 301-415-1115 to discuss the need for a teleconference concerning the RAIs and to discuss a due date for the response.

Respectfully, Nick DiFrancesco Project Manager Nuclear Regulatory Commission Division of Operating Reactor Licensing nicholas.difrancesco@nrc.gov Tel: (301) 415-1115 Fax: (301) 415-1222

-DRAFT-REQUEST FOR ADDITIONAL INFORMATION LICENSE AMENDMENT REQUEST CLINTON POWER STATION (CPS)

EXELON GENERATION COMPANY, LLC DOCKET NO.: 50-461

1. In Table A.2-1 of Attachment 2 of the submittal, the peer review element identified as TH-8 states that additional room heatup calculations are needed to support modeling assumptions for room cooling requirements. The impact is identified as primarily a documentation issue, and further that the PRA already makes appropriate assumptions regarding the need for

room cooling in the appropriate areas. There is insufficient information for the staff to reach a conclusion on the disposition of this peer review item. Specifically, for any areas for which room cooling is assumed to not be required, where there is not a documented room heatup analysis to support the assumption, the licensee should identify room cooling assumptions and their bases. Note that there are similar concerns with Table A.2-2 of Attachment 2, gap

1. 2, which should also be addressed in the response.

2. In Table A.2-2 of Attachment 2 of the submittal, gap #3 regarding the process for developing pre-initiator human error events identifies four specific deficiencies of the analysis. The importance is stated as primarily a documentation issue. No adequate basis is provided for this statement. In fact, the status of the item implies that the requirements are not actual but only inferred and states without a basis that other BWRs which attempted to rigorously follow the standard model fewer pre-initiator events. The licensee needs to provide a more rigorous basis for why its method for identification of pre-initiator human error events actually conforms to the requirements of the standard and that the deficiency is only a matter of documentation.

3. In Table A.2-2 of Attachment 2 of the submittal, gap #5 regarding failure data and unavailability data development is judged to have a non-significant impact, judged to have a minimal impact, and that the model is reasonably consistent with data from the plant MR database, which is adequate for future applications. No basis is provided for how these judgments have been reached given the identified gaps to the probabilistic risk assessment standard requirements. The licensee should address the specific impact of the deficiency on the failure data to justify the stated non-significance for this application.

-DRAFT-