ML12086A137
| ML12086A137 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 03/26/2012 |
| From: | Benjamin Parks NRC/NRR/DSS/SRXB |
| To: | |
| Tam P | |
| References | |
| TAC ME7947, TAC ME7948, TAC ME8203, TAC ME8204 | |
| Download: ML12086A137 (5) | |
Text
AUDIT PLAN 10 CFR 50.46(a)(3) REPORT REVIEWS LICENSEES UTILIZING WESTINGHOUSE FURNISHED REALISITC EMERGENCY CORE COOLING SYSTEM EVALUATION MODELS Introduction By letters dated March 15-19, 2012, five licensees1 submitted 30-day reports pursuant to Title 10 of the Code of Federal Regulations (10 CFR), §50.46(a)(3), associated with eleven NRC-licensed facilities. The reports discussed the estimated effects on peak cladding temperature (PCT), of thermal conductivity degradation (TCD), and of offsetting changes, to the applications of the emergency core cooling system (ECCS) evaluation models for the affected facilities.
During its review of the reports, the Reactor Systems Branch (SRXB) identified questions associated with the safety analyses to support the 50.46 reports that warrant resolution with an audit. The staff questions, which have been drafted as requests for additional information, and which will be transmitted to each licensee following the audit, fall within the following topical areas:
The method used to estimate the effects of thermal conductivity degradation on peak cladding temperature, The rationale for the offsetting evaluation model application changes made and how their PCT effects were estimated, and Conformance of the analyses supporting the 50.46 reports to the respective ECCS evaluation models.
Purpose and Scope The audit will be conducted in accordance with NRR Office Instruction LIC-111, Regulatory Audits. The scope includes an evaluation of the methodology used to determine the estimated effect of TCD on PCT, including plant specific inputs and results. The audit will be conducted to assess the adequacy of licensee actions taken to comply with 10 CFR 50.46 requirements.
1 The licensees and plants are as follows:
First Energy Nuclear Operating Co. (FENOC), Beaver Valley Power Station (BVPS)
Exelon Generation Co. (EGC), Braidwood Station Unit 2 and Byron Station Unit 2 Duke Energy Carolinas, LLC (Duke), Catawba Nuclear Station and McGuire Nuclear Station Indiana Michigan Power Co. (American Electric Power, AEP), D. C. Cook Nuclear Plant Dominion Energy Kewaunee, Inc., Kewaunee Power Station Audit Agenda and Schedule The audit will be held at Westinghouses offices in Cranberry Township, Pennsylvania, from Wednesday, March 28, 2012, through Friday, March 30. 2012. The audit will be divided into portions that will include generic review and plant specific review.
The agenda will include review and assessment of the following items:
ASTRUM run matrices Cases executed to develop off-setting margin assessments including:
o Peaking factor adjustments and their rationale o Containment pressure changes Code Qualification Document (CQD) TCD and offset sensitivity studies Coefficients used in the PAD 4.0 + TCD thermal conductivity equation Thermal conductivity model impact of code version changes in HOTSPOT Differences between TRANSURANUS and PAD codes and their impacts Code improvements, error corrections, and model and/or model application changes since NRC approval of the methods Adherence to NRC-approved methodology in safety analyses The schedule is proposed as follows:
Wednesday, 3/28 7:45 AM Audit Team in-processing 8:00 AM Entrance Briefing*
8:30 AM Westinghouse and Licensee Remarks*
9:00 AM Generic Technical Topics 4:00 PM NRC Staff Caucus*
4:30 PM Daily Status Briefing*
Thursday, 3/29 8:00 AM Evaluation Model-Specific Topics 12:45 PM Plant-Specific Topics, Assigned as Follows Parks:
CQD Plants Gall:
AEP Plants Woodyatt:
EGC Plants Miller:
FENOC - BVNPS 1 4:00 PM NRC Staff Caucus*
4:30 PM Daily Status Briefing*
Note: Friday staff assignments will be provided during this briefing Friday, 3/30 8:00 AM Continuation of Staff Review Activities 1:00 PM NRC Staff Caucus*
2:00 PM Exit Meeting*
- Teleconference NRC Staff-Internal Meeting Audit Team The audit team will consist of:
Benjamin Parks, Audit Team Lead, Reactor Systems Branch Technical Reviewer Diana Woodyatt, Reactor Systems Branch Technical Reviewer Joshua Miller, Reactor Systems Branch Technical Reviewer Jennifer Gall, Reactor Systems Branch Technical Reviewer Anthony Ulses, Chief, Reactor Systems Branch William Ruland, Director, Division of Safety Systems The following support personnel are requested:
Licensing Staff, familiar with the subject matter, from the licensee organizations Cognizant staff engineers from Westinghouse (specifically with respect to analysis using ASTRUM, CQD and WCOBRA/TRAC )
Plant-Specific Information Requested for Staff Review The SRXB staff requests that the following ASTRUM data be available in tabular form by WCOBRA/TRAC case number used pre-and post-completion of the estimation of the effect of thermal conductivity degradation on PCT: ASTRUM input treated statistically, as well as key results including peak cladding temperature, local oxidation, time of PCT, time of accumulator injection, and time of HPSI injection.
Logistical Considerations Planning The SRXB staff requests a conference call between the relevant parties at FENOC, Duke, AEP, Dominion, EGC, and Westinghouse to take place Monday, March 26, 2012 prior to conducting the audit.
Information Security The audit team expects to review and discuss proprietary information during the audit. The team will not remove any licensee-or vendor-generated information from Westinghouse facilities. Any such information that is processed on NRC machines will be deleted, destroyed, or saved to read-only media and left onsite. Licensee-specifc information will be discussed and reviewed in a private and secure setting.
Requested Accommodations The following accommodations are requested:
A facility large enough to accommodate six NRC staff members in addition to the participating personnel from Westinghouse and licensee organizations, for the duration of the audit.
For Thursday afternoon and Friday morning, breakout rooms to review and discuss plant-specific information.
Telecommunications equipment to conduct entrance, exit, and daily status update meetings with remote participants. The audit team will use NRC teleconference infrastructure to accommodate remote NRC participants.
Documentation of Audit Within 15 days of the audit, the NRC staff will prepare an audit results summary report summarizing the information reviewed during the audit, and any open items identified as a result of the audit. The NRC staff will also document its understanding of the proposed resolution of any identified open items. The audit team will make every reasonable effort to ensure that the audit report is a publicly available document.
Any information provided by Westinghouse and/or licensee organizations relevant to the 50.46(a)(3) report assessments will be formally requested for submittal by the appropriate licensees in accordance with governing NRC processes.