ML111950094

Summary of Meeting with STP Nuclear Operating Company to Discuss Risk-Informed GSI-191, Assessment of Debris Accumulation on Pressurized-Water Reactor (PWR) Sump Performance, Resolution Approach for South Texas, Units 1 and 2

ML111950094
Person / Time
Site:	South Texas
Issue date:	08/04/2011
From:	Balwant Singal Plant Licensing Branch IV
To:	South Texas
Singal, B K, NRR/DORL, 301-415-301
References
TAC ME5358, TAC ME5359, GSI-191
Download: ML111950094 (5)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 August 4, 2011 LICENSEE: STP Nuclear Operating Company FACILITY: South Texas Project, Units 1 and 2

SUMMARY

OF JULY 7, 2011, PRE-LICENSING PUBLIC MEETING VIA CONFERENCE CALL WITH STP NUCLEAR OPERATING COMPANY TO DISCUSS THE PROPOSED RISK-INFORMED APPROACH TO THE RESOLUTION OF GSI-191, "ASSESSMENT OF DEBRIS ACCUMULATION ON PWR SUMP PERFORMANCE" (TAC NOS. ME5358 AND ME5359)

On July 7, 2011, a public meeting via conference call was held between the U.S. Nuclear Regulatory Commission (NRC), and representatives of STP Nuclear Operating Company (STPNOC, the licensee), at NRC Headquarters, Rockville, MD. The meeting notice and agenda, dated June 24, 2011, is located at Agencywide Documents Access and Management System (ADAMS) Accession No. ML111640211. The purpose of the meeting was to discuss the proposed risk-informed approach to the resolution of GSI-191, "Assessment of Debris Accumulation on PWR [pressurized-water reactor] Sump Performance." South Texas Project (STP) is the lead plant and STPNOC plans to submit a license amendment request (LAR) in mid-2012. The licensee met previously with the NRC staff on June 2, 2011, and provided an over-view of its proposed approach. The purpose of the July 7, 2011, conference call was to discuss STPNOC's response to the NRC staff's questions regarding Loss-of-Coolant Accident (LOCA) Frequencies. Computational Fluid Dynamics (CFD) Verification Plans could not be discussed due to the unavailability of the appropriate NRC staff and it was decided that this matter would be discussed in the meeting scheduled for July 26, 2011.

The licensee's presentation slides and additional materials provided for the meeting are located at ADAMS Accession No. ML111890371. A list of meeting attendees is provided in the enclosure to this meeting summary.

Meeting Summary The licensee provided the copies of the following presentations in advance of the meeting:

1. LOCA Initiating Event Frequencies and Uncertainties (Draft)

2. Development of LOCA Initiating Event Frequencies for South Texas Project GSI 191 (Draft Report)

3. STPNOC Proposed Response to NRC Staff Questions on LOCA Frequency Analysis

4. Flow Chart - Data and Computational Flow Overview (GSI-191 Risk-Informed Closure Project

-2 However, only item 1 was discussed during the meeting and items 2,3, and 4 were provided for NRC staff information.

The licensee presented an overview of the methodology proposed to be used for determining LOCA initiating event Frequencies and Uncertainties. The presentation covered the following in more detail:

• LOCA frequencies scope and objectives

• Technical approach

• Step-by-step procedure with examples

• Technical issues to be addressed

• Resolution of NRC staff questions from June 2, 2011. meeting The NRC staff asked if the detailed analysis performed by STPNOC would have an independent peer review or if would be submitted directly for NRC staff review. The NRC staff stated its concern that the analysis may require a more detailed review by the NRC staff. if an independent peer review is not performed. STPNOC representatives indicated that a Technical Oversight Group (TOG). including industry experts, would perform a peer review before the application is submitted to NRC. The licensee stated that the process used by the TOG would be described in the application. The NRC staff suggested that STPNOC's quality assurance plan may warrant discussions as a subtopic during future pre-licensing meetings. The NRC staff also suggested that the licensee provide a description how the components (especially welds) affected by future repairs and/or maintenance and preemptive weld overlays are treated in the analysis.

The NRC stated that the staff would review the licensee's materials and may provide additional comments in a future meeting. The NRC staff stated that, as result of a preliminary review, it did not appear that all the NRC staff questions from the June 2, 2011, meeting were addressed.

The staff also stated its belief that there would be some additional questions as a result of additional materials presented during the July 7,2011, meeting.

At the conclusion of the meeting, the NRC staff agreed to review all the materials provided by STPNOC for the July 7, 2011, meeting and provide comments for consideration by STPNOC and possible discussions during a future meeting.

- 3 Members of the public were in attendance during the conference call. No Public Meeting Feedback Forms were received.

Please direct any inquiries to me at (301) 415-3016, or Balwant.Singal@nrc.gov.

Sincerely, R d'\. \ \.jJ t "- '1 \=--b \~'-coS<

B'arwant K. Singal, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-498 and 50-499

Enclosure:

List of Attendees cc w/encl: Distribution via Listserv

LIST OF ATTENDEES JULY 7,2011, PRE-LICENSING MEETING RISK-INFORMED APPROACH TO RESOLUTION OF GSI-191 ISSUE STP NUCLEAR OPERATING COMPANY SOUTH TEXAS PROJECT. UNITS 1 AND 2 DOCKET NOS. 50-498 AND 50-499 NAME TITLE ORGANIZATION John Tsao Senior Materials Engineer NRC/NRR/DCI/CPNB

• Robert Tregoning Senior Technical Advisor NRC/RESIDE Stephen Dinsmore Senior Reliability Risk Analyst NRC/NRR/DRA/APLA i Donnie Harrison Branch Chief NRC/NRR/DRA/APLA Balwant K. Singal Senior Project Manager NRC/NRR/DORL Wes Schultz STPNOC Sarah Wright Administrative Assistant STPNOC Steve Blossom Project Manager, Special Projects STPNOC Jamie Paul Licensing STPNOC Kee Risk Management STPNOC

• Rick Grantom Manager Risk Project STPNOC Karl Fleming* President KNF Consulting Services I Tim Sande* l:!incipal Mechanical Engineer Alion Science and Technology

! Amir Afzali** Manager Southern Nuclear

• Elmira Popova** - University of Texas at Austin I Paul Stevenson** - ~nghOUSe Electric Nathan Palm** - nghouse Electric

• Represented STPNOC

• • Public Abbreviations:

NRC - U.S. Nuclear Regulatory Commission NRR - Office of Nuclear Reactor Regulation DORL - Division of Operating Reactor licensing STPNOC - STP Nuclear Operating Company DRA - Division of Risk Assessment APLA - PRA Licensing Branch DCI- Division of Component Integrity CPNB - Piping and NDE Branch RES - Office of Nuclear Regulatory Research DE - Division of Engineering Enclosure

ML111950094 OFFICE NAME NRRlLPL4/PM BSingal NRR/LPL4/LA JBurkhardt NRRlDSS/SSIB/BC SBailey NRRlDRAlAPLAlBC DHarrison NRRlLPL4/BC MMarkley N~~

BSingal DATE 7/25/11 7/25/11 7/25/11 7/25/11 8/4111 8/4/11 II