ML16028A152

1/14/2016 Summary of Public Meeting with STP Nuclear Operating Company Regarding Modifications to the Licensee'S Risk-Informed Generic Safety Issue (GSI) 191 Application and Supplements for South Texas Project, Units 1 and 2

ML16028A152
Person / Time
Site:	South Texas
Issue date:	02/18/2016
From:	Lisa Regner Plant Licensing Branch IV
To:
Regner L
References
CAC MF2400, CAC MF2401
Download: ML16028A152 (5)

Text

LICENSEE: STP Nuclear Operating Company FACILITY: South Texas Project, Units 1 and 2

SUMMARY

OF JANUARY 14, 2016, PUBLIC CONFERENCE CALL WITH STP NUCLEAR OPERATING COMPANY TO DISCUSS THE LICENSE AMENDMENT AND EXEMPTION REQUESTS TO USE A RISK-INFORMED APPROACH TO THE RESOLUTION OF GENERIC SAFETY ISSUE 191, "ASSESSMENT OF DEBRIS ACCUMULATION ON PWR SUMP PERFORMANCE" (CAC NOS. MF2400, MF2401, MF2402, MF2403, MF2404, MF2405, MF2406, MF2407, MF2408, AND MF2409)

On January 14, 2016, a public teleconference 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, Maryland. The meeting notice and agenda, dated January 4, 2016, are located in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML16004A326. A list of meeting attendees is provided in the Enclosure to this meeting summary.

By letter dated June 19, 2013 (ADAMS Accession No. ML131750250), as supplemented by letters dated October 3, October 31, November 13, November 21, and December 23, 2013 (two letters); and January 9, February 13, February 27, March 17, March 18, May 15 (two letters),

May 22, June 25, and July 15, 2014; and March 10, March 25, and August 20, 2015 (ADAMS Accession Nos. ML13295A222, ML13323A673, ML13323A128, ML13338A165, ML14015A312, ML14015A311, ML14029A533, ML14052A053, ML14072A076, ML14086A383, ML14087A126, ML14149A353, ML14149A354, ML14149A434, ML14178A481, ML14202A045, ML15072A092, ML15091A440, and ML15246A125, respectively), STPNOC submitted exemption requests accompanied by a license amendment request (LAR) for a risk-informed approach to resolve Generic Safety Issue (GSl)-191, "Assessment of Debris Accumulation on PWR [Pressurized-Water Reactor] Sump Performance," at South Texas Project, Units 1 and 2 (STP).

The purpose of this public teleconference call was to discuss the NRC staff's remaining unresolved concerns associated with the licensee's letter dated August 20, 2015. This submittal provided information on STPNOC's revised methodology to resolve GSl-191 using a nsk combined with a deterministic - 'Risk over Deterministic' or 'RoverD' - methodology.

The NRC staff discussed several follow-up questions related to debris generation and transport calculations. Specifically, questions remain about the type, size, and quantity of debris that transports to the strainers and what surrogate materials were used to represent these in the deterministic test conducted by STPNOC. Also. the staff is unclear about STPNOC's use of fines, miscellaneous debris, and large debris in the Rovero analysis. The NRC staff suggested that an audit of the licensee's debris generation and transport.analyses would aid in the review.

The NRC staff discussed the status of its thermal-hydraulic review and asked for an update from STPNOC on the resolution of draft requests for additional information (RAls) sent in an e-mail dated December 11, 2015 (ADAMS Accession No. ML16022A176). The NRC staff questioned whether a sensitivity study had been conducted for the axial power shape for the long-term core cooling analysis. STPNOC staff stated it believes the axial power shape conducted to be limiting. The licensee stated that the quality assurance analysis had been completed and that it would support an NRC regulatory audit to review the analysis. The NRC staff stated that it was completing its safety evaluation with open items and would provide questions to resolve these open items by the end of February. The resolution of these open items would be facilitated by the audit suggested by STPNOC. A draft RAI timeframe of early February was discussed as a goal for NRC staff, with a mid-to-late February audit timeframe.

The NRC staff also requested to review the STP current licensing basis Hot Leg Switchover time calculation to help the staff resolve a remaining open item concerning boric acid precipitation. The NRC staff suggested a regulatory audit at Westinghouse Offices in Rockville as a possible solution.

The NRC and STPNOC staff discussed an open item related to resolution of Westinghouse Nuclear Safety Advisory Letters (NSALs) and lnfoGram (IG) resolution as they impact STP's containment mass and energy analysis which, in turn, impacts resolution of GSl-191 (e.g., sump level and temperature). STPNOC stated that it had written corrective action program items for the NSALs and IG and would provide information to the NRC staff on the actions taken.

The NRC staff stated that a draft of the Round 3 RAI was available and would be sent by e-mail following the meeting (this is available in ADAMS at Accession No. ML16022A008). All of the questions discussed at this meeting are provided in the draft RAI. Future clarification calls and public meetings will be scheduled as necessary. The NRC staff stressed that the draft Round 3 RAI provided is not likely to be the last set of questions since neither the risk- nor the thermal-hydraulic-related questions were included. These draft questions will be provided when they become available, possibly in 4 to 6 weeks.

No members of the public attended the meeting and no Public Meeting Feedback Forms were received.

If you have any questions, please contact me at 301-415-1906 or via e-mail at Lisa. Regner@nrc.gov.

Sincerely, Lisa M. Regner, Senior Project Manager Plant Licensing Branch IV-1 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 JANUARY 14, 2016, PUBLIC CONFERENCE CALL WITH STP NUCLEAR OPERATING COMPANY REGARDING RISK-INFORMED APPROACH TO RESOLUTION OF GSl-191 SOUTH TEXAS PROJECT, UNITS 1 AND 2 DOCKET NOS. 50-498 AND 50-499 NAME ORGANIZATION Lisa Regner U.S. Nuclear Regulatory Commission (NRC)

Robert Pascarelli NRC Matt Yoder NRC Josh Kaizer NRC Paul Klein NRC Ahsan Sallman NRC Steve Smith NRC John Tsao NRC Steve Laur NRC Caroline Tilton NRC Andrea Russell NRC Ashley Smith NRC Reed Anzalone NRC Osvaldo Pensado Southwest Research Institute (contractor for NRC)

Rob Engen STP Nuclear Operating Company (STPNOC)

Ernie Kee STPNOC Wayne Harrison STPNOC Linda Dyer STPNOC Wes Schulz STPNOC Charlie Albury STPNOC Bruce Letellier Alion Science & Technology Janet Leavitt Alion Science & Technology Dominic Munoz Alien Science & Technology Rodolfo Vaghetto Texas A&M Stephen Kinsey MPR Associates, Inc.

Enclosure

ML16028A152 *via email OFFICE NRR/DORL/LPL4-1/PM N RR/DORL/LPL4-1 /LA NRR/DSS/SSI B/BC NRR/DSS/SNPB/BC NAME LRegner JBurkhardt VCusumano JDean DATE 2/01/2016 2/01/2016 2/02/2016 2/17/2016 OFFICE NRR/DSS/STSB/BC N RR/ORA/AP LA/BC NRR/DE/ESGB/BC NRR/DE/EPNB/BC NAME RElliott SRosenberg GKulesa DAiiey DATE 2/11/2016 2/03/2016 2/02/2016 2/02/2016 OFFICE NRR/DORL/LPL4-1 /BC NRR/DORL/LPL4-1 /PM NAME RPascarelli LRegner DATE 2/18/2016 2/18/2016