ML16092A085

3/17/2016 Summary of Public Meeting with STP Nuclear Operating Company Regarding Open Items, Risk-Informed Generic Safety Issue (GSI) 191 Application and Supplements for South Texas Project, Units 1 and 2 (CAC Nos. MF2401-MF2409)

ML16092A085
Person / Time
Site:	South Texas
Issue date:	04/13/2016
From:	Lisa Regner Plant Licensing Branch IV
To:	South Texas
Regner L
References
CAC MF2400, CAC MF2401, CAC MF2402, CAC MF2403, CAC MF2404, CAC MF2405, CAC MF2406, CAC MF2407, CAC MF2408, CAC MF2409
Download: ML16092A085 (5)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 April 13, 2016 LICENSEE: STP Nuclear Operating Company FACILITY: South Texas Project, Units 1 and 2

SUMMARY

OF MARCH 17, 2016, PUBLIC MEETING 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 March 17, 2016, a Category 1 public meeting 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 February 29, 2016, are located in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML16060A058. 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, July 15, 2014; and March 10, March 25, and August 20, 2015 (ADAMS Accession Nos. ML13295A222, ML13323A673, ML13323A128, ML13338A165, ML14015A312, ML14015A311, ML14029A533, ML14052A110, ML14072A075, ML14086A383, ML14087A126, ML14149A353, ML14149A354, ML14149A439, ML14178A467, ML14202A045, ML15072A092, ML15091A440, and ML15246A125, respectively), STPNOC submitted exemption requests accompanied by license amendment requests 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 August 20, 2015, document. This submittal provided information on STPNOC's revised methodology to resolve GSl-191 using a risk combined with a deterministic - 'Risk over Deterministic' or 'RoverD' - methodology. In particular, the meeting discussion topics included the in-core thermal-hydraulic review concerning large hot-leg breaks, resolution of the boric acid precipitation issue associated with current licening basis hot-leg switchover time, STP resolution of cavity epoxy debris, the technical specification change, the Title 1O of the Code of Federal Regulations (1 O CFR)

Section 50.46 exemption change, and the schedule for completion. There were no handouts used for this meeting.

The licensee provided an update on consideration of an option to shift all hot-leg, large-break loss-of-coolant accident (LOCA) locations to a risk-informed methodology to simplify the analysis. 1 The licensee stated that the assumption of core failure due to debris allows elimination of the T-H analysis per 10 CFR 50.46(b )(5) for double-ended guillotine breaks in the hot leg. The licensee stated that the largest hot-leg break size to be used as the threshold is approximately 16 inches.

The licensee asked for a status update regarding the NRC staff's consideration of the current licensing basis analysis to determine hot-leg switchover timing. The NRC staff responded that the analysis reviewed during a February 4, 2016, audit2 in Rockville, Maryland, includes a first-of-a-kind use of the barrel-baffle region as part of the core mixing volume. The NRC staff, therefore, needs justification from the licensee in order to consider allowing the licensee to credit this volume. This request was captured in a draft request for additional information sent by e-mail dated March 18, 2016 (ADAMS Accession No. ML16081A004).

The STPNOC staff stated that it was considering treating the epoxy coatings as qualified but degraded and that in the STP analysis epoxy coatings would fail as chips. These coatings are considered degraded since they are not in a qualified coatings inspection program and there is no continuity of inspection documentation. Portions of the coatings in containment have been visually observed and show no sign of degradation. The NRC staff stated that it would need the documentation of qualification; however, STP should not consider the epoxy coatings qualified because of the lack of continuous inspections. The NRC and STPNOC staffs agreed that a meeting dedicated to coatings discussions is needed. This has been scheduled for April 14, 2016, from 2:30-4:00 p.m. eastern daylight time.

STPNOC offered to address the NRC staff's concerns on the technical specification change (see draft question sent to STP by e-mail dated January 27, 2016, at ADAMS Accession No. ML16092A054) by providing clarification in the technical specifications basis document.

The NRC staff stated that it will review the clarification to determine if it is acceptable, and that STPNOC staff should also provide the basis for the 90-day allowed outage time if actual containment debris is found to be outside analyzed limits. The licensee stated that the 90-day timeframe was based on its control room envelope heating ventilation and cooling analysis, and that it would provide this basis in its next response.

The licensee stated that it understood that the exemption to 10 CFR 50.46 that is required for this risk-informed action is 10 CFR 50.46(a)(1) instead of 50.46(d). The licensee will submit this change by letter since the justification provided in the August 20, 2015, submittal will not change. The NRC staff notified the licensee that the draft environmental assessment for the STP exemptions and amendments could not be published until the letter is received.

The next public meetings will be on March 31 and April 14, 2016.

There were no public comments and no meeting feedback forms submitted.

1 Discussed on March 3, 2016; see meeting summary at ADAMS Accession No. ML16092A044.

2 The Audit Summary is found at ADAMS Accession No. ML16096A065.

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

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 MARCH 17. 2016. 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)

Vic Cusumano NRC Paul Klein NRC Josh Kaizer NRC Reed Anzalone NRC Steve Laur NRC Andrea Russell NRC Steve Smith NRC Marioly Diaz-Colon NRC Matt Yoder NRC Caroline Tilton NRC Osvaldo Pensado Southwest Research Institute (contractor for NRC)

Roland Dunn STP Nuclear Operating Company (STPNOC)

Mike Murray STPNOC Ernie Kee STPNOC Wayne Harrison STPNOC Duane Gore STPNOC Wes Schulz STPNOC Drew Richards STPNOC Bruce Letellier Alien Science & Technology Janet Leavitt Alien Science & Technology Dominic Munoz Al ion Science & Technology Rodolfo Vaghetto Texas A&M Ron Holloway Wolf Creek Nuclear Operating Company Brian Krystek Engineering Planning and Management, Inc.

Tim Sande ENERCON Kip Walter ENERCON Craig Sellers Calvert Cliffs Phillip Grissom Southern Co.

Enclosure

ML16092A085 *per email OFFICE NRR/DORL/LPL4-1 /PM NRR/DORL/LPL4-1/LA NRR/DSS/STSB/BC(A)* NRR/DSS/SSIB/BC*

NAME LRegner JBurkhardt SAnderson VCusumano DATE 4/1/16 4/1/16 4/4/16 4/1/16 OFFICE NRR/DSS/SNPB/BC* NRR/DE/ESGB/BC* NRR/DORL/LPL4-1 /BC NRR/DORL/LPL4-1 /PM NAME JDean GKulesa RPascarelli LRegner DATE 4/11/16 4/1/16 4/12/16 4/13/16