ML14323A576

11/6/14 Summary of Meeting with STP Nuclear Operating Company to Discuss Revised Pilot Submittal and Request for Exemptions for a Risk-Informed Approach to Resolve Generic Safety Issue 191 at South Texas Project, Units 1 and 2 (TAC MF2400-M

ML14323A576
Person / Time
Site:	South Texas
Issue date:	12/12/2014
From:	Balwant Singal Plant Licensing Branch IV
To:	South Texas
Singal B
References
GSI-191, TAC MF2400, TAC MF2401, TAC MF2402, TAC MF2403, TAC MF2404, TAC MF2405, TAC MF2406, TAC MF2407, TAC MF2408, TAC MF2409
Download: ML14323A576 (5)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 December 12, 2014 LICENSEE: STP Nuclear Operating Company FACILITY: South Texas Project, Units 1 and 2

SUMMARY

OF NOVEMBER 6, 2014, 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 GSI-191, "ASSESSMENT OF DEBRIS ACCUMULATION ON PWR SUMP PERFORMANCE" (TAC NOS. MF2400, MF2401, MF2402, MF2403, MF2404, MF2405, MF2405, MF2406, MF2407, MF2408, AND MF2409)

On November 6, 2014, a 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 October 27, 2014, are located in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML14301A325. The licensee's handouts from the meeting are available in ADAMS at Accession No. ML14315A087. A list of meeting attendees is provided in the Enclosure to this meeting summary.

By letter dated June 19, 2013 (Agencywide Documents Access and Management System (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 (ADAMS*Accession Nos. ML13295A222, ML 13323),\673, ML13323A128, ML13338A165, ML14015A312, ML14015A311, ML14029A533, ML14052A053, ML14072A076, ML14086A383, ML14087A126, ML14149A353, ML14149A354, ML14149A434, ML14178A481, and ML14202A045, respectively), STPNOC submitted exemption requests accompanied by a license amendment request (LAR) for a risk-informed approach to resolve the issue of potential impact of debris blockage on emergency recirculation during design-basis accidents Generic Safety Issue (GSI)-191, "Assessment of Debris Accumulation on PWR (Pressurized-Water Reactor] Sump Performance," at South Texas Project, Units 1 and 2 (STP).

The NRC staff issued a Request for Additional Information (RAI) by letter dated April 15, 2014 (ADAMS Accession No. ML 14087A07.5). The licensee provided its response to the RAI request by letters dated May 22, June 25, and July 15, 2014.

The purpose of the meeting was to discuss the proposed strainer head loss test plan and results

• of the on-site audit conducted on September 16 and 17, 2014, at the University of New Mexico in Albuquerque, New Mexico, and the agenda for the forthcoming December 2014 public meeting, in support of its LAR and exemptions.

Meeting Summary The following key topics, summarized in the licensee's presentation slides, were discussed by STPNOC during the meeting:

• Review of the proposed STP strainer head loss test approach and its description for risk-informed resolution.

• High-level plan for the test and analysis of the test results.

• Assessment of the available test data and application of the test results.

Results of Discussions

• During the presentation, the licensee indicated that due to NRC staff concerns about NUREG/CR-6224, "Parametric Study of the Potential for BWR [Boiling Water Reactor]

ECCS [Emergency Core Cooling System] Strainer Blockage Due to LOCA [Loss-of-Coolant Accident] Generated Debris," October 1995 (ADAMS Accession No. ML083290498), head loss correlation, a new head loss correlation approach will be used in the future and the details of the revised approach will be discussed with the NRC staff in the forthcoming public meeting. The staff indicated its concern on the overall review schedule of the LAR, if the licensee decides to adopt the revised approach.

• The NRC staff stated its concern about the uncertainties involved with the testing and the concept that *repeatability would have to be demonstrated to produce justification for correlation validity. The NRC staff also stated that inconsistent test results might result in increasing the scope of testing.

• The NRC staff stated that similar tests performed in the past had significant variation in

• test results and stated that these tests may not provide adequate data to verify if the correlation is accurate and reasonable.

• The NRC staff requested the licensee to explain the effect of compression on the debris bed in the future meeting. The licensee was also requested to explain how effect of compression on the debris bed is accounted for in the correlation.

• The NRC staff asked for clarification as to what type of chemical precipitate surrogates would be used during the proposed testing. The licensee stated that surrogates prepared using the methodology prescribed in WCAP-16530-NP-A, "Evaluation of Post-Accident Chemical Effects in Containment Sump Fluids to Support GSI-191" (ADAMS Accession No. ML081150379), would b~ generated externally to the test loop and added after the debris bed is formed. I o The NRC staff stated its concern about the overall schedule for the LAR. The revised proposed approach represents a significant change to the existing submittal and is likely to impact the timing of licensee submittals and the overall review schedule. The NRC staff requested the licensee to explain in the future meeting how the schedule for the proposed testing supports the existing review schedule.

The licensee agreed to discuss the NRC staff concerns in more detail during the forthcoming public meeting in December 2014.

Due to the time constraint, the licensee agreed to review the draft audit report and provide comments after the meeting via e-mail. It was decided to discuss the agenda for the forthcoming public meeting in December 2014 during a separate call.

Action Items No action items were identified.

No Public Meeting Feedback Forms were received for this meeting.

Please direct any inquiries to me at 301-415-3016, or balwant.singal@nrc.gov.

Sincerely,

~t-8~.-

Balwant K. Singal, 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 NOVEMBER 6, 2014, MEETING WITH STP NUCLEAR OPERATING COMPANY REGARDING RISK-INFORMED APPROACH TO RESOLUTION OF GSI-191 SOUTH TEXAS PROJECT, UNITS 1 AND 2 DOCKET NOS. 50-498 AND 50-499 NAME TITLE ORGANIZATION Balwant K. Singal Senior Project Manager U.S. Nuclear Regulatory Commission (NRC)

John Stang Senior Project Manager NRC Steve Smith Reactor Systems Engineer NRC Victor Cusumano Branch Chief NRC Andrea Russell* Project Manager NRC Matthew Yoder* Sr. Chemical Engineer NRC Ashley Guzzetta Engineer NRC Steve Laur* Senior Risk Analyst NRC Steven M. Unikewicz* Senior Principal Engineer Alion Science and Technology Tim Sande* - Enercon Phil Grissom* - Southern Nuclear Company Paul Leonard* - -

Steve Blossom* STPNOC Project Manager STP Nuclear Operating Company (STPNOC)

Bruce Letellier** -- _ Alion Science and Technology (Aiion)

Edward Blandford** Assistant Professor University of New Mexico (UNM)

Ernie Kee* Technical Team Lead STPNOC Janet Leavitt** Director Lab Operations Ali on Wayne Harrison** Licensing Lead STPNOC Wes Scl:lulz* Design Engineering STPNOC Linda Dyer* -- STPNOC Seyed Reihani** -- University of Illinois Daniel LaBrier -- UNM

• Attended via phone

• • Attended via phone in support of STPNOC Enclosure

ML14323A576 *via email OFFICE NRR/DORLILPL4-1/PM NRR/DORLILPL4-1/LA NRR/DSS/SSI.B/BC NRR/DE/ESGB/BC NAME BSingal JBurkhardt* VCusumano PKiein {A)

DATE 11/20/14 11/20/14 - 11/24/14 12/8/14 OFFICE NRR/DRA/APLAIBC NRR/DORLILPL4-1/BC NRR/DORL/LPL4-1/PM NAME HHamzehee EOesterle (A} BSingal DATE 12/2/_14- 12/12/14 12/12/14