ML16175A108

Summary of 4/21/2016 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

ML16175A108
Person / Time
Site:	South Texas
Issue date:	06/24/2016
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: ML16175A108 (5)

Text

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

SUMMARY

OF APRIL 21, 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 April 21, 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 March 22, 2016, are located in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML16112A073. 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, August 20, 2015, April 13, and May 11, 2016 1 (ADAMS Accession Nos. ML13295A222, ML13323A673, ML13323A128, ML13338A165, ML14015A312, ML14015A311, ML14029A533, ML14052A110, ML14072A075, ML14086A383, ML14087A126, ML14149A353, ML14149A354, ML14149A439, ML14178A467, ML14202A045, ML15072A092, ML15091A440, ML15246A125, ML16111B204, and ML16154A127, 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 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.

Specifically, the meeting focused on debris contribution due to epoxy coatings in the reactor cavity including topics associated with quantity, service history, current condition, cumulative dose, qualification data, debris characteristics and the transport evaluation. The STPNOC handout for this meeting can be located in ADAMS at Accession No. ML16111A027.

1 Two additional letters were submitted by STPNOC on June 9 and 11, 2016; however, the ADAMS Accession Nos.

were not available as of the issuance of this meeting summary.

The STPNOC staff used the handout referenced above to discuss the open items associated with epoxy coatings. STPNOC stated that there were no corrective action items noted for the epoxy coatings in question since 1979. They were not specifically inspected due to infrequent access to the reactor cavity area, however, pictures taken during other work in containment showed that the coatings appear intact and that the Unit 2 coatings do not cover the wall all the way to the ceiling. This reduced area results in less total mass for Unit 2. The coatings also are not considered qualified due to the excessive calculated cumulative radiation dose, the fact that they were not part of the qualified coatings inspection program, and that the coatings had not been consistently inspected. The licensee intends to designate the coatings "qualified but degraded" in order to treat the potential debris as chips during a loss of coolant accident (LOCA). Debris transport studies have shown that coatings which fail in the form of chips are unlikely to transport to the Emergency Core Cooling System strainer surface.

The NRC staff asked for the basis of the coatings size distributions for various chip sizes assumed in the licensee's analysis. STPNOC stated they came from Comanche Peak testing results. The NRC staff requested that this clarification be included in the response. In addition, the NRC staff asked whether the coatings would be in the zone of influence if there is a LOCA near the reactor cavity. The licensee stated that a pipe rupture at the hot leg and cold leg nozzles would not directly impinge upon the epoxy coated surfaces in question and therefore would not result in particulate coatings debris. The NRC requested a detailed discussion on the floor drain system and how it impacts the debris transport analysis. The licensee is continuing to evaluate the potential for transport through the drains.

The NRC staff asked for a clarification whether the dose calculations included power uprates, and whether water holdup in the reactor cavity would impact debris quantities and fiber amounts in the transport analysis.

Mr. Marvin Lewis, a member of the public, expressed concerns over the blockage of the filters during reactor coolant accidents. Mr. Tim Sande, Enercon, requested information on the NRC staff's review schedule.

The next public meeting is expected to be held on July 28, 2016.

There was no meeting feedback received.

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

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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 APRIL 21, 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 Steve Smith NRC Marioly Diaz-Colon NRC Matt Yoder NRC Osvaldo Pensado Southwest Research Institute (contractor for NRC)

Rob Engen STP Nuclear Operating Company (STPNOC)

Mike Murray STPNOC Ernie Kee STPNOC Wayne Harrison STPNOC Steve Blossom STPNOC Wes Schulz STPNOC Drew Richards STPNOC Bruce Letellier Alion Science & Technology Janet Leavitt Alion Science & Technology Dominic Munoz Alion Science & Technology Enclosure

ML16175A108 *per email OFFICE NRR/DORULPL4-1 /PM NRR/DORULPL4-1 /LA NRR/DSS/SSIB/BC*

NAME LRegner JBurkhardt* VCusumano DATE 6/23/16 6/23/16 6/23/16 OFFICE NRR/DE/ESGB/BC (A)* NRR/DORULPL4-1 /BC NRR/DORULPL4-1 /PM NAME MYoder A Pascarelli LRegner DATE 6/23/16 6/24/16 6/24/16