ML16302A453

Closeout of Request for Additional Information Questions That Are No Longer Applicable, Resolution of Generic Safety Issue (GSI) 191 (CAC Nos. MF2400-MF2409)

ML16302A453
Person / Time
Site:	South Texas
Issue date:	12/12/2016
From:	Lisa Regner Plant Licensing Branch IV
To:	Gerry Powell 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: ML16302A453 (6)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. G. T. Powell Executive Vice President and CNO STP Nuclear Operating Company South Texas Project P.O. Box 289 VVadsworth, TX 77483 December 12, 2016

SUBJECT:

SOUTH TEXAS PROJECT, UNITS 1 AND 2 - RE: CLOSEOUT OF REQUEST FOR INFORMATION QUESTIONS THAT ARE NO LONGER APPLICABLE ASSOCIATED VVITH THE RESOLUTION OF GENERIC SAFETY ISSUE 191 (CAC NOS. MF2400, MF2401, MF2402, MF2403, MF2404, MF2405, MF2406, MF2407, MF2408, AND MF2409)

Dear Mr. Powell:

On September 13, 2004, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-VVater Reactors" (Agencywide Documents Access and Management System (ADAMS) Accession No. ML042360586), to address a generic safety concern, generic safety issue (GSI) 191, over possible blockage of emergency core cooling sump strainers during design-basis accidents at pressurized-water power reactors.

The STP Nuclear Operating Company (STPNOC) responded to GL 2004-02 for the South Texas Project, Units 1 and 2 (STP), by letter dated March 8, 2005, as supplemented by letters dated July 13 and August 31, 2005; January 30, 2006; and February 29 and December 11, 2008 (ADAMS Accession Nos. ML050770105, ML052000281, ML052500311, ML060370145, ML080700338, and ML083520326, respectively).

On June 4, 2012 (ADAMS Accession No. ML13025A360), STPNOC submitted a letter stating its intention to resolve GSl-191, site specifically, through a risk-informed approach; further, it stated it did not intend to respond to the open NRC request for additional information (RAI) questions issued by letters dated June 2, 2005, February 9, 2006, and December 23, 2009 (ADAMS Accession Nos. ML051530285, ML060390246, and ML093410607, respectively). The licensee stated that it would not use a deterministic method and would submit a license amendment request and exemption requests to resolve GSl-191.

Subsequently, by letter dated June 19, 2013 (ADAMS Package Accession No. ML131750250),

as supplemented by letter dated October 3, 2013 (ADAMS Accession No. ML13295A222),

STPNOC submitted license amendment and exemption requests.

The NRC staff's review of the license amendment and exemption requests is ongoing; however, the NRC staff has determined that the June 4, 2012, license amendment and exemption requests supersede the previous submittals; therefore, the NRC's review of

STPNOC's efforts to respond to GL 2004-02 prior to June 2012 have been terminated. For this reason, the RAls issued on June 2, 2005, February 9, 2006, and December 23, 2009, are no longer applicable.

By letters dated October 31, November 13, November 21 and December 23, 2013 (two letters);

January 9, February 13, February 27, March 17, March 18, May 15 (two letters), May 22, June 25, and July 15, 2014; March 10, and March 25, 2015 (ADAMS Accession Nos. ML13323A673, ML13323A128, ML13338A165, ML14015A312, ML14015A311, ML14029A533, ML14052A110, ML14072A075, ML14086A383, ML14087A126, ML14149A353, ML14149A354, ML14149A439, ML14178A467, ML14202A045, ML15072A092, and ML15091A440, respectively), STPNOC submitted supplemental information in support of the license amendment and exemption requests to resolve GSl-191 using a risk-informed methodology.

By letter dated August 20, 2015, STPNOC provided a supplement to the license amendment and exemption requests changing its approach from strictly risk-informed, to a deterministic and risk-informed methodology, called 'RoverD'. Additional supplements were submitted by STPNOC on April 13, May 11, June 9, June 16, July 18, July 21 (two letters), July 28, September 12, October 20, and December 7, 20161 (ADAMS Accession Nos. ML15246A125, ML16111B204, ML16154A117, ML16176A148, ML16196A241, ML16209A226, ML16229A189, ML16230A232, ML16221A393, ML16272A162, ML16302A015, and [see footnote], respectively) in response to NRC staff RAls.

Due to the methodology change described in the letter dated August 20, 2015, the licensee submitted a clarification letter dated June 9, 2016, providing a list of RAI question responses that it stated are no longer applicable with the basis for eliminating this content from the NRC staff's review.

The NRC staff reviewed the questions and the licensee's basis for removing questions from the NRC staff's review as provided in the June 9 and December 7, 2016, letters. The NRC's conclusions are provided in the Enclosure to this document.

This was discussed with Mr. Wayne Harrison, Mr. Drew Richards, and Mr. Steven Blossom of your staff on November 16, 2016.

1 The ADAMS Accession No. was not available at the time of the issuance of this letter.

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

Docket Nos. 50-498 and 50-499

Enclosure:

As stated cc w/encl: Distribution via Listserv Lisa M. Regner, Senior Project Manager Plant Licensing Branch IV-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

REQUEST FOR ADDITIONAL INFORMATION QUESTIONS THAT ARE NO LONGER APPLICABLE RESOLUTION OF GENERIC SAFETY ISSUE 191 STP NUCLEAR OPERATING COMPANY SOUTH TEXAS PROJECT, UNITS 1AND2 DOCKET NOS. 50-498 AND 50-499 The NRC staff determined that the following questions in request for additional information (RAI) letter dated April 15, 2014 (ADAMS Accession No. ML14087A075), are no longer applicable:

CASA Grande, General - 1.a, 1.b, and 1.c.

CASA Grande, Plant Configuration - 1.a, 1.b, 2.a, 2.b, 3.a, 3.b, and 3.c.

CASA Grande, LOCA [loss-of-coolant accident] Frequencies - 1.a, 1. b, 3, and 4.

CASA Grande to PRA [probabilistic risk assessment] Interface, General - 1.a, 1.b, 2.a, 2.b, 3, 4.a, 4.b, 4.c, 5, 6.a, 6.b, and 6.c.

STP PRA Model, Success Criteria -1, 2.a, 2.b, 3.a, 3.b, and 3.d.

STP PRA Model, Human Reliability Analysis - 1, 2, 3.a, 3.b, 3.c, 4.a, 4.b, 5, and 6.

Results Interpretation, Quantification - 1.a, 1.b, and 2.

Results Interpretation, Uncertainty Analysis - 1.a, 1.b, 1.c, 4.a, 4.b, 4.c, 4.d, 5, and 6.

Radiation Protection and Consequence Branch - 1 and 3.

Mechanical and Civil Engineering Branch - 1.

Component Performance, NOE [non-destructive examination] and Testing Branch (EPNB) - 1, 2, 3, 4, 5, 6.a, and 6.b.

Steam Generator tube Integrity and Chemical Engineering Branch (ESGB), Chemical Effects - 1.a, 1.b, 1.c, 1.d, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11.a, 11.b, 12, 13.a, 13.b, 13.c, 14.a, 14.b, 14.c, 15, 16, 17, 18.a, 18.b, 18.c, 19, 20, 21, 22.a, and 22.b.

ESGB, Coatings - 2, 4, 5, 6.a, 6.b, and 6.c.

Containment and Ventilation Branch (SCVB) - 1.b, 2.b, 3.b, 5, 8, and 9.b.

Reactor Systems Branch (SRXB) - 2.a, 2.b, 2.c, 2.d, 2.e, 5.a, 5.b, 5.c, 6, and 8.

Enclosure Safety Issue Resolution Branch (SSIB)-3, 5, 9, 11.a, 11.b, 11.d, 11.e, 14, 15.a, 15.b, 15.c, 15.d, 16.a, 16.b, 16.c, 16.d, 17.a, 17.b, 17.c, 17.d, 17.e, 17.f, 18, 19, 20, 21, 22, 23, 24, 25, 26.a, 26.b, 26.d, 26.e, 26.f, 28, 30, 33, 34, 35, 36, 37, 38, 40, and 41.a.

Technical Specifications Branch (STSB) - 1 and 2.

The NRC staff determined that the response to SNPB-4 in the April 15, 2015, RAI is no longer applicable because the plant's licensing basis analysis for boric acid precipitation (BAP) was changed. The original RAI and its response are superseded by question SNPB-3-33 in an NRC RAI dated April 11, 2016 (ADAMS Accession No. ML16082A507), which discussed the new STP BAP analysis.

The NRC staff determined that question CASA Grande, LOCA Frequencies - 1.b is still applicable; there is information the NRC staff intends to use in its safety evaluation regardless of STP's methodology change. This was discussed with Wayne Harrison of your staff and a mutually agreeable resolution determined as...

The NRC staff determined that the following questions in RAI dated March 3, 2015 (ADAMS Accession No. ML14357A171), are no longer applicable:

PRA Licensing Branch (APLA), Project Quality Assurance - 2.

ESGB, Chemical Effects - 33 and 34.

SSIB -45, 53, and 58.

The NRC staff determined that questions SCVB - 10 through 18 in the RAI dated March 3, 2015, are still applicable. The licensee's revised responses to each of these questions were provided in an August 20, 2015, supplement (ADAMS Accession No. ML15246A128) and the NRC staff intends to use the information in its safety evaluation.

This information was discussed with Mr. Wayne Harrison of your staff on xxxxx.

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

Docket Nos. 50-498 and 50-499

Enclosure:

As stated Sincerely,

/RA/

Lisa M. Regner, Senior Project Manager Plant Licensing Branch IV-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation cc w/encl: Distribution via Listserv DISTRIBUTION:

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