ML15163A017
| ML15163A017 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 06/18/2015 |
| From: | Lisa Regner Plant Licensing Branch IV |
| To: | Koehl D South Texas |
| Regner L | |
| References | |
| TAC MF6176, TAC MF6177 | |
| Download: ML15163A017 (5) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. Dennis L. Koehl President and CEO/CNO STP Nuclear Operating Company South Texas Project P.O. Box 289 Wadsworth, TX 77483 June 18, 2015
SUBJECT:
SOUTH TEXAS PROJECT, UNITS 1 AND 2 - SUPPLEMENTAL INFORMATION NEEDED FOR ACCEPTANCE OF REQUESTED LICENSING ACTION RE: LICENSE AMENDMENT REQUEST TO EXTEND INTEGRATED LEAK RATE TEST FROM 10 TO 15 YEARS (TAC NOS. MF6176 AND MF6177)
Dear Mr. Koehl:
By letter dated April 29, 2015 (Agencywide Documents and Management System (ADAMS)
Accession No. ML15128A352), STP Nuclear Operating Company (STPNOC, the licensee) submitted a license amendment request for the South Texas Project, Units 1 and 2 (STP). The proposed amendment request would extend the integrated leak rate test from 10 years to 15 years. The purpose of this letter is to provide the results of the U.S. Nuclear Regulatory Commission (NRC) staff's acceptance review of this amendment request. The acceptance review was performed to determine if there is sufficient technical information in scope and depth to allow the NRC staff to complete its detailed technical review. The acceptance review is also intended to identify whether the application has any readily apparent information insufficiencies in its characterization of the regulatory requirements or the licensing basis of the plant.
Consistent with Section 50.90 of Title 10 of the Code of Federal Regulations (10 CFR), an amendment to the license (including the technical specifications) must fully describe the changes requested, and following as far as applicable, the form prescribed for original applications. Section 50.34 of 10 CFR addresses the content of technical information required.
This section stipulates that the submittal address the design and operating characteristics, unusual or novel design features, and principal safety considerations.
The NRC staff has reviewed your application and concluded that the information delineated in the enclosure to this letter is necessary to enable the staff to make an independent assessment regarding the acceptability of the proposed amendment in terms of regulatory requirements and the protection of public health and safety and the environment.
In order to make the application complete, the NRC staff requests that STPNOC supplement the application to address the information requested in e-mail dated June 1, 2015 (ADAMS Accession No. ML15156A383), and restated in the Enclosure by June 29, 2015. This will enable the NRC staff to begin its detailed technical review. If the information responsive to the NRC staff's request is not received by the above date, the application will not be accepted for review pursuant to 10 CFR 2.101, and the NRC will cease its review activities associated with the application. If the application is subsequently accepted for review, you will be advised of
any further information needed to support the staff's detailed technical review by separate correspondence.
The information requested and associated time frame in this letter was discussed with Mr. Lance Sterling of your staff during the teleconference held on June 10, 2015.
If you have any questions, please contact the STP Project Manager, Lisa Regner, at (301) 415-1906 or Margaret Watford, at (301) 415-1233.
Docket Nos. 50-498 and 50-499
Enclosure:
Supplemental Information Needed cc w/encl: Distribution via Listserv Lisa M. Regner, Senior Project Manager Plant Licensing Branch, LPL4-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
SUPPLEMENTAL INFORMATION NEEDED LICENSE AMENDMENT REQUEST TO EXTEND INTEGRATED LEAK RATE TEST FROM10YEARST015YEARS STP NUCLEAR OPERATING COMPANY SOUTH TEXAS PROJECT. UNITS 1 AND 2 DOCKET NOS. 50-498 AND 50-499 By letter dated April 29, 2015 (Agencywide Documents and Management System (ADAMS)
Accession No. ML15128A352), STP Nuclear Operating Company (STPNOC, the licensee) submitted a license amendment request for the South Texas Project, Units 1 and 2 (STP). The proposed amendment request would extend the integrated leak rate test (ILRT) from 10 years to 15 years.
The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed your application and concluded that the information below is necessary to enable the staff to make an independent assessment regarding the acceptability of the proposed amendment in terms of regulatory requirements and the protection of public health and safety and the environment.
- 1.
Electric Power Research Institute (EPRI) Topical Report (TR)-1009325, Revision 2-A, dated October 2008, states, in part, that Where possible, the analysis should include a quantitative assessment of the contribution of external events (e.g., fire and seismic) in the risk impact assessment for extended ILRT intervals. For example, where a licensee possesses a quantitative fire analysis and that analysis is of sufficient quality and detail to assess the impact, the methods used to obtain the impact from internal events should be applied for the external event. If the external event analysis is not of sufficient quality or detail to directly apply the methodology provided in this document, the quality or detail will be increased or a suitable estimate of the risk impact from the external events should be performed. This assessment can be taken from existing, previously submitted and approved analyses or other alternate method of assessing an order of magnitude estimate for contribution of the external event to the impact of the changed interval.
The licensee stated in the submittal that the probabilistic risk assessment (PRA) used to support its application includes a seismic PRA and a fire PRA. As the licensee showed in other applications that other external events such as tornados and external flooding have relatively large contributions to the overall plant risk, the NRC staff requests the licensee to describe how the impact of all external events is considered in the PRA for extended ILRT intervals, per the guidance in EPRI TR-1009325, Revision 2-A.
- 2.
In the safety evaluation report (SER) for the EPRI TR-1009325, Revision 2, dated June 25, 2008 (ADAMS Accession No. ML081140105), the NRC staff required the Enclosure licensee to submit documentation indicating that the technical adequacy of its PRA is consistent with the requirements of NRC Regulatory Guide (RG) 1.200, "An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities," relevant to the ILRT extension application. Consistent with the information provided in Regulatory Issue Summary (RIS) 2007-06, "Regulatory Guide 1.200 Implementation," dated March 2007 (ADAMS Accession No. ML070650428), the NRC staff will use Revision 2 of RG 1.200 dated March 2009 (ADAMS Accession No. ML090410014), to assess technical adequacy of the PRA used to support risk-informed applications received after March 2010. In Section 3.2.4.1 of the SER for Nuclear Energy Institute (NEI) 94-01, Revision 2 and EPRI TR-1009325, Revision 2, the NRC staff states that Capability Category I of the American Society of Mechanical Engineers PRA standard shall be applied as the standard for assessing PRA quality for ILRT extension applications. This is because the approximate values of core damage frequency and large early release frequency and their distribution among release categories are sufficient to support the evaluation of changes to ILRT frequencies. The license amendment request states that "STPNOC's PRA complies with RG 1.200, Rev. 2 with two exceptions. It does not comply with RG. 1.200 Rev. 2 with respect to Fire PRA [... ]and Sei'smic PRA requirements." The NRC staff requests the licensee to provide documentation, such as peer review findings and a description of STP's disposition or impact, gap assessments, etc., that demonstrates compliance of the STP's internal events PRA with Revision 2 of RG 1.200, at Capability Category I as required for the ILRT license amendment request.
ML15163A017 OFFICE N RR/DORL/LPL4-1 /PM NAME JKlos DATE 6/15/15 OFFICE N RR/ORA/ APLA/BC NAME SRosenberg DATE 6/17/15 Sincerely, IRA/
Lisa M. Regner, Senior Project Manager Plant Licensing Branch, LPL4-1 Division of Operating Reactor Licensing Office of Nuclea~ Reactor Regulation RidsNrrDraApla Resource RidsNrrDssScvb Resource RidsNrrDssStsb Resource RidsNrrLAJBurkhardt Resource RidsNrrPMSouthTexas Resource RidsRgn4MailCenter Resource NRR/DORL/LPL4-1/PM N RR/DORL/LPL4-1 /LA LRegner JBurkhardt 6/15/15 6/12/15 NRR/DORL/LPL4-1 /BC N RR/DORL/LPL4-1 /PM MMarkley LRegner 6/18/15 6/18/15