ML15251A216
| ML15251A216 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 09/03/2015 |
| From: | Lisa Regner Plant Licensing Branch IV |
| To: | Sterling L South Texas |
| References | |
| TAC MF6176, TAC MF6177 | |
| Download: ML15251A216 (6) | |
Text
1 NRR-PMDAPEm Resource From:
Regner, Lisa Sent:
Thursday, September 03, 2015 9:18 AM To:
Sterling, Lance (lsterling@STPEGS.COM)
Cc:
Richards, Drew (amrichards@STPEGS.COM)
Subject:
STP ILRT RAI (MF6176 and MF6177)
Attachments:
SCVB RAI MF6176 and MF6177 - to licensee.docx By letter dated April 29, 2015, (Agencywide Documents Access and Management System (ADAMS) Accession Number ML15128A352), STP Operating Company (STPNOC), the licensee for South Texas Project Unit 1 and Unit 2 (STP), submitted a License Amendment Request (LAR) for a permanent extension of the frequency for the containment Type A Integrated Leak Rate Test from ten years to fifteen years. The Containment and Ventilation Branch (SCVB) has reviewed the licensees request and prepared the attached Request for Additional Information. These are questions from SCVB, and there may be additional questions from the Probabilistic Risk Assessment Licensing Branch.
Please let me know if youd like me to schedule a clarification call on any of these questions. If no clarification call is requested, your response is expected within 30 days of this email. If this schedule is not feasible, please contact me to discuss.
- Thanks, Lisa Regner Lisa M Regner, Sr. Project Manager, Branch LPLIV-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Lisa.Regner@NRC.Gov Office: O8D08 Mail Stop: O8B01 (301) 415-1906
Hearing Identifier:
NRR_PMDA Email Number:
2363 Mail Envelope Properties (5cdb7084e5e54c1991393a0fc00a018a)
Subject:
STP ILRT RAI (MF6176 and MF6177)
Sent Date:
9/3/2015 9:17:50 AM Received Date:
9/3/2015 9:17:53 AM From:
Regner, Lisa Created By:
Lisa.Regner@nrc.gov Recipients:
"Richards, Drew (amrichards@STPEGS.COM)" <amrichards@STPEGS.COM>
Tracking Status: None "Sterling, Lance (lsterling@STPEGS.COM)" <lsterling@STPEGS.COM>
Tracking Status: None Post Office:
HQPWMSMRS05.nrc.gov Files Size Date & Time MESSAGE 1197 9/3/2015 9:17:53 AM SCVB RAI MF6176 and MF6177 - to licensee.docx 27650 Options Priority:
Standard Return Notification:
No Reply Requested:
No Sensitivity:
Normal Expiration Date:
Recipients Received:
REQUEST FOR ADDITIONAL INFORMATION LICENSEAMENDMENTREQUESTFOR EXTENSIONOFCONTAINMENTLEAKAGERATETESTINGPROGRAM SOUTH TEXAS PROJECT UNITS 1 AND 2(TAC NOS MF6176 AND MF6177)
ByapplicationdatedApril 29,2015(AgencywideDocumentsAccessandManagementSystem(ADAMS)AccessionNumberML15128A352),STP Operating Company (STPNOC, the licensee) requestedchangestotheTechnicalSpecifications(TSs)for South Texas Project (STP) Unit 1 and Unit 2. Theproposedchangewouldpermit theexisting Containment Integrated Leak Rate Testing (ILRT)frequencytobeextendedfrom10yearsto15yearsonapermanentbasis.
TheNRCstaffhasreviewedtheLicenseAmendmentRequest(LAR)andrequeststhefollowingadditi onalinformationtocompleteitsreview:
SCVBRAI-1 LAR Attachment 1, Section 4.5 Nuclear Safety Advisory Letters (NSAL), discusses the adverse impact of NSAL 11-05, Westinghouse LOCA [loss of coolant accident] Mass and Energy Release Calculation Issues and NSAL 14-02, Westinghouse Loss-Of-Coolant Accident Mass and Energy Release Calculation Issue for Steam Generator Tube Material Properties. The combined effect of the two NSALs on peak containment pressure and temperature was discussed under LAR Attachment 1, Section 4.5.1, which states the following:
An operability review was performed and documented in CREE 11-12472-1. The results of the evaluation show the condition does not result in any equipment being inoperable. However, the change in LOCA mass and energy results in a change to the peak containment pressure and temperature as presented in the UFSAR and TS 6.8.3.j. As a compensatory action (CR 11-12472-3), 0PSP11-ZA-0005, Local Leakage Rate test Calculations, Guidelines, and Program has been revised to require a Pa of 43.2 psig to ensure sufficient margin until the UFSAR is updated to reflect the corrected value. Therefore, the determination of the condition is OPERABLE BUT NON-CONFORMING.
The peak calculated containment internal pressure for the design basis loss of coolant accident (LOCA), Pa, as currently stated in TS 6.8.3.j Containment Leakage Rate Testing Program of the UFSAR is 41.2 psig. The LAR did not address any immediate or future actions that the licensee plans to undertake due to the increase in Pa as a result of the NSALs.What would have been the extrapolated ILRT and combined LLRT(local leak rate test) results of the previous tests if the tests had been performed at 43.2 psig? Will they still result in significant margins for the performance criteria as indicated by the previous tests?
Please provide additional information as to when a final calculated peak containment pressure as a result of the NSALs will be determined, plans for revising the UFSAR and the TSs, and the reasons why the increased pressure would not impact operability for the remaining period before the next ILRT based on both the current frequency and extended frequency requested by the LAR.
2 ENCLOSURE
SCVBRAI-2 LAR Attachment 1 Tables 4.4.1-3 (Unit 1) and Table 4.4.1-4 (Unit 2) identify the components that have not demonstrated acceptable performance for Type C testing during the previous two outages.
Table 4.4.1-3 (Unit 1) identifies issues related to supplementary containment purge valves problems (Penetration M-43) and states that fixes were made to achieve satisfactory results.
Table 4.4.1-4 (Unit 2) identifies two penetrations (M-44 and M-48) that exceeded the administrative leakage limit, all of which were accepted for continued service with leakage still left above the administrative limit but below the maintenance criteria. In fact, Penetration M-44 appears to have exceeded administrative leakage limit in two consecutive Type C tests.
The licensee stated that,as a result, the extended interval for the next Type C test is not allowed for these penetrations. However, continued operation is allowed even when the penetrations continue to fail the administrative leakage limit. Provide additional information on actions to be taken to assure that these penetrations will be maintained in a condition where they are able to perform their leak tightness to within the administrative limits.