ML15156A383

NRR E-mail Capture - Email to South Texas Project, Unit 1 and 2 Amendment to Extend ILRT, Unacceptable with Opportunity to Supplement

ML15156A383
Person / Time
Site:	South Texas
Issue date:	06/01/2015
From:	Lisa Regner Plant Licensing Branch IV
To:	Sterling L South Texas
References
TAC MF6176, TAC MF6177
Download: ML15156A383 (3)

Text

1 NRR-PMDAPEm Resource From:

Regner, Lisa Sent:

Monday, June 01, 2015 4:27 PM To:

Sterling, Lance (lsterling@STPEGS.COM)

Cc:

Regner, Lisa; Watford, Margaret

Subject:

Acceptance Review of STP ILRT LAR (NOC-AE-15003227)

The staff has reviewed your Integrated Leak Rate Testing license amendment request (LAR) and found risk assessment insufficiencies in your submittal. Below are the identified PRA insufficiencies that will need to be addressed promptly for the staff to begin its review, otherwise the LAR will be unacceptable for review.

The other involved technical review branches (containment & ventilation, and mechanical & civil engineering) have found their associated sections of the LAR acceptable for review. Also, the DORL Project Managers review determined the LAR is acceptable.

The NRC staff requests a conference call with STP staff to ensure you understand what we need for the ILRT LAR review. Please propose a date and time that is acceptable prior to Wednesday, June 10. Please contact Ms. Margaret Watford, the backup STP PM.

Our procedures allow for no more than 13 days from the date of the call between the NRC and STP staff for your response.

1. EPRI TR-1009325, Revision 2-A states that [w]here 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 PRA used to support this 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, describe how the impact of all external events is considered in the risk assessment 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 that the licensee submit documentation indicating that the technical adequacy of their Probabilistic Risk Assessment (PRA) is consistent with the requirements of 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 (ADAMS Accession No. ML070650428), Regulatory Guide 1.200 Implementation, the NRC staff will use Revision 2 of RG 1.200 (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 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 (ASME) PRA standard shall be applied as the standard for assessing PRA quality for IRLT extension applications, since approximate values of

2 CDF and large early release frequency (LERF) and their distribution among release categories are sufficient to support the evaluation of changes to ILRT frequencies.

The LAR states that STPNOCs PRA complies with Regulatory Guide (RG) 1.200, Rev.2 with two exceptions. It does not comply with RG. 1.200 Rev. 2 with respect to Fire PRA [] and Seismic PRA requirements. Provide documentation, such as peer review findings and a description of their disposition or impact, gap assessments, etc., that demonstrates compliance of the SPTNOCs internal events PRA with Revision 2 of RG 1.200, at Capability Category I as required for the ILRT application.

Lisa Regner Sr. PM NRR/DORL/LPL4-1 301-415-1906 O8D08

Hearing Identifier:

NRR_PMDA Email Number:

2138 Mail Envelope Properties (E85CAE0ED2FC5449B808712D77E97576EFBBCF2331)

Subject:

Acceptance Review of STP ILRT LAR (NOC-AE-15003227)

Sent Date:

6/1/2015 4:26:30 PM Received Date:

6/1/2015 4:26:32 PM From:

Regner, Lisa Created By:

Lisa.Regner@nrc.gov Recipients:

"Regner, Lisa" <Lisa.Regner@nrc.gov>

Tracking Status: None "Watford, Margaret" <Margaret.Watford@nrc.gov>

Tracking Status: None "Sterling, Lance (lsterling@STPEGS.COM)" <lsterling@STPEGS.COM>

Tracking Status: None Post Office:

HQCLSTR02.nrc.gov Files Size Date & Time MESSAGE 4404 6/1/2015 4:26:32 PM Options Priority:

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