L-2015-016, Response to Request for Additional Information (RAI) Regarding License Amendment Request to Permanently Extend the Integrated Leak Rate Test (ILRT) Frequency to 15 Years

Response to Request for Additional Information (RAI) Regarding License Amendment Request to Permanently Extend the Integrated Leak Rate Test (ILRT) Frequency to 15 Years

ML15118A541
Person / Time
Site:	Saint Lucie
Issue date:	02/06/2015
From:	Costanzo C Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2015-016, TAC MF4694, TAC MF4695
Download: ML15118A541 (4)

Text

February 6, 2015 L-2015-016 10 CFR 50.90 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555-0001 Re: St. Lucie Units I and 2 Dockets Nos. 50-335 and 50-389 Response to Request for Additional Information (RAI) Regarding License Amendment Request to Permanently Extend the Integrated Leak Rate Test (ILRT)

Frequency to 15 Years (MF4694 and MF4695)

References:

1. FPL letter L-2014-230 dated August 26, 2014: St. Lucie Plant - Application for Technical Specifications Change to Permanently Extend the Integrated Leak Rate Test (ILRT) Frequency to 15 Years (ADAMS Accession No. ML14241A496)

2. FPL letter L-2015-015 dated January 14, 2015: St. Lucle Plant, Units 1 and 2 -

Response to Request for Additional Information (RAI) Regarding License Amendment Request to Permanently Extend the Integrated Leak Rate Test (ILRT)

Frequency to 15 Years (ADAMS Accession No. ML15029A496)

3. NRC letter dated January 22, 2015: Request for Additional Information Re lLRT LAR for St. Lucie I & 2 (TACs MF4694 & MF4695) - CORRECTION (ADAMS Accession No. ML15023A081)

Per Reference I above, Florida Power & Light Company (FPL) requested an amendment to the Renewed Facility Operating Licenses for St. Lucie Unit 1 and Unit 2. The license amendment request (LAR) would modify the St. Lucie Units I and 2 Technical Specifications to permanently extend the frequency of the containment integrated leak rate test (ILRT) from once per 10 years to once per 15 years. This application was supplemented by letter dated January 14, 2015 (Reference 2).

By letter dated January 22, 2015 (Reference 3), NRC staff requested additional information regarding the LAR. The enclosure to this letter provides a detailed response to a request for additional information (RAI) from the PRA Licensing Branch (APLA).

The information provided In this submittal does not impact the 10 CFR 50.92 evaluation of "No Significant Hazards Consideration" previously provided in FPL letter L-2014-230.

This submittal makes no new commitments or changes to existing commitments.

Should you have any questions regarding this submittal, please contact Mr. Eric Kalzman, Licensing Manager, at (772) 467-7734.

Flonda Power &Light Company/k 71 6501 S. cean Dr ive, Je B h, FL. 3495 7

Page 2 L-2015-016 I declare under penalty of perjury that the foregoing is true and correct.

Executed on February _., 2015.

Respectfully submitted, Christopher R. Costanzo Site Vice President St. Lucie Nuclear Plant

Enclosure:

St. Lucie Units 1 and 2 ILRT LAR RAI Response cc: USNRC Regional Administrator, Region II USNRC Senior Resident Inspector, St. Lucie Units 1 and 2 USNRC Project Manager, St. Lucie Units 1 and 2 Ms. Cindy Becker, Florida Department of Health

Enclosure to L-2015-016 Page 1 of 2 Enclosure St. Lucie Units I and 2 ILRT LAR RAI Response Response to Request for Additional Information (RAI) Regarding License Amendment Request to Permanently Extend the Integrated Leak Rate Test (ILRT) Frequency to 15 Years (MF4694 AND MF4695)

APLA RAI 1

Enclosure to L-2015-016 Page 2 of 2 APLA RAI 1 Section 3.5.2 of the enclosure to the LAR states in part that "the most recent [Probabilistic Risk Assessment (PRA)] self-assessment ensured compliance with [Regulatory Guide (RG)] 1.200, Revision 2 by identifying gaps in relation to the [ASME/ANS] PRA standard as endorsed by the Regulatory Guide." The NRC staff notes that the results of this gap assessment were discussed in responses to St. Lucie (PSL) PRA RAI 16, which is related to the licensee's LAR to adopt National Fire Protection Association (NFPA) Standard 805 (NFPA 805). Specifically, the 90-day responses (ADAMS Accession No. ML14114A458) and 120-day responses (ADAMS Accession No. ML14135A395) describe gaps and their "impact on fire PRA."

Confirm that the results of this gap assessment, as discussed in the NFPA 805 PSL PRA RAI 16 responses, are applicable to the ILRT frequency extension LAR. If additional gaps are identified that are relevant to this submittal, then provide a list of these gaps and discuss their impact.

RESPONSE

In response to NFPA-805 RAIs, a self-assessment (gap analysis) of the PRA model has been conducted. This assessment revealed that the current open findings and observations (F&Os) are those identified by the most recent peer review of Interfacing System LOCA (ISL) analysis and respective models. Preliminary evaluation of the impact of revising the ISL models to close the respective F&Os resulted in a reduction to ISL contribution for core damage frequency/large early release frequency (CDF/LERF) such that Unit 1 CDF and LERF (where ISL contribution is the highest) were reduced by 8% and 54%, respectively. Thus, the current models are considered conservative and update of ISL logic to close the respective F&Os was postponed until the next periodic update of the models.

The results of the self-assessment (gap analysis) are applicable to the ILRT frequency extension LAR for Units 1 and 2. However, the impact of the open F&Os on the ILRT frequency extension LAR should not be considered critical. While the absolute value for LERF is significantly reduced, the ALERF remains unchanged and the percentage increase in person-rems resulting from the reduction in the ISL LERF contribution would still be significantly less than 1%. Therefore, it is our judgment that changes to ISL contributions have minimal impact on the conclusion presented in the ILRT frequency extension LAR.