ML15069A391
| ML15069A391 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 03/16/2015 |
| From: | Farideh Saba Plant Licensing Branch II |
| To: | Nazar M Florida Power & Light Co, Nextera Energy |
| Saba F DORL/LPL2-2 301-415-1447 | |
| References | |
| TAC MF1373, TAC MF1374 | |
| Download: ML15069A391 (5) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. Mano Nazar President and Chief Nuclear Officer Nuclear Division NextEra Energy P.O. Box 14000 Juno Beach, FL 33408-0420 March 16, 2015
SUBJECT:
ST. LUCIE PLANT, UNIT NOS. 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION ON LICENSE AMENDMENT REQUEST TO ADOPT NATIONAL FIRE PROTECTION ASSOCIATION STANDARD 805, "PERFORMANCE-BASED STANDARD FOR FIRE PROTECTION FOR LIGHT WATER REACTOR ELECTRIC GENERATING PLANTS"(TAC NOS. MF1373 AND MF1374)
Dear Mr. Nazar:
By letter dated March 22, 2013, as supplemented by letters dated June 14, 2013, and February 24, March 25, and April 25, 2014, Florida Power & Light Company (the licensee, FPL) submitted a license amendment request for the St. Lucie Plant, Unit Nos. 1 and 2 (St. Lucie).
The proposed amendment requested approval to transition the fire protection licensing basis from Title 10 of the Code of Federal Regulations (10 CFR) Section 50.48(b) to 10 CFR 50.48(c),
National Fire Protection Association Standard 805, "Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants."
The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the information provided by the licensee and participated in an audit at St. Lucie the week of November 18, 2013. By correspondence dated June 7 and December 26, 2013, the NRC staff requested additional information. By letters dated June 14, 2013, and February 24, March 25, April 25, July 14, August 27, September 10, and October 10, 2014, the licensee responded to the staff's request for additional information (RAI).
The NRC staff determined that they need additional information to complete the review. Draft followup Probabilistic Risk Assessment (PRA) RAls were e-mailed to the licensee on February 5, 2015, and discussed during a clarification call between the NRC and licensee staff on February 9, 2015. During a telephone conversation on March 3, 2015, with Mr. William Cross of FPL, the NRC staff agreed with the licensee's proposed response date of April 2, 2015.
The enclosure to this letter contains the NRC staff's followup PRA RAI.
If you have any questions, please contact me at (301) 415-1447 or farideh.saba@nrc.gov.
Enclosure:
Request for Additional Information Docket Nos. 50-335 and 50-389 cc w/enclosure: Distribution via Listserv Sincerely,
~,/7'J l~ t. ~ k Farideh E. Saba, Senior Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
REQUEST FOR ADDITIONAL INFORMATION LICENSE AMENDMENT REQUEST TO ADOPT NATIONAL FIRE PROTECTION ASSOCIATION STANDARD 805.
"PERFORMANCE-BASED STANDARD FOR FIRE PROTECTION FOR LIGHT WATER REACTOR ELECTRIC GENERATING PLANTS" FLORIDA POWER AND LIGHT COMPANY ST. LUCIE PLANT. UNIT NOS. 1 AND 2 DOCKET NOS. 50-335 AND 50-389 By letter dated March 22, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13088A173), as supplemented by letters dated June 14, 2013, and February 24, March 25, April 25, July 14, August 27, September 10, and October 10, 2014 (ADAMS Accession Nos. ML13170A156, ML14070A097, ML14114A458, ML14135A395, ML14198A087, Ml14253A216, ML14259A373, and ML14296A435, respectively), Florida Power and Light Company (the licensee) submitted a license amendment request (LAR) for the St. Lucie Plant, Unit Nos. 1 and 2 (St. Lucie). The proposed amendment requested approval to transition the fire protection licensing basis from Title 1 O of the Code of Federal Regulations (10 CFR) Section 50.48(b) to 10 CFR 50.48(c), National Fire Protection Association Standard 805, "Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants."
The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the information provided by the licensee and determined that it needs additional information for the following Probabilistic Risk Assessment (PRA) Request for Additional Information (RAI) to complete the review.
PRA RAI 01.m.01.01 The response to PRA RAI 01.m.01 indicates that the electrical fire non-suppression probability (NSP) curve from Supplement 1 to NUREG/CR-6850, "Fire PRA Methodology for Nuclear Power Facilities," is applied to fires induced by a high energy arcing fault (HEAF) event.
Points 3 and 8 on page P-7, as well as the second bullet in Section M.5 of NUREG/CR-6850, clearly state that in the second stage of an HEAF fire (i.e., after the energetic stage) the HEAF NSP curves should be used, not the electrical fire NSP curves. Furthermore, Figure 14-10 in Supplement 1 provides HEAF NSP curves in contrast to Figure 14-14 in Supplement 1, which provides NSP curves for electrical fires.
i)
Use the accepted method or justify the use of the proposed method based on unique, plant-specific characteristics.
Enclosure ii)
If an accepted method is not used, provide the results of a sensitivity study using the accepted method instead of the proposed method.
PRA RAI 11.c.01.01 The response to PRA RAI 11.c.01 tabulates abandonment frequencies for each of the three fire-induced main control room (MCR) abandonment scenario bins. Multiplying the frequencies for each of the bins by their corresponding conditional core damage probability and then summing the results yields core damage frequency (CDF) estimates associated with MCR abandonment of 4.76E-05/year (yr) and 1.66E-05/yr, respectively, for Unit Nos. 1 and 2. These results exceed the CDF estimates of 1.58E-05/yr and 1.0?E-05/yr reported in the revised LAR Attachment W for Fire Areas Unit No. 1-1 F and Unit No. 2-2F, respectively. Also, there appears to be a difference between the abandonment frequencies reported in the text (i.e., 6.26E-03/yr for Unit No. 1 and 1.95E-03/yr for Unit No. 2) and the total abandonment frequencies reported in the table (i.e., 6.1 OE-05/yr for Unit No. 1 and 2.05E-05/yr for Unit No. 2). Clarify these apparent discrepancies.
PRA RAI 19.01 The response to PRA RAI 19 indicates fire initiating event frequencies from Supplement 1 to NUREG/CR-6850 were used. Chapter 10 of this supplement states that a sensitivity analysis should be performed when using the fire ignition frequencies in the supplement instead of those provided in Table 6-1 of NUREG/CR-6850. Provide the risk estimates and the change-in-risk estimates from this study. If these estimates exceed the acceptance guidelines (i.e., affect the decision being made), discuss additional defense-in-depth measures that can be applied to scenarios within those fire areas that now result in the acceptance guidelines being exceeded.
ML15069A391 RidsNrrDraApla Resource LRonewicz, NRR RidsNrrLABClayton Resource RidsACRS_MailCTR Resource HBarrett, NRR OFFICE DORL/LPL2-2/PM DORL/LPL2-2/LAiT DORL/LPL2-2/LA DRA/AFPB/BC DORL/LPL2-2/BC DORL/LPL2-2/PM NAME FSaba LRonewicz BClayton HHamzehee SHelton FSaba (DPelton for)
DATE 3/12/15 3/11/15 3/12/15 3/16/15 3/16/15 3/16/15