ML15273A209

Nuclear Regulatory Commission Report for the Audit of Florida Power and Light Company'S Flood Hazard Reevaluation Report Submittals Relating to the Near-Term Task Force Recommendation 2.1-Flooding for St. Lucie Plant Units 1 and 2

ML15273A209
Person / Time
Site:	Saint Lucie
Issue date:	10/01/2015
From:	Minarik A Japan Lessons-Learned Division
To:	Nazar M NextEra Energy
Minarik, Anthony, NRR/JLD 415-6185
References
TAC MF6113, TAC MF6114
Download: ML15273A209 (8)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 October 1, 2015 Mr. Mano Nazar President and Chief Nuclear Officer Nuclear Division NextEra Energy P.O. Box 14000 Juno Beach, FL 33408-0420

SUBJECT:

NUCLEAR REGULATORY COMMISSION REPORT FOR THE AUDIT OF FLORIDA POWER AND LIGHT COMPANY'S FLOOD HAZARD REEVALUATION REPORT SUBMITTALS RELATING TO THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1-FLOODING FOR ST. LUCIE PLANT, UNITS 1AND2 (TAC NOS. MF6113 AND MF6114)

Dear Mr. Nazar:

By letter dated June 1, 2015 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML15147A591), the U.S. Nuclear Regulatory Commission (NRC) informed you of the staff's plan to conduct a regulatory audit of Florida Power and Light Company's (the licensee, FPL) Flood Hazard Reevaluation Report (FHRR) submittals related to the Near-Term Task Force Recommendation 2.1-Flooding. The audit was intended to support the NRC staff review of the licensees FHRRs and the subsequent issuance of a staff assessment.

The audit was conducted on July 23, 2015, and was performed consistent with NRC Office of Nuclear Reactor Regulation, Office Instruction LIC-111, "Regulatory Audits," dated December 29, 2008, (ADAMS Accession No. ML082900195). Therefore, the purpose of this letter is to provide you with the final audit report, which summarizes and documents the NRC's regulatory audit of FPL's FHRR submittals. The details of this audit have been discussed with Mr. Ken Frehafer of your staff.

M. Nazar If you have any questions, please contact me at (301) 415-6185 or by e-mail at Anthony.Minarik@nrc.gov.

Sincerely, Docket Nos. 50-335 and 50-389

Enclosure:

Audit Report cc w/encl: Distribution via Listserv

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 U.S. NUCLEAR REGULATORY COMMISSION AUDIT REPORT FOR THE AUDIT OF FLORIDA POWER AND LIGHT COMPANY'S FLOOD HAZARD REEVALUATION REPORT SUBMITTALS RELATING TO THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1-FLOODING FOR ST. LUCIE PLANT, UNITS 1 AND 2 BACKGROUND AND AUDIT BASIS By letter dated March 12, 2012, the U.S. Nuclear Regulatory Commission (NRC) issued a request for information to all power reactor licensees and holders of construction permits in active or deferred status, pursuant to Title 10 of the Code of Federal Regulations (10 CFR),

Section 50.54(f) "Conditions of license" (hereafter referred to as the "50.54(f) letter"). The request was issued in connection with implementing lessons-learned from the 2011 accident at the Fukushima Dai-ichi nuclear power plant, as documented in The Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident. Recommendation 2.1 in that document recommended that the NRC staff issue orders to all licensees to reevaluate seismic and flooding for their sites against current NRC requirements and guidance. Subsequent Staff Requirements Memoranda associated with Commission Papers SECY 11-0124 and SECY 0137, instructed the NRC staff to issue requests for information to licensees pursuant to 10 CFR 50.54(f).

By letter dated March 10, 2015, Florida Power and Light Company (FPL, the licensee) submitted its Flood Hazard Reevaluation Reports (FHRRs) for St. Lucie Plant, Units 1 and 2 (St. Lucie) (Agencywide Documents Access and Management System (ADAMS) Accession Package No. ML15083A306). The NRC is in the process of reviewing the aforementioned submittals and has completed a regulatory audit of FPL to inform the licensee of its development of the submittals, identify any similarities/differences with past work completed and ultimately aid in its review of licensees' FHRRs. This audit summary is being completed in accordance with the guidance set forth in NRC Office of Nuclear Reactor Regulation, Office Instruction LIC-111, "Regulatory Audits," dated December 29, 2008 (ADAMS Accession No. ML082900195).

AUDIT LOCATION AND DATES The audit was completed by document review via electronic reading room and teleconference on July 23, 2015, from 9:00 am to 10:00 am.

Enclosure

AUDIT TEAMS Title Team Member Organization Team Leader, NRR/JLD Anthony Minarik NRC Branch Chief, NRO/DSEA Christopher Cook NRC Technical Lead Laura Quinn-Willingham NRC Technical Suooort Peter Chaput NRC Technical Suooort Henry Jones NRC Technical Support Christopher Bender Taylor Eng./NRC Support DOCUMENTS AUDITED of this report contains a list, which details all the documents that were reviewed by the NRC staff, in part or in whole, as part of this audit. The documents were located in an electronic reading room during the NRC staff review. The documents, or portions thereof, that were used by the staff as part of the technical analysis and/or as reference in the completion of the staff assessment, were submitted by the licensee and docketed for transparency and completeness of information, as necessary. They are identified in Table 1.

AUDIT ACTIVITIES In general, the audit activities consisted mainly of the following actions:

• Review background information on site topography and geographical characteristics of the watershed.

• Review site physical features and plant layout

• Understand the selection of important assumptions and parameters that would be the basis for evaluating the individual flood causing mechanisms described in the 50.54(f) letter.

• Review model input/output files to computer files such as Delft-3D and FL0-2D to have an understanding of how modeling assumptions were programmed and executed Table 1 on the following page, provides more detail and summarizes specific technical topics (and resolution) of important items that were discussed and clarified during the audit. The items discussed in Table 1 may be referenced/mentioned in the staff assessment in more detail.

Table 1: Sample of Technical Topics of Discussion Info Need Information Need Description Post-Audit Status No.

1 All Flood Causing Mechanisms - The licensee stated that the current Com~arison of Reevaluated Flood Hazard design-basis and CLB values are the with Current Design-Basis same, therefore the NRC Staff can interpret mentioning of the CLB as the

Background:

The FHRR for the St Lucie site current design-basis in the FHRR.

provides comparisons of the reevaluated flood The NRC staff accepts this response hazards with the current licensing basis (CLB) as sufficient and the issue resolved, for all flood causing mechanisms for which a therefore no substantial discussion was CLB had been established in Section 3.0. In needed during the audit. However, the FHRR Section 5.14 of the report is a summary NRC did request that the licensee of this comparison. The 50.54(f) letter provide a letter stating this explanation requested a comparison with the current on the docket.

design-basis.

Request: The licensee is requested to provide clarification regarding the inconsistencies identified in the FHRR with regard to the comparison of the reevaluated flood hazard to the current design-basis and submit a revised hazard comparison consistent with the instructions provided in the 50.54(f) letter.

2 Local Intense Preci~itation The licensee discussed that the 20-feet by 20-feet resolution is sufficient for the

Background:

The FHRR presents a local flow conditions. During the audit, the intense precipitation (LIP) flood reevaluation licensee provided additional discussion using a grid size of 20-feet in the FL0-2D regarding how vehicle barrier systems model. This approach may not capture the and other obstructions were modeled potentially most conservative and bounding with this grid size.

flood condition resulting from precipitation Additional discussion regarding events of different magnitude and duration. durations have been made irrelevant by LIP duration white paper.

Request: Provide justification that the 20-feet grid size described FHRR is bounding in terms of flood depth. This justification should include sensitivity analysis of LIP event for grid sizes less than 20-feet (e.g. 10-feet, 5-feet).

Info Need Information Need Description Post*Audit Status No.

3 Local Intense Preci(:!itation The licensee directed staff to the

Background:

The FHRR includes Figure 4-6, figures in calculation package FPL-Points of Interest (POI), and Figure 4-7, 072-CALC-003 "Local Intense Maximum Water Depths at POis for All Precipitation (LIP) Flooding Simulations, which combined locate the Calculation", Revision 1, Section 7, openings to safety related structures and the Attachment A During the audit, NRC LIP time-depth plots at selected locations. staff explained that the information was This information focuses on specific points at being requested to assist in the the site, and may not provide enough completion of the staff assessment.

information regarding overall areas of LIP The NRC staff informed the licensee flooding concern. This type of graphical that docketing of the final LIP analysis information could be used to determine where FL0-2D output files would be to focus mitigating strategies, interim actions necessary for the NRC Staff to and other flood mitigation and protection document its review of the LIP activities (e.g. improving drainage along a analysis. The NRC staff has no further building rather than installing multiple flood issues on this topic.

doors).

Request: Provide detailed figures or maps of the flooding depths that result from LIP flooding across the entire site, rather than depths and elevations at select locations. The figures or maps can only be for the LIP event that produces the Qreatest flooding depth.

EXIT MEETING/BRIEFING:

On July 23, 2015, the NRC staff closed out the discussion of the technical topics described above. The NRC staff determined the information that would need to be provided to resolve some of the items discussed during the audit and the licensee agreed to provide the information as soon as possible. This information included the following:

1) An explanation via letter that references to the current licensing basis in the FHRR could be taken to mean the current design-basis.

2) The FL0-2D output files related to the final LIP analysis.

ATTACHMENT 1 FHRR Reference Lists FPL-072-CALC-001, FL0-2D Bathvmetrv and Topography Processing Calculation, Rev. 1 FPL-072-CALC-002, Local Intense Precipitation Rainfall Distribution Calculation, Rev. 1 FPL-072-CALC-003, Local Intense Precipitation (LIP) Flooding Calculation, Rev. 1 FPL-072-CALC-004, DELFT3D BATHYMETRY AND TOPOGRAPHY CALCULATION FPL-072-CALC-005, REGIONAL HURRICANE CLIMATOLOGY CALCULATION FPL-072-CALC-006, PROBABLE MAXIMUM STORM (PMS) PARAMETERS AND STORM TRACKS CALCULATION FPL-072-CALC-007, 10% EXCEEDANCE HIGH AND LOW TIDES CALCULATION FPL-072-CALC-008, SEA LEVEL RISE CALCULATION FPL-072-CALC-009, DELFT3D SURGE MODEL GEOMETRY CALCULATION FPL-072-CALC-010, DELFT3D SURGE MODEL CALIBRATION FPL-072-CALC-011, PROBABLE MAXIMUM STORM SURGE (PMSS) CALCULATION FPL-072-CALC-012, SEICHE CALCULATION FPL-072-CALC-013, PROBABLE MAXIMUM STORM SURGE (PMSS) WAVE RUNUP AND COMBINED EFFECTS CALCULATION FPL-072-CALC-017, PROBABLE MAXIMUM STORM SURGE - HYDROSTATIC, HYDRODYNAMIC, DEBRIS, AND SEDIMENTATION LOADING CALCULATION

M. Nazar If you have any questions, please contact me at (301) 415-6185 or by e-mail at Anthony.Minarik@nrc.gov.

Sincerely, IRA/

Anthony Minarik, Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation Docket Nos. 50-335 and 50-389

Enclosure:

Audit Report cc w/encl: Distribution via Listserv DISTRIBUTION:

PUBLIC JLD R/F RidsNRRJLD Resource JUribe, NRR RidsNrrPMStlucie Resource MShams, NRR ARivera, NRO MFranovich, NRR KErwin, NRO LQuinn-Willingham, NRO CCook, NRO YChen, NRO PChaput, NRO JBowen, NRR RidsNrrDorlLPL2-2 Resource ADAMS Accession No.: ML15273A209 OFFICE NRR/JLD/JHMB/PM NRR/JLD/JHMB/LA NRR/JLD/JHMB/BC NRR/JLD/JHMB/PM NAME AMinarik Slent MShams AMinarik DATE 10/1/2015 10/1/2015 10/1/2015 10/1/2015 OFFICAL RECORD COPY