ML14076A074

Palo Verde, Units 1, 2 and 3 - APS Extension Request for Flooding Hazard Reevaluation Submittal

ML14076A074
Person / Time
Site:	Palo Verde
Issue date:	03/10/2014
From:	Mims D C Arizona Public Service Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-06850-DCM/MAM/PJH
Download: ML14076A074 (3)

Text

10 CFR 50.54(f)DWIGHT C. MIMSSenior Vice President, NuclearRegulatory

& Oversight Palo VerdeNuclear Generating Stationaps P.O. Box 52034Phoenix, AZ 85072Mail Station 7605Tel 623 393 5403102-06850-DCM/MAM/PJH March 10, 2014U.S. Nuclear Regulatory Commission ATTN: Document Control Desk11555 Rockville PikeRockville, MD 20852

References:

1. NRC Letter, Request for Information Pursuant to Title 10 of theCode of Federal Regulations 50.54(f)

Regarding Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task Force Review of Insightsfrom the Fukushima Dai-ichi

Accident, dated March 12, 20122. NRC Letter, Prioritization of Response Due Dates for Request forInformation Pursuant to Title 10 of the Code of Federal Regulations 50.54(f)

Regarding Flooding Hazard Reevaluations forRecommendation 2.1 of the Near-Term Task Force Review ofInsights from the Fukushima Dai-ichi

Accident, dated May 11, 20123. NRC Letter, Supplemental Information Related to Request forInformation Pursuant to Title 10 of the Code of Federal Regulations 50.54(f)

Regarding Flooding Hazard Reevaluations forRecommendation 2.1 of the Near-Term Task Force Review ofInsights from the Fukushima Dai-ichi

Accident, dated March 1,2013

Subject:

Palo Verde Nuclear Generating Station (PVNGS)Units 1, 2, and 3Docket Nos. STN 50-528, 50-529, and 50-530APS Extension Request for Flooding Hazard Reevaluation Submittal On March 12, 2012, the U. S. Nuclear Regulatory Commission (NRC) issuedReference 1 to request information associated with Near-Term Task Force (NTTF)Recommendation 2.1 for flooding, including a reevaluation of licensees' floodinghazards.

The NRC subsequently identified in Reference 2 the submittal date to reportthe results of the flooding hazard reevaluation for the Palo Verde Nuclear Generating Station (PVNGS),

a Category 2 plant, as March 12, 2014. Reference 3 providesguidance regarding request for extensions of the hazard reevaluation submittal dates.A member of the STARS (strategic Teaming and Resource Sharing)

AllianceCallaway

• Comanche Peak -Diablo Canyon

• Palo Verde -Wolf CreekA I 102-06850-DCM/MAM/PJH ATTN: Document Control DeskU.S. Nuclear Regulatory Commission APS Extension Request for Flooding Hazard Reevaluation Submittal Page 2Arizona Public Service Company (APS) requests an extension of the scheduled submittal date for the flooding hazard reevaluation report to December 12, 2014. Inaccordance with Reference 3, the following information is provided as requested:

Reason for the extension:

Reference 1, Enclosure 2, Flooding, Request 1, Hazard Reevaluation Report, Item1.b requires evaluation of the flooding hazard for each flood causing mechanism, based on present-day methodologies and regulatory guidance of each floodcausing mechanism that may impact the site.Reference 1, Enclosure 2, Item 1.d, also requires the flooding hazardreevaluation report to include interim evaluations and actions taken or planned toaddress any higher flooding hazards relative to the design basis, prior tocompletion of an integrated assessment, if the assessment is required.

APS requires additional time to complete review and validation of the floodinghazard reevaluation results by independent consultants.

These reviews arenecessary to ensure further interim evaluations or actions are prescribed, ifneeded, to provide the complete flooding hazard reevaluation report. Reference 3emphasizes that incomplete hazard reports would not be of substantive benefitfor staff review and would not be acceptable.

Therefore, APS concludes the continuing external validation and review of thecurrent results are necessary to provide a complete flooding hazard reevaluation report that affords the maximum safety and regulatory benefit.This extension is justified on the following basis:a. The cover letter of Reference 1 states that the current regulatory approachand the resultant plant capabilities provide confidence that an accident withconsequences similar to the Fukushima accident is unlikely to occur in theUnited States. Reference 1 concludes that continued plant operation and thecontinuation of licensing activities do not pose an imminent risk to publichealth and safety.b. APS has completed walkdowns of the PVNGS site which verified the currentflooding licensing basis is being met. Therefore, PVNGS is protected fromcurrent design basis flood events.c. The events being analyzed in the flooding hazard reevaluation are beyond theplant's design and licensing basis. The reevaluation results do not, therefore, constitute an operability concern.d. The current licensing bases and the previously submitted flooding hazardwalkdown report, dated November 27, 2012, screened out flood hazards forprobable maximum storm surge and seiche, probable maximum tsunamiflooding, ice effects, and channel diversions because these hazards are not 102-06850-DCM/MAM/PJH ATTN: Document Control DeskU.S. Nuclear Regulatory Commission APS Extension Request for Flooding Hazard Reevaluation Submittal Page 3credible at PVNGS. The remaining reevaluated flooding

hazards, local intenseprecipitation (LIP) and probable maximum flood (PMF) are very lowprobability events. The time frame of the submittal extension is short, relativeto the probability of occurrence of the flood events being evaluated, andwould result in an insignificant contribution to overall risk.e. The flooding hazard reevaluation report would be issued prior to the submittal date for Category 3 plants, identified in Reference 2, as March 12, 2015.Those plants were assigned that due date partially based on theirsusceptibility to the hazards that were screened out by the PVNGS floodinghazard evaluation.

Since the submittal date extension, is prior to the Category3 plant submittal date, the extended due date provides the requested information within the established priority scheme established in Reference 2.For these reasons the duration of the extension request is reasonable and will notimpact safe plant operation.

APS will submit the flooding hazard reevaluation to theNRC by December 12, 2014.No commitments are being made to the NRC by this letter.Should you have any questions concerning the content of this letter, please contactMark McGhee, Department Leader, Regulatory

Affairs, at (623) 393-4972.

I declare under penalty of perjury that the foregoing is true and correct.Executed on(Date)Sincerely, DCM/MAM/PJ Hcc: E. J. LeedsM. L. DapasJ. K. RankinA. E. GeorgeM. A. BrownL. M. RegnerNRC Director, Office of Nuclear Reactor Regulation NRC Region IV Regional Administrator NRC NRR Project ManagerNRC NRR Project ManagerNRC Senior Resident Inspector for PVNGSNRC NRR/JLD/JPMB Project Manager