ML14076A074

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. MIMS Senior Vice President, Nuclear Regulatory

& Oversight Palo Verde Nuclear Generating Station aps P.O. Box 52034 Phoenix, AZ 85072 Mail Station 7605 Tel 623 393 5403 102-06850-DCM/MAM/PJH March 10, 2014 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, MD 20852

References:

1. NRC Letter, Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident, dated March 12, 2012 2. NRC Letter, Prioritization of Response Due Dates for Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Flooding Hazard Reevaluations for Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident, dated May 11, 2012 3. NRC Letter, Supplemental Information Related to Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Flooding Hazard Reevaluations for Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident, dated March 1, 2013

Subject:

Palo Verde Nuclear Generating Station (PVNGS)Units 1, 2, and 3 Docket Nos. STN 50-528, 50-529, and 50-530 APS Extension Request for Flooding Hazard Reevaluation Submittal On March 12, 2012, the U. S. Nuclear Regulatory Commission (NRC) issued Reference 1 to request information associated with Near-Term Task Force (NTTF)Recommendation 2.1 for flooding, including a reevaluation of licensees' flooding hazards. The NRC subsequently identified in Reference 2 the submittal date to report the results of the flooding hazard reevaluation for the Palo Verde Nuclear Generating Station (PVNGS), a Category 2 plant, as March 12, 2014. Reference 3 provides guidance regarding request for extensions of the hazard reevaluation submittal dates.A member of the STARS (strategic Teaming and Resource Sharing) Alliance Callaway

• Comanche Peak -Diablo Canyon

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

Reason for the extension:

Reference 1, Enclosure 2, Flooding, Request 1, Hazard Reevaluation Report, Item 1.b requires evaluation of the flooding hazard for each flood causing mechanism, based on present-day methodologies and regulatory guidance of each flood causing mechanism that may impact the site.Reference 1, Enclosure 2, Item 1.d, also requires the flooding hazard reevaluation report to include interim evaluations and actions taken or planned to address any higher flooding hazards relative to the design basis, prior to completion of an integrated assessment, if the assessment is required.APS requires additional time to complete review and validation of the flooding hazard reevaluation results by independent consultants.

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

Therefore, APS concludes the continuing external validation and review of the current 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 approach and the resultant plant capabilities provide confidence that an accident with consequences similar to the Fukushima accident is unlikely to occur in the United States. Reference 1 concludes that continued plant operation and the continuation of licensing activities do not pose an imminent risk to public health and safety.b. APS has completed walkdowns of the PVNGS site which verified the current flooding licensing basis is being met. Therefore, PVNGS is protected from current design basis flood events.c. The events being analyzed in the flooding hazard reevaluation are beyond the plant'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 hazard walkdown report, dated November 27, 2012, screened out flood hazards for probable maximum storm surge and seiche, probable maximum tsunami flooding, ice effects, and channel diversions because these hazards are not 102-06850-DCM/MAM/PJH ATTN: Document Control Desk U.S. Nuclear Regulatory Commission APS Extension Request for Flooding Hazard Reevaluation Submittal Page 3 credible at PVNGS. The remaining reevaluated flooding hazards, local intense precipitation (LIP) and probable maximum flood (PMF) are very low probability events. The time frame of the submittal extension is short, relative to the probability of occurrence of the flood events being evaluated, and would 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 their susceptibility to the hazards that were screened out by the PVNGS flooding hazard evaluation.

Since the submittal date extension, is prior to the Category 3 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 not impact safe plant operation.

APS will submit the flooding hazard reevaluation to the NRC 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 contact Mark 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 H cc: E. J. Leeds M. L. Dapas J. K. Rankin A. E. George M. A. Brown L. M. Regner NRC Director, Office of Nuclear Reactor Regulation NRC Region IV Regional Administrator NRC NRR Project Manager NRC NRR Project Manager NRC Senior Resident Inspector for PVNGS NRC NRR/JLD/JPMB Project Manager