ML15286A028

Summary of Presubmittal Meeting with Arizona Public Service Company to Discuss Revised Methodology for Spent Fuel Pool Criticality Analysis and Associated Technical Specification Changes for Palo Verde, Units 1, 2, and 3 (CAC MF6600-MF6602)

ML15286A028
Person / Time
Site:	Palo Verde
Issue date:	10/23/2015
From:	Watford M Plant Licensing Branch IV
To:	Arizona Public Service Co
Watford M
References
CAC MF6600, CAC MF6601, CAC MF6602
Download: ML15286A028 (5)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 October 23, 2015 LICENSEE: Arizona Public Service Company FACILITY: Palo Verde Nuclear Generating Station, Units 1, 2, and 3

SUMMARY

OF SEPTEMBER 1, 2015, TELECONFERENCE WITH ARIZONA PUBLIC SERVICE COMPANY TO DISCUSS UPCOMING LICENSE AMENDMENT REQUEST REGARDING A REVISED METHODOLOGY FOR SPENT FUEL POOL CRITICALITY ANALYSIS FOR PALO VERDE NUCLEAR GENERATING STATION, UNITS 1, 2, AND 3 (CAC NOS. MF6600, MF6601, AND MF6602)

On September 1, 2015, the U.S. Nuclear Regulatory Commission (NRC) staff held a Category 1 public teleconference with staff from Arizona Public Service Company (APS, the licensee) at NRC Headquarters, One White Flint North, 11555 Rockville Pike, Rockville, Maryland. The purpose of the meeting was to discuss the licensee's upcoming license amendment request (LAR) to revise its spent fuel pool (SFP) criticality analysis for the Palo Verde Nuclear Generating Station, Units 1, 2, and 3 (Palo Verde). The meeting notice and agenda, dated August 18, 2015, are available in Agencywide Documents Access and Management System (ADAMS) at Accession No. ML15231A027. The enclosure to this document contains the meeting attendance list. The licensee provided slides for the public meeting, dated August 27, 2015, which are available in ADAMS at Accession No. ML15244B263. This was a follow-up teleconference to a May 11, 2015, public meeting with APS staff. The licensee's slides and meeting summary from the May 11, 2015, public meeting are available in ADAMS at Accession*

Nos. ML15134A359 and ML15140A314, respectively.

The licensee presented its plans for licensing changes associated with the updated SFP criticality analysis and the addition of neutron absorbing inserts to the SFP racks. The licensee stated that an amendment to revise its SFP criticality analysis was necessary to replace a non-conservative technical specification (TS) analysis related to its power uprates and to account for the site's future transition to Westinghouse Next Generation Fuel (NGF). The licensee focused on addressing specific topics, including follow-up items from the May 11, 2015, public meeting.

APS discussed the SFP arrays and referenced Figure 3.7.17-1, "Allowable Storage Arrays," in the proposed TS page in its slides. The proposed TS page listed Arrays A through F with a description of the allowable layout for each. For the new fuel storage, the licensee stated its plan to address the treatment of concrete and the elevated temperature in its analysis. The NRC staff questioned the long-term effects of hydrogen on the concrete, in addition to the seismic integrity of the neutron absorbing inserts in the SFP racks. The NRC also questioned the change in the hydrodynamic behavior of the SFP racks. The licensee stated the fuel assemblies and inserts have been seismically analyzed and noted that it plans to evaluate the current analysis of record to determine if the proposed inserts would affect the hydrodynamic behavior of the SFP racks.

The licensee then discussed the soluble boron requirements and neutron absorber monitoring program associated with the LAR. The licensee stated the soluble boron at 2150 parts per million will remain unchanged in TS 3.7.15, "Fuel Storage Pool Boron Concentration," in the LAR. The licensee is adding a new TS surveillance program, the neutron absorber monitoring program, which is based on industry operating experience for NETCO-SNAP-INs (a type of neutron absorbing insert). The licensee noted the existing stainless steel L-inserts are excluded from the program. The licensee then discussed the fuel reconstitution, including the highest enrichment and lowest burnup limits. Fuel reconstitution is when one or more fuel pins is removed from fuel assembly and put in another assembly. The licensee noted that most conservative enrichment and burnup limits are used to determine fuel reconstitution storage requirements.

The licensee next addressed the linkage between the NGF LAR and this LAR. Linked actions are those where the NRC approval of one licensing action is contingent upon the NRC approval of another currently under review. Generally, the NRC staff does not accept linked actions because all prerequisite actions should be completed before a licensee submits an application for review. The licensee does not consider the LARs linked since the review of the SFP criticality LAR does not require approval of the NGF LAR in order for staff to perform a review.

However, the licensee acknowledges that the SFP criticality LAR needs to be approved and implemented prior to implementation of the NGF LAR. The staff explained why linked amendments are undesirable and emphasized that the licensee should reevaluate its schedule to complete all prerequisites before submitting the NGF LAR. The NRC staff asked if this LAR included NGF in the analysis. The licensee confirmed and stated the NGF LAR will not include a new criticality analysis because NGF will be considered as part of this LAR.

The transition plan was then discussed in detail by the licensee. The licensee stated its plan to have two sets of TS 3.7.17, "Spent Fuel Assembly Storage," current and proposed TS, while completing the module-by-module transition in each unit. The licensee would apply the two sets of TS 3.7.17 during each module-by-module transition, and thus both sets of TS would apply concurrently to the transitioning unit's SFP. The licensee noted that it will always be in compliance with one set of TS 3.7.17, current or proposed, and during the transition, it plans to never enter TS 3. 7 .17 Condition A for fuel storage pool configuration requirements not met.

From a human factors standpoint, NRC staff asked how operators will know which TS page to follow. The licensee stated it plans to title each TS page to distinguish them as "prior" versus "post" transition. However, the licensee noted it is still finalizing the path forward with the two sets of TS pages. NRC staff questioned how long the licensee has to implement the amendment and complete the transition. The licensee stated it plans to implement the amendment within 90 days, or as specified by the NRC staff in the amendment, and the transition is estimated to take 24 months, as one unit is completed at a time. The licensee noted that after the transition is complete, APS will submit an administrative amendment to remove the "prior" TS page so that there will be one final TS 3. 7 .17.

• The NRC staff asked how the licensee will account for fuel assemblies at storage rack module boundaries that could create unanalyzed configurations, during the transition from the current TS to the proposed TS, which were not performed as part of old or new criticality analyses. The licensee stated that there will be sufficient neutron decoupling between storage rack modules during the transition to the storage configurations allowed by the proposed TS and a decoupling analysis will be provided as part of the LAR.

After the licensee finished its presentation, the NRC staff asked the licensee several questions about the LAR. The licensee stated its plan to use the Title 10 of the Code of Federal Regulations (10 CFR) 50.59 process to install the neutron absorbing inserts to the SFP racks.

The NRC staff then asked about how the licensee plans to prevent a multiple mislead accident, where multiple fuel assemblies are mistakenly loaded into incorrect storage locations. The licensee stated that it will credit an administrative control that does not allow fresh fuel assemblies to be positioned face adjacent, which would significantly limit the consequences of a multiple assembly mislead. The NRC staff notes that appropriate fuel handler training will also be necessary to credit this administrative control as part of the criticality analysis and should be discussed in sufficient detail in the LAR. The licensee also discussed the use of blocking devices stating that Nuclear Energy Institute (NEI) 12-16, "Guidance for Performing Criticality Analyses of Fuel Storage at Light-Water Reactor Power Plants," which is currently under review and has not yet been endorsed by the NRC staff, will be followed and that the blocking devices will not be locked in place or credited in the multiple mislead accident analysis.

The licensee plans to submit an LAR in November 2015, and requests that the NRC approve the LAR within 18 to 24 months of the submittal date. The licensee stated it projects a 90-day implementation of the amendment, including revising the TS pages, ,revising procedures, training operations staff, followed by a 24-month transition period, including actual movement of the fuel. The NRC staff asked if the licensee plans to use fuel move sheets and if there are manual checks of the each array in the SFP. The licensee stated that a move sheet must be approved in order to move fuel in the SFP and there are several manual checks before moving any fuel.

Two members of the public attended the meeting via telephone. There were no public comments. The NRC also did not receive public meeting feedback forms.

If you have any questions, please contact me at (301) 415-1233 or via e-mail at Margaret.Watford@nrc.gov.

• s;~~

Margaret M. Watford, Project Manager Plant Licensing Branch IV-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. STN 50-528, STN 50-529, and STN 50-530

Enclosure:

List of Attendees cc w/encl: Distribution via Listserv

LIST OF ATTENDEES SEPTEMBER 1, 2015, PUBLIC MEETING WITH ARIZONA PUBLIC SERVICE COMPANY REGARDING PROPOSED PALO VERDE. UNITS 1. 2. AND 3 SPENT FUEL POOL CRITICALITY ANALYSIS AMENDMENTS Maggie Watford U.S. Nuclear Regulatory Commission (NRC)

Kent Wood NRC Amrit Patel NRC Tim Lupold NRC Khadijah West NRC Samir Darbali NRC Aloysius Obodoako NRC Farhad Farzam NRC George Andrews Arizona Public Service (APS)

Bob Neville APS Tom Weber APS Carl Stephenson APS Mike Dilorenzo APS Ryne Burgess APS Edison Fernandez APS John McCulloch APS John Conly APS Andrew Blanco Westinghouse Electric Co.

Scot Leuenroth NETCO Enclosure

Meeting Notice ML15231A027; Meeting Slides ML152448263; Meeting Summary ML15286A028

• concurrence b1y ema1*1 OFFICE NRR/DORULPL4-1/PM NRR/DORULPL4-1/LA NRR/DSS/STSB/BC NRR/DSS/SRXB/BC NRR/DE/EICB/BC NAME MWatford JBurkhardt RElliott* CJackson* MWaters*

DATE 10/13/15 10/13/15 10/14/15 10/14/15 10/13/15 OFFICE NRR/DE/EMCB/BC NRR/DE/ESGB/BC NRR/DORULPL4-1/BC NRR/DORULPL4-1 /PM NAME TLupold* GKulesa* MMarkley MWatford DATE 10/14/15 10/19/15 10/23/15 10/23/15