ML14231A017

Vermont Yankee Nuclear Power Station - Technical Specifications Proposed Change No. 309, Defueled Technical Specifications and Revised License Conditions for Permanently Defueled Condition - Supplement 4 (TAC No. MF3714)

ML14231A017
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	08/13/2014
From:	Wamser C J Entergy Nuclear Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TAC MF3714
Download: ML14231A017 (7)

Text

SpEntergyEntergy Nuclear Operations, Inc.Vermont Yankee320 Governor Hunt RdVernon, VT 05354Tel 802 257 7711Christopher J. WamserSite Vice PresidentBVY 14-061August 13, 2014ATTN: Document Control DeskU.S. Nuclear Regulatory CommissionWashington, DC 20555SUBJECT: Technical Specifications Proposed Change No. 309, Defueled TechnicalSpecifications and Revised License Conditions for Permanently Defueled Condition-Supplement 4 (TAC No. MF3714)Vermont Yankee Nuclear Power StationDocket No. 50-271License No. DPR-28REFERENCES: 1. Letter, Entergy Nuclear Operations, Inc. to NRC, "TechnicalSpecifications Proposed Change No. 309, Defueled TechnicalSpecifications and Revised License Conditions for PermanentlyDefueled Condition," BVY 14-010, dated March 28, 2014(ML14091A291) (TAC No. MF3714)2. Email, NRC to Entergy Nuclear Operations, Inc. "RAI -DefueledTechnical Specification Amendment (TAC No. MF3714)," dated July29, 2014 (ML14210A161)Dear Sir or Madam:By letter dated March 28, 2014 (Reference 1), Entergy Nuclear Operations, Inc. (ENO) proposedan amendment to Renewed Facility Operating License (OL) DPR-28 for Vermont Yankee NuclearPower Station (VY). The proposed amendment would revise the VY OL and TechnicalSpecifications (TS) to be consistent with the expected permanently shutdown and defueledcondition of VY.In Reference 2, the NRC provided ENO with a request for additional information (RAI). Attachment1 of this letter contains the response to the RAI.The conclusions of the no significant hazards consideration and the environmental considerationscontained in Reference 1 are not affected by, and remain applicable to, this supplement.There are no new regulatory commitments made in this letter.If you have any questions on this transmittal, please contact Mr. Philip Couture at 802-451-3193.

BVY 14-061/ page 2 of 2I declare under penalty of perjury that the foregoing is true and correct.Executed on August 13, 2014.Sincerely,CJW/plcAttachment: 1. Response to Request for Additional Informationcc: Mr. William M. DeanRegion 1 AdministratorU.S. Nuclear Regulatory Commission2100 Renaissance Blvd, Suite 100King of Prussia, PA 19406-2713Mr. James S. Kim, Project ManagerDivision of Operating Reactor LicensingOffice of Nuclear Reactor RegulationU.S. Nuclear Regulatory CommissionMail Stop 08C2AWashington, DC 20555USNRC Resident InspectorVermont Yankee Nuclear Power Station320 Governor Hunt RoadVernon, VT 05354Mr. Christopher Recchia, CommissionerVT Department of Public Service112 State Street, Drawer 20Montpelier, VT 05620-2601 BVY 14-061Docket 50-271Attachment 1Vermont Yankee Nuclear Power StationProposed Change 309 -Supplement 4Response to Request for Additional Information BVY 14-061 / Attachment 1 / Page 1 of 4REQUEST FOR ADDITIONAL INFORMATIONBY CONTAINMENT AND VENTILATION BRANCHVERMONT YANKEE NUCLEAR POWER STATION.TECHNICAL SPECIFICATION CHANGES AND REVISED LICENSE CONDITION FORPERMANENTLY DEFUELED CONDITIONDOCKET NO. 50-271In a letter dated March 28, 2014 (Reference 1), pursuant to Section 50.90 of Title 10 of theCode of Federal Regulations (CFR), Entergy Nuclear Operations, Inc. (ENO) submitted alicense amendment request to Renewed Facility Operating License (OL) DPR-28 forVermont Yankee Nuclear Power Station (VY). The submitted amendment revises the OL andrevises the associated Technical Specifications (TS) to Permanently Defueled TechnicalSpecifications (PDTS). ENO is requested to provide response to the following RAIs for NRCstaff to complete its review:SCVB-RAI-1The staff understands that in the defueled state, the fuel pool cooling will be performed bythe non-safety related fuel pool cooling system and also should to be backed up by asafety-related system in case the non-safety pool cooling is lost due to an event, such as aseismic event, or loss of offsite power. In case there is no safety-related pool cooling backup system and given the secondary containment and the standby gas treatment systemhave been removed from TS, please respond to the following questions:(a) Would the fuel pool be allowed to boil with offsite steam release?(b) What system will provide the makeup water to the spent fuel pool to maintain itslevel?(c) What will be the off site dose from the steam release, and verify that it is within the 10CFR 100 allowed limit.Response(a) Once VY is permanently defueled, the plan is to transition to a electrical distribution schemewhere the normal and backup power supplies for fuel pool cooling will be provided asfollows:" Normal power will be provided from the 115 kV switchyard through thestartup transformers" Backup power will be provided from the Vernon Hydroelectric Station (VHS)tie line and will also be available from the Station Blackout Diesel Generator(SBO DG)The 115 kV switchyard is currently credited as the immediate access offsite power sourcein the Bases for TS 3.1O.A.4. The normal supply to the 115 kV switchyard bus is from thetwo paralleled, but independent, 345 kV/1 15 kV autotransformers described above. In theunlikely event that both autotransformers are out of service, an alternate immediate accesssource through the Chestnut Hill/Vernon Road line, Vernon 115 kV yard and K-40 Tie Linemay be made available.

BVY 14-061 / Attachment 1 / Page 2 of 4The VHS tie line is a reliable source of offsite power that was formerly credited as analternate ac source for compliance with 10 CFR 50.63, "Loss of all Alternating CurrentPower," and is currently used to meet certain 10 CFR 50 Appendix R requirements.The SBO DG is considered a reliable power source. Reliability was initially demonstrated byan initial test program preventative maintenance and testing is performed per plantprocedures to verify reliability, and it receives augmented quality treatment. Although notrequired to meet any regulatory requirements in the permanently defueled condition, theSBO DG was designed to meet the requirements of 10 CFR 50.63.Based on a full core offload with an initial spent fuel pool temperature of 1 10°F and nocredit for cooling or makeup water, the spent fuel pool time to boil (TTB) will beapproximately 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br /> following 10 days after shutdown and increases to approximately25 hours following 50 days after shutdown. VY currently maintains the ability to start andalign the SBO DG to breaker 3V4 within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, providing a reliable power supply for fuelpool cooling. The SBO DG can be started in the control room or manually started locally.Maintaining the ability to start and align the SBO DG within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> provides adequateassurance that backup power can be provided to restore fuel pool cooling well before theTTB is reached in the event of a loss of offsite power. Additional details on the SBO DG canbe found in Reference 2.Were a loss of all power to occur and spent fuel pool cooling could not be restored in atimely manner, VY maintains procedures and strategies for the movement of any necessaryportable equipment that will be relied upon for mitigating the loss of spent fuel pool water.These diverse strategies implement the requirements of License Condition 3.N, "MitigationStrategy License Condition," and provide defense-in-depth capability to provide makeupwater or spray to the spent fuel pool prior to the onset of fuel pool boiling.Based on the above, the VY spent fuel pool will not be allowed to boil(b) Procedure ON-3157, Loss of Fuel Pool Level/Cooling, and Appendix G of PP 7019, SevereAccident Guidelines, establishes multiple makeup sources to the spent fuel pool from onsiteand offsite. Following permanent defueling these sources will include:* Fire Water system* Service Water system* Cooling Tower #2 deep basin via an engine driven emergency makeup pump(c) Based on the response to parts (a) and (b), the spent fuel pool will not be allowed to boiland no offsite release is postulated to occur due to a steam release from the VY spent fuelpool while irradiated fuel is stored in the pool.SCVB-RAI-2Please confirm that spent fuel kce will not increase while the entire fuel is in the spent fuelpool. In case it increases, please discuss the effects of its increase on the decay heatgenerated in the pool, the pool temperature, and the offsite dose.ResponseTS 5.5.B requires that the kef Of the fuel in the spent fuel pool be less than or equal to 0.95. ENOconfirms that spent fuel ke, will remain below 0.95 with all fuel in the spent fuel pool. The basis forthis is provided in Reference 3, which documented NRC approval of expansion of the spent fuelpool storage capacity to the current level of 3,353 fuel assemblies. The criticality analyses BVY 14-061 / Attachment 1 / Page 3 of 4performed to support the capacity expansion included several assumptions which tended tomaximize the reactivity of the spent fuel storage racks. These include:1) Racks contain most reactive fuel authorized to be stored without any control rods or anyuncontained burnable poison, and with the fuel at the burnup corresponding to thehighest reactivity during its burnup history.2) Unborated pool water at the temperature yielding the highest reactivity (4 0C) over theexpected range of water temperatures.3) Assumption of infinite array (no neutron leakage) of storage cells except for certainaccident assessments.4) Neutron absorption in minor structural material was neglected (i.e., spacer grids areanalytically replaced by water).5) The narrowest panel width of the three existing Boral panels was used.6) The B-10 density in the Boral panels was assumed to be the minimum value in allpanels.7) Uniform average U-235 enrichments were used for all fuel rods in a fuel assemblyinstead of distributed enrichments.The maximum reactivity calculated for a 10x10 fuel assembly in the Holtec racks that were installed aspart of the expansion was 0.9280 and 0.9469 for the existing racks when combined with all knownuncertainties. This met the NRC staff's criterion of ke, no greater than 0.95 including all uncertainties atthe 95/95 probability/confidence level.As identified above, the analysis associated with the increase of the VY spent fuel pool capacity wasbased on a maximum pool storage capacity of 3,353 fuel assemblies. Once the VY core is fullydefueled with all fuel assemblies placed in the pool, there will be a total of 2,995 spent fuel assembliesin the pool, providing additional assurance that the maximum calculated reactivity will not be exceeded.Aging Management ProgramAs described in Section 15.2.40 of the VY Updated Final Safety Analysis Report, an aging managementprogram is in place to manage loss of material and reduction of neutron absorption capacity of Boralneutron absorption panels in the spent fuel racks. The loss of material and the reduction of the neutron-absorbing capacity will be determined through coupon testing, direct in situ testing or both. Such testingwill include periodic verification of boron loss through areal density measurement of coupons or throughdirect in situ techniques, such as measurement of boron areal density, measurement of geometricchanges in the material (blistering, pitting and bulging), and detection of gaps through blacknesstesting.As part of License Renewal Commitment 52, VY plans to perform neutron attenuation testing using anin-situ method prior to the end of 2014.Decay Heat and Offsite DoseAny increase in pool temperature as result of the decay heat associated with a full core offload isalready contemplated in the Bases for TS 3/4.12.H:The Spent Fuel Pool Cooling System is designed to maintain the pool water temperature below1250F during normal refueling operations. If the reactor core is completely discharged, thetemperature of the pool water may increase to greater than 125°F The RHR Systemsupplemental fuel pool cooling may be used under these conditions to maintain the pool watertemperature less than 1500F.Since the spent fuel temperature limitations are not expected to be exceeded following the full coreoff load, a corresponding increase in offsite dose is not expected to occur.

BVY 14-061 / Attachment 1 / Page 4 of 4REFERENCES'1. Letter, Entergy Nuclear Operations, Inc. to NRC, "Technical Specifications ProposedChange No. 309 Defueled Technical Specifications and Revised License Conditions forPermanently Defueled Condition Vermont Yankee Nuclear Power Station Docket No. 50-271", BVY 14-010, dated March 28, 2014 (ML14091A291) (TAC No. MF3714)2. Letter, NRC to Entergy Nuclear Operations, Inc., 'Vermont Yankee Nuclear Power Station -Issuance of Amendment to Renewed Facility Operating License RE: Change to LicensingBasis Regarding Station Blackout (TAC No. MF0422)," NVY 13-090, dated August 15, 2013(ML13212A201)3. Letter, NRC to Vermont Yankee Nuclear Power Corporation, "Vermont Yankee NuclearPower Station -Issuance of Amendment RE: Spent Fuel Pool Storage Capacity Expansion(TAC No. MA3490)," NVY 99-124, dated December 21, 1999