ML20029C185

Application for Amend to License NPF-86,changing Tech Specs to Support Increased Enrichment of Reload Fuel Assemblies, Based on Extension of Operating Cycle to 18 Months Commencing W/Cycle 3

ML20029C185
Person / Time
Site:	Seabrook
Issue date:	03/18/1991
From:	Feigenbaum T PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20029C186	List: ML20029C185 ML20029C187 ML20029C190
References
NYN-91049, NUDOCS 9103260396
Download: ML20029C185 (4)

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.. 4 New Hampshire Ted C. Folgenboom

~ Ya- President and Chief Executive Officer NYN 91049 March 18,1991 United States Nuclear Regulatory Commbslon.

Washington,- D.C. - 20555

- Attention: Document Control Desk

Reference:

Facility Operating License No NPF 86, Docket No. 50 443

Subject:

Reques1.. for License - Amendment;- lecreased ' Enrichment of Reload Fuel Assemblics .

. Gentlemen: -

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-Pursuant to 10CFR50.90, New Harnpshire Yankee (NHY) hereby. proposes to amend the Seabrook Station Operating License (Facility Operatin'g License NPF 86) by incorporating the proposed changes provided herein as' Enclosure 1, into the Seabrook_ Station Technics' Specifications.. This request for license amendment is submitted in support of NHY's plans ,

to extend the length of'its' operating ' cycle to eighteen: mouths commencing with Cycle 3.  !

' The : current- Technical - Specification requirements partaining to reload fuel assembly enrichment will not accommodate such~ an extension in the length of the operating cycle.

The proposed changes involve an increase in the maximum enrichment of reload fuel assemblies authorized by Technical Specification 5.3.1 (Fuel Assemblics) to 5.0 weight percent 3

- ! Uranium 235 from the current 3.5 weight percent Uranium 235. - Additionally the. proposed - .

- changes -involvc.T the addit.lon of two new Technical Specifications, 3/4.9.13 -(Spent Fuel-1

', Assembly Storage) and 3/4.9.141(New Fuel Assembly Storage)- and _their associated - bases.

1 Technical Specification'3/4.9.13 and 3/4.9.14 specify the Limiting Couditions For Operation  ;

and Surveillance Requirements associated with the storage of fuel'assemblics in the Spent- ,

-Feel Fool (existing fuel storage racks) and in the-New Fuel Storage Vault (existing fuel storage racks).- The. criticality analyses for the Spent Fuel Pool and New Feel Storage Vault- 4 which underlie the proposed s Limiting Conditions for Operation are - enclosed herein as Enclosure 2. New Hampshire Yankee will develop procedures to implement the new Limiting -

' Conditions for Operation and Surveillance Rsquirements for the Spent Fuel Pool and New

" Fuel Storage Vault prior to seceipt of reload fuel assemblies with' enrichments greater-than 3.5 weight percent- Uranium 235.

d 9103260396 910318 PDR ADOCK 05000443 P PDR New Hampshire Yankee Division of Public Service Company of New Hampshire ggg P.O. Box 300

• Seabrook, NH 03874

• Telephone (603) 474 9521 -A f i

a United States Nuclear Regulatory Commission March 18,1991

' Attention: Document Control Desk Page two New Hampshire Yankee has reviewed the proposed changes utilizing the criteria 1 specified in 10CFR50.92 and has determined that the proposed changes do not involve a i Significant Hazards Consideration pursuant thereto as discussed below: l

1. The proposed changes do not involve a significant increase in the probability or I consequences of an accident prefously evaluated. There is no increase in the probability of a fuel assembly drop accident in the Spent Fuel Pool since the mass of the fuel assembly does not increase when the fuel enrichment is increased There is not a significant increase in the consequences of a fuel assembly drop accident in the Spent Fuel Pool since the fission product inventories in the fuel assemblies do not change significantly due to an increase in the fuel enrichment. The existing FSAR analyses for the fuel assembly drop accident indicate that radiological consequences are -well within 10CFR100 limits. This conclusion remains valid at the increased fuel assembly enrichment. There is no increase in the probability or consequences of misplacing fuel assemblies in the Spent Fuel Pool because fuel assembly placement will be procedurally controlled and surveilled pursuant to the proposed Technical Specifications and criticality analyses demonstrate that the pool will remain suberitical assuming misplacement does occur. There is no increase in the probability or corsequences of introducing optimum moderation conditions in the New Fuel Storage Vault as a result of an increase in fuel enrichment. The New Fuel Storage Vault has been analyzed under a range of moderation conditions frorr ts.'ly flooded to optimum moderation at the increased fuel enrichment. These analyws demonstrate that the New Fuel Storage Vault remains suberitical under these rederation conditions.

2. The proposed changes do not create the podbility o' a new or different kind of accident than previously evaluated. Spent fuel naating accidents are not new or different types of accidents in that they are already analyzed in the FSAR, Criticality accidents in the New Fuel Storage Vault or Spent Fuel Pool are not new or different types of accidc6 in that they are already analyzed in the FSAR for fuel enrichments up to 3.5 weg! pi cent Uranium 235. Additional criticality analyses have been performed for inct enrichments up to 5.0 weight percent Uranium 235.

-3. The proposed changes do not involve a significant reduction in a margin of safety.

Criticality analyses have been performed which demonstrate that the New Fuel Storage Vault will remain suberitical under a range of moderation conditions from fully flooded to optimum moderation. Criticality analyses have been performed which demonstrate that the Spent Fuel Pool will be at least five percent suberitical under a fuel assembly misplacement accident with soluble boron (2000 parts per million) present in the pool and will remain subcritical with no soluble boron present.

New Ilampshire- Yankee requests approval of the Technical Specification changes proposed herein by September 1,1991, as this is the approximate time at which NHY will be specifying the reload fuel for Cycle 3.

United States Nuclear Regulatory Commission March 18,1991 Attention: Document Control Desk Page three Should you have any questions regarding this request or should you wish to have NHY representatives discuss the enclosed analyses at a meetings please contact Mr. Terry L. Harpster at (603) 474-9521, extension 2765.

Very truly yours,

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VeAd&ffE f JM-6u~-~

Ted C. Feig6nbaum Enclosures TCF:ALL/ssi cc: - Mr. Thotrss T. Martin Regional Administrator United States Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406 Mr. Gordon E. Edison, Sr. Project Manager Project Directorate I 3 Division of Reactor Projects U.S. Nuclear Regulatory Commission Washington, DC 20555 Mr. Noel Dudley NRC Senior Resident inspector P.O. Box 1149 Seabrook, NH 03874

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New ilampshire Yankee M aitch 114, It'91 ENCLOSURE 1 TO NYN 91049 l

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