ML19352A148

Application for Amend of Licenses NPF-4 & NPF-7,submitted as Proposed Tech Spec Changes Increasing Fuel Enrichment Limits to 4.1 Weight Percent of U-235.Approval Requested by 810501

ML19352A148
Person / Time
Site:	North Anna
Issue date:	03/06/1981
From:	Ferguson J Virginia Power (Virginia Electric & Power Co)
To:	Harold Denton, Clark R Office of Nuclear Reactor Regulation
Shared Package
ML19352A149	List: ML19352A148 ML19352A150 ML19352A151 ML19352A152
References
109, NUDOCS 8103110529
Download: ML19352A148 (4)

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Mr. Harold R. Denton, Director Serial No. 109 Office of Nuclear Reactor Regulation N0/WRM/CBF:ms Attn: Mr. Robert A. Clark, Chief Docket Nos. 50-338 Operating Reactors Branch No. 3 50-339 Division of Licensing License Nos. NPF-4 U. S. Nuclear Regulatory Commission NPF-7 Washington, D. C. 20555 Gentlemen:

AMENDMENT TO OPERATING LICENSES NPF-4 AND NPF-7 NORTH ANNA STATION UNITS NO. 1 AND NO. 2 PROPOSED TECHNICAL SPECIFICATION CHANGE Pursuant to 10 CFR 50.90, the Virginia Electric and Power Company requests an amendment, in the form of changes to the Technical Specifications, to Operat-ing Licenses NPF-4 and NPF-7 for the North Anna Power Station, Units No. I and No. 2. The proposed changes are enclosed.

\epco is presently participating in a Department of Energy demonstration and evaluation program concerned with high burnup technology. The implementation-of high burnup technology would involve the use of higher enrichment fuel than what. z.. . presently utilized at North Anna. There is currently a. technical srv.cifica." ton limit on the core enrichment of 3.5 weight percent U-235 (Design feature 5.3 Reactor Core, paragraph 5.3.1). However, we plan to order fuel in May, 1981 with a 3.6 w/o enrichment and this fuel is scheduled to have a discharge burnup of_approximately 36,000 MWD /MTU when discharged in 1985. The continued utilization of higher enrichment fuel could eventually allow increased discharge fuel burnups of up to 45,000 MWD /MTU, subject to demon-stration of ' adequate fuel performance. In anticipation that adequate fuel performance will be demonstrated, the poposed changes will increase the present. enrichment limits to 4.1 weight percent of U-235.

Implementation of high burnup technology would result in the ~ generation of fewer spent fuel assemblies and in the long run could decrease fuel cycle costs by as much as fiftean (15) percent. The table provided in Attachment 2 gives Linformation on the uranium fuel requirements for a range of discharge burnups on both an annual basis and . a lifetime basis for one unit at North Anna.

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Viuuista Es.rcrasc AW lbw ru CoM paw to The proposed Technical Specification change would increase the present enrich-ment limit to 4.1 weight percent of U-235. In support of this change, additional criticality analyses have been perform-d c1 both the new and spent fuel racks for the proposed enrichment. The analysis of the new fuel storage racks was performed by Nuclear Energy Services, Inc. (NES). The analysis was performed on the Surry new fuel racks but, as the same spacing and design war.

utilized at North Anna, the Surry analysis is applicable even though the Surrr Analysis was performed with 15x15 fuel rather than 17x17 fuel. Sensitivity studies by NES show that the use of 17x17 versus 15x15 fuel will only cause a 0.7% Ak/k increase in the calculated Keff and results in a Keff which is still much less than 0.9t.. The analysis of the spent fuel racks was performed by NUS Corporation, t!.e designer of racks. These studies show that the Keff in all cases will be less than 0.98 (actual Keff worst case 0.909) for the new fuel storage area and less than 0.95 (actual Keff worst case .9496) for the spent fuel racks. These analyses were done using the same acceptance criteria as was used in the original analyses and include conservatisms to account for calculational uncertainties. These analyses are provided as Attachment 3 and 4.

The use of higher burnup fuel in the reactor core can also potentially impact the results of the safety analysis of the plant and fuel performance. A general evaluation of the impact of extending fuel burnup to 45,000 MWD /FITU is presented in Attachment 5. This evaluation, which has been reviewed by Westinghouse, has determined that the fuel performance will retain its current high level of reliability and the safety analyses are not significantly impacted at increased fuel burnup levels. In addition, the Westinghouse reload safety evaluation methodology will continue to serve as the mechanism employed to insure continued plant safety at increased fuel burnup levels and to incorporate into the safety analyses any identified fuel performance changes as required.

This proposed change has been reviewed and approved by the Station Nuclear Safety and Operating Committee and the System Nuclear Safety and Operating Committee. It has been determined that this request does not involve an unreviewed safety question.

We have evaluated this request in accordance with the criteria in 10 CFR 170.22. It has been determined that this request involves a safety issue which the Staff should be able to determin.: does not pose a significant hazards consideration; therefore, a Class III license amendment fee is required for Unit I and a Class I license amendment fee is required for Unit 2. Accordingly, a voucher check in. the amount of $4,400.00 is enclosed as payment of the required fees.

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Vauoista EtzCTRIC AMD POWER COMPANY 70 i

In order to achieve a discharge fuel burnup of 36,000 MWD /MTU, fuel of i approximately 3.6 weight percent enrichment must be procured. We request that the enclosed proposed changes be reviewed and approved prior to May 1,1981 in ordes to allow sufficient time for procurement of this higher enrichment fuel. '

i Very truly yours, f/ ys-J. H. Ferguson Executive Vice President Power Attachcents:

1. Proposed Technical Specification Change

2. North Anna Fuel Requirements

3. Nuclear Design Analysis Report for the New Fuel Storage Racks

4. Criticality Analysis of the Spent Fuel Storage Racks

5. Safety Evaluation of Reactor Operation to Extended Fuel Burnups

6. Voucher Check No. 9112 for 4,400.00

'cc: Mr. James P. O'Reilly, Director Office of Inspection and Enforcement ,

Region II J

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COMMONWEALTH OF VIRGINIA )

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CITY OF PICHMOND )

Before me,- a Notary Public, in and for the City and Common-wealth aforesaid, today personally appeared J. H. Ferguson, who being duly sworn, made oath and said (1) that he is Executive Vice President-Power, of the Virginia Electric and Power Company, (2) that he is duly g authorized to execute and file the foregoing Amendment in behalf of that Company, and (3) that the statements in the Amendment are true to the best of his knowledge and belief.

Given under my hand and notarial seal this bw day of b Ch ,jati Hy Commission expires Qrt.tu ( a A a l1 198 3 .

f G fjulwe" 0 C)( M n Notary Wublic MS C n u N s.L d nec h (b y LLLC.b yr hL (SEAL)

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