ML20148E105

Safety Evaluation Supporting Amend 204 to License DPR-66

ML20148E105
Person / Time
Site:	Beaver Valley
Issue date:	05/28/1997
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20148E087	List: ML20148E081 ML20148E098 ML20148E105
References
NUDOCS 9706020276
Download: ML20148E105 (4)

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NUCLEAR REGULATORY COMMISSION I WASHINGTON D.C. 3066M201 4

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SAFETY EVALUATION BY lHE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 204 TO FACILITY OPERATING LICENSE NO. 1)PR-66 DUOVESNE LIGHT COMPANY OHIO EDISON COMPANY PENNSYLVANIA POWER COMPANY BEAVER VALLEY POWER STATION. UNIT NO. 1 l DOCKET NO. 50-334

1.0 INTRODUCTION

By letter dated February 27, 1997, the Duquesne Light Company (the licensee) submitted a request for changes to the Beaver Valley Power Station. Unit No. 1 Technical Specifications (TSs). The requested changes would change TS 5.3.1.2.a to increase the maximum allowable U-235 enrichment of new fuel assemblies in the new fuel storage racks to 5.0 weight percent with a l tolerance of +0.05 weight percent, and modifies TS 5.3.1.2.c to increase the maximum allowable K ,, to less than or equal to 0.98 for moderation by aqueous foam.

2.0 EVALUATION The analysis of the reactivity effects of fuel storage in the new fuel storage racks was performed by the licensee with the NITAWL-II XSDRNPM-S. and KENO-Va methodology described in the Westinghouse Spent Fuel Rack Criticality Analysis Methodology topical report. WCAP-14416-NP-A. which has been approved by the U.S. Nuclear Regulatory Commission (NRC) staff. The staff has concluded that the analysis methods used are acceptable and capable of predicting the reactivity of the Beaver Valley new fuel storage rack with a high degree of confidence.

Fresh fuel is normally stored dry in the new fuel racks. However, to meet the criterion stated in Section 9.1.1 of the NRC Standard Review Plan (SRP). K must not exceed 0.95 with the racks fully loaded with fuel of the highest ,,,

anticipated reactivity and flooded with unborated water. Furthermore. K must be no greater than 0.98 under low density (i.e., optimum moderation),,

conditions. The maximum calculated reactivity must include a margin for uncertainties in reactivity calculations and in manufacturing tolerances such that the true K confidence (95/$$)will not exceed level. these limits at a 95% probability and 95%

These uncertainties are described in Section 9.12 of the Beaver Valley Updated Final Safety Analysis Report (UFSAR).

9706020276 970528 PDR ADOCK 05000334 '

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! ' l The fuel assembly parameters used in the criticality analysis are based on the Westinghouse 17x17 Optimized Fuel Assembly (0FA) design. The reactivity of the OFA design is bounding with respect to other Westinghouse fuel types such ,

as Standard (STD). VANTAGE-5H (V5H) Vantage +. and Performance +. All fuel  !

rods were assumed to contain UO2 at a maximum enrichment of 5.05 weight percent U-235 over their entire length. No credit was taken for any natural or reduced enrichment axial blankets, fission product buildup, spacer grids or spacer sleeves, or burnable absorbers. These are conservative assumptions and are acceptable.

For the full density moderation analysis, the moderator was conservatively assumed to be ]ure water at a density of 1.0 gm/cc (68 F). The calculated K included a metlod bias determined from benchmark critical comparisons, a 95/Y$

uncertainty in the method bias, and 95/95 uncertainties arising from l consideration of mechanical and material thickness tolerances as well as asymmetric positioning of fuel assemblies. The maximum calculated K was 0.9298. Since K is less than 0.95. including uncertainties at a 9Y/95 probability /confYdencelevel,thestaff'sacceptancecriterionforprecluding criticality is met under full density water flooding conditions for storage of Westinghouse 17x17 fuel assemblies with nominal enrichments up to 5.0 weight percent U-235.  :

For the low density, optimum moderation analysis, worst case assumptions for UO material properties and storage rack dimensions were used. A method bias de[ ermined from benchmark criticals as well as approariate 95/95 uncertainties were included. The analysis shows that the maximum ( under low density )

moderation conditions of 0.9385 occurs at 0.07 gm/cc w,'a'ter density. Since l K,,, is less than 0.98, including uncertainties at a 95/95 probability / l confidence level, the staff's acceptance criterion for precluding criticality under low density, optimum moderation conditions, is met.

The following TS changes have been proposed as a result of the requested enrichment increase. The staff finds these changes as well as the proposed additional administrative changes acceptable.

1) TS 5.3.1.2.a has been revised to increase the new fuel (i.e., fresh fuel) rack U-235 enrichment limit to 5.00 weight percent. The maximum  !

enrichment limit has been modified by adding the words "with a tolerance i of 0.05 weight percent." ,

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2) TS 5.3.1.2.c has been revised to change the K,,, limit to less than or l equal to 0.98 for aqueous foam.

Based on the review described above, the staff finds the criticality aspects i of the proposed enrichment increase to the Beaver Valley Power Station. Unit l No. 1 (BVPS-1), new fuel storage racks are acceptable and meet the requirements of General Design Criterion 62 for the prevention of criticality i l in fuel storage and handling. Although the BVPS-1 TSs have been modified to '

specify the above mentioned fuel as acceptable for storage in the new fuel racks, evaluations of reload core designs using any enrichment will.

o of course, be performed on a cycle-by-cycie basis as part of the reload safety evaluation process. Each reload design is evaluated to confirm that the cycle core design adheres to the limits that exist in the accident analyses and TSs to ensure that reactor operation is acceptable.

3.0 STATE CONSULTATION

In accordance with the Commission's regulations, the Pennsylvania State official was notified of the proposed issuance of the amendment. The State official had no comments.

4.0 ENVIRONMENTAL CONSIDERATION

Pursuant to 10 CFR 51.21, 51.32, and 51.35, an environmental assessment and finding Reaister Federal of no significant on May impact have been pre 21, 1997 (62

. Accordingly, FR 27791) based upon the pared and pu environmental assessment, the staff has determined that the issuance of this amendment will not have a significant effect on the quality of the human environment.

5.0 CONCLUSION

The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonaMe assurance that the health and safety of the public will not be endangered by operation in the proposed manner. (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributor: L. Kopp Date: May 28, 1997 l

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UNITED STATES NUCLEAR REGULATORY COMMISSION DUQUESNE LIGHT COMPANY DOCKET NO. 50-334 NOTICE OF ISSUANCE OF AMENDMENT TO FACILITY OPERATING LICENSE The U.S. Nuclear Regulatory Comission (Commission) has issued Amendment j l No. 204 to Facility Operating License No. DPR-66 issued to Duquesne Light Company, et al., (the licensee) which revised the Technical Specifications for l operation of the Beaver Valley Power Station, Unit No.1, located in Shippingport, Pennsylvania. The amendment is effective as of the date of issuance, to be implemented within 60 days.

l The amendment modified Technical Specification (TS) 5.3.1.2.a to increase the maximum allowable U-235 enrichment of new fuel assemblies in the new fuel storage racks to 5.0 weight percent with a tolerance of +0.05 weight percent, and modified TS 5.3.1.2.c to increase the maximum allowable K ,, to i less than or equal to 0.98 for moderation by aqueous foam. l The application for the amendment complies with the standards and 1

requirements of the Atomic Energy Act of 1954, as amended (the Act), and the l Commission's rules and regulations. The Commission has made appropriate findings as required by the Act and the Commission's rules and regulations in 10 CFR Chapter I, which are set forth in the license amendment.

Notice of Consideration of Issuance of Amendment to Facility Operating License and Opportunity for a Hearing in connection with this action was l published in the FEDERAL REGISTER on March 25, 1997 (62 FR 14166). No request i

for a hearing or petition for leave to intervene was filed following this notice.

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The Comission has prepared an. Environmental Assessment related to the l action and has determined not to prepare an environmental impact statement.

Based upon the environmental assessment, the Comission has concluded that the issuance of the amendment will not have a significant effect on the quality of the human environment (62 FR 27791). .

1 For further details with respect to the action see (1) the application for amendment dated February 27, 1997. (2) Amendment No. 204 to License No.

DPR-66. (3) the Comission's related Safety Evaluation, and (4) the Comission's Environmental Assessment. All of these items are available for  !

public inspection at the Comission's Public Document Room the Gelman Building. 2120 L Street NW., Washington. DC, and at the local public document room located at the B.F. Jones Memorial Library. 663 Franklin Avenue, Aliquippa. PA 15001.

Dated at Rockville. Maryland. this 28th day of May 1997.

FOR THE NUCLEAR REGULATORY COMMISSION or . h/N}

Donald S. Brinkman Senior Project Manager Project Directorate I-2 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation 4

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