ML20206G551
| ML20206G551 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 04/02/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20206G542 | List: |
| References | |
| NUDOCS 8704150042 | |
| Download: ML20206G551 (3) | |
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NUCLEAR REGULATORY COMMISSION o
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.....,o SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 62 TO FACILITY OPERATING LICENSE NO. NPF-12 SOUTH CAROLINA ELECTRIC A GAS COMPANY SOUTH CAROLINA PUBLIC SERVICE AUTHORITY VIRGIL C. SUMMER 'NUCLFAR STATION, UNIT NO. 1
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DOCKET NO. 50-395 INTRODUCTION By letter dated December 9, 1986, South Carolina Electric and Gas Company (the licensee) requested a change to Facility Operating License No. NPF-12 for the Virgil C. Summer Station. The proposed change is to Technical Specification 5.3.1, " Fuel Assemblies." The proposed revision would allow the licensee the flexibility to reconstitute fuel assemblies in order to reduce coolant activity and utilize the remaining energy in fuel assemblies which contain small numbers of defective fuel rods. Supplemental and background information was provided by letter dated March 2,1987, which did not change the initial amendment request; therefore, this amendment was not renoticed.
1 EVALUATION The intent of the proposed change to the Sunner Technical Specifications is to allow for the reduction in the number of fuel rods per assembly in cases where I
leaking fuel rods can be identified and replaced with Zircaloy-4 or stainless i
steel rods or vacancies. Replacement of leaking fuel rods will permit utili-zation of the remaining energy in fuel assemblies containing defective fuel rods.
In general, substitution of a limited number of fuel rods with filler rods or water holes has a negligible effect on core physics parameters and consequently on the safety analysis. The wording of the change specifically provides that the substitutions may be made if justified by a cycle specific reload analysis.
The licensee states that in each reload core the reconstituted assemblies will be evaluated using standard methods described in the approved Westinghouse Reload Methodology Topical Report, WCAP-927?. The reload analysis will ensure that the safety criteria and design limits, including peaking factors and core average linear heat rate effects, are not exceeded. Thus, the final safety evaluation of implementation of substitutions allowed by this change will be made as part of the reload analysis performed for the affected cycle.
8704150042 870402 PDR ADOCK 05000395 P
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The radiolooical risk due to fuel reconstitution will be no greater than that resulting from the " worst case" single fuel assembly handling accident analyzed in the Virgil C. Sunner Final Safety Analysis Report (FSAR). The FSAR fuel handling accident postulates a worst-case radiological release due to the dropping of a fuel assembly, which results in the rupture of all assembly fuel rods and their subsequent fission product release. This FSAR accident is a bounding analysis for fuel reconstitutions since only one fuel assembly at a time may be moved and reconstituted.
The process of irradiated fuel rod movement from fuel assemblies has been extensively utilized by Westinghouse in cooperation with various utilities.
These movements have been part of engineering product evaluation programs and have utilized fuel assemblies having removable rods whereby access is provided to the rods without nozzle removal.
Also, a fuel modification campaign was recently completed by Westinghouse for a domestic utility.
In this case, three fuel assemblies were reassembled (full transfer of all rods to a new skeleton) and two reconstituted (substitution of several stainless rods for detected failed rodsl. This effort was implemented by bottom nozzle removal.
The licensee has experienced a limited amount of fuel rod movement similar to that involved with reconstitution with the Vantage 5 demonstration assemblies currently in the reactor core. On previous occasions, a small number of pins have been removed and then replaced in those assemblies. Also, the NRC staff notes that the last NRC Systematic Assessment of Licensee Performance conducted in 1986 for the V.C. Summer facility had ratings of Category I for the functional area of " Radiological Controls," Category 2 for the functional area of " Refueling / Outages," and Category 2 for the functional area of " Quality Programs and Administrative Controls Affecting Ouality."
Based on the above evaluation, the NRC staff fir.ds that there is industry experience with individual fuel rod movement, that fuel assembly reconstitution is bounded by FSAR accident analysis, and that reconstituted assemblies will have cycle specific evaluations perfonned using an approved model. Therefore, the proposed change is acceptable.
ENVIRONMENTAL CONSIDERATION This amendment involves a change in the installation of a facility component located within the restricted area as defined in 10 CFR Part 20. The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public connent on such findino. Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR Section 51.22fc)(9). Pursuant to 10 CFR 51.22(b) no environ-mental impact statement or environmental assessment need be prepared in I
connection with the issuance of this amendment.
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CONCLUSION We have concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Comission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Dated: April 2, 1987 Principal Contributors:
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J. Hopkins, Project Directorate #?, DPLA K. El-Adham, Reactor Systems Branch, DPLA i
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