ML20072S868
| ML20072S868 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 09/02/1994 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20072S860 | List: |
| References | |
| NUDOCS 9409140271 | |
| Download: ML20072S868 (3) | |
Text
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S UNITED STATES i
j NUCLEAR REGULATORY COMMISSION
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waswiworow, o.c. rosss-oooi SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS. 65 AND 54 TO FACILITY OPERATING LICENSE N05. NPF-76 AND NPF-80 HOUSTON LIGHTING & POWER COMPANY l
CITY PUBLIC SERVICE BOARD OF SAN ANTONIO CENTRAL POWER AND LIGHT COMPANY CITY OF AUSTIN. TEXAS DOCKET NOS. 50-498 AND 50-499 SOUTH TEXAS PROJECT. UNITS 1 AND 2
1.0 INTRODUCTION
By application dated April 14, 1994, Houston Lighting & Power Company, et.al.
(the licensee), requested changes to the Technical Specifications (TSs)
(Appendix A to Facility Operating License Nos. NPF-76 and NPF-80) for the South Texas Project, Units 1 and 2 (STP).
The proposed changes to TS 5.3.1 would permit fuel assembly reconstitution to restore the usefulness of fuel assemblies containing damaged or leaking fuel rods. These changes are j
consistent with the guidance in NRC Generic Letter (GL) 90-02, Supplement 1,
" Alternative Requirements for Fuel Assemblies in the Design Features Section of Technical Specifications."
2.0 DISCUSSION The proposed changes will allow fuel assembly reconstitution with zircaloy or stainless steel filler rods, in accordance with NRC-approved methodologies.
Supplement I to GL 90-02 defines the acceptability of the use of reconstituted fuel assemblies, including inert filler rods.
The GL also provides model TS wording. The reconstitutions may be performed under provisions of 10 CFR 50.59 provided that the required safety analyses are performed with NRC staff-approved methodologies, which are applied to assembly configurations that lie within the scope of the reviewed fuel lattice configurations.
The proposed revision also allows the use of a limited number of lead test assemblies without requiring a specific TS change, provided they are placed in nonlimiting core regions.
9409140271 940902 1
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i-i 3.0 EVALUATION i
The proposed amendment would modify TS 5.3.1, " Fuel Assemblies," to allow limited substitutions of zirconium alloy or stainless steel filler rods for
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fuel rods, in accordance with NRC-approved applications of fuel rod 1
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configurations." The licensee states that cycle-specific reload safety evaluation analyses will be performed in accordance with NRC-approved topical j
report WCAP-13060-P-A, " Westinghouse Fuel Assembly Reconstitution Evaluation Methodology," and other applicable NRC-approved methodologies.
WCAP-13060-P-A describes the methodology for using inert filler rods to replace failed or damaged fuel rods during reconstitution of fuel assemblies for core reloads.
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The WCAP-13060-P-A methodology is applicable for Westinghouse reconstituted i
assemblies with mixing vane grid designs. The approval of WCAP-13060-P-A, and this evaluation, is contingent upon analytical confirmation that the exact configuration and associated core power distribution of proposed reconstituted i
assemblies do not introduce a change in radial gradients in the flow and enthalpy distribution that could invalidate the applicability of the critical j
heat flux (CHF) correlation used for departure from nucleate boiling (DNB) j predictions. These limitations are consistent with the guidance from Supplement I to GL 90-02, ensure compliance with General Design Criteria (GDC) j 10, and are acceptable.
i In the application, the licensee states that it will meet the above requirement by performing a cycle-by-cycle evaluation of correlation parameters of the departure from nucleate boiling ratio (DNBR) correlation for the reconstituted assembly. The limited substitution of filler rods in i
accordance with NRC-approved methodology will ensure that relevant thermal-hydraulic and design issues are considered to establish values for core parameters and placement of rods. Also, the staff notes that the proposed TS 2
5.3.1 wording is consistent with the model TS provided in the GL.
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Based on the evaluation described above, the staff finds that the proposed i
changes to the South Texas Project TSs to allow fuel assembly reconstitution with zircaloy or stainless steel filler rods in accordance with NRC-approved methodologies, are consistent with the requirements described in Supplement 1 to GL 90-02 and are acceptable.
4.0 STATE CONSULTATION
l In accordance with the Commission's regulations, the Texas State official was notified of the proposed issuance of the amendments. The State official had no comments.
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5.0 ENVIRONMENTAL CONSIDERATION
2 The amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendments involve no j
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 l
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, I significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (59 FR 29628). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance l
of the amendments.
6.0 CONCLUSION
l The Commission has 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, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common l
defense and security or to the health and safety of the public.
Principal Contributor:
A. Bryant l
l Date:
September 2, 1994 t
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