ML20072A109
| ML20072A109 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 08/09/1994 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20072A108 | List: |
| References | |
| NUDOCS 9408120135 | |
| Download: ML20072A109 (4) | |
Text
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UNITED STATES y"
j j-NUCLEAR REGULATORY COMMISSION 2
WASHINGTON. D.C. 20655-0001
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SAFETY EVALVATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT N05.186 AND 167 TO FACILITY OPERATING LICENSE NOS. NPF-4 AND NPF-7 yJRGINIA ELECTRIC AND POWER COMPANY OLD DOMINION ELECTRIC COOPERATIVE NORTH ANNA POWER STATION. UNITS NO. I AND NO. 2 DOCKET NOS. 50-338 AND 50-339 1.0 JNTRODUCTION By letter dated November 19,1993 (Ref.1), the Virginia Electric and Power Company (the licensee) proposed changes to the Technical Specifications (TS) for the North Anna Power Station, Units No I and No. 2 (NA-1&2). The proposed changes would allow the use of a limited number of solid rods of zirconium alloy or stainless steel as inert filler rods to replace fuel rods which have been identified as failed or damaged.
Such reconstitution will i
permit a damaged fuel assembly to be reused in another operating cycle without requiring the selection of a replacement fuel assembly and a reload core design change during a refueling outage.
2.0 DISCUSSION The licensee's safety evaluation (SE) for the substitution of inert filler rods for failed or damaged fuel rods addresses the mechanical, neutronic and thermal-hydraulic analyses and approved methodology used to demonstrate that all applicable design criteria and pertinent licensing basis acceptance criteria are satisfied.
The proposed changes to TS 5.3.1
" Fuel Assemblies" will also delete the individual fuel rod uranium weight limit to allow for Westinghouse fuel pellet design improvements which slightly increase the fuel stack weight.
Supplement 1 of Generic Letter (GL) 90-02, " Alternative Requirements for Fuel Assemblies in the Design Features Section of Technical Specifications," dated July 31, 1992 (Ref. 2), recognizes the acceptability of the use of reconstituted fuel assemblies including inert filler rods. GL 90-02, Supplement 1, also provides model TS wording which has been incorporated into the new Standard Technical Specifications (STS) Section 4.2.1.
These reconstitutions may be performed under the 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.
9408120135 940809 DR ADOCK 05000338 p
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2 3.0 EVALUATION The proposed amendment would modi'y TS Section 5 - Desian Features, 5.3 Reacter Core, 5.3.1, " Fuel Asslolies," to allow " limited substitutions of zirconium alloy or stainless steel filler rods for fuel rods, in accordance with approved applications of fuel rod configurations." The licensee intends to use a limited number of inert filler rods to replace failed or damaged fuel rods for reconstituting Westinghouse LOPAR or VANTAGE-5H fuel assemblies.
The licensee states that cycle-specific reload safety evaluation (RSE) analyses will be performed in accordance with the approved topical report WCAP-13060-P-A, " Westinghouse Fuel Assembly Reconstitution Evaluation Methodology," (Ref.
- 3) and other applicable approved Westinghouse and licensee methodologies.
l 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. This methodology is applicable for Westinghouse reconstituted assemblies with mixing vane grid designs.
The RSE analyses are performed according to the approved licensee's methodologies (Ref. 4) described in TS Section 6, and also conform to the Westinghouse fuel reconstitution topical report WCAP-13060-P-A methodology which was recently approved (Ref. 5).
The SE approval is contingent upon analytical confirmation that the exact configuration and associated core power distribution of the proposed reconstituted assemblies does not introduce a change in radial gradients in the flow and enthalpy distribution that could invalidate the applicability of the CHF correlation used for DNB predictions.
These limitations are consistent with the guidance from Supplement 1 of GL 90-02 and ensure compliance with General Design Criteria (GDC) 10 and are therefore acceptable. The specific TS 5.3.1 wording is also consistent with the model TS from the GL and from the new STS and will ensure that full l
reconstitution will be supported by an analysis of the nuclear, thermal-l hydraulic and mechanical design and the overall effect on the core. Therefore l
the proposed change is acceptable.
The licensee also furnished a summary of its Surry reconstitution history.
I Based on the guidance furnished in Supplement 1 to GL 90-02, the licensee's l
RSE approach is consistent with the staff requirements, and is therefore l
acceptable for NAPS Units 1 and 2.
l Therefore, based on all of the above, the staff finds the revised RSE process j
to be used by the licensee for fuel reconstitution to be acceptable.
4.0 STATE CONSVLTATION In accordance with the Commission's regulations, the Virginia State official was notified of the proposed issuance of the amendment.
The State official had no comment.
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5.0 ENVIRONMENTAL CONSIDERATION
These 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 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 these amendments involve no significant hazards consideration and there has been no public comment on such finding (58 FR 67863). Accordingly, these amendments meet 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 of the amendments.
6.0 CONCLUSION
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 defense and security or to the health and safety of the public.
Principal Contributor:
E. Kendrick Date: August 9, 1994
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4 REFERENCES 1.
Letter from W. L. Stewart (VEPCO) to Document Control Desk (U.S. NRC),
" North Anna Power Station Units 1 and 2 Proposed Technical Specifications Changes - Reconstituted Fuel Assemblies," Serial No.93-706, November 19, 1993.
2.
Supplement I to Generic Letter 90-02, " Alternative Requirements for Fuel 1
Assemblies in the Design Features Section of Technical Specifications,"
dated July 31, 1992.
j 3.
WCAP-13060-P-A, " Westinghouse Fuel Assembly Reconstitution Evaluation Methodolcgy," Westinghouse Electric Corporation, Commercial Nuclear Fuel Division, July 1993.
4.
VEP-FRD-42, Rev.1-A, " Reload Nuclear Design Methodology," Virginia i
Electric and Power Company Topical Report, September 1986.
1 5.
Letter from A. C. Thadani (NRC) to S. R. Tritch ()f), " Acceptance for Referencing of Topical Report WCAP-13060-P, ' Westinghouse Fuel Assembly Reconstitution Evaluation Methodology, (TAC No. M82139)," March 30,1993.
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