ML20245H906
| ML20245H906 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 02/27/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20245H904 | List: |
| References | |
| NUDOCS 8903060080 | |
| Download: ML20245H906 (3) | |
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UNITED STATES f
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WASHINGTON, D. C. 20555 A
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.109 TO FACILITY OPERATING LICENSE NO. DPR-28 VERMONT YANKEE NUCLEAR POWER CORPORATION VERMONT YANKEE NUCLEAR POWER STATION DOCKET NO. 50-271
1.0 INTRODUCTION
By letter dated November 30, 1988, with clarification submitted December 21, 1988, and January 6, 1989, the Vermont Yankee Nuclear Power Corporation (the licensee) requested changes to the Vermont Yankee Radiological Technical Specifications (TS) as incorporated in Facility Operating License DPR-28.
These changes are:
1.
Revise Safety Limit 1.1A to specify that, for certain fuel types, a MCPR equal to or greater than 1.04 (1.05 for single loop operation) constitutes compliance with the fuel cladding integrity safety limit.
2.
Revise LC0 3.11.2 to adjust MCPR Operating Limits so that they are based on a MCPR Safety Limit of 1.04.
2.0 EVALUATION General Design Criterion 10 requires that the reactor core be designed with appropriate margin, to assure that specified acceptable fuel design limits are not exceeded during any condition of normal operation, including the effects of abnormal operational transients.
In order to avoid fuel damage caused by overheating of the cladding, transient consequences are limited such that more than 99.9% of the fuel rods would be expected to avoid boiling transition during a transient event. Because of this, the staff has required a safety limit stated in terms of a statistically determined Minimum Critical Power Patio (MCPR). The current MCPR Fuel Cladding Integrity Safety Limit of 1.07 for reload cores (Ref. 1) was established in 1978 (Ref. 2) based on fuel design characteristics typical of those utilized at the time.
By letter dated December '?7,1987 (Ref. 3), the staff accepted for referencing in license applications use of a MCPR Fuel Cladding Integrity Safety Limit of 1.04 The use of the 1.04 MCPR Fuel Cladding Integrity Sa'ety Limit for plants of the Verront Yankee type is accepted for application to the second successive reload core of P8X8R, BP8x8R, GE8x8E, or GE8x8EB fuel types with high bundle R-factor (1.04).
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Proposed Technical-Specification 1.1A; limits use of the l.04 MCPR Safety. Limit.
to applications which meet the'above criterion.
As discussed.in Reference 3: ~ "Under this criterion-the bundles nearest the MCPR operating limit during the operating cycle will be either the. fresh.
bundles or those bundles exposed.for one cycle only. The remaining exposed fuel'(i.e., the. fuel entering the third cycle of operation) could not be l
. operated near their MCPPmlimits without' driving the high bundle R-factor fuel to powers:in excess of their Technical Specification li-its."
l In the proposed Technical Specifications, for single loop operations, the MCPR l
Safety Limit is raised by 0.01 to 1.05 to account for additional instrumentation--
uncertainties 'under single-loop operating conditions, as discussed in the staff safety evaluation accompanying License Amendment No. 94 dated August 4, 1986.-
.The proposed changes:to Technical Specifications 1.1A and 3.11.2 place the same limitations on use of a 1.04 MCPR Fuel Cladding Integrity Safety Limit'as
_were_found acceptable by the staff in Reference 3.
The proposed changes are, therefore,. acceptable'.
3.0 ENVIRONMENTAL' CONSIDERATION-This amendment involves a change in the installation or use 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 published a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 551.22(c)(9). Pursuant to 10 CFR 951.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
4.0 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 Commission's regulations, and the issuance of this amendment.will not be inimical to the comon defense and security or to the. health and safety of the public.
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.5.0 RE'FERENCES f
1.
" General Electric Standard Application for Reactor Fuel,"
NEDE-24011-P-A-6, April 1983.
2.
" Basis for 8x8 Retrofit Fuel Thermal Analysis Application," NEDE-24131, September 1978.
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'3.
l.etter.(and~ attachment) from A. C. Thadani, NRC, to J. S. Charnley, GE, dated-December 27, 1987, " Acceptance for Referencing of Amendment 14 to General Electric 1.icensing Topical. Report NEDE-24011-P-A, " General Electric Standard Application for Reactor Fuel,. (TAC No.' 60113)."
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Princ.ipal Contributor:
V. Rooney Dated : February 27,.1989 h
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