ML17174A311
| ML17174A311 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities  |
| Issue date: | 12/28/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17174A309 | List: |
| References | |
| NUDOCS 8001090135 | |
| Download: ML17174A311 (3) | |
Text
6 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, 0. C. 20555 SAFETY* EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 45 TO PROVISIONAL OPERATING LICENSE NO. DPR-19 AND AMENDMENT NO. 54 TO FACILITY OPERATING LICENSE NO. DPR-29 COMMONWEALTH EDISON COMPANY Introduction DRESDEN NUCLEAR-POWER STATION, UNIT NO. 2 QUAD CITIES NUCLEAR POWER STATION, UNIT NO. l DOCKET NOS. 50-237 AND 50-254 By letter dated December 4, 1979 (Reference 1), Commonwealth Edison Company, the licensee, proposed amendments to Appendix A, Technical Specifications, to Provisional Operating License No. DPR-19 for the Dresden Nuclear Power Station, Unit No. 2 and Facility Operating License No. DPR-29 for ~he Quad Cities Nuclear Power Station, Unit No. 1.
The amendments would ex~end Maximum Average Planar Linear Heat Generation Rate (MAPLHGR) curves to larger exposure values for improved 7x7 (7D230) and 7x7 mixed oxide fuel bundles.
Evaluation The extension of the MAPLHGR curves by addenda to Reference 2 has been proposed by the licensee in Reference 1.
The analysis methods for the MAPLHGR calculations of Reference 2 have been previously accepted by our letter of February 3, 1979 (Reference 3). The only change to Reference 2 from that previously accepted is to*extend the range of exposure from 30,000 MWD/t (short ton) to 40,000 MWD/t for the 7D230 and the 7x7 mixed oxide bundles MAPLHGR curves.
In our review of this change we identified two areas which required additional information.
.One relates to the 1% plastic strain criterion of the Zircaloy.
fuel rod cladding as the safety l.imit below which fuel damage due to over-straining is not expected to occur. At extended exposures, i.e., beyond 8 0 0 1 0 9 0 J 3. s 40,000 MWD/t peak local exposure, this safety limit had not been calculated.
The licensee has agreed with us that operation beyond this exposure is restricted and would require additional analyses (Reference 4). Also, the probabilty of a high exposure bundle achieving power levels which would challenge the 1% plastic strain criterion is extremely small. This probability is based on reactor operation vs. fuel exposure characteristics and the licensee documentation of operational margin of linear power density in Reference 4.
In addition, the licensee has confirmed by Reference 4 that because APLHGR for high burnup rods are generally only 80% to 90% of MAPLHGR limits, there are no significant effects of enhanced fission gas release at extended exposures.
This confirmation is in agreement with our generic evaluation (Reference 5), thus assuring that the enhancement of fission
- gas r~lease at extended exposures was ~dequately considered.
Enhanced fission gas release at extended exposures and the exposure restriction due to the 1% plastic strain limit are subjects of ongoing generic reviews.
Although their treatment for the current application is.
acceptable, future generically related changes may be necessary.
We have~
reviewed the extension of the MAPLHGR curves to 40,000 MWD/t average planar exposure and have found it to be acceptable.
Environmental Considerations We have determined that these amendments do not authorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact.
Having made this determination, we have further concluded that these amendments involve an action which is insignificant from the standpoint of environmental impact, and pursuant to 10 CFR Section 51.5(d)(4) that an environmental impact statement, or negative declaration and environmental impact appraisal need not be prepared in connection with the issuance of these amendments.
Conclusion We have concluded, based on the considerations discussed above, that:
(1) because the amendments do not involve a significant increase in the probability or consequences of accidents previously considered and do not involve a significant decrease in a safety margin, the amendments do not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of these amendments will not be inimical to the common defense 2nd security or to the health and safety of the public.
Dated:
December 28, 1979
References:
- l. Letter from D. L. Peoples (Commonwealth Edison Co.), to the Director of Nuclear Reactor Regulation (USNRC), "Dresden Station Unit 2, Quad Cities Station Unit 1, Proposed Amendment to Appendix A, Technical Specifications, to Provisional Operating License DPR-19 and Facility Operating License No. DPR-29, NRC Docket Nos. 50-237 and 50-254, 11 December 4, 1979.
- 2.
"Loss-Of-Coolant Accident Analysis Report for Dresden Units 2, 3 and Quad Cities Units 1, 2 Nuclear Power Stations, 11 NED0-24146 A, April 1979.
- 3.
Letter from T. A. Ippolito (USNRq to C. Reed (CECo),.February 3, 1979.
- 4.
Letter from R. F. Janecek (CECo) to H. R. Denton (USNRC), December 20, 1979.
- 5.
Memorandum from P. S. Check to A. Schwencer, et. al., "Enhanced Fission Gas
- Release, 11 October 13, 1978.