ML19345C659
| ML19345C659 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities  |
| Issue date: | 11/12/1980 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19345C657 | List: |
| References | |
| NUDOCS 8012080102 | |
| Download: ML19345C659 (4) | |
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMEN 0 MENT NO. 50 TO PROVISIONAL OPERATING LICENSE NO. DPR-19, AMENUMENT N0. 59 -TO FACILITY OPERATING LICENSE N0. DPR-29, AND AMENDMENT NO. 54 TO FACILITY OPERATING LICE _NSE NO. DPR-30 COMMONWEALTH EDIS0N COMPANY AND IOWA-ILLIN0IS GAS AND ELECTRIC COMPANY DRESDEN STATION UNIT NO. 2 QUAD CITIES STATION UNIT NO. 1 QUAD CITIES STATION UNIT NO. 2 DOCKET N05. 50-237, 50-254, 50-265 Introduction 3
Bf letter dated March 19,1980 (Ref.1), Conmonwealth Edison Company (CECO, the licensee) proposed amendments to Appendix A. Technical Specifications 4
for Operating Licenses DPR-19, DPR-29 and DPR-30 for Dresden Unit 2 and Quad Cities Units 1-and 2, respactively.
The amer.dments would extend the Maximum Average Planar Linear Heat Generation Rate (iw'LHGR) curves for standard 8x8 (80250 and 80267) fuel types to exposure values beyond those currdntly given l
in the Technical Specifications.
Evaluation j
The extension of the MAPLHGR curves by addenda to Reference 2 has been pro-l posed by the licensee.
The analysis methods for the MAPLHGR calculations of Reference 2 have been previously accepted and approved by our letter of February 3,1973 (Ref. 3) and December 28,1979 (Ref. 4). The licensee's letter of March 19, 1980 presents the results of an analysis that extends MAPLHGR curves to 40,000 MWD /t (short ton) for standard 8x6 (80250 and 8D262) fuel types. These results are presented as a revision to NEDO 24146A (Ref. 2).
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F In our review of this proposed change, as in an earlier review (Ref. 4) we identified two areas having safety implications which require consideration.
One relates to the 1% plastic strain criterion of the Zircaloy fuel rod cladding as the safety limit below which fuel damage due to overstraining is not expected to occur. At extended exposures, i.e., beyond 40,000 MWD /t peak pellet exposure, this safety limit had not been calculated. As in an earlter like case (Pef. 5) the licensee has agreed with us in that operation beyond this exposure-is restricted and would require additional analyses.
Also, the probability of a high exposure bundle achieving power levels that would challenge the 1% plastic strain limit 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
'n Reference 5.
Another area of consideration identified in our review is the enhancement of fission gas release at extended exposures. The licensee has confirmed by Reference 5 that,'because APLHGR for high burnup rods is 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 (Ref. 6).
Exposure restrictions due to the 1% plastic strain limit and enhanced fission gas release at extended exposures are subjects of ongoing generic review by the staff. Although their treatment for the current application is acceptable, future generically related changes may be necessary. We have reviewed the licensee's proposal for extending the MAPLHGR curves to 40,000 MWD /t ior standard 8x8_ fuel types and have fount it to be acceptable.
Environmental Considerations In addition to the two areas of consideration having safety implications, the staff considered the proposed changes in the light of Tables S-3 and S-4 of 10 CFR Part 51, which address uranium fuel cycle and fuel transportation environmental impacts. The assumed maximum average level of irradiation of the irradiated fuel from the reactor is 33,000 MWD /MT (megawatt days per metric ton) or about 29,900 MWD /t (megawatt days per short ton ). Although these amendments establish MAPLHGR limits for fuel burnup out to 40,000 MWD /t, these amendments will not cause the average fuel burnup of 33,000 MWD /MT (29,900 MWD /t) for irradiated ~ fuel from the reactor to be exceeded.
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 maile this determination, we have further conc'uded that these amendments involve an action which is instonificant frrm the standpoint of environmental hpact, and pursuant to 10 CFx Section bl.5(d)(4) tLt an environmental imp =ct statement, or negative declaration and environmental impact appraisal ner:d not be prepared in connection with the issuance of these amendments.
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. 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 con-ducted in compliance with the Commission's regulations and the issuance of these amendments will not-be inimical to the common defense and security or to the health and safety of the public.
Dated: November 12, 1980
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REFERENCES-1.
. March 19,1980 - Letter from D. L. 'eoples (Connonwealth Edison) to the Director of Nuclear Reactor Regulation (USNRC), "Dresden Station Unit 2, Quad Cities Station Units 1 and 2, Proposed Amendment _to_ Appendix A, Technical Specifications to include Extended Exposure MAPLHGR Curves, NRC Docket ~ Nos. 50-237 and 50-254/265,"
March 19,1980.
2.
" Loss-of-Coolant Accident Analysis Report for Dresden Units 2, 3 and Quad Cities Units l_, 2 Nuclear Power Stations',' NED0-24146A, April 1979.
Letter from T. A. Ippclito (USNRC) to C. Reed (CECO), February 3,1979.
3.
4.
Letter from T. A. -Ippolitt (USNRC) to D. L. Penrles (CECO),
December 28, 1979, i
5.
Letter from R. F. Janacek (CECO) to H. R. Denton (USNRC), December 20, 1979.
6.
Memorandum from P. S. Check to A. Schwencer, et.al.," Enhanced Fission Gas _ Release," October 13, 1978.
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