ML19309B949
| ML19309B949 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities  |
| Issue date: | 03/10/1980 |
| From: | Ippolito T Office of Nuclear Reactor Regulation |
| To: | Peoples D COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 8004070381 | |
| Download: ML19309B949 (3) | |
Text
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UNITED STATES
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March 10, 1980 Docket Nos. 50-254 50-265 and 50-249 Mr. D. Louis Peoples Director of Nuclear Licensing Connonwealth Edison Conpany P. 0, Box 767 Chicago, Illinois 60690
Dear Mr. Peoples:
During the last several years, data have begun to indicate that the i
fission gas release rate from LWR fuel pellets is increased (enhanced) with burnup. Many of the current fuel performance analyses do not consider the impact of burnup release on safety.
By letters dated November 23, 1976, the NRC staff requested all LWR licensees to assess the higher fission gas release for fuel burnups above 20,000 Megawatt-day per metric ton (MWD /T).
Also, by NRC staff letter dated January 18, 1978, all U. S. LWR fuel suppliers were requested to revise their fuel performance analyses to include the enhancement of fission gas release at higher burnups.
All responses to the November 23, 1976 letters have been reviewed. We have concluded that no immediate licensing action is required for operat-ing reactors. This conclusion is valid for typical reported LWR fuel bundle and batch burnups.
Any extension of these burnups or other fac-tors which significantly affect fission gas release, LOCA PCT or fuel rod internal pressure is outside the scope of the conclusion.
The effect of enhanced release on BWR ECCS performance has been discussed with General Electric (GE). GE has pointed out that because of opera-tional restrictions and physical limitations, the LOCA analysis is not limiting in high burnup fuel (25,000 WD/T).
High burnup fuel generally cannot achieve linear power densities near the LOCA limit early in cycle.
The limiting fuel bundle is usually in its second cycle of reactor opera-tions where burnup levels are below 40,000 WD/T. Late in a BWR fuel cycle, there is less axial power peaking reducing the feasibility for any given axial location to exceed LOCA linear power density limits, and the fuel bundle power is generally limited by MCPR considerations.
- Thus, it is unlikely that a high burnup bundle can exceed the ECCS performance criteria in case of a LOCA. The argument is appropriate for Exxon fuel bundle design also based on the review of Exxon analyses for operating BWRs.
Therefore, no immediate licensing action is necessary on operating BWRs.
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8004070 9 6l
o Mr. D. Louis Peoples Inasmuch as you and/or the staff will be evaluating all future reloads against fuel vendors' revised fuel performance codes which provide for increase in fission gas release at higher burnups, we consider this a satisfactory resolution of this concern.
Sincerely, Thomas A. Ippolito, Chief Operating Reactors Branch #3 Division of Operating Reactors cc:
See next page
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Mr. D. Louis Peoples Commonwealth Edison Company 3-cc:
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Mr. D. R. Stichnoth Jimmy L. Barker President U. S. Nuclear Regulatory Commission Iowa-Illinois Gas and P. O. Box 706 Electric Company Morris, Illinois 60450 206 East Second Avenue Davenport, Iowa 52801 Mr. John W. Rowe Isham, Lincoln & Beale Counselors at Law One First National Plaza, 42nd Floor Chicago', Illinois 60603 Mr. Nick Kalivianakas Plant Superintendent Quad Cities Nuclear Power Station 22710 - 206th Avenue - North Cordova, Illinois 61242
' Anthony Z. Roisman Natural Resources Defense Council 917 15th Street, N. W.
Washington, D. C. 20005 Moline Public Library
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504 - 17th Street Moline, Illinois 61265 Susan N. Sekuler Assistant Attorney General Environmental Control Division 188 W. Randolph Street Suite 2315 Chicago, Illinois 60601 Mr. N. Chrissotimos, Inspector US Nuclear Regulatory Commission Box 756 Bettendorf Iowa 52722 Mr. B. B. Stephenson Plant Superintendent Dresden Nuclear Power Station Rural Route #1 Morris, Illinois 60450
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