ML19296D701
| ML19296D701 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 02/25/1980 |
| From: | Schwencer A Office of Nuclear Reactor Regulation |
| To: | Goodwin C PORTLAND GENERAL ELECTRIC CO. |
| References | |
| TAC-07722, TAC-7722, NUDOCS 8003130027 | |
| Download: ML19296D701 (2) | |
Text
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FEBRUARY : 51380 Docket No. 50-344 Mr. Charles Goodwin, Jr.
Assistant Vice President Por tland General Electric Company 121 S. W. Salmon Street Portland, Oregon 97204
Dear Mr. Goodwin:
During the last several years, data have begun to indicate that the 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-enhanced 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 reviss their fuel performance analyses to include the enhance-ment of fission gas release at higher burnups.
All responses to the November 23, 1976 letters have been reviewed.
We have concluded that no imediate licensing action is required for operating reactors.
This conclusion is valid for typical reported LWR fuel bundle and batch burn-ups. Any extension of these burnups or other factors which significantly affect fission gas release, LOCA PCT or fuel rod internal pressure is outside the scope of the conclusion.
Westinghouse was the only fuel supplier calculating that the increased release would cause internal fuel rod pressure to exceed coolant system pressure.
The staff has approved revised design criteria which allow internal rod pressures greater than system pressure. The staff is also completing the review of a Westinghouse revised fuel performance code. The staff, in evaluating reloads, has been requesting licensees using Westinghouse fuel to quantify the burnup when the newly approved design criteria will be violated.
In the reloads eval-uated thus far, there appears to be a significant burnup margin to the newly approved evaluated design criteria to compensate for modifications which may result from the staff's review of the Westinghouse revised fuel performance code.
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,
//
0}/h.MW2"d A. Schwencer, Chief Operating Reactors Branch #1 Division of Operating Reactors cc: See next page 80031300 2.7 7
Mr. Charles Goodwin, Jr.
FEBRUARY 2 5 580 Portland General Electric Company cc:
Mr. J. W. Durham, Esquire Robert M. Hunt, Chairman Vice President and Corporate Counsel Board of County Corm 1issioners Portland General Electric Company Columbia County 121 S.W. Salmon Street St. Helens, Oregon 97501 Portland, Oregon 97204 Warren Hastings, Esquire Counsel for Portland General Electric Company 121 S.W. Salmon Street Portland, Oregon 97204 Mr. Jack W. Lentsch, Manager Generation Licensing and Analysis Portland General Electric Company 121 S.W. Salmon Street Portland, Oregon 97204 Columbia County Courthouse Law Library, Circuit Court Room St. Helens, Oregon 97501 Director, Oregon Department of Energy Labor and Industries Building, Room 111 Salem, Oregon 97310 Richard M. Sandvik, Esquire Counsel for Oregon Energy Faciliiy Siting Counsel and Oregon Department of Energy 500 Pacific Building 520 S.W. Yamhill Portland, Oregon 97204 Michael Malmrose U. S. Nuclear Regulatory Conmission Trojan Nuclear Plant P. O. Box 0 Rainier, Oregon 97048 Mr. Donald W. Godard, Supervisor Siting and Regulation Oregon Department of Energy Labor and Industries Building, Room 111 Salem, Oregon 97310