ML19296D695
| ML19296D695 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 02/25/1980 |
| From: | Schwencer A Office of Nuclear Reactor Regulation |
| To: | Dunn C DUQUESNE LIGHT CO. |
| References | |
| TAC-8974, NUDOCS 8003130020 | |
| Download: ML19296D695 (2) | |
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FEBRUARY 2 5 1980 Docket No. 50-334 Mr. C. N. Dunn, Vice President Operations Division Duquesne Light Co@any 435 Sixth Avenue Pittsburgh, Pennsylvania 15219
Dear Mr. Dunn:
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 revise 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 immediate 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 e"aluating 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 approvco 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 perforr,ance codes which provide for increase in fission gas release at higher burnups, we consider this a satisfactory resolution of this concern.
Sincerely, ON W s
A. Schwencer, Chief Operating Reactors Branch #1 Division of Operating Reactors cc: See next page B003130 OM
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i Mr. C. N. Dunn FEoRuARY 15 Eso Duquesne Light Corpany cc: Gerald Charnoff, Esquire Mr. Janes A. Werling Jay E. Silberg, Esquire Plant Superintendent Shaw, Pittman, Potts and Trowbridge Beaver Valley Power Station 1800 M Street, N.W.
P. O. Box 4 Washington, D. C.
20036 Shippingport, Pennsylvania 15077 Karin Carter, Esquire Mr. John A. Levin Special Assistant Attorney General Public Utility Commission Bureau of Administrative Enforcement P. O. Box 3265 5th Floor, Executive House Harrisburg, Pennsylvania 17120 Harrisburg, Pennsylvania 17120 Mr. J. D. Sieger, Superintendent Mr. Roger Tacan of Licensing and Compliance Stone and Wecster Engineering Duquesne Light Company Corporation Post Office Box 4 P. O. Box 2325 Shippingport, Pennsylvania 15077 Boston, Massachusetts 02107 Mr. J. D. Woodward R & D Center Westinghouse Electric Corporation Building 7-303 Pittsburgh, Pennsylitania 15230 B. F. Jones Memorial Library 663 Franklin Avenue Aliquippa, Pennsylvania 15001 Mr. Jack Carey Technical Assistant Duquesne Light Company P. O. Box 4 Shippingoort, Pennsylvania 15077 Mr. R. E. Ma rt i n Duquesne Lign: Corpany 435 Sixth Avenue Pittsburgh, Pennsylvania 15219 Marvin Fein Utility Counsel City of Pittsburch 313 City-County Building Pittsburgh, Pennsylvania 15219