ML19296D706
| ML19296D706 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 02/25/1980 |
| From: | Schwencer A Office of Nuclear Reactor Regulation |
| To: | Burstein S WISCONSIN ELECTRIC POWER CO. |
| References | |
| NUDOCS 8003130036 | |
| Download: ML19296D706 (2) | |
Text
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MBRUARY 2 5 7980 k et Nos. 50-266 and 50-301 Mr. Sol Burstein Executive Vice President Wisconsin Electric Power Company 231 West Michigan Street Milwaukee, Wisconsin 53201
Dear Mr. Burstein:
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 V. S. LWR fuel suppliers were requested to revise their fuel performance analyses to include the enhance-ment of fission gas release at higher burncps.
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 Westinghoyse 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.
Inasnuch 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.
Si cerely, t /
NWY-7 A. Schwencer, Chief Operating Reactors Branch #1 Division of Operating Reactors cc: See next page 8 0 n 3 1 8 0 d 2 (o
Mr. Sol Burstein Wisconsin Electric Power Company FEBRUARY 2 5 560 cc:
Mr. Bruce Churchill, Esquire Shaw, Pittman, Potts and Trowbrides 1800 M Street, N.W.
Washington, D. C.
20036 Document Department University of Wisconsin Stevens Point Library Stevens Point, Wisconsin : :dl Mr. Glenn A. Reed, Manager Nuclear Operations Wisconsin Electric Power Company Point Beach Nuclear Plant 6610 Nuclear Road Two Rivers, Wisconsin 54241 9