ML19309C120
| ML19309C120 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 03/10/1980 |
| From: | Ippolito T Office of Nuclear Reactor Regulation |
| To: | Bauer E PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| References | |
| NUDOCS 8004080194 | |
| Download: ML19309C120 (3) | |
Text
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UNITED STATES l
NUCLEAR REGULATORY COMMISSION o
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WASHINGTON, D. C. 20555 N...../
March 10,1980 Docket Nos. 50-277 and 50-278 Mr. l%ard G. Bauer, Jr.
Vice President and General Counsel Philadelphia Electric Company 2301 Market Street Philadelphia, Pennsylvania 19101
Dear Mr. Bauer:
1 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 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 Magawatt-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.
i 1
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 1 r 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 l
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 =20,000 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 l
BWRs.
Therefore, no immediate licensing action is necessary on operating j
BWRs.
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Mr. Edward G. Bauer, Jr. 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.
Sincerely, Th
. Ippolito, Chief Operating Reactors Branch #3 Division of Operating Reactors cc: See next page
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Mr. Edward G. Bauer, Jr.
Philadelphia Electric Company cc:
Eugene J. Bradley Philadelphia Electric Company Assistant General Counsel 2301 Market Street Philadelphia, Pennsylvania 19101 Troy B. Conner, Jr.
1747 Pennsylvania Avenue, N. W.
Washington, D. C.
20006 Raymond L. Hovis Esquire 35 South Duke Street York, Pennsylvania 17401 Warren K. Rich, Esquire Assistant Attorney General Department of Natural Resources Annapolis, Maryland 21401 Government Publications Section State Library of Pennsylvania Education Building Commonwealth and Walnut Streets Harrisburg, Pennsylvania 17126 M. J. Cooney, Superintendent Generation Division - Nuclear Philadelphia Electric Company 2301 Market Street Philadelphia, Pennsylvania 19101 Edward Greemnan U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Peach Bottom Atomic Power Station P. O. Box 399 Del ta.. Pennsylvania 17314 Philadelphia Electric Company ATTN: Mr. W. T. Ullrich Peach Bottom Atomic Power Station Delta, Pennsylvania 17314
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