ML19309C117
| ML19309C117 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 03/10/1980 |
| From: | Ippolito T Office of Nuclear Reactor Regulation |
| To: | Whitmer C GEORGIA POWER CO. |
| References | |
| GL-80-19, NUDOCS 8004080189 | |
| Download: ML19309C117 (3) | |
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March 10, 1980 Docket Nos. 50-321 and 50-366 Mr. Charles F. Whitmer Vice President - Engineering
. Georgia Power Conpany P. O. Box 4545 Atlanta, Georgia 30302
Dear Mr. Whitmer:
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 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
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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 l.
c'annot 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 MWD /T. Late in a BWR fuel l
cycle, there is less axial power peaking reducing the feasibility for l
any given axial location to exceed LOCA linear power density limits, and l
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 ininediate licensing action is necessary on operating BWRs.
8004086/h
Mr. Charles F. Whitmer 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 burriups, we consider this a satisfactory resolution of this concern.
Sincerely, A
A Th
- 4. Ippo ito, Chief Operating Reactors Branch #3 Division of Operating Reactors cc: See next page
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Mr. Ch rles F. Whitmer Georgia Power Company cc:
G. F. Trowbridge, Esquire Shaw, Pittman, Potts and Trowbridge 1800 M Street N. W.
Washington, D. C.
20036 Ruble A. Thomas Vice President P. O. Box 2625 Southern Services, Inc.
Birmingham, Alabama 35202 Ozen Batum P. O. Box 2625 Southern Services, Inc.
Birmingham, Alabama 35202 Mr. William Widner Georgia Power Company Power Generation Department P. O. Box 4545 Atlanta, Georgia 30302 Mr. L. T. Gucwa Georgia Power Company Engineering Department P. O. Box 4545 Atlanta, Georgia 30302 Appling County Public Librarf Parker Street Baxley, Georgia 31413 Mr. R. F. Rogers U. S. Nuclear Regulatory Commission P. O. Box 710 Baxley, Georgia 31513 i
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