ML20070Q834
| ML20070Q834 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/23/1991 |
| From: | Broughton T GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| C311-91-2004, NUDOCS 9103290213 | |
| Download: ML20070Q834 (2) | |
Text
_ _ _ _
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TE, Wrn Dial Number; (7..j 9L8-8005 March 23,1991 0311-91-2004 f
U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C.
20555 Gentlemen:
Subject:
Three Mile Island Nuclear Station, Unit 1 (TM1-1)
Operating License No. DPR-50 Docket No. 50-289 Revised LOCA Evaluation This letter provides information regarding recent B&W Nuclear Services Corporation (BWNSC) Loss of Coolant Accident (LOCA) evaluations as they relate to TMI-1. This information supplements the information contained in GPU Nuclear letter -(#L311-90-2056) dated July 2, 1990.
BWNSC has provided GPU Nuclear with the results of LOCA analyses performed for the 6-foot and 4-foot core elevations. The peak cladding temperature (PCT) of 2194 F for the 6-foot elevation reported in our July 2, 1990 letter has been revised to-2073 F.
The revised analysis uses a linear heat rate (LHR) of 16.1 kw/ft versus the prior value of 16.C kw/ft. The TACO-2 fuel pin performance code was used as an input in both cases.
A reduced LOCA LHR limit of 16.1 kw/f t has been applied generically by the 177 fuel assembly lowered-loop plants to account for plant specific variations of the generic input parameters.
As reported in BWNSC letter (JHT 190-126), J. H. Taylor to Dr. T. E. Murley, dated August 23, 1990, a revised analysis for the 4-foot core elevation using the BWC Critical Heat Flux correlation indicates a PCT of 2160 F with a LHR of 16.1 kw/ft., using TACO-2 initial fuel pin inputs. When the NRC approved TACO-3 code was used in a subsequent analysis, again with a LHR of 16.1 ka/f t, a PCT of 1786 F is demonstrated. Gpu Nuciear confirms the conservatism of the above analysis results for TMI-1.
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GPU Nuc! ear Corporation a subs d ary of Gene'ai Pubhc Uhhbes Corporahon 00
Document Control Desk C311-91-2004 Page 2 The 16.1 kw/ft LOCA LHR limit administratively established for the 6-foot core elevation will continue to apply for the remaindse of the current cycic-(Cycle 8).
Beginning-of-cycle LOCA LHR limits have been applied to all other core elevations during the current cycic.
BWNSC has informed us that a recalculation of burnup-dependent LHRs has shown acceptable results for the two foot and four foot elevations, We will reestablish burnup-dependent LOCA LHR limits after receipt of the decumented results.
Sincerely, ay3 is T. G.
ghton Vice Pres'ident and Director, TMI-1 PC/ pip cc:
Administrator, Region 1 TMI-1 NRC Project Manager Senior NRC Resident Inspector
,