NRC-92-0092, Forwards Rev 0 to GE-NE-523-22-0292, Updated NUREG-0619 Feedwater Nozzle Fatigue Crack Growth Analysis,Fermi Nuclear Plant,Unit 2
| ML20099B989 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 07/29/1992 |
| From: | Orser W DETROIT EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20099B991 | List: |
| References | |
| CON-NRC-92-0092, CON-NRC-92-92, RTR-NUREG-0619, RTR-NUREG-619 NUDOCS 9208030210 | |
| Download: ML20099B989 (2) | |
Text
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July 29, 1992 NPI-92-0092 U. S. Nuclear Ragulatory Commission Attnt Document Control Deck Washington. D. C.
20555
References:
1)
Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43 2)
GE Report NEDE-21821-A. "BWR Feedwater Nozzle /Sparger Final Report". dated February 1980-3)
NUREG-0619. "3WR Feedwater Nozzle and Control Drive Return Line Nozzle Cracking", dated November 1980 4)
NRC Generic Letter 81-11. dated February 20. 1981 5)
Detroit Edison Letter to NRC. " Dest ee of Conf ormance with NURIC-0619". EF2-53449 dated June 4. 1981 6)
Det roit Edison Letter to NRC. "Feedwater Nozzle Crack Growth Analysis". NRC-89-0237, dated November 1989 7)
NRC Letter to Detroit Edison. "Feedwater Nozzle Crack Growth Analysis (TAC No. 77675)". dated August 21, 1991
Subject:
Revised Feedwater Nozzle _ Crack Growt_h Analysis The purpose of this letter is to submit the revised feedwater nozzle crack growth analysis as discussed in References 6 and 7..
Reference 6 submitted a Fermi 2 plant unique fracture mechanics analysis of the feedwater' nozzles. This analysis was required by Generic Letter 81-11-(Reference 4), as recommended in NUREG-0619 (Reference 3), to allow continued use of an existing high quality. Iow flow sontroller that did not possess all six characteristics of NEDE-21821-A (Reference 2). The initial analysis results indicate that stresses from existing controller's temperature and flow profiles would not result in the growth of a crack more than one inch depth in n c, 0N[
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USf;EC July 29, 1992 NRC-92-0092 Page 2 8.9 years of plant operation, as compared t o t he Genetic Letter 81-11
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required 40 years life of the plant.
The initial results were based on the use of conservatively estimated thetwal cycle history data since suf ficient actual operating data were not available.
- However, as stated in Ref er erce 5. it t,s int ended that actual t emperature fluctuation data f rom the fir st fuel cycle will be used as input to the analysis.
Theref ore. Detroit Edison cremitted in Reference 6 to perform a revised feedwater nozzle crack growth analysis using actual plant oper ating data. The reviced analysis was to be completed prior to returning to power operation af tet the third refueling outage.
This was found acceptable in Reference 7 which required that the analysis be submitted 90 days prior to restart of Fermi 2 for Cycle 4 currently echeduled for October 31. 1992.
Detroit Edison has now completed a revised plant unique f racture mechanics analysis of the Fermi 2 feedwater nozLles using actual recorded temperaturn data collected during 1990-1991. This data is considered to be conservative with respect to future plant operation.
The results of the revised analysis show that stresses from the existing couttoller's temperature and flow profiles would not result in the growth of an assumed initial 0.25 inch crack to greater than one inch depth during the 38.3 years af ter initial plant startup.
This is based on the 1989 ASME Code.Section XI. f atigue crack growth methods.
Since thia analysis still includes conservative thermal cycle projections based on the early years of plant operation, it is our engineering judgement that with projections baced on several years of plant operation the analysis would hava predicted the crack growth to no greater than one inch in 40 years Afe of the plant.
Therefore. Det roit Edison concludes that Fermi 2 meets the intent of the requirements regarding feedwater nozwle crack growth, as specified in NUREG-0619 and amended by Generic Letter 81-11.
A copy of the General Electric Report No. GE-NE-5 23-22-029 2 Revision O. " Updated NUREG-0619 Petdwater Nozzle Fatigue Crack Growth Analysia" ia enclosed.
If you have any questions, please contact Mr. Girija S. Shukla at (313) 586-4270.
Gibce rely.
Enclosure cc:
T. G. Colburn A. B. Davis M. P. Phillips i
S. Stasek 1
.,