ML18067A781
| ML18067A781 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 11/14/1997 |
| From: | Bordine T CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| RTR-REGGD-01.099, RTR-REGGD-1.099 NUDOCS 9711210091 | |
| Download: ML18067A781 (2) | |
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- ' *f' November 14, 1997 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT mom.. c. sOnliaS Manager
- Licensing REACTOR VESSEL - CHARPY UPPER SHELF ENERGY FOR REACTOR VESSEL WELD 9-112 - REVISION l
The Charpy upper shelf energy (USE) of circumferential weld 9-112 on the Palisades reactor vessel has been reestimated as 53 ft-lbs at the end-of-life (EOL). Applying Position 1 of Regulatory Guide 1.99, Rev. 2, the decrease in upper shelf energy, based on NRC report dated September 25, 1996, "Safety Evaluation of Report CEN-622,
'Generic Upper Shelf Values for Linde 0091, 124 and 1092 Reactor Vessel Welds',
June 1995; 'Supplemental Information to C-E Owners Group Report CEN-622', June*
1996," of the circumferential weld 9-112 is estimated as 36.8% resulting in an USE of 53 ft-lbs at end-of-life (EOL). The reactor vessel USE remains limited by plate D-3804-1 with an USE of 51 ft-lbs at EOL.
Consumers Energy letter dated July 3, 1992, provided material properties representative of the Palisades reactor vessel circumferential weld 9-112, which was
fabricatedwith_weld_wir_e_b_e§t__n!!_rTlbe_r 27204 using Linde 124 flux. The weld that was considered most representative of the* P-ali"sacfe-s-wefci wasa *s-urveillanceweld lotate_d ___ ---- ---- -- --- ---
in another reac~~eil_larice=pr.egr:am~fabricated with weld wire heat number 27204 using Linde 1092 flux. When reported on July 3, 1992, this was the only weld
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known to be fabricated solely with weld wire heat number 27204 with measured initial
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and irradiated Charpy energies. The initial Charpy USE of that wel.d was reported as AOO't O
.98 ft.,lbs..
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-21 Q'Q J 2Palisades Nuclear Plant
- 27780 Blue Star Memorial Highway
- Cove;/, Ml 49043
- Tel: 616 764 2913
- Fax: 616 764 2490
Based on the NRC report dated September 25, 1996, Consumers Energy now considers the generic 95/95 lower tolerance limit of 84 ft-lbs for welds fabricated with Linde 124 flux to be the most appropriate value for the initial USE of the Palisades reactor vessel beltline circumferential weld 9-112.
2 In the Consumers Energy letter dated April 4, 1996, it was identified that the reactor vessel will reach the pressurized thermal shock screening criteria for the limiting weld material (located in axial welds 2-112A, B, & C and 3-112A, B, & C) at a fluence level of 1.55 x 1019 n/cm2. Consumers Energy estimates that the fluence at circumferential weld 9-112 will be 2.08 x 1019 n/cm2 at that time. Based on the attenuation through the vessel to the Xt location, the circumferential weld 9-112 fluence values are estimated to be 1.23 x 1019 n/cm2. Applying Position 1 of Regulatory Guide 1. 99, Rev. 2, the decrease in upper shelf energy of the circumferential weld 9-112 is estimated as 36. 8%
- resulting in an USE of 53 ft-lbs at end-of-life (EOL).
The reactor vessel USE remains limited by plate D-3804-1 with an USE of 51 ft-lbs at EOL.
SUMMARY
OF COMMITMENTS This letter contains no new commitments and no revisions to existing commitments.
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Thomas C. Bordine Manager, Licensing CC Administrator, Region Ill, USNRC Project Manager, NRR, USNRC NRC Resident Inspector - Palisades
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