ML17227A828

Suppls 920706 Response to GL 92-01,Rev 1 Re Reactor Vessel Structural Integrity,Per 921216 & 18 Telcons W/Nrc. C-E Owners Group Evaluation Performed to Date Demonstrate That ASME App G Margins Will Continue to Be Satisfied

ML17227A828
Person / Time
Site:	Millstone
Issue date:	01/04/1993
From:	Debarba E, Opeka J NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
B14329, GL-92-01, GL-92-1, NUDOCS 9301080175
Download: ML17227A828 (7)

Text

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.. 'yFADXLj50-336 Millstone Nuclear Power Station, Unit 2, Northeast Nu 05000336 AUTH.NAME AUTHOR AFFILIATION DEBARBA,E.A. Northeast Nuclear Energy Co.

DEBARBA,E.A. Northeast Utilities RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

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SUBJECT:

Responds to request for addi info re Millstone Nuclear Power Station Unit 2 for GL 92-001.

D DISTRIBUTION CODE: R02SD COPIES RECEIVED:LTR l ENCL / SIZE:

TITLE: Generic Letter 92-01 Responses (Reactor Vessel Structural Integrity 1$

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PDl-4 LA 1 1 PD1-4 PD 1 1 VISSINGiG 2 2 D INTERNAL: ACRS 6 6 NRR MCDONALD,D 1 1 D

NRR/DET/ECMB 2 2 NUDOCS-ABSTRACT 1 1 OC/LF B 1 0 OGC/HDS1 1 0 FILE Ol 1 1 RES/DSIR/EIB 1 1 EXTERNAL: NRC PDR 1 1 NSIC 1 1 D

NOTE TO ALL"RIDS" RECIPIENTS:

S PLEASE HELP US TO REDUCE WASTE} CONTACI'HE DOCUMENT CONTROL DESK, ROOM P1-37 (EXT. 504-2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 20 ENCL 18

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UTILITIES 'ORTHEAST General Offices ~ Selden Street, Berlin, Connecticut THE CONHECTCUT UOHT ANO POWER COMPANY WESTERN MASAACHTSETTS tlECTIYC COMPANY HOLYOKE WATtllPOWtR COMPANY P.O. BOX 270 NORTHEAST UTRITES StRYCE COMPANY HARTFORD, CONNECTICUT 06141%270 NORTHEAST NVCEEAR ENEROY COMPANY (203) 665-5000 January 4, 1993 Docket No. 50-336 B14329 Re: Generic Letter "

92-01, Revision 1 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Gentlemen:

Hillstone Nuclear Power Station, Unit No. 2 Reactor Vessel Structural Integrity, 10CFR50.54(f)

(Generic Letter 92-01, Revision 1)

Res onse to Re uest for Additional Information In a letter dated March 6, 1992,"'he NRC Staff issued Generic Letter 92-01, Revision 1, "Reactor Vessel Structural Integrity, 10CFR50.54(f)." A response to Generic Letter 92-01 was provided on July 6, 1992."'etailed information related to the subject was provided in Table 1 of the July 6, 1992, letter.

Based on telephone discussions held with the NRC Staff on December 16 and December 18, 1992, Northeast Nuclear Energy Company (NNECO) is hereby providing additional information related to the upper shelf energy of the Hillstone Unit No. 2 reactor vessel, as requested.

In accordance with 10CFR50.54(f), NNECO, on behalf of Hillstone Unit No. 2, hereby provides the attached additional information to supplement the information provided by NNECO in our July 6, 1992, letter.

(1) J. G. Partlow letter to All Holders of Operating Licenses or Construction Permits for Nuclear Power Plants (Except Yankee Atomic Electric Company, Licensee for the Yankee Nuclear Power Station), "Reactor Vessel Structural Integrity, 10CFR50.54(f), (Generic Letter 92-01, Revision 1),"

dated Harch 6, 1992.

(2) J. F. Opeka letter to the U.S. Nuclear Regulatory Commission, "Reactor Vessel Structural Integrity, 10CFR50.54(f), (Generic Letter 92-01, Revision 1)," dated July 6, 1992.

9301080175 930104 PDR('),ADOCK P'-'.'<<'.: lj fi 00000336 PDiTl OS3422 REV 448

U.S. Nuclear Regulatory Commission B14329/Page 2 January 4, 1993 I'f you have any questions, please contact us.

Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY FOR: J. F. Opeka Executive Vice President BY:

E. A. DeBarba Vice President Enclosure cc: T. T. Hartin, Region I Administrator G. S. Vissing, NRC Project Manager, Millstone Unit No. 2 P. D. Swetland, Senior Resident Inspector, Millstone Unit Nos. 1, 2, and 3 Subscribed and sworn to before me this 4+ day of 19 ~3 Not y Public Date',Commission Expires: 3 al QG

Docket No. 50-336 B14329 Millstone Nuclear Power Station, Unit No. 2 Additional Information for the Response to Generic Letter 92-01 January 1993

Millstone Nuclear Power Station, Unit No. 2 Additional Information for the Response to Generic Letter 92-01 TOPIC: Additional information related to the Upper Shelf Energy of the Millstone Nuclear Power Station, Unit No. 2 reactor vessel, as requested by the Nuclear Regulatory Commission.

RESPONSE'NECO has developed the following plan to address the potential end-of-life low Upper 'Shelf Energy (USE) issues identified during the NRC review of the Millstone Unit No. 2 submittal on Generic Letter 92-01, Revision 1, "Reactor Vessel Structural Integrity, 10CFR50.54(f)." The plan can be summariz'ed as follows:

The ABB/CE Owner's Group (CEOG) has performed a bounding low USE analysis in accordance with the ASHE Appendix X methodology for all of the ABB/CE Nuclear Steam System Supply (NSSS) plants. The preliminary version of this analysis, which was submitted to the NRC on November 13, 1992, demonstrated the required margins of safety for materials with USE as low as 45 ft-lbs. Since the end-of-life USE of the Millstone Unit No. 2 reactor vessel is not predicted to fall below 45 ft-lbs, the CEOG report is considered applicable to the Hillstone Unit No. 2 vessel.

2. The final version of the above ASHE Appendix X evaluation is expected to be submitted for NRC review by April 30, 1993, and it is expected to confirm the results reached during the preliminary evaluation.

3. Haterial from the vessel plates, which could be predicted to fall below the 50 ft-lbs requirement, has recently been located in the vessel archives. The pedigree of this material is currently being evaluated to determine the feasibility of testing these materials to obtain the actual, unirradiated, transverse USE. This test program is expected to be completed April 30, 1993.

In summary, the USE of the Millstone Unit No. 2 reactor vessel is currently above 50 ft-lbs, as required by 10CFR50, Appendix G, and it is not expected to decrease below 50 ft-lbs prior to the completion of the material testing program currently under evaluation. Furthermore, the CEOG evaluations performed to date, demonstrate that the ASHE Appendix G margins will continue to be satisfied to USE values as low as 45 ft-lbs, which bound the Hillstone Unit No. 2 worst case, end-of-life USE values.

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