BSEP-97-0060, Forwards Supplemental Info Re GL 92-01, Reactor Vessel Structural Integrity. Evaluation Rept on Reactor Vessel, Also Encl

Forwards Supplemental Info Re GL 92-01, Reactor Vessel Structural Integrity. Evaluation Rept on Reactor Vessel, Also Encl

ML20137V803
Person / Time
Site:	Brunswick
Issue date:	04/14/1997
From:	Campbell W CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20137V806	List: BSEP-97-0060, Forwards Supplemental Info Re GL 92-01, Reactor Vessel Structural Integrity. Evaluation Rept on Reactor Vessel, Also Encl ML20137V812
References
BSEP-97-0060, BSEP-97-60, GL-92-01, GL-92-1, NUDOCS 9704170412
Download: ML20137V803 (3)

Text

i' CP&L i

Carolina Powr & Light Company William R. Campbell PO Box 10429 Vice President Southport NC 28461 Brunswick Nuclear Plant SERIAL: BSEP 97 0060 ,

APR 141997 United States Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, DC 20555 ,

BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2 DOCKET NOS. 50-325 & 50-324/ LICENSE NOS. DPR 71 & DPR-62 ,

SUPPLEMENTAL INFORMATION FOR GENERIC LETTER 92-01, REACTOR VESSEL STRUCTURAL INTEGRITY Gentlemen:

The purpose of this letter is to provide the results of the Brunswick Steam Electric Plant Unit Nos.1 and 2, specific upper shelf energy equivalent margins analysis for reactor vessel N16 forged nozzles. Carolina Power & Light (CP&L) Company committed to provide j these results in CP&L's response to Generic Letter 92 01, Revision 1, Supplement 1, dated November 16,1995 (Serial No. BSEP 95-0572).

The analysis of the nozzles for both reactor vessels, included as Attachment 2, demonstrates that the lower value of end-of-life upper shelf energy is anticipated to remain higher than the minimum value requkes by the American Society of Mechanical Engineers (ASME) Code Section XI, Appendix G. l Please refer any questions regarding this letter to Mr. Keith Jury, Manager Regulatory Aff airs, at (910) 457-2783.

Sincerely, hW William R. Campbell 7

GMT/

Enclosures:

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1. Discussion M00GO

2. N 16 Nozzles Upper Shelf Energy Evaluation lEl,EREl$E%*EEE * '

3. List of Regulatory Commitments ,

i cc: Mr. L. A. Reyes, NRC Regional Administrator,' Region ll )

Mr. C. A. Patterson, NRC Senior Resident inspector - Brunswick Steam Electric Plant Mr. D. C. Trimble, Jr., NRR Project Manager - Brunswick Steam Electric Plant The Honorable J. A. Sanford, Chairman - North Carolina Utilities Commission 9704170412 970414 ,

PDR ADOCK 05000324 P PDR i

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ENCLOSURE 1 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS,1 AND 2 NRC DOCKET NOS. 50-325 & 50-324 OPERATING LICENSE NOS. DPR-71 & DPR-62 SUPPLEMENTAL INFORMATION FOR GENERIC LETTER 92-01 REACTOR VESSEL STRUCTURAL INTEGRITY Discussion Carolina Power & Light (CP&L) Company's response to Generic Letter 92-01, Revision 1, Supplement 1, dated November 16,1995 (Serial No. BSEP 95-0572), committed to provide a plant-specific upper shelf energy (USE) equivalent margins analysis for each of the Brunswick Steam Electric Plant reactor pressure vessels' N16 forged nozzles.

.0CFR50, Appendix G, requires that the upper shelf Charpy V Notch (CVN) Energy of the j reactor vessel beltline region be greater than 75 ft-lbs initially, and remain above 50 ft-lbs throughout the operating license of the plant. If this minimum requirement is not mainta!ned, the licensee is required to demonstrate that lower values of USE will provide margins of safety against fracture equivalent to those required by the American Society of Mechanical Engineers (ASME) Code Section XI, Appendix G.

Each reactor vessel contains two 2-inch nominal pipe size forged instrument nozzles, N16A and N168, within the upper beltline region. Although all of the nozzle forgings are from the same heat of material, the Unit 1 nozzle forgings have significantly lower reported Charpy impact energy at 40 degrees F than those contained within the Unit 2 vessel. Although most of the reactor vessel beltline materials had been previously bounded by the Boiling Water Reactor (BWR) Owners Group USE equivalent margins analysis report, NEDO-32205-A, "10CFR50, Appendix G Equivalent Margin Analysis for Low Upper Shelf Energy in BWR/2 Through BWR/6 Vessels", forged materials were not addressed by the report. As a .

result, CP&L decided to perform a plant-specific equivalent margin analysis as required by l 10CFR50, Appendix G. l 1

The report (96124-TR-01) provided in Attachment 2 shows that, based on an extensive database search, the N16 nozzles for both reactor vessels should have had an initial USE of at least 70 ft-lbs. In addition, a conservative projection of the end-of-life fluence shows I that the initial USE is not anticipated to drop more than 18% for either reactor vessel.

Therefore, the end-of-life USE of the nozzles for both vessels is anticipated to remain higher than the minimum screening criteria of 50 ft-lbs. However, for added conservatism, an equivalent margins analysis was also performed per the guidelines provided in USNRC Regulatory Guide 1.161. This analysis demonstrates that the Nia nozzles would meet the  ;

ASME Code, Section XI, Appendix K, and Regulatory Guide 1.161 J-R fracture toughness requirements, with an end-of life USE as low as 29 ft-lbs. It is further shown in Section 3.0 of the attached report that a 29 ft-Ib end-of life USE value would be equivalent to an initial USE of 35 ft-lbs, conservatively assuming the 18% drop in USE over the life of the vessels. As noted above, based on the material database search conducted as a part of this project, it has been shown that the subject nozzle material should have an initial USE of at least 70 f t-lbs.

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ENCLOSURE 2-BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2  ;

DOCKET NOS,50-325 AND 50 324 ' ,..

OPERATING LICENSE NOS. DPR-71 AND DPR-62 l SUPPLEMENTAL INFORMATION FOR GENERIC LETTER 92-01 REACTOR VESSEL STRUCTURAL INTEGRITY. l 1

)

N 16 NOZZLES UPPER SHELF ENERGY EVALUATION

~ Technical Report No. 96124-TR-01  !

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