ML17075A034

Request for Additional Information

ML17075A034
Person / Time
Site:	Vogtle
Issue date:	03/22/2017
From:	Michael Orenak Plant Licensing Branch II
To:	Pierce C Southern Nuclear Operating Co
ORENAK M, DORL/LPLII-1, 415-3229
References
CAC MF9136, CAC MF9137
Download: ML17075A034 (3)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 March 22, 2017 Mr. Charles R. Pierce Regulatory Affairs Director Southern Nuclear Operating Co., Inc.

P.O. Box 1295, Bin 038 Birmingham, AL 35201-1295

SUBJECT:

VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION (CAC NOS. MF9136 AND MF9137)

Dear Mr. Pierce:

By application dated January 26, 2017 (Agencywide Documents Access and Management System (ADAMS) Package Accession No. ML17026A438), Southern Nuclear Operating Company, Inc. (SNC, the licensee) submitted Request for Alternative VEGP-ISl-ALT-13 for the Vogtle Electric Generating Plant (VEGP), Units 1 and 2 in accordance with Title 10 of the Code of Federal Regulations, Section 50.55a(z)(2), on the basis of hardship. Alternative VEGP-ISl-ALT-13, propose an extension of the third 10-year inspection interval for the VEGP Category B-N-2 and B-N-3 examinations (visual examinations of the reactor vessel interior attachments beyond the beltline region and the core support structure) from 10 to 20 years.

The U.S. Nuclear Regulatory Commission staff has reviewed the submittal and has determined that additional information is needed to complete its review. The NRC staff discussed the additional information with representatives of your staff on March 21, 2017.

During that call, Mr. Joyce agreed to provide your response within 30 days of the date of this letter.

Sincerely,

yvvJ_ ~

Michael Orenak, Project Manager Plant Licensing Branch, 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-424 and 50-425

Enclosure:

Request for Additional Information

REQUEST FOR ADDITIONAL INFORMATION ALTERNATIVE REQUESTS VEGP-ISl-ALT-13 CATEGORY B-N-2 AND B-N-3 EXAMINATION EXTENSION FROM 10 TO 20 YEARS SOUTHERN NUCLEAR OPERATING COMPANY, INC.

VOGTLE ELECTRIC GENERATING PLANT, UNITS 1AND2 SOUTHERN NUCLEAR OPERATING COMPANY DOCKET NOS. 50-424 AND 50-425 By application dated January 26, 2017 (Agencywide Documents Access and Management System (ADAMS) Package Accession No. ML17026A438), Southern Nuclear Operating Company, Inc. (SNC, the licensee) submitted Request for Alternative VEGP-ISl-ALT-13 for the Vogtle Electric Generating Plant (VEGP), Units 1 and 2. Alternative VEGP-ISl-ALT-13, propose an extension of the third 10-year inspection interval for the VEGP Category B-N-2 and B-N-3 examinations (visual examinations of the reactor vessel interior attachments beyond the beltline region and the core support structure) from 10 to 20 years.

The U.S. Nuclear Regulatory Commission staff reviewed the submittal and determined that the following additional information is needed to complete its review.

Request for Additional Information 1 The licensee states on page E-4 of VEGP-ISl-ALT-13 that it is unaware of any industry operating experience related to primary water stress corrosion cracking (PWSCC) for similar vessel attachment welds made of 82/182 weld material and the Alloy 600 base metal.

Please provide:

a) The RPV attachment component stresses due to mechanical, thermal, and interference fit.

b) The temperature of the RPV attachment component during operation (an important factor in PWSCC).

c) An assessment of the environment condition to discount PWSCC as a degradation mechanism for the vessel attachments.

d) Information on the remaining residual stresses in attachment welds after complete vessel post-weld heat treatment.

Enclosure

SUBJECT:

VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION (CAC NOS. MF9136 AND MF9137)

DATED: MARCH 22, 2017.

DISTRIBUTION:

PUBLIC LPL2-1 R/F RidsNrrDorllpl2-1 Resource RidsNrrPMVogtle Resource RidsNrrEvib Resource Rids Rgn2Mai1Center Resource RidsNrrLAKGoldstein Resource RidsACRS_MailCTR Resource SSheng, NRR ADAMS A ccess1on No.: ML17075A034 *b1y e-ma1*1 OFFICE DORL/LPL2-1 /PM DORL/LPL2-1 /LA DE/EVIB/BC* DORL/LPL2-1 /BC DORL/LPL2-1 /PM NAME MOrenak KGoldstein DRudland MMarkley MOrenak DATE 3/20/17 3/17/17 3/15/17 3/22/17 3/22/17 OFFICIAL RECORD COPY