ML11094A008

(Fnp) - Request for Additional Information on Inservice Inspection Plan

ML11094A008
Person / Time
Site:	Farley
Issue date:	04/27/2011
From:	Martin R Plant Licensing Branch II
To:	Ajluni M Southern Nuclear Operating Co
Martin, R E, NRR/DORL 415-1493
References
TAC ME5273, TAC ME5274
Download: ML11094A008 (3)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 April 27, 2011 Mr. M. J. Ajluni Nuclear Licensing Director Southern Nuclear Operating Company, Inc.

40 Inverness Center Parkway Post Office Box 1295, Bin - 038 Birmingham, AL 35201-1295

SUBJECT:

JOSEPH M. FARLEY NUCLEAR PLANT, UNITS 1 AND 2 (FNP)-REQUEST FOR ADDITIONAL INFORMATION ON INSERVICE INSPECTION PLAN (TAC NOS. ME5273 AND ME5274)

Dear Mr. Ajluni:

By letter dated January 5, 2011 (Agencywide Documents Access and Management System (ADAMS), Accession No. ML110060173), Southern Nuclear Operating Company, Inc. (SNC) submitted Relief Request (RR) FNP-ISI-ALT-12, Version 2.0, for U.S. Nuclear Regulatory Commission (NRC) review and approval, which requests the use of alternative risk-informed inservice inspection (RI-ISI) selection and examination criteria for Category B-F, B-J, C-F-1, and C-F-2 pressure retaining piping welds. To enable completion of the review, the NRC staff requests additional information as follows:

In Enclosure 1, Section 2.2 of the RR, under the fourth bullet, the FNP examination program for dissimilar metal butt welds is discussed. The second paragraph's first sentence states, "Even though Code Case N-716 only considers the RPV [reactor pressure vessel] hot leg nozzle Alloy 82/182 weld locations to be susceptible to PWSCC [primary water stress corrosion cracking],

SNC has selected all six welds to be ultrasonically examined for PWSCC within the scope of Code Case N-716." The third sentence of this paragraph states, 'However, the examination frequency of these eight welds is currently based on the frequencies established by the requirements of Materials Reliability Program (MRP)-139, Revision 1." Clarify this discrepancy in the number of welds considered to be susceptible to PWSCC and examined in accordance with MRP-139.

In Enclosure 1, Section 3.1 (5) of the RR, SNC states that, "During the review, it was determined that in order to reduce the flooding scenario frequencies due to the postulated rupture of fire protection piping in the auxiliary building areas (210, 211, 228, and 234 for Unit 1 and 2210, 2211, 2228, and 2234 for Unit 2) that supplementary visual inspection of the associated fire protection piping is required every quarter. With these inspections, no piping segments with a contribution to CDF [core damage frequency] greater than 1E-06 (1 E-07 for LERF [large early release frequency]) were identified:'

This appears to be a deviation from the methodology of Code Case N-716 which would apply high safety Significance to the segments with a contribution to CDF greater than 1E-6 and require additional volumetric examinations. Please provide justification for this approach.

Discuss how the quarterly visual exams reduce the flooding frequencies. Were the degradation mechanisms applicable to the fire protection piping evaluated? Discuss the classification results if the quarterly visual examinations are not performed.

M. Ajluni -2 We request that a response be provided within 30 days of the date of this letter.

Sincerely, 7n~

Robert . Martin, Senior Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-348, 50-364 cc: Distribution via Listserv

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