ML20075A032

Request for Additional Information (E-mail Dated 3/15/2020) Alternative Request IR-4-03 for Use of an Alternative Non-Code Methodology to Demonstrate Structural Integrity

ML20075A032
Person / Time
Site:	Millstone
Issue date:	03/15/2020
From:	Richard Guzman NRC/NRR/DORL/LPL1
To:	Sinha S Dominion Energy Nuclear Connecticut
Guzman R
References
EPID L-2020-LLR-0038
Download: ML20075A032 (2)

Text

From: Guzman, Richard To: Shayan.Sinha@dominionenergy.com

Subject:

Millstone Unit 3 - REQUEST FOR ADDITIONAL INFORMATION: Alternative Request IR-4-03 For Use of an Alternative Non-Code Methodology to Demonstrate Structural Integrity [EPID: L-2020-LLR-0038]

Date: Sunday, March 15, 2020 7:15:08 PM

Shayan, The NRC staff is reviewing the information provided in the subject alternative request dated March 14, 2020, and has determined that additional information is needed to complete its review. Shown below is the NRC staffs request for additional information (RAI) question.

Please provide your response as soon as possible, in support of DENCs requested approval date as specified in the submittal. Please contact me if you have any questions.

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Rich Guzman Sr. PM, Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Office: O-9C7 l Phone: (301) 415-1030 Richard.Guzman@nrc.gov REQUEST FOR ADDITIONAL INFORMATION (RAI)

DOMINION ENERGY NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION, UNIT 3 ALTERNATIVE REQUEST IR-4-03 FOR USE OF AN ALTERNATIVE NON-CODE METHODOLOGY TO DEMONSTRATE STRUCTURAL INTEGRITY OF CLASS 3 MODERATE-ENERGY PIPING DOCKET NO. 50-423 By letter dated March 14, 2020, Dominion Energy Nuclear Connecticut, Inc. (Dominion, the licensee) submitted relief request (RR) IR-4-03, to use a non-code methodology in lieu of repair allowed by the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI, IWA-4000, in order to address a through-wall leak in a reinforced branch connection of the service water system at Millstone Power Station, Unit 3 (Millstone 3). Specifically, the licensee requested NRC verbal authorization of the alternate method for evaluating structural integrity of the through-wall leak condition identified on the Millstone 3 A train service water header. The NRC staff is reviewing the submittal and has determined that additional information as requested below is needed to support completion

of its review.

Request for Additional Information for RR IR-4-03 In the licensees relief request under Compensatory Actions, it states that ultrasonic testing (UT) will be used to verify that the degradation of the piping base metal adjacent to and under the reinforcement pad fillet weld and the reinforcing pad base metal is within the bounds of the structural integrity determination provided in Attachment 2. Please define the acceptance criteria which will be used for the UT examinations as described in your compensatory actions. Please clarify that if the structural integrity determination does not meet the bounds of the analysis, the licensee will repair the location in accordance with the ASME Code immediately.

Please provide a sketch which provides the location of the portion of joint that will be monitored by UT for structural integrity. Identify the potential leak paths, system water flow, and areas to be examined by UT as part of your compensatory actions.