ML21200A256

7/19/2021 E-mail Pressurizer Steam Space Line Classification

ML21200A256
Person / Time
Site:	Millstone
Issue date:	07/19/2021
From:	Richard Guzman NRC/NRR/DORL/LPL1
To:	Sinha S Dominion Energy Nuclear Connecticut
Guzman R
References
EPID L-2021-LRM-0063
Download: ML21200A256 (2)

Text

From: Guzman, Richard To: "Shayan.Sinha@dominionenergy.com"; "timothy.f.olsowy@dominionenergy.com" Bcc: Guzman, Richard

Subject:

RE: Millstone Unit 3 Pressurizer Steam Space Line Classification Item (NSAL-07-9)

Date: Monday, July 19, 2021 5:26:00 PM

Shayan, Thanks for providing a summary of DENCs intended path forward regarding the subject Millstone Unit 3 condition report item. The NRC staff understands that since these components are classified as ASME Class 2 in the Millstone Unit 3 Current Licensing Basis, prior NRC approval is not needed for the proposed path forward where a Class 2 designation would be retained.

Thank you, 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 From: Shayan.Sinha@dominionenergy.com <Shayan.Sinha@dominionenergy.com>

Sent: Thursday, July 08, 2021 4:16 PM To: Guzman, Richard <Richard.Guzman@nrc.gov>

Subject:

[External_Sender] Millstone Unit 3 Pressurizer Steam Space Line Classification Item (NSAL-07-9)

Rich, Westinghouse Nuclear Safety Advisory Letter (NSAL) 07-9 Revision 1 identified the potential for postulated breaks in lines connected to the pressurizer to result in ECCS actuation, in which case the line should be classified as ASME Class 1 in accordance with American National Standards Institute (ANSI) N18.2-1973. However, Millstone Unit 3 has lines that fit this category that currently include Class 2 components. Based on this finding, Dominion opened a Condition Report (CR1113539) in 2019 to initiate further review of this item.

Dominion is in the process of evaluating the piping, valves, tubing, and flexible hoses for the lines within the scope of the issue. Currently, we are finding that no increase in quality or safety would be realized by upgrading the design and replacing the components with Class 1 equivalents or making other design changes. If this conclusion is finalized, our preferred path forward would be to retain a Class 2 designation for the applicable components.

The applicable components were approved as Class 2 within the Millstone Unit 3 Current Licensing Basis (FSAR Chapter 5, etc.), and this classification would not change under this path forward. The regulation 10 CFR 50.55a(z) states in part that A proposed alternative must be submitted and authorized prior to implementation, however, the Class 2 designation has already been

implemented. Also while reviewing precedents, Dominion found that Southern Nuclear Company (SNC) submitted Alternative Requests FNP-ISI-ALT-05-02 and VEGP-ISI-ALT-04-02 for Farley 1/2 and Vogtle 1/2, respectively to address NSAL-07-9 in October of 2017 (ML17285B088). However, SNC withdrew the Alternative Request from NRC review in April of 2018 (ML18113A447), and gave the reason that during a meeting it was determined that the proposed alternatives are not required to be submitted due to NRC previous approval of this issue as a construction code approval. The NRC responded in May of 2018 (ML18115A267), stating that the proposed alternatives are not required due to previous U.S. Nuclear Regulatory Commission (NRC) approval during plant construction. We believe that these conclusions would also apply to the corresponding Millstone Unit 3 item.

Based on the paragraph above, our interpretation is that prior NRC approval would not be required if our preliminary conclusion is finalized (i.e. that no increase in quality or safety would be realized by upgrading the design and replacing the components with Class 1 equivalents or making other design changes). Please let us know if you agree or disagree with this understanding or have any other feedback for our consideration on this topic.

Thank you, Shayan Shayan Sinha Dominion Energy Nuclear Regulatory Affairs Shayan.sinha@dominionenergy.com (804) 273-4687 CONFIDENTIALITY NOTICE: This electronic message contains information which may be legally confidential and or privileged and does not in any case represent a firm ENERGY COMMODITY bid or offer relating thereto which binds the sender without an additional express written confirmation to that effect. The information is intended solely for the individual or entity named above and access by anyone else is unauthorized. If you are not the intended recipient, any disclosure, copying, distribution, or use of the contents of this information is prohibited and may be unlawful. If you have received this electronic transmission in error, please reply immediately to the sender that you have received the message in error, and delete it. Thank you.