Dominion Energy Requests NRC Approval to Use Later ASME Code Edition

Strategic Insights -

Dominion Energy Nuclear Connecticut, Inc., a subsidiary of Dominion Energy, has submitted a request to the U.S. Nuclear Regulatory Commission (NRC) to use a specific provision of a later edition of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (BPV) Code, Section XI, for several of its power stations. The request, dated September 3, 2020, aims to utilize IWA-4540(b) of the 2017 Edition of the ASME BPV Code for Millstone Power Station Units 2 and 3, North Anna Power Station Units 1 and 2, Surry Power Station Units 1 and 2, and Virgil C. Summer Nuclear Station Unit 1.

The proposed use of the 2017 Edition of the ASME BPV Code would exempt certain components from pressure testing after repair or replacement activities. Dominion Energy has requested NRC approval by September 30, 2020, to support refueling outages scheduled for fall 2020. The company has provided a table detailing the applicable code editions and addendas for each power station, with the majority currently operating under the 2013 Edition of the ASME BPV Code.

The NRC has reviewed similar requests from other nuclear power plants, including Vogtle Electric Generating Plant, Units 1 and 2, and Comanche Peak Nuclear Power Plant, Units 1 and 2. Dominion Energy's request is supported by references to NRC Regulatory Issue Summary 2004-12 and other regulatory documents that outline the use of later editions and addendas to the ASME Code.

Key Takeaways:

  • Dominion Energy Nuclear Connecticut, Inc. has submitted a request to the NRC to use IWA-4540(b) of the 2017 Edition of the ASME BPV Code for several of its power stations.
  • The proposed use of the 2017 Edition would exempt certain components from pressure testing after repair or replacement activities.
  • The request is supported by references to NRC Regulatory Issue Summary 2004-12 and other regulatory documents.
  • The majority of Dominion Energy's power stations are currently operating under the 2013 Edition of the ASME BPV Code.
  • The company has requested NRC approval by September 30, 2020, to support refueling outages scheduled for fall 2020.
  • Similar requests have been made by other nuclear power plants, including Vogtle Electric Generating Plant, Units 1 and 2, and Comanche Peak Nuclear Power Plant, Units 1 and 2.

Statistics:

  • Number of power stations involved: 6 (Millstone Power Station Units 2 and 3, North Anna Power Station Units 1 and 2, Surry Power Station Units 1 and 2, and Virgil C. Summer Nuclear Station Unit 1)
  • Number of components affected: All Class 1, 2, and 3 components located within the ASME Section XI boundaries
  • Requested date for approval: September 30, 2020
  • Applicable code editions and addendas: 2013 Edition of the ASME BPV Code ( majority of power stations), 2017 Edition of the ASME BPV Code (proposed use)

Sources:

  • Dominion Energy Nuclear Connecticut, Inc., Letter to NRC, September 3, 2020
  • NRC Regulatory Issue Summary 2004-12, "Clarification on Use of Later Editions and Addenda to the ASME OM Code and Section XI," July 28, 2004.
  • NRC Memorandum, "Summary of the June 25, 2020, Public Meeting with the Nuclear Industry to Discuss Title 10 of the Code of Federal Regulations Section 50.55a(b)(2)(xxvi) Condition on the Pressure Testing of Class 1, 2, and 3 Mechanical Joints," July 8, 2020.
  • Federal Register, 85 FR 26540, May 4, 2020.