ML19331A520

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Summary of Meeting with Duke Energy Carolinas, LLC to Discuss Submitted License Amendment Request for Oconee Nuclear Station, Units 1, 2, and 3 Regarding High Energy Line Break Licensing Basis
ML19331A520
Person / Time
Site: Oconee  Duke Energy icon.png
Issue date: 12/12/2019
From: Farideh Saba
Plant Licensing Branch II
To:
Duke Energy Carolinas
Saba F
References
EPID L-2019-LLA-0184
Download: ML19331A520 (17)
v • d • e


Text

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,, **** ... December 12, 2019 LICENSEE: Duke Energy Carolinas, LLC FACILITY: Oconee Nuclear Station, Units 1, 2, and 3

SUBJECT:

SUMMARY

OF NOVEMBER 6, 2019, MEETING WITH DUKE ENERGY CAROLINAS, LLC TO DISCUSS SUBMITTED LICENSE AMENDMENT REQUEST FOR OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3 REGARDING HIGH ENERGY LINE BREAK LICENSING BASIS (EPID L-2019-LLA-0184)

On November 6, 2019, the U.S. Nuclear Regulatory Commission (NRC) staff held a Category 1 public meeting with representatives from Duke Energy Carolinas, LLC (the licensee) at NRC Headquarters, One White Flint North, 11555 Rockville Pike, Rockville, Maryland. The purpose of the meeting was to discuss and receive clarification on the licensee's amendment request (LAR), which was submitted on August 28, 2019 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19240A925), regarding changes to the high energy line break (HELB) licensing basis in the Updated Final Safety Analysis Report (UFSAR) for the Oconee Nuclear Station, Units 1, 2, and 3 (Oconee). The meeting notice and agenda, dated October 18, 2019, are available in ADAMS under Accession No. ML19302E188. A list of attendees and the meeting presentation material are provided in Enclosures 1 and 2, respectively.

The licensee's opening remarks quantified that the August 28, 2019 submittal (current LAR) supersedes the original 1973 HELB licensing basis and the 2011 LAR, for which the NRC suspended its review. The licensee presented background material regarding the Oconee's HELB current basis and a timeline of the HELB licensing. Enclosure 2 of this meeting summary contains the presentation slides that the licensee provided to the NRC staff. The licensee further discussed the commitments associated with HELB. The licensee stated that 8 HELB commitments remain to be completed out of the 45 original HELB commitments from the 2017 re-baseline. The remaining commitments include structural modifications to selected columns in the Turbine Building and control complex cooling modifications.

The NRC staff noticed that these modifications are listed in Attachment 1, "Conforming Actions,"

to the LAR that will be implemented under 10 CFR 50.59 in parallel with the review and approval of the LAR. The NRC staff asked the licensee to clarify what process will be used for revising the listed "Conforming Actions," after the LAR approval. The licensee responded that the changes to the listed modifications will be performed using 10 CFR 50.59 criteria similar changes to other licensing basis like UFSAR.

During the licensee's presentation, the NRC staff asked clarifying questions and the licensee provided additional explanations. The NRC staff asked for clarification on location of the equipment and components listed in Attachment 9 of the LAR. The licensee responded that the equipment and components were in the east penetration room and the west penetration room.

Furthermore, for the equipment listed in Attachment 9 of the LAR, the NRC staff noted that the components were reviewed for the new pressure and temperature profiles and asked the methodology used (i.e. testing and/or analysis) to maintain qualification for the equipment. The licensee responded that analysis was utilized to maintain the qualification of the affected equipment. In addition, the staff is considering an audit to verify the qualification of affected equipment.

The licensee discussed a conforming action of environmental quc;1lification of the safe shutdown facility related components located in the west penetration and the cask decontamination tank rooms. The staff sought clarification on the specific equipment that would be affected, and the licensee responded that the equipment to be evaluated were the cabling and transmitters.

The NRC staff asked information about the protected service water (PSW) piping e.g., the construction code for the PSW piping, the pipe classification per American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, and the operating and design pressure and temperature. The licensee provided operating conditions of the PSW piping and stated that the PSW piping was constructed in accordance with the original Construction Code, USAS B31.1. The NRC staff asked about the ASME Code Classification of the letdown piping inside the Standby Shutdown facility, the licensee indicated they will provide the information at a later date. The staff asked about the non-rigorously analyzed piping as discussed in Section 2.4 of the LAR. The licensee explained that the non-rigorous pipe stress analysis was performed using industry handbooks.

The NRC staff asked clarification regarding operating actions (Attachment 11) that are time critical, human performance (Attachment 12), modification of the columns the turbine building (Attachment 6), details of thermal hydraulic analysis (Attachments 4 and 5), and discussions about the impact of HELB on radiation protection. The NRC staff and the licensee discussed the possibility for regulatory audits on-site or through electronic means and both agreed that an audit would be very beneficial for providing additional clarification during the review. The details of the audits will be discussed and provided in a regulatory audit plan.

The staff did not make any regulatory decisions or commitments at the meeting. No members of the public attended the meeting or were announced over the telephone.

Any inquiries can be directed to me at 301-415-1447 or via e-mail at farideh.saba@nrc.gov.

Farideh E. Saba, Senior Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-269, 50-270, and 50-287

Enclosures:

1. List of Attendees
2. Meeting Presentation Material cc: Listserv

Enclosure 1 List of Attendees

LIST OF ATTENDEES NOVEMBER 6 1 2019, MEETING WITH DUKE ENERGY CAROLINAS, LLC OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3 SUBMITTED LICENSE AMENDMENT REQUEST REGARDING HIGH ENERGY LINE BREAK LICENSING BASIS U.S. Nuclear Regulatory Commission Mike Markley Farideh Saba Mike Mahoney Gordon Curran Steve Jones John Parillo Ahsan Sallman Jorge Cintron-Rivera*

John Tsao Shilp Vasavada Sheila Ray Seung Min Brian Green Dabin Ki Samuel Cuadrado Brian Wittick Duke Energy Carolinas, LLC Dean Hubbard Timothy Brown Jason Patterson Chris King Eric Henshaw Chris Wasik Mclain Hubbard Todd Grant Bob Leatherwood*

Cam Eflin*

Reene' Gambrell

  • Participated by phone*

Enclosure 2 Meeting Presentation Material

High Energy Line Break License Amendment Public Meeting

{_~DUKE One White Flint, Rockville, MD November 6, 2019

~ ENERGY.

Duke Attendees:

  • Howard T Grant (Todd), General Manager, Oconee Engineering
  • Dean M Hubbard (Dean), Director, Oconee Regulatory Projects
  • Timothy D Brown (Tim), Manager, Oconee Regulatory Projects
  • Christopher P King (Chris), Manager, Oconee Regulatory Projects
  • Jason A Patterson (Jason), Lead Engineer, Oconee Regulatory Projects
  • Mclain M Hubbard (Mclain), Senior Engineer, Oconee Regulatory Projects
  • Michael E Henshaw (Eric), Principal Engineer, Corporate Safety Analysis
  • Christopher J Wasik (Chris), Licensing Consultant, Corporate Regulatory Affairs and Licensing
  • Opening Remarks
  • HELB Licensing Timeline
  • Existing HELB Commitments
  • New HELB Licensing Documentation
  • New HELB Conforming Actions
  • Oconee Nuclear Station submitted a license amendment on 8/28/2019 to clarify and update the High Energy Line Break (HELB) licensing basis.
  • The submittal supersedes the original 1973 HELB current licensing basis and the 2011 LAR submittal.
  • This is the culmination of many hours of analysis, plant surveys, and meetings with the NRC technical staff.
  • The revised LAR is based on over 3600 breaks/cracks postulated per unit and over sixty new calculations that were created in the reconstitution project.
  • The remaining 2017 re-baselined HELB commitments are to be completed. New conforming actions are provided in this LAR.
  • HELB was originally licensed during the 1973 timeframe to the Giambusso/Schwencer requirements.
  • No structural damage preventing ability to reach cold shutdown.
  • Single active failure required.
  • Environmental conditions shall not impact mitigating electrical equipment.
  • Oconee responded to the Giambusso/Schwencer letters through design report MOS OS-73.2, "Analysis of Effects Resulting from Postulated Piping Breaks Outside Containment for Oconee Nuclear Station, Units 1, 2, & 3."
  • High Energy (HE) Systems are defined as systems whose normal service (100% power) operating temperature is greater than 200 degrees For normal service operating pressure greater than 275 psig.
  • HELB was not defined as a design basis event in the Oconee CLB.
  • The Atomic Energy Commission approved the design report as part of the initial Units 2 & 3 SER (7/6/1973).
  • July 1998 Oconee completes a self assessment of the HELB Design Basis.
  • December 1998 NRC Inspection Report violations - Oconee committed to reconstitute the HELB licensing basis.
  • 2001-2005 Oconee worked with the NRC to gain agreement on criteria for identifying high energy systems, postulated break and crack locations, modes of plant operations applicable to the postulation of breaks, and application of single failures.
  • 2007 NRC letter provided general agreement with the criteria to be used in the HELB analyses ("McGinty Letter").
  • 2008-2009 Oconee submitted unit specific LARs.
  • 2011 The Unit specific LARs were consolidated into one LAR and resubmitted.
  • 2012 The NRC suspended review of the HELB LAR to concentrate on licensing PSW (which was credited in the HELB LAR).
  • PSW SER Received-August 13, 2014.
  • PSW Installation Complete - December 22, 2015.
  • Revised HELB LAR submitted - August 28, 2019.
  • NRC accepted revised HELB LAR for review - October 1, 2019.

HELB Commitments from 2017 Re-baseline

  • 45 Original Commitments.
  • 8 Remain to be completed.

Notable HELB Commitments Completed

  • Flood outlet devices, flood impoundment, and exterior door improvements for the Units 1, 2, & 3 East Penetration Room (EPR) and Auxiliary Building.

Notable HELB Commitments Completed / continued

  • Remote operators for Unit 1 and 3 valves HP-103 & HP-107 on the individual suction-lines to the 'A' & '8' High Pressure lnjeclion (HPI) pumps.
  • Operator change out of Unit 2 and 3 normal letdown valves HP-1 & HP-2.

Remaining HELB Commitments

  • Structural modifications to selected columns in the Turbine Building.
  • Control Complex Cooling modifications.
  • Remote operators for Unit 2 valves HP-103 & HP-107 on the individual suction-lines to the 'A' & 'B' High Pressure Injection (HPI) pumps.
  • Operator change out of Unit 1 normal letdown valves HP-1 & HP-2.
  • Proposes the PSW system or SSF for HELB mitigation when a HELB results in the loss of plant systems needed for safe shutdown (SSD) inside the turbine building (TB).
  • Proposes normal plant systems (i.e., high pressure injection (HPI),

emergency feedwater (EFW)) or the SSF for HELB mitigation when a HELB results in the loss of plant systems needed for SSD inside the auxiliary building (AB).

  • Proposes normal plant systems for HELB mitigation when a HELB occurs outside of the TB or AB.
  • Excludes certain systems and subsystems from HELB consideration due to the short time these systems operate at HE conditions.
  • Modifies break selection criteria as allowed by Generic Letter (GL) 87-11 and portions of the Standard Review Plan (SRP) Branch Technical Position (BTP) Mechanical Engineering Branch (MEB) 3-1.
  • Proposes the use of NUREG/CR-2913 for the determination of effective length of jets from a HELB or critical crack.
  • Proposes the use of a repair strategy for establishment of cold shutdown (CSD) for breaks postulated to occur in the TB.
  • Maintains HELB as a separate and distinct requirement versus the pipe ruptures considered as design basis events (e.g. Main Steam Line Breaks).

/

New HELB Licensing Documentation

  • Licensing Document Changes
  • Supersedes original 1973 CLB responses to the Giambusso/Schwencer letters.
  • Supersedes the 2011 LAR submittal and associated RAls.
  • Significant rewrite of UFSAR Chapter 3.6, including:
  • Methodology for the identification of HE systems.
  • Methodology for the identification of break/crack locations.
  • Methodology for the determination of break types.
  • Shutdown Sequence Evaluation Criteria.
  • Interaction Evaluation Criteria.
  • Overall HELB Mitigation Strategy (including Safe Shutdown objectives and functions to meet those objectives).
  • No changes to Technical Specifications.
  • Cover Letter
  • Enclosure
  • 1.0 Summary Description.
  • 2.0 Detailed Description.
  • System Design and Operation.
  • Current Technical Specifications Requirements.
  • Reason for the Proposed Change.
  • Description of the Proposed Change.
  • LAR Composition / continued
  • Enclosure / continued
  • 3.0 Technical Evaluation.
  • Purpose and Methodology.
  • Regulatory Requirements.
  • Arbitrary Intermediate HELBs and Critical Cracks.
  • Excluded Systems.
  • Operations Response, Training and Procedures.
  • Thermal Hydraulic Analyses.
  • LAR Composition / continued
  • Enclosure / continued
  • 4.0 Regulatory Evaluation.
  • Precedent.
  • Significant Hazards Consideration.
  • 5.0 Environmental Consideration.
  • 6.0 References.
  • LAR Composition / continued
  • Attachments
  • Attachment 1 Commitments/Conforming Actions
  • Attachment 2 UFSAR Markups.
  • Attachment 3 UFSAR Retypes.
  • LAR Composition / continued
  • Attachments / continued
  • Attachment 9 Regulatory Requirements.
  • Attachment 10 Definitions.

New HELB Conforming Actions

  • Elimination of cross connect Control Rod Drive power between units.
  • Upgraded SSF Letdown line.
  • Environmental Qualification of SSF related components located in the West Penetration and the Cask Decontamination Tank Rooms.
  • Substantial resources and time have been invested to address regulatory questions and to assure that the site is prepared to respond to an unlikely HELB event.
  • A majority of the prior HELB commitments have been met including significant plant modifications that have already been completed.
  • Additional modifications to support an updated HELB response are planned and budgeted to complete the site's HELB response.
  • The site looks forward to working with the NRC to complete the HELB LAR review.

SUBJECT:

SUMMARY

OF NOVEMBER 6, 2019, MEETING WITH DUKE ENERGY CAROLINAS, LLC TO DISCUSS SUBMITTED LICENSE AMENDMENT REQUEST FOR OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3 REGARDING HIGH ENERGY LINE BREAK LICENSING BASIS (EPID L-2019-LLA-0184) DATED DECEMBER 12, 2019 DISTRIBUTION:

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DATE 12/03/19 12/03/19 12/11/19 OFFICE NRR/DORL/LPL2-1/PM NAME FSaba DATE 12/12/19 OFFICIAL RECORD COPY

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