ML19240A327

Draft BTP 7-19 Revision Presentation- August 29, 2019

ML19240A327
Person / Time
Issue date:	08/28/2019
From:	Tekia Govan NRC/NRR/DIRS/IRGB
To:
Govan T, 415-6197, NRR/DIRS
References
Download: ML19240A327 (10)

Text

Modernization Plan #1D BTP 7-19 Update Public Meeting NRC Staff Presentation August 29, 2019

Agenda

• Description of Changes Proposed for BTP 7-19

• Discussion with and feedback from NEI/Stakeholders

• Next Actions

• Schedule 2

Major Changes in Proposed BTP

• Reorganization of BTP to align review guidance with acceptance criteria

• Clarification of applicability

• Incorporation of categorization scheme and graded approach for addressing CCF in DI&C systems

- D3 Assessment

- Qualitative assessment

• Clarification of criteria for addressing spurious operation

• Clarification of criteria for manual system level actuation 3

Process Flow for CCF Assessment

• Determine category of proposed DI&C system (i.e., A1, A2, B1, B2)

• Identify any integration or interconnectivity of the proposed DI&C system with other categories of systems

• If A1 system, perform D3 assessment

- Use of means to eliminate CCF from further consideration

- Use of diverse means

- Use of analysis to demonstrate consequences of CCF is within acceptable limits

• If A2 or B1 system (or integrated B2 system), perform qualitative assessment 4

Spurious Operation

• Evaluate potential for spurious operation due to CCF in DI&C system

• Evaluation should focus on those spurious operations that may induce initiating events that can challenge plant safety

• Design features or defensive measures can be credited to reduce scope of evaluation 5

Manual System Level Actuation and Indications SRM-SECY-93-087 Positions 3 and 4 Clarifications

• Refers to the displays and manual controls described in Position 4 of the SRM on SECY-093-87

• Displays and manual controls necessary to monitor and perform system level actuation of safety critical functions

• Need to be located within the main control room

• Displays and controls provided for Position 4 can be credited as diverse means for addressing Position 3 6

Still Under Consideration Industry Feedback Requested

• How Leak-Before-Break (LBB) criteria can be credited in excluding large break LOCAs and MSLB events from evaluation

• Need feedback from industry regarding crediting LBB

- Applicability to PWRs and BWRs

- What operator or maintenance actions will be taken if a leak is detected to allow LBB to be credited for exclusion of the two events 7

Next Steps and Schedule Milestones Activity Completion Date A.1 Begin revision to draft BTP 7-19 In progress A.2 Category 2 public meeting to discuss the direction of draft BTP 7-19 Completed April 4, 2019 A.3 Category 2 public meeting to discuss topic focused areas of BTP 7-19 Completed June 26, 2019 A.4 Finalize draft BTP 7-19 for staff review Completed August 19, 2019 A.5 Final Category 2 public meeting to discuss BTP 7-19 prior to NRC review and concurrence August 29, 2019 A.6 Agency review and concurrence on draft BTP 7-19 in preparation for public comment October 2019 period A.7 ACRS Subcommittee Meeting November 2019 A.8 Issue Draft BTP 7-19 for public comment period (60 day comment period) December 2019 Public meeting, if needed - January 2020 A.9 Public comment period ends February 2020 A.10 Public Comment/ACRS Comment Resolution Complete March 2020 A.11 ACRS Full Committee Meeting April 2020 A.12 Prepare Final BTP 7-19 Concurrence May 2020 Receive OMB Clearance Approval (non-major rule determination)

A.13 Issuance of Final BTP 7-19 June 2020 8

Questions 9

Acronyms

• BTP: Branch Technical Position

• BWR: Boiling Water Reactor

• CCF: Common Cause Failure

• D3: Defense-in-Depth and Diversity

• DI&C: Digital Instrumentation and Controls

• LBB: Leak-Before-Break

• LOCA: Loss of Coolant Accident

• MSLB: Main Steamline Break

• NEI: Nuclear Energy Institute

• PWR: Pressurized Water Reactor

• SRM: Staff Requirements Memorandum 10