ML25100A232
| ML25100A232 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 04/10/2025 |
| From: | Halnon G Advisory Committee on Reactor Safeguards |
| To: | |
| References | |
| Download: ML25100A232 (19) | |
Text
Advisory Committee on Reactor Safeguards Operations Subcommittee Greg Halnon Vice Chairman, ACRS Advisory Committee on Reactor Safeguards (ACRS)
U.S. Nuclear Regulatory Commission 1
Subcommittee Meeting
- ACRS Introduction
- NRC Region 1 Inspection Oversight
- ACRS Scope of Review
- Materials Technical Issues and Mitigation
- Site Aging Management Program Performance
- Adequacy of Oversight Program 2
ACRS Purpose 3
ACRS provides independent technical advice to the Commission on matters that concern safety in support of the NRCs Mission NRC Mission Statement The NRC protects public health and safety and advances the nations common defense and security by enabling the safe and secure use and deployment of civilian nuclear energy technologies and radioactive materials through efficient and reliable licensing, oversight, and regulation for the benefit of society and the environment. (January 2025)
ACRS - History 4
1950 1960 1970 1980 1990 2000 2010 Chicago Critical Pile AEC is established Shippingport NRC is established Industrial Committee on Reactor Location Problems established The two Committees are combined into ACRS 1957 Amendment to the Atomic Energy Act of 1954 establishes the ACRS as a Statutory Committee Advising the AEC Enactment of the Energy Reorganization Act transferred the ACRS intact from AEC to NRC AEC forms Reactor Safeguard Committee 2020 ADVANCE Act passed
ACRS and the Federal Advisory Committee Act Openness and Candor Transparency Deliberations are conducted in public Letter Reports and Memorandums are publicly available 5
ACRS Responsibilities Independently reviews and reports to the Commission on safety studies and reactor facility license applications Independently advises the Commission on hazards of proposed or existing reactor facilities and the adequacy of proposed reactor safety standards Independently reviews and advises on matters referred to it by the Commission, including nuclear materials, radiation protection, and waste management Independently reviews and evaluates NRCs regulatory research program and reports to the Commission Upon request, reviews and advises on hazards of DOE nuclear activities and facilities 6
Role of the ACRS Safety Focused, Independent, and Objective
- Independent of NRC staff and reports directly to the Commission
- Consists of up to 15 members appointed by the Commission to 4-year terms (renewable)
- Consultants used to assist some reviews
- Broad, diverse set of academic, industry, and national laboratory technical expertise to enable integrated, multidisciplinary reviews
- Reviews structured to be cross-cutting and not duplicative of NRC staff work
- Reviews focus on safety, scientific and technical rigor, and completeness The ACRS only speaks through its published letter reports.
7
Current ACRS Subcommittees 8
Current ACRS Subcommittees 9
10 ACRS REVIEW PROCESS Committees Reviews and Recommendations Documents and Presentations Provided by Program Offices (NRR, NRO, RES, NMSS, etc.)
Documents and Presentations Provided by Nuclear Industry (Licensees, EPRI, NEI, etc.)
Documents and Presentations Provided by other Government Agencies (DOE, NIST, etc.)
Letter Reports Public Comments White Papers Technical Feedback During Both Full Committee and Subcommittee Meetings Meeting Summaries Site visits, hands-on reviews
Conduct of ACRS Review
- Subcommittee gathers information such as documents, presentations, discussions, site visits
- Subcommittee provides assessment and recommendation for Full Committee consideration
- Full Committee presentation, either summary or brief summary presentation of key issues, and collegial deliberation
- Preparation of Letter Report with conclusions and recommendations to Chairman or EDO
- The Committee speaks only through its Letter Reports (there is an opportunity for added comments) 11
Current ACRS Review Activities 12 Independent Advice to the Commission Licensing Reviews Regulatory Policies and Practices Operating Reactors Safety Oversight Safety Research Reviews New Reactors / Facilities
- Design Certification
- Early Site Permit
- Combined License
- Construction Permit
- Operating License
- New Facilities Operating Reactors
- License Amendments (Power Uprates, Topical Reports, etc.)
Rulemaking
- New/Revised Rules Guidance Documents
- Regulatory Guides
- Standard Review Plans
- Interim Staff Guidance
- Bulletins and Generic Letters Consideration of International Safety Approaches Significant Operating Events Generic Issues Reactor Oversight Process Assessment of Significant Ongoing Research Activities Triennial Reviews of NRCs Regulatory Research Program Nuclear Materials and Waste Waste Management Radiation Health Effects Health Physics
Operating Reactors Safety Oversight
- The ACRS has always been attentive to safety improvements in operation of nuclear power plants.
- Significant contribution toward resolution of many generic safety issues
- Deliberations regarding the role and effectiveness of the NRC Reactor Oversight Process (ROP) in monitoring plant performance 13
Summary
- Plant Operations Subcommittee monitors industry press, NRC reports, Operating Experience programs
- Significant issues are brought before the committee for information gathering and assessment
- Changing industry, regulatory, and technical landscape necessitates safety-oriented yet efficient reviews by ACRS
- Our approach is focused on safety significant issues in applications and regulatory matters
- ACRS reviews provide timely advice to the Commission in support of the NRCs mission 14
For More Information About ACRS 15 https://www.nrc.gov/about-nrc/regulatory/advisory/acrs.html
Alkali Silica Reaction 16
17 Note: Adapted from NRC Presentation, Seabrook Station Public Meeting: Safety Implications and Status of Alkali-Silica Reaction Condition in Safety Related Structures, 12/11/12 Alkali (in Cement)
Reacts with Silica (in Aggregate) and Water Silica Gel Forms Cracking Occurs As Gel Expands Alkali-Silica Reaction
18 Micro-cracking in the aggregate Visual signs of cracking on the surface of the concrete ASR Example Note: Adapted from NRC Presentation, Seabrook Alkali Silica Reaction (ASR) Information Briefing, 4/27/22
19 Safety Implications?
- ASR Progresses Slowly
- Limited to Hi Silica Aggregate
- Limited to Local Regions
- Long-Term Manageable
- No Indications of Rebar Degradation
- Visible Deformations
- Small Building Displacement
- Verification of Adequate Safety Margin Implementation of Monitoring Program Note: Adapted from NRC Presentation, Seabrook Station Public Meeting: Safety Implications and Status of Alkali-Silica Condition in Safety Rerated Structures, 12/11/12