ML24283A105
| ML24283A105 | |
| Person / Time | |
|---|---|
| Issue date: | 10/04/2024 |
| From: | Jeffrey Poehler, Robert Tregoning NRC/RES/DE |
| To: | |
| References | |
| Download: ML24283A105 (12) | |
Text
NRC Materials Harvesting Activities Robert Tregoning and Jeff Poehler NRC Office of Nuclear Regulatory Research October 4th, 2024 NEA/NRC Workshop on Concrete Harvesting Rockville, Maryland USA
Materials Harvesting
- Historically, NRC, industry and others have performed research on materials harvested from a broad range of components
- Current harvesting objectives focus on materials aging during long-term operation:
- Confirm results from laboratory experiments and analytical simulations
- Reduce uncertainty of aging and NDE effectiveness
- Support continued evolution of effective aging management 2
Control rod drive mechanism (CRDM)
Nozzle 63 from the North Anna Unit 2 reactor (NUREG/CR-7142)
Current Situation
- Past harvesting efforts were generally been reactive as limited opportunities arose
- More demand than supply
- More recently, several plants have shut down and entered the decommissioning process
- More supply than in the past
- Generally operated for longer periods, which provides more highly aged components for harvesting
- Harvesting can be complex and costly so its important to optimize value
- Current situation calls for a more proactive, strategic approach 3
Proactive Harvesting Strategy 4
- 1. Identify and prioritize harvesting interests
- 2. Consider use of previously harvested materials when possible
- 3. Develop database on harvesting opportunities
Prioritization Criteria 5
Criticalness of Technical Issue Addressed Importance of Harvested Materials over Laboratory Aging Applicability to US Operating Fleet Regulatory Considerations Related to Inspections and AMPs Cost Complexity Technical Programmatic
NRC Prioritization
- Scope
- Metallic components
- Concrete components
- Electrical cables
- Electrical equipment
- Components for fire research
- Initial prioritization completed in 2019:
- Updated priorities: to be completed in 2024 6
Previously Harvested Materials
- NRC staff have catalogued previously harvested materials from prior NRC-sponsored research, including:
- PNNL - large array of components from penetrations up to large piping sections used for NDE research
- Battelle - large primary system piping and elbows
- ANL - smaller irradiated reactor internals materials
- Other sources of previously harvested materials:
- U.S. Department of Energy (DOE) Nuclear Fuels and Materials Library (NFML)
- Studsvik - SMILE-related and other harvested materials
- Halden Reactor Project 7
Harvesting Opportunities Database
- NRC has worked with EPRI to develop a harvesting opportunities database template
- Examples of column headings shown below:
- Gathering information has proven difficult 8
Harvesting Coordination and Outreach
- Partnering and information sharing is essential to manage harvesting costs and complexity
- NRC cooperates with:
- U.S. Department of Energy (DOE)
- Electric Power Research Institute (EPRI)
- International organizations
- Holds periodic domestic and international coordination meetings
- NRC also periodically holds public meetings on harvesting to solicit feedback from stakeholders, the most recent were 6/27/2022 (public meeting) and 10/6/2022 (presentation to Advisory Committee on Reactor Safeguards) 9
Prior International Workshops NRC Ex-Plant Materials Harvesting Workshop (2017)
- Harvesting decision-making
- Planning and implementing harvesting programs
- Using harvested materials in research
- Lessons-learned from prior harvesting efforts NRC-NEA International Metals Harvesting Workshop (2020)
- Develop understanding of common priorities
- Discuss valuable harvesting activities being conducted in participating countries
- Assess interest in collaboration 2nd NRC-NEA Workshop on International Harvesting (2022)
- Reviewed actions and findings from 2020 workshop
- Discuss valuable harvesting activities being conducted in participating countries
- Deeper discussion on harvesting priorities and opportunities for collaborations and information sharing 10
Conclusions and Key Messages
- Harvesting is an important tool for enhancing our understanding of materials and component aging
- NRC is pursuing a proactive harvesting strategy that includes:
- Maintaining and updating harvesting priorities
- Maximizing use of existing materials
- Seeking harvesting opportunities from domestic and international sources that align with priorities
- NRC maximizes collaboration with other organizations to gain the maximum benefit for the lowest possible cost 11
Acronym List ANL Argonne National Laboratory B&W Babcock and Wilcox BWR Boiling water reactor CE Combustion Engineering CGR Crack growth rate DOE Department of Energy EPRI Electric Power Research Institute FT Fracture toughness IASCC Irradiation-assisted stress corrosion cracking INL Idaho National Laboratory XRF Micro X-ray fluorescence MWt Megawatt-thermal NDE Nondestructive examination NEA Nuclear Energy Agency OECD Organization for Economic Co-operation and Development PNNL Pacific Northwest National Laboratory PWR Pressurized water reactor PWSCC Primary water stress corrosion cracking RPV Reactor Pressure Vessel SCC Stress corrosion cracking SEM Scanning electron microscopy SMILE Studsvik Materials Integrity for Life Extension SONGS San Onofre Nuclear Generating Station SS Stainless steel TEM Transmission electron microscopy UPV Ultrasonic pulse velocity XRD X-ray diffraction 12