ML24172A295
| ML24172A295 | |
| Person / Time | |
|---|---|
| Issue date: | 06/25/2024 |
| From: | Robert Tregoning NRC/RES/DE |
| To: | |
| Rezai, A., NRR/DNRL, 301-415-1328 | |
| Shared Package | |
| ML24159A553 | List: |
| References | |
| Download: ML24172A295 (18) | |
Text
Overview of NRC Materials Research Supporting Long-Term Operation Rob Tregoning Nuclear Regulatory Commission Industry/NRC Materials Technical Exchange Meeting June 25-27, 2024
2 Materials and Aging Research Research objectives
- Improve timeliness of regulatory decision-making on the use of new materials, manufacturing technologies, and inservice inspection techniques through independent and confirmatory research
- Address materials degradation during long-term plant operation
- Inform and enhance the use of risk information in regulatory decision making Strategic Focus Areas
- Support resolution of safety-significant technical issues
- Maintain core capabilities to support emerging technical needs related to corrosion, metallurgy, component integrity assessment, and non-destructive examination
- Enhance modeling/analytical tools to support efficient regulatory decision-making
- Foster collaborations with domestic and international counterparts to stimulate information sharing and cooperative research approaches More information contained in U.S.NRCs Research Prospectus for Fiscal Years 2022 - 2024 (ML22235A651)
3 Long-Term Operation (LTO) & Aging Management What are we doing? Supporting guidance development, coordinating related research activities, developing a systematic approach for harvesting materials and components from reactors.
Motivation: Provide assurance that aging effects will be adequately managed during LTO.
Regulatory Application: Refine, as appropriate, existing aging management programs and guidance Collaboration: DOE and EPRI Significant activities
- Draft report on knowledge gaps in online monitoring and structural health management for NPP LTO in FY24
- Collaborating with EPRI on cables aging management workshop (June 13-14, 2024)
- Workshops on structural materials (metals and concrete) research for LTO (October 1-4, 2024)
4 Materials Harvesting What are we doing? Extracting materials from decommissioning or operating plants for laboratory testing Objective: Improve understanding of material degradation associated with LTO Motivation: Confirm information on aging mechanisms generated through other research programs and operating experience Regulatory Application: Inform aging management approaches for LTO Collaboration: DOE, EPRI, OECD/NEA, other international partners Significant activities
- OECD/NEA SMILE project (2021-2025), potential SMILE 2 project (2026-)
- Obtained Ringhals A690 CRDM nozzles and SGT piece
- Updating NRCs harvesting priorities
5 Irradiation Assisted Degradation (IAD)
What are we doing? Testing highly irradiated materials to characterize irradiation effects on materials performance Motivation: Confirm adequacy of reactor internals aging management programs Regulatory Application: Support reviews of internals inspection/ evaluation guidance, ASME Code changes and associated rulemaking Collaboration: EPRI, OECD/NEA, DOE Significant activities
- Testing Zorita RVI materials
- Participating in OECD/NEA SMILE project
- Participating in FIDES project
6 Primary Water Stress Corrosion Cracking (PWSCC)
What are we doing? Evaluating Alloy 690/52/152 crack growth rate (CGR), crack initiation, and long-term aging performance Motivation: Provide assurance of reactor coolant pressure boundary integrity Regulatory Application: Support reviews of proposed changes to the inspection requirements in the ASME Code and associated rulemaking Collaboration: EPRI, DOE Significant activities
- Evaluating temperature and dissolved hydrogen effects on CGR
- Investigating HAZ, dilution zone, and pre-existing defects effects on crack initiation
- Participating in expert panel CGR evaluations
7 Steam Generator Tube Integrity Program (SG-TIP)
What are we doing? Evaluating effectiveness of SGT NDE Motivation: Confirm adequacy of industry practices and new inspection approaches used for SGT ISI Regulatory Application: Review acceptability of current and new approaches to inspection techniques and changes to SG guidelines as proposed by industry Collaboration: EPRI, CNSC, KINS, KAERI, GRS, MPA, and IRSN Significant activities
- Report evaluating eddy current sizing capabilities for PWSCC at expansion transition regions of SG tubing
- Independent assessments of industry ET approach and probe-probe equivalency.
8 Probabilistic Integrity Assessment What are we doing? Developing probabilistic methods to assess structural integrity of RPV and piping components Motivation: Confirm continued integrity of safety-critical components subject to degradation Regulatory Application: Support review of related Code and industry applications and evaluate emergent operating experience Collaboration: EPRI and CSNI (xLPR)
- Significant activities
- Issue FAVPRO v1.0.x PFM code for RPV integrity and associated manuals and QA documentation
- Continue development and modernization of the xLPR code (i.e., V2.4) for probabilistic piping integrity
- Confirming LOCA frequency estimates from NUREG-1829
9 Piping Integrity What are we doing? Developing and enhancing analytical methods and tools for assessing structural integrity of reactor piping systems; specific topics on
- Leak-before-break (LBB)
- High energy line break (HELB)
- Thermal embrittlement (TE) of cast austenitic stainless steel (CASS) and austenitic stainless-steel welds (ASSW)
Motivation: Confirm integrity of safety-critical piping systems during LTO Regulatory Application: Enhance guidance for piping structural integrity calculations Collaboration: EPRI and CSNI Significant Activities
- Supporting review of industrys risk-informed HELB method
- Considering developing alternative HELB framework for existing and new reactors
- Updating Flaw Evaluation Software (FES) for evaluating PWSCC in piping and CRDM nozzles
- Completing reports on TE of CASS and ASSW
10 Nondestructive Evaluation (NDE)
What are we doing? Evaluating effectiveness and reliability of NDE techniques Motivation: Confirm adequacy of industry procedures and practices Regulatory Application: Support reviews of ASME Code modifications and proposed revisions of current requirements Collaboration: EPRI, IRSN, and PIONIC Significant activities
- Completed report on assessment of ML applied to UT NDE
- Evaluating effectiveness of virtual and synthetic flaws for training and qualification testing
- Assessing NDE capabilities for carbon fiber reinforced composite repairs
- Assessing capabilities of ML and automated data analysis in NDE
11 Concrete Research What are we doing? Evaluating concrete aging and performance for LTO Motivation: Understand significance of aging mechanisms identified through research and operating experience Regulatory Application: Confirm adequacy and reduce uncertainties associated with aging management programs Collaboration: EPRI, DOE, and other international partners Significant activities
- Evaluating effects of irradiation on concrete biological shield structures and concrete-rebar bond
- Exploring harvesting of irradiated concrete materials
- Completing study on creep and shrinkage effects on prestressed concrete containment vessels (PCCVs)
12 Cables Research What are we doing? Evaluating cable aging effects on environmental qualification (EQ) and condition monitoring (CM) for LTO Motivation: Ensure acceptable cable performance and reduce uncertainties associated with aging management programs Regulatory Application: Confirm adequacy of industry-proposed CM techniques to effectively identify adverse cable performance Collaboration: EPRI, DOE, and other international partners Significant activities
- Studied relationship between cable performance and condition monitoring attributes
- Evaluated efficacy of Tan-Delta testing
- Exploring innovative CM techniques and their ability to support condition-based qualification (CBQ)
Condition Monitoring Future Focused Material Science Submerged Cables NRC Research Condition Monitoring Future Focused Material Science Submerged Cables NRC Research NUREG 7300 Published 2023 Cable Condition Monitoring Study:
Condition monitoring while aging samples Performed LOCA testing NUREG 7300 Published 2023 Cable Condition Monitoring Study:
Condition monitoring while aging samples Performed LOCA testing EMDA Uncertainties Review research efforts Summarize findings and attributes Evaluate conclusions and results EMDA Uncertainties Review research efforts Summarize findings and attributes Evaluate conclusions and results Innovative Condition Monitoring Identify innovative methods Evaluate merits and trends Identify methods applicable to CBQ per RG 1.89 Rev. 2 Innovative Condition Monitoring Identify innovative methods Evaluate merits and trends Identify methods applicable to CBQ per RG 1.89 Rev. 2 Motivation NRC Commission direction Performance during LTO:
Degradation and aging effects understanding Condition monitoring EQ extension and service life Aging management Motivation NRC Commission direction Performance during LTO:
Degradation and aging effects understanding Condition monitoring EQ extension and service life Aging management Tan Delta Testing Research Information Letter RES-2021-011 Statistical Analysis of EPRI Tan Delta Guides Evaluated confidence level in EPRI recommended guidelines for test results evaluation Tan Delta Testing Research Information Letter RES-2021-011 Statistical Analysis of EPRI Tan Delta Guides Evaluated confidence level in EPRI recommended guidelines for test results evaluation Condition Monitoring Future Focused Material Science Submerged Cables NRC Research NUREG 7300 Published 2023 Cable Condition Monitoring Study:
Condition monitoring while aging samples Performed LOCA testing EMDA Uncertainties Review research efforts Summarize findings and attributes Evaluate conclusions and results Innovative Condition Monitoring Identify innovative methods Evaluate merits and trends Identify methods applicable to CBQ per RG 1.89 Rev. 2 Motivation NRC Commission direction Performance during LTO:
Degradation and aging effects understanding Condition monitoring EQ extension and service life Aging management Tan Delta Testing Research Information Letter RES-2021-011 Statistical Analysis of EPRI Tan Delta Guides Evaluated confidence level in EPRI recommended guidelines for test results evaluation
14 Summary NRC Office of Nuclear Regulatory Research conducts confirmatory research to establish technical bases that support regulatory decisions and development of regulatory guidance documents NRC staff exchanges information with domestic and international counterparts on materials performance and aging management of nuclear power plant structures and components and conducts independent analyses
- Research results
- Operating experience Research activities are prioritized to address potential safety-significant technical issues.
Long-lead-time confirmatory research is an important consideration in proactive aging management.
- For more information contact: Robert.Tregoning@nrc.gov
15 Select Recently Published Reports 15
2nd Workshop on International Harvesting Cooperation: Summary Report, November 2022 (ML23347A144)
NRC Technical Assessment of Zorita Materials Testing Results, RIL 2022-05, May 2022 (ML22132A039)
Chemical Compositional Analysis and Microstructural Characterization of Harvested Zorita Reactor Pressure Vessel (RPV) Internals, INL/EXT-21-62220, March 2021 (ML22249A319)
Cracking Behavior of Irradiated Ex-Plant Materials, ANL-22/22, June 2022 (ML21124A112)
Primary Water Stress Corrosion Cracking of High-Chromium Nickel-Base Welds at or Near Interfaces - 2020, NUREG/CR-7277, April 2023 (ML23095A385)
CSNI Leak-Before-Break Benchmark - Summary of Phase I, SMiRT 26, July 2022 (ML22161A476).
Technical Support for Component Integrity - Postulated Pipe Rupture Locations, TLR-RES/DE/REB-2022-09, October 2022 (ML22277A504)
16 Select Recently Published Reports 16
Evaluation of Factors Affecting Durability of Carbon Fiber Reinforced Polymer Composite Repairs
- Single-Ply Laminate Study, TLR-RES/DE/REB-2022-02, April 2022 (ML22118A351)
Risk-informed Assessment of French Stress Corrosion Cracking Operational Experience Relative to US Fleet (ML23236A080)
Development and testing of coarse-grained models for ultrasonic simulations of cast austenitic stainless steel, Ultrasonics, September 2023 (ML23318A217)
Evaluating Flaw Detectability Under Limited-Coverage Conditions, NUREG/CR-7304, October 2023 (ML23284A269)
An Assessment of Machine Learning Applied to Ultrasonic Nondestructive Evaluation, ORNL/SPR-2023/3245, February 2024 (ML24046A150)
Classification of Ultrasonic B-Scan Images from Welding Defects Using A Convolutional Neural Network, NPIC&HMIT 2023, July 2023 (ML23241A961)
17 Select Recently Published Reports 17
NUREG/CR-7280, Review of Radiation Induced Concrete Degradation and Potential Implications for Structures Exposed to High, Long-Term Radiation Levels in Nuclear Power Plants, July 2021 (ML21202A265)
RIL 2021-07, Radiation Effects on Concrete - An Approach for Modeling Degradation of Concrete Properties, August 2021 (ML21238A064)
NUREG/CR-7281, Radiation Evaluation Methodology for Concrete Structures, July 2021 (ML21216A100)
RIL 2022-06, Aging of PCCV with Emphasis on Creep and Creep Rupture, March 2022 (ML22075A007)
RIL 2022-07, Assessment of the San Onofre Concrete Susceptibility against Radiation Damage, 2022 (ML22119A092)
18 Select Recently Published Reports 18 Assessing In-Situ Mechanical Properties of ASR-Affected Concrete, NIST Technical Note 2121, February 2021 Assessing Bond and Anchorage of Reinforcing Bars in ASR-Affected Concrete, NIST Technical Note 2127, February 2021 Assessing Cyclic Performance of ASR-Affected Concrete Shear Walls, NIST Technical Note 2180, September 2021 Material Research Support for the Structural Performance of Nuclear Power Plant Concrete Structures Affected by Alkali-Silica Reaction, NISTIR 8415, May 2022