ML20136A043
| ML20136A043 | |
| Person / Time | |
|---|---|
| Issue date: | 05/19/2020 |
| From: | Mark Yoo NRC/NRR/DNRL/NVIB |
| To: | |
| Yoo M | |
| References | |
| Download: ML20136A043 (16) | |
Text
Reactor Vessel Material Surveillance Programs May 19, 2020 Public Meeting
Purpose
- Share recent experiences with implementation of Reactor Vessel Material Surveillance Programs
- Solicit external stakeholder feedback based on these experiences 2
Overview
- Background
- NRC Guidance
- Recent Experiences
- Summary
- External Stakeholder Feedback 3
Background - Appendix H
- Appendix H to 10 CFR Part 50 established in 1973 to monitor reactor vessel integrity due to its special importance to safety
- Requires monitoring via periodic withdrawal and testing of surveillance capsules
- References ASTM E185-82, Standard Practice for Conducting Surveillance Tests For Light-Water Cooled Nuclear Power Reactor Vessels, as the latest edition 4
Background - ASTM E185-82
- Recommended number of capsules and withdrawal schedule based on 32 Effective Full Power Years (EFPY) (i.e., 40 years)
- Does not explicitly address more than 32 EFPY
- Last capsule 1-2 times End of Life fluence and may be held without testing following withdrawal
- Later editions (e.g., 2002) identify need for additional surveillance for extended plant operation 5
Background - Updated ASTM Standards
- Considered incorporating more recent standards into Appendix H (i.e., 2016 edition)
- Large number of conditions to offset some new requirements (i.e., no corresponding benefit to public health and safety and the environment)
- Public meeting on June 2017
- Stakeholders supported retaining ASTM E185-82 and limited revisions to Appendix H to 10 CFR Part 50
- Staff pursued limited-scope Direct Final Rule -
- Heat-Affected Zone Specimens
- Tensile Specimens
- Correlation Monitor Materials
- Thermal Monitors
- Reporting Requirements 6
NRC Guidance Guidance in the Standard Review Plan (Section 5.3.1 of NUREG-0800)
- The material surveillance program criteria of ASTM E-185 cited in 10 CFR Part 50, Appendix H, is predicated on an assumed 40-year reactor vessel design life. For those applicants proposing a facility with greater than a 40-year design life, the criteria of ASTM E185 must be supplemented to provide for monitoring of the reactor vessel materials for the entire reactor vessel design life 60-year reactor designs have incorporated an additional capsule to account for the extra 20-year design life
- Advanced Passive 1000 (AP1000)
- Advanced Boiling-Water Reactor (ABWR)
- Economic Simplified Boiling-Water Reactor (ESBWR)
- Advanced Power Reactor 1400 (APR1400) 7
NRC Guidance - License Renewal
- Limitations in Appendix H to 10 CFR Part 50 addressed using license renewal guidance
- Additional capsules may be needed for periods of extended operation
- One capsule with neutron fluence greater than RPV end-of-license fluence
- Generic Aging Lessons Learned for Subsequent License Renewal (GALL-SLR) Report - Final Report (NUREG-2191):
- Unnecessary to withdraw capsule if surveillance data for 80-years of operation is already available
- Dont redirect or postpone already scheduled capsule withdrawals for the purposes of attaining projected 80-year neutron fluences 8
Recent Experiences
- Pressurized Water Reactor (PWR)
- Turkey Point Units 3 and 4
- Surry Power Station Units 1 and 2
- Boiling Water Reactor (BWR)
- BWR Vessel & Internals Project (BWRVIP)
Integrated Surveillance Program (ISP) for Subsequent License Renewal (SLR)
- Peach Bottom Units 2 and 3 9
Turkey Point Units 3 and 4 Capsule Schedule 10 0
2 4
6 8
10 12 1970 1980 1990 2000 2010 2020 2030 2040 2050 2060 2070 Neutron Fluence (10^19)
Calendar Year 80 years 80 years 60 years 60 years 40 years 40 years
Surry Power Station Unit 1 Capsule Schedule 11 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 1970 1980 1990 2000 2010 2020 2030 2040 2050 2060 2070 Neutron Fluence (10^19)
Calendar Year 60 years 60 years 80 years 80 years 40 years 40 years
Surry Power Station Unit 2 Capsule Schedule 12 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 1970 1980 1990 2000 2010 2020 2030 2040 2050 2060 2070 Neutron Fluence (10^19)
Calendar Year 80 years 80 years 60 years 60 years 40 years 40 years
- BWRVIP-321* is currently under NRC review
- Methodology involves irradiating, reconstituting, and testing previously-tested ISP capsule materials, as necessary
- Ensure that any BWR pursuing SLR will have appropriate surveillance data available for its representative materials in a timely manner
- Implementation of BWRVIP-86, Rev 1-A** (ISP for license renewal) remains unchanged 13
- BWRVIP-321: BWR Vessel and Internals Project, Plan for Extension of the BWR Integrated Surveillance Program (ISP) Through the Second License Renewal (SLR) - (ADAMS Accession Number - ML19071A248)
Peach Bottom Atomic Power Station Units 2 and 3
- BWRVIP-86, Revision 1-A (ISP for license renewal)
- Aging Management Program enhanced to be consistent with GALL-SLR
- Withdraw and test one capsule per unit
- Separate from the coordinated effort of the BWRVIP (i.e., BWRVIP-321) 14
Summary
- Currently, Appendix H is well-suited to address surveillance requirements for initial 40 years of plant operation
- 60-year reactor designs incorporate an additional capsule beyond ASTM E185-82
- To allow flexibility, license renewal has addressed surveillance needs through the use of guidance 15
External Stakeholder Feedback
- Implications of repeated rescheduling of capsule withdrawals
- Potential enhancements to Regulatory Framework 16