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 12 80 years 10 Neutron Fluence (10^19) 8 60 years 6
40 years 60 years 4
80 years 2
40 years 0
1970 1980 1990 2000 2010 2020 2030 2040 2050 2060 2070 Calendar Year 10
Surry Power Station Unit 1 Capsule Schedule 9.0 8.0 7.0 80 years Neutron Fluence (10^19) 6.0 60 years 5.0 4.0 40 years 60 years 3.0 2.0 80 years 1.0 40 years 0.0 1970 1980 1990 2000 2010 2020 2030 2040 2050 2060 2070 Calendar Year 11
Surry Power Station Unit 2 Capsule Schedule 8.0 80 years 7.0 6.0 Neutron Fluence (10^19) 60 years 5.0 4.0 40 years 3.0 60 years 2.0 40 years 1.0 80 years 0.0 1970 1980 1990 2000 2010 2020 2030 2040 2050 2060 2070 Calendar Year 12
- 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
- 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