ML19308B926
| ML19308B926 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 11/05/2019 |
| From: | Bennett Brady NRC/NRR/DNRL/NLRP |
| To: | |
| Burton B, NRR-DNRL 415-2981 | |
| References | |
| Download: ML19308B926 (23) | |
Text
Advisory Committee on Reactor Safeguards Plant License Renewal Subcommittee Peach Bottom Atomic Power Station Units 2 and 3 Subsequent License Renewal Safety Evaluation Report (SER) with Confirmatory Item November 5, 2019 Bennett Brady, Senior Project Manager Office of Nuclear Reactor Regulation
Presentation Outline Overview of Safety Review of Peach Bottom SLRA SER Section 2, Scoping and Screening Review SER Section 3, Aging Management Review SER Section 4, Time-Limited Aging Analyses Closure of Confirmatory Item Specific Areas of Review - Reactor Vessel and Internals, Irradiated Concrete, and Electrical Cables SLRA Review Conclusion Region Presentation on Inspections and Plant Material Conditions Region Conclusion Summary Conclusion 2
Overview of Safety Review of Peach Bottom SLRA 3
- Application Submitted - July 10, 2018
- Acceptance Determination - September 6, 2018
- Safety Evaluation Report with Confirmatory Item -
October 7, 2019 Unit Initial License Initial License Renewal Application Renewed License Expiration Date Subsequent License Renewal Application 2
10/25/1973 07/02/2001 05/07/2003 08/08/2033 07/10/2018 3
07/02/1974 07/02/2001 05/07/2003 07/02/2034 07/10/2018
4 Dates Location Operating Experience Audit September 17-27, 2018 Rockville, MD In-office Audit November 13, 2018 - April 29, 2019 Rockville, MD Audits and Inspections
SER Overview
- SER with Confirmatory Item Issued October 7, 2019
- Confirmatory Item (CI) 3.0.3.2.3-1 BWR Vessel Internals
- Requests for Additional Information (RAIs)
- 48 RAIs issued, 4 of which were follow-up RAIs 5
SER Section 2 Structures and Components Subject to Aging Management Review (AMR)
- Section 2.1 Scoping and Screening Methodology
- Section 2.2 Plant Level Scoping Results
- Sections 2.3, 2.4, 2.5, Scoping and Screening Results 6
Aging Management Review (AMR)
- Section 3.0 Use of the Generic Aging Lessons Learned Report
- Section 3.1 Reactor Vessel, Internals, and Reactor Coolant System
- Section 3.2 Engineered Safety Features
- Section 3.3 Auxiliary Systems
- Section 3.4 Steam and Power Conversion Systems
- Section 3.5 Containment, Structures and Component Supports
- Section 3.6 Electrical and Instrumentation and Control Commodities 7
SER Section 3
SLRA - Original Disposition of AMPs 11 new GALL programs 8 consistent 3 consistent with enhancements 35 existing GALL programs 8 consistent 27 consistent with enhancements/exceptions 1 plant-specific with enhancement SER - Final Disposition of AMPs 11 new GALL programs 8 consistent 3 consistent with enhancements 35 existing GALL programs 8 consistent 27 consistent with enhancements/exceptions 1 plant-specific with enhancement evaluated against Appendix A1 of the SRP-SLR 8
3.0.3 - Aging Management Programs (AMPs)
SER Section 3
Time-Limited Aging Analyses (TLAAs) 4.1 Identification of TLAAs 4.2 Reactor Vessel and Internals Neutron Embrittlement Analyses 4.3 Metal Fatigue Analyses 4.4 Environmental Qualification of Electric Equipment 4.5 Concrete Containment Tendon Prestress Analysis 4.6 Primary Containment Fatigue Analysis 4.7 Other Plant-Specific TLAAs 9
SER Section 4
Confirmatory Item 3.0.3.2.3-1 BWR Vessel Internals 10 Issue: SLRA, AMP B.2.1.7 BWR Vessel Internals proposed to either:
install core plate wedges or submit for NRC approval an inspection plan for the core plate rim hold-down bolts to mitigate stress corrosion cracking.
Staff determined the second option - a future inspection plan - does not provide sufficient information for the staffs evaluation.
Resolution: Applicant enhances AMP B.2.1.7, in accordance with BWRVIP-25, Revision 1, to:
install wedges or inspect core plate rim hold-down bolts, or demonstrate instead via analysis that the installation of wedges and inspections of the core plate rim hold-down bolts are not required.
The staff determined each of the three proposed options was acceptable.
Specific Areas of SLRA Review
- Reactor Pressure Vessel Neutron Embrittlement
- Reactor Vessel Internals - Irradiation-Assisted Stress Corrosion Cracking
- Irradiated Concrete and Containment
- Electrical Cable Qualification and Condition Assessment 11
RPV Neutron Embrittlement at High Fluence
- Neutron fluence of PBAPS Units 2 and 3 at 80 years estimated at 2.23 x 1018 n/cm2
- Not considered high fluence
- Reactor Vessel Material Surveillance Program (B.2.1.20) enhancement
- Unit 2: withdraw 120 degree capsule (reconstituted specimens) at 60-62 EFPY
- Unit 3: withdraw 120 degree capsule at 60-62 EFPY
- Evaluation of time-limited aging analyses in SLRA Section 4.2
- Implements Regulatory Guide 1.99, Revision 2, including consideration of surveillance program data 12
Reactor Internals Irradiation-Assisted Stress Corrosion Cracking (IASCC)
- IASCC of reactor vessel internals managed by:
- BWR Vessel Internals program (B.2.1.7)
- VT-1 and EVT-1 examinations to detect cracks
- Water Chemistry program (B.2.1.2)
- License renewal application (for 60 years) Section 4.3.2.2 identified a threshold value of 5.0E+20 n/cm2 (E > 1 MeV)for IASCC and embrittlement
- Fluence for core shroud and top guide projected to exceed this value for 80 years
- Dispositioned in accordance with 10 CFR 54.21(c)(1)(iii)
- Inspections of core shroud (BWRVIP-76-R1-A) and top guide (BWRVIP-26-A) 13
14 Irradiation of Concrete and Steel
Concrete The shield wall concrete provides radiation shielding and only the lower 10 ft of the wall concrete performs a structural function
- SRP-SLR thresholds are not exceeded at the peak location
- A plant-specific program is not needed Steel
- Used NUREG-1509 transition temperature approach
- 80-yr nil-ductility transition temperature (NDTT) is less than the lowest service temperature (LST) of 100° F
- Loss of fracture toughness is not an aging effect that needs to be managed for the RPV structural steel component supports Irradiation of Concrete and Steel 15
Electrical Cable Qualification and Condition Assessment 16 Peach Bottom has installed the Smartcover' system on electrical cable manholes to monitor water accumulation:
Float-less transmitter design for level monitoring and alarm Self-monitoring capability Alarms are generated to alert operators if high water level is sensed or a malfunction occurs Staff accepted five-year inspection frequency as an exception for annual inspection per GALL-SLR EQ qualified cables are covered under the EQ program per 10 CFR 50.49 Exelon used the provisions of re-analysis per 10 CFR 50.49 to monitor and extend the qualified life of the cables The staff audited the re-analysis methods and calculations and confirmed consistency with current rules and guidelines
- On the basis of its review of the SLRA and the resolution of the confirmatory item, the staff determined that the requirements of 10 CFR 54.29(a) have been met for the subsequent license renewal of Peach Bottom Atomic Power Station Units 2 and 3.
17 SLRA Review Conclusion
Region I AMP Inspections 18 License Renewal Inspection Program for Period of Extended Operations Inspection Dates Results U2 IP 71003 Phase 1 4Q 2012 ML13029A013 No Findings U3 IP 71003 Phase 1 Not performed N/A U2 IP 71003 Phase 2 March 2013 ML13071A608 No Findings U3 IP71003 Modified Phase 2 4Q 2014 ML14121A474 No Findings U2 and U3 IP71003 Phase 4 4Q 2018 ML18355A401 No Findings
Flow Accelerated Corrosion Program (existing)
Maintenance Rule Structural Monitoring Program (existing)
Ventilation System Inspection and Testing Activities (enhanced)
Outdoor, Buried and Submerged Component Inspection Activities (enhanced)
Fire Protection Activities (enhanced)
In-accessible Medium Voltage Cables not subject to 10 CFR 50.49 Environmental Qualification Requirements (New) 19 AMPs Reviewed During 71004 Phase 4 Inspection Region I AMP Inspections
Region I AMP Inspections 20 ROP Baseline Inspections Inspection Date Age Management Program IP71111.08 ISI Annually alternate units Reactor Pressure Vessel and Internals ISI Program IP71111.07T Heat Sink 2013, 2016, 2019 GL 89-13 Activities Heat Exchanger Inspection Activities IP71111.21M DBAI 4Q 2017 Ensure the selected SSCs that are subject (operating in the post-40-year licensing period) to aging management review pursuant to 10 CFR Part 54 are being managed for aging in accordance with appropriate aging management programs.
IP71152 PI&R Sample The structural monitoring program did not match the procedural requirements for all elements 1Q 2018 Maintenance Rule Structural Monitoring Program IP71152 PI&R Sample Review of Unit 2 Torus Coating Defects 4Q 2015 Torus Water Chemistry IP71152 PI&R Sample Cable reliability program 2Q 2018 Inaccessible Medium-Voltage Cables not subject to 10 CFR 50.49 Environmental Qualification Requirements IP71152 PI&R Sample External flood seal 4Q 2018 Maintenance Rule Structural Monitoring Program IP71152 PI&R Sample U-3, Static O-Ring Pressure Switch Failure 2Q 2019 10 CFR 50.49 Environmental Qualification Requirements
- No findings from License Renewal Program inspections and the AMPs being appropriately implemented
- Green NCV of 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, involving Exelons E-1 EDG underground cable failure
- Green NCV of 10 CFR Part 50, Appendix B, Criterion III, Design Control, involving High Pressure Coolant Injection (HPCI) System Exhaust Pressure Switches Exceeded Documented Qualified Life 21 Resident Inspector Insight and Inspection Results Region I AMP Inspections
- Regional Inspections The inspectors found the aging management programs were being implemented in accordance with the license condition. The region will continue to monitor AMPs using the baseline Reactor Oversight Process.
22 Region Conclusion
Summary Conclusion
- Completes the staffs presentation on the safety review of the Peach Bottom SLRA as documented in the Safety Evaluation Report with Confirmatory Item and the Region I presentation on inspections and plant material conditions
- Additional questions 23