ML17347A128
| ML17347A128 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 12/14/2017 |
| From: | Tennessee Valley Authority |
| To: | Plant Licensing Branch II |
| Hon A DORL/LPL2-2 301-415-8480 | |
| References | |
| Download: ML17347A128 (19) | |
Text
10 CFR 50.69 License Amendment Request Pre-Submittal Meeting with NRC December 14, 2017
Purpose of Meeting
- Background
- Recognize NRC/Industry Efforts
- Recent Operating Experience
- Overview of TVAs efforts to adopt 10 CFR 50.69 for Sequoyah Nuclear Plants (SQN)
- Risk Characterization
- License Amendment Request
- Project Status Sequoyah 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 2
10 CFR 50.69 Overview Sequoyah 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 3 It has the potential to provide the industry substantial cost savings and drive the goals of the Delivering the Nuclear Promise Initiative Reduce Burden Low Safety Significant Areas High Safety Significant Areas Increase Focus Increase Focus
Overview - Categorization Sequoyah 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 4 50.69 Safety Related Non Safety Related Low Risk High Risk
Overview - Exempted Special Treatment Requirements Sequoyah 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 5
NRC/Industry Efforts
- NEI 00-04, 10 CFR 50.69 SSC Categorization Guideline as endorsed in RG 1.201
- Delivering the Nuclear Promise Efficiency Bulletins (EB)
17-09 Industrywide Coordinated Licensing of 10 CFR 50.69
17-16 Industry Coordination of Categorization and Alternative Treatments for 10 CFR 50.69 Implementation Plans
- LAR Coordinating Committee (EB 17-09)
Peer review prior to submittal
Comments resolved prior to submittal
LAR template refinements with each review Sequoyah 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 6
SQN Risk Characterization Internal Events (With Internal Flooding)
Full Scope Peer Review performed against ASME/ANS RA-Sa-2009, as endorsed by RG 1.200 Revision 2 PRA model technical adequacy has been previously evaluated by the Staff for TSTF-425 and TSTF-446 PRA model has been updated three times since the RG 1.200 Rev. 2 peer review Changes to the as-built, as-operated plant are reviewed continuously to determine if model impacts require an off-cycle update Facts & Observations (F&O) closure peer review performed after the Staffs endorsement of the process and in accordance with the NEI 05-04 Appendix X approach Peer Review of F&O findings determined all findings have met closure requirements and do not constitute the criteria for an upgrade Sensitivity studies will be performed in accordance with NEI 00-04 for areas such as Human Reliability Analysis (HRA) and Common Cause Failures (CCF)
Sequoyah 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 7
SQN Risk Characterization - cont.
Fire Risk (Deviation from NEI 00-04)
- NEI 00-04 provides two options: 1) Fire PRA, 2) System, Structure or Component (SSC) list developed from the IPEEE Fire Induced Vulnerability Evaluation (FIVE)
- TVA proposes using the Appendix R Safe Shutdown Equipment List (SSEL)
- Similar to the NEI 00-04 Seismic Hazard (SSEL) approach
- Appendix R is a living program subjected to periodic regulatory inspection
- SSC candidate safety-significance determined by the Fire SSEL
- Includes SSCs credited for mitigation of Multiple Spurious Operations (MSOs) and any deviations/exemptions taken from the fire protection program
- Proposed approach is conservative compared to the FIVE approach because it does not use a successive screening methodology Sequoyah 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 8
SQN Risk Characterization - cont.
- Fire Risk (Deviation from NEI 00-04)
Sequoyah 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 9 Ref. NEI LAR Template, and September 6, 2017 Public Meeting
SQN Risk Characterization - cont.
Sequoyah 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 10 Ref. NEI Slide From 9/6/17 Public Meeting
SQN Risk Characterization - cont.
Seismic Risk Seismic Margins Analysis (SMA) performed for the IPEEE SSEL developed from the SMA SSEL has been reviewed against the current as-built, as-operated plant If the SSC is on the list, it is candidate safety-significant Other External Hazards Screening performed in support of the IPEEE based on the requirements of NUREG-1407 SSCs credited in the screening of an external hazard are considered candidate safety-significant Updated against the current as-built, as-operated plant Sequoyah 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 11
SQN Risk Characterization - cont.
Shutdown Risk Based on the NUMARC 91-06 Key Safety Functions (KSFs)
A running and alternative system/train for the KSFs is designated SSCs that support the primary and alternative methods to satisfy KSFs are candidate safety-significant If SSC failure would initiate a shutdown event (e.g., loss of Decay Heat Removal), the component is safety-significant Sequoyah 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 12
SQN Risk Characterization - Summary Sequoyah 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 13
Summary TVAs risk characterization process follows NEI 00-04 with one exception: the determination of candidate safety-significance of SSCs for internal fire hazards.
The PRA represents the current as-built, as-operated plant.
Treatment of other hazards (non-PRA modeled) represent the as-built, as-operated plant.
Sequoyah 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 14
SQN License Amendment Request Add the following License Condition:
TVA is approved to implement 10 CFR 50.69 using the processes for categorization of Risk-Informed Safety Class (RISC)-1, RISC-2, RISC-3, and RISC-4 structures, systems, and components (SSCs) specified in the license amendment dated [XXXX].
Prior NRC approval, under 10 CFR 50.90, is required for a change to the categorization process specified above.
TVA shall complete the items listed in Attachment 1, List of Categorization Prerequisites, of TVA letter dated [XXXX], prior to implementation.
Sequoyah 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 15
SQN License Amendment Request
- LAR follows the EB 17-09 Template
- One deviation from the NEI 00-04 process (Fire)
- PRA Models include Internal Hazards and Internal Flooding (RG 1.200 Rev. 2, Full Scope)
- No remaining open F&O findings Sequoyah 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 16
SQN Categorization Project A project has been established to perform an initial system categorization feasibility study using the current draft industry guidance Sequoyah 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 17
SQN LAR - Timeline 12/8/17 - Draft LAR reviewed by Industry Coordinating Committee 12/14/17 - Pre-submittal Meeting with the NRC 12/18/17 - SQN PORC reviews LAR 12/22/17 - LAR is ready to submit Sequoyah 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 18