ML21068A029
| ML21068A029 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 03/09/2021 |
| From: | Struble G Luminant, Vistra Operations Company |
| To: | Dennis Galvin NRC/NRR/DORL/LPL4 |
| Galvin D | |
| References | |
| EPID L-2021-LRM-0031 | |
| Download: ML21068A029 (24) | |
Text
TSTF-505, Revision 2, License Amendment Request March 24, 2021 Comanche Peak Nuclear Power Plant (CPNPP)
Pre-Submittal Meeting Risk Informed Completion Times
Agenda Introduction License Amendment Request PRA Models and CRMP Summary Implementation Next Steps Questions Slide 2
Meeting Goals Discuss license amendment content Discuss Identify variances from TSTF-505 Identify Provide Configuration Risk and PRA overview Provide Validate submittal timeline Validate Slide 3
License Amendment Request Slide 4
CPNPP LAR Content Based on TSTF-505, Revision 2 and NEI 06-09 18 LCOs Modes 1 and 2 only New TS Section 5.5 Program (RICT)
Variances from TSTF-505, Revision 2 RICT for LCOs not in TSTF-505 Other variances Slide 5
CPNPP TS 3.3.5, LOP DG Start Instrumentation Conditions not in TSTF-505 or NUREG-1431 (W)
CPNPP TS 3.3.5.B - Two channels per bus for the Preferred offsite source bus undervoltage function inoperable CPNPP TS 3.3.5.C - Two channels per bus for the Alternate offsite source bus undervoltage function inoperable CPNPP TS 3.3.5.D - Two channels per bus for the 6.9 kV bus loss of voltage function inoperable CPNPP TS 3.3.5.E - Two channels per bus for one or more degraded voltage or low grid undervoltage function inoperable TSTF-505 TS 3.3.5.B - one or more Functions inoperable, the functions are not called out separately RICT added for each Required Action CT Slide 6
CPNPP TS 3.5.2, ECCS - Operating Conditions not in TSTF-505 or NUREG-1431 (W)
CPNPP TS 3.5.2.A - One train inoperable because of the inoperability of a centrifugal charging pump.
CPNPP TS 3.5.2.B - One or more trains inoperable for reasons other than one inoperable centrifugal charging pump. - AND - At least 100% of the ECCS flow equivalent to a single OPERABLE ECCS train available.
ECCS is modeled in PRA (Two train system)
RICT added for each Required Action CT Slide 7
CPNPP TS 3.7.4, SG ARVs Condition not in TSTF-505 or NUREG-1431 (W)
CPNPP TS 3.7.4.C - Three or more required ARV lines inoperable.
SG ARVs are modeled in PRA RICT added for Required Action CT Slide 8
CPNPP TS 3.7.8, SSWS Condition not in TSTF-505 or NUREG-1431 (W)
CPNPP TS 3.7.8.A - Required SSW Pump on the opposite unit or its associated cross-connects inoperable.
SSWS is modeled in PRA RICT added for Required Action CT Slide 9
CPNPP TS 3.7.19, Safety Chilled Water Condition not in TSTF-505 or NUREG-1431 (W)
CPNPP TS 3.7.19.A - One safety chilled water train inoperable.
Safety Chilled Water is modeled in PRA RICT added for Required Action CT Slide 10
CPNPP TS 5.5.23, RICT program CPNPP TS 5.5.23 - Establishes the RICT Program with numbering different from TSTF-505 as allowed in the TSTF.
RICT Program description added Slide 11
Other Variances TSTF-505 LCOs and Conditions not in CPNPP TS will not be adopted There are some wording differences that do not impact the intent of the Condition, Required Action, or Completion Time Slide 12
PRA Models and Configuration Risk Management Program (CRMP)
Slide 13
Internal Events and Internal Flood PRA Full Scope Peer review by PWROG completed in March 2011 Performed against requirements in ASME/ANS PRA Standard (2009) and clarifications in RG 1.200, R2 Used to support the TSTF-425 Surveillance Frequency Control Program An Independent Assessment using the Appendix X process of NEI 05-04 was subsequently performed in 2018 All finding level Facts & Observations dispositions were CLOSED All identified suggestion level F&Os were CLOSED All SRs are MET at CC-II or higher, with the exception of two SRs which are MET at CC-I. The assessments of these SRs are not considered limiting since use of model results would be conservative or non-impactive for the TSTF-505 application Slide 14
Internal Fire PRA Peer review by PWROG completed in 2018 Performed against requirements in ASME/ANS PRA Standard Part 4 (2009) and RG 1.200, R2 An Independent Assessment using the Appendix X process of NEI 05-04 was subsequently performed in 2018 All SRs found MET at CC-II after Appendix X F&O Closure Slide 15
Seismic Risk Seismic penalty will be applied to all RICT calculations No CPNPP Seismic PRA Seismic CDF penalty estimated using plant-level HCLPF hazard level with CPNPP seismic hazard curve Seismic risk estimate using NRC approach for GI-199 (NTTF)
Plant level HCLPF SSC based on IPEEE and NTTF reviews Seismic LERF penalty based on Seismic CDF and plant-limiting HCLPF for containment integrity Slide 16
High Wind Risk High Winds CDF/LERF penalty will be applied to all RICTs CPNPP High Winds PRA model is not peer-reviewed Based on the Internal Events PRA model, unresolved missile characterization Penalties for the RICT calculation are developed based upon:
Conditional LOOP probability estimates developed from the PRA model for specific risk-significant components out of service (OOS), and the assumed failure of all SSCs in the plant yard, switchyard, and Turbine Building Initiating Event interval frequencies (IEFs) based on likelihood of wind-speed interval causing a LOOP, and mean hazard frequencies. LOOP recovery given a high-wind event is excluded from the IEF calculations Frequencies across all wind intervals are summed to obtain the penalty Slide 17
Summary of PRA Models PRA Models developed and peer-reviewed Internal Events Internal Flood Internal Fire Updated screening for RG 1.200, R2 hazards Seismic and High Winds not screened Penalties on Seismic and High Winds used in RICT calculations Total CDF / LERF, including penalties, meet RG 1.174, RG 1.177 criteria for Risk Managed Technical Specifications Slide 18
RICT CRMP Model The EPRI Phoenix Risk Monitor (PhoenixRM) tool will be used as the Real Time Risk Monitor Incorporates all PRA models (and RICT penalties) into a one-top model The PhoenixRM At-Power module is currently used for the existing Technical Specification Configuration Risk Monitor Program (CRMP)
The PhoenixRM RICT module will be used for the RICT/RMAT calculations Capable of processing multiple overlapping configurations Slide 19
Implementation Plan Slide 20
Implementation Managed through station-level Change Management Plan Operations coordinates RICT implementation Cross-functional team prepares station for implementation Procedure changes, training, and qualifications Site-wide communications, leadership alignment meetings, and department specific meetings Slide 21
Procedures and Training Procedure changes New RICT/RMTS Program procedure and supporting instructions Address RICT and RMAT, PRA functions, and risk tracking Level 1 Training Hands-on for Operations and Work Control Classroom training on RICT impact on plant operations and station processes Level 2 Training High level training for managers on process, expectations, and limitations Level 3 Training Awareness for all others Slide 22
Whats Next Submit the LAR March/April 2021 Develop and revise procedures, implement PhoenixRM software and train personnel during NRC LAR review Implement within 180 days of approval Slide 23
Questions Slide 24