ML25078A076
| ML25078A076 | |
| Person / Time | |
|---|---|
| Issue date: | 03/11/2025 |
| From: | Ball E, Dejesus-Segarra J NRC/RES/DRA/PRAB |
| To: | |
| References | |
| Download: ML25078A076 (6) | |
Text
RIC 2025 From Data to Decisions: The Role of Standardized Plant Analysis Risk (SPAR) Models in Nuclear Safety Jonathan DeJesus and Erick Ball Office of Nuclear Regulatory Research Division of Risk Analysis Probabilistic Risk Assessment Branch
Data
- System information
- Licensees share system information with Idaho National Laboratory
- Quantitative https://nrcoe.inl.gov/
- Initiating event frequencies
- Example: loss of offsite power
- Basic event probabilities
- Number of failures and number of demands: failure probability per demand; typically, fails to start
- Number of failures and number of hours: failure rates per time; typically, fails to run success failure 2.36 x 10-2 per year SBO = Station Blackout
Case Study: Using the SPAR Model for Inspection Planning (1 of 3)
Inspection guidance from Inspection Procedure 71111.04 (ML23121A148)
Select systems or trains with a high risk significance for the current plant configuration (considering out-of-service, inoperable, or degraded condition) 3 Next step: Map the current plant configuration into the SPAR model Hypothetical inspection sample:
Emergency diesel generator DGN02 and support systems during emergency diesel generator DGN01 maintenance the week of January 30, 2025.
Disclaimer: The model used in this exhibit does not represent an actual plant. It is a model the NRC uses for training purposes.
Case Study: Using the SPAR Model for Inspection Planning (2 of 3) 4 1.
Select the system.
2.
Select the component.
3.
Modify the component failure mode to Out for Test &
Maintenance.
Case Study: Using the SPAR Model for Inspection Planning (3 of 3) 5 4.
Change the duration to 3 days.
8.
Allow time for calculation to run.
7.
Select Finish.
6.
Document basis for duration in the analysis notes.
5.
Add short analysis title.
Decision Input: Using the SPAR Model for Inspection Planning 6
Insights Increase in core damage frequency dominated by fire (FRI) events and human performance (i.e., XHE basic events)
Suggested systems for inspection: Station Blackout Diesel Generator (SBO DG) and Auxiliary Feedwater (AFW)
Takeaway: SPAR models provide an input for performing risk-informed inspections, which enable nuclear safety.