ML23061A064
| ML23061A064 | |
| Person / Time | |
|---|---|
| Site: | Nuclear Energy Institute |
| Issue date: | 03/14/2023 |
| From: | Uhle J Nuclear Energy Institute |
| To: | Office of the Chief Human Capital Officer |
| References | |
| Download: ML23061A064 (6) | |
Text
Risk-informed Decision-making for Advanced Reactors: Combining Risk and Determinism Jennifer Uhle Vice President Nuclear Energy Institute March 2023
©2023 Nuclear Energy Institute
Risk and Determinism for Operating Plants Regulations based on deterministic requirements provide the foundation for assuring the safety of operating nuclear power plants Risk Analysis provides a tool to assess the risk that remains even when regulations are followed: residual risk is never zero Risk Analysis provides an estimate of the residual risks associated with the deterministic requirements SBO rule reduced residual risk significantly Filtered vents did not reduce residual risk enough Risk Analysis combined with determinism improves safety
©2023 Nuclear Energy Institute 2
Residual Risk Can Never Be Zero Due to CCF Level of Residual Risk in Operating Plants Lots Example Deterministic Requirement:
Redundancy of EDGs Little No One Two Three Four . . . . Twenty-seven EDG EDG EDGs EDGs EDGs EDGs
©2023 Nuclear Energy Institute 3
Safety of Advanced Reactors Operating Plants are Safe Using Determinism and Risk
- Reliance on ac power (for the most part)
- Redundancy of safety systems with margin
- Diverse means to perform some safety functions
- Defense-in-depth through multiple barriers
- Human factors to reduce human error probability
- Knowledge-base benefits from vast operating experience Advanced Reactors are Safer and Will Use Risk and Determinism
- Passive safety systems with margin
- Diverse means to perform some safety functions
- Defense-in-depth through multiple barriers
- Human factors to reduce human error probability
- Uncertainties are larger and addressed with more margin
- Existing knowledge-base will grow with time
©2023 Nuclear Energy Institute 4
Risk-informed Regulatory Decision-making Uncertainties Conservative PRA/ Safety Realism Decisions Improving the State of the Practice
©2023 Nuclear Energy Institute 5
Key Take-aways RIDM has served us well and will continue to do so Advanced reactors offer enhanced safety
- Removal of failure modes through passive safety systems
- Natural processes reduce source term
- Uncertainty is accounted for through additional margin
- Residual risk in not zero - seismic risk NRC must efficiently determine reasonable assurance of adequate protection An efficient, right-sized regulatory framework is needed for wide-scale deployment The Atomic Energy Act indicates that the U.S. should use nuclear power to make the maximum contribution to the general welfare - nuclear power needs to play a key role in carbon reduction
©2023 Nuclear Energy Institute 6