ML23206A159
| ML23206A159 | |
| Person / Time | |
|---|---|
| Issue date: | 07/27/2023 |
| From: | Sushil Birla NRC/RES/DE |
| To: | |
| Sushil Birla 301-415-2311 | |
| References | |
| Download: ML23206A159 (6) | |
Text
Identifying Hazards from Engineering Digital I&C Systems:
State of the Art July 27, 2023 Halden (HTO) Workshop:
Modern Hazard Analysis for Safety Assurance Presenter: Sushil Birla Office of Nuclear Regulatory Research Division of Engineering The views expressed herein are those of the author and do not represent an official position of the U.S. NRC.
1
Objective Assess through discussion:
- 1. Can the state-of-the-art techniques identify all significant hazards in the design of a cyber-physical system as simple as a nuclear reactor protection system?
- 2. If not:
- 1. Limitations?
- 2. Promising directions to overcome these limitations?
2
Insignificant: Support consistent judgment Judge Safety claim satisfied unconditionally Residual uncertainty has insignificant effect.
No one can find:
- Any uncontrolled hazard.
- Any unmitigated defeater.
The safety claim is not satisfied with the given evidence.
The evidence gaps are identified.
The safety claim does not hold.
- Fallacies in logic.
- Deficiencies in evidence.
3
State-of-the-art: Meaning State-of-the-art Capability demonstrated in leading-edge implementations.
- Not yet scaled up.
State-of-the-practice Best-in-class; best practices, e.g.:
as seen in leading-edge industry consensus standards Current practice Prolific in many organizations 4
Reference Framework Verification Validation (V&V)
Vp Vc Vr Va Vdd Vi Vt Requirements from NPP Safety Analysis System Development Detailed Plans Concept Requirements Architecture Implementation Testing design HAp HAc HAr HAr HAdd HAi HAi Safety Engineering Adapted from IEEE Std 1012 5
- HAp - Hazard analysis of plans
- HAr - Hazard analysis of requirements
- HAa - Hazard analysis of architecture
- HAdd - Hazard analysis of detailed design
- HAi - Hazard analysis of implementation
- HAt - Hazard analysis of testing (including test specifications and oracles)
- IEEE - Institute of Electrical and Electronics Engineers
- NPP - Nuclear Power Plant
- NRC - U.S. Nuclear Regulatory Commission
- V&V - Verification and Validation
- Vp - V&V of plans
- Vr - V&V of requirements
- Va - V&V of architecture
- Vdd - V&V of detailed design
- Vi - V&V of implementation
- Vt - V&V of testing (including test specifications and oracles) 6