Developed by the UK Control and Instrumentation Nuclear Industry Forum (CINIF), EMPHASIS is a production excellence assessment. The assessment requires a thorough examination of a manufacturer’s processes, and evidence relating to the design and build of the specific product under evaluation.
Two of PR electronics’ key products have now successfully completed this process.
AWE identified both the PR 9116-EMP and PR 9113-EMP as instruments, which were potentially suitable replacements for obsolete safety-related equipment and that also had potential applications in new-build projects. The organization has an internal policy that any software-based components that are used for nuclear safety applications must be qualified using a “two legged” approach consisting of an assessment of production excellence and by the application of independent confidence building measures. This policy is aligned with the Office for Nuclear Regulation (ONR) Safety Assessment Principle ESS 27.
AWE and PR electronics began discussions on this topic in 2016. It was agreed that the PR 9113-EMP and PR 9116-EMP would be suitable for the overall assessment process, as they had been developed in accordance with IEC 61508:2002. Additionally, both devices had been previously assessed and certified by Exida. AWE employed the services of Atkins to carry out both the EMPHASIS assessment and the independent confidence building measures. The work was commenced with a target of achieving SIL2.
Following successful completion of the EMPHASIS assessment, the independent confidence-building phase was commenced. Depending on the Safety Integrity Level (SIL) required, this may involve measures such as:
- Reviewing the accuracy and validity of the Failure Modes, Effects and Diagnostics Analysis (FMEDA) and subjecting it to a sensitivity analysis
- Performing static analysis of the source code
- Statistical testing to establish the required reliability to a specified confidence level
- Stress testing
- Negative testing
- Reviewing field data
The EMPHASIS assessment of the PR 9116-EMP and PR 9113-EMP identified only three areas that required further clarification. These were of relatively low significance and were easily addressed. The independent confidence building phase included MALPAS semantic analysis of the relevant parts of the source code and extensive physical testing of both devices. Again, these activities only resulted in minor observations that were fed back to PR electronics for consideration.
The resulting report identified that the PR 9113-EMP and PR 9116-EMP satisfied the enhanced UK nuclear industry criteria for use in SIL2 nuclear safety applications. The report was valid for all potential configurations of both devices (including the non intrinsically-safe “A” models).
This approval is testament to the robust and high-quality processes and activities of PR electronics. AWE have agreed to share their findings with the wider CINIF membership (including EDF Energy, Sellafield Ltd., Horizon Nuclear Power, URENCO and Magnox), enabling the PR 9113-EMP and PR 9116-EMP to be used in safety applications throughout the UK nuclear industry.