The project 4721R01550 focused on creating a systematic assessment method for the use of commercial off‑the‑shelf (COTS) components in safety‑critical instrumentation and control systems of nuclear power plants. In the first work package, a comprehensive literature survey was carried out to capture national and international practices regarding COTS deployment. Fourteen key documents were identified, including the VDI/VDE guideline 3528, the IAEA NR‑T‑3.31 report, the British Standard IEC 62671, the U.S. Department of Energy guidance on commercial grade dedication, and several European and U.S. standards covering hardware, software, and system safety for categories A, B, and C functions. These documents were examined in detail to extract requirements for qualification, categorisation, and documentation of COTS parts.
The survey also extended to 23 countries, with five—Belgium, Finland, Canada, the United Kingdom, and the United States—selected for in‑depth analysis. The comparative study highlighted differences in regulatory expectations, qualification pathways, and risk‑management approaches. For example, the U.S. Nuclear Regulatory Commission emphasizes a rigorous qualification process that includes design review, performance testing, and ongoing monitoring, whereas the U.K. approach places greater emphasis on supplier quality management and post‑market surveillance. These insights were used to map out a set of common themes and gaps that the assessment framework would need to address.
In the second work package, the team synthesized the findings from the literature review and the country studies with the requirements from German nuclear safety regulations, such as the BMU safety requirements and the KTA 3501 reactor protection system standard. The resulting assessment approach evaluates COTS components across nine dimensions: selection and procurement, manufacturer and supplier quality management, design and development process, component complexity, technical characteristics and intended application, qualification procedures, fault detection and prevention, change management, maintenance and support, and documentation. The framework is designed to be applied to components intended for safety‑critical functions classified as category A, B, or C, ensuring that each component meets the appropriate level of reliability and traceability.
No specific numerical performance metrics were reported in the summary, but the framework incorporates quantitative criteria where applicable, such as failure‑rate thresholds, mean time between failures, and test coverage requirements. The assessment tool is intended to be used by plant operators, designers, and regulators to make informed decisions about integrating COTS parts without compromising safety.
The project was executed by a consortium of German research institutions and industry partners over a multi‑year period, supported by funding from the German government under the project number 4721R01550. The collaboration brought together expertise from nuclear safety regulation, industrial engineering, and software safety, enabling a holistic view of the challenges and opportunities associated with COTS integration in nuclear facilities. The outcome is a practical, regulatory‑aligned methodology that can be adopted by operators and designers to safely incorporate commercially available components into future nuclear plant upgrades and new builds.