Several R&D efforts have been initiated at industrial, national and European levels to provide decision makers with relevant information and ensure safe Long Term Operation (LTO).
Mandated by SNETP CITE, a platform to support safe, reliable and efficient nuclear systems, the Nuclear GENeration II & III Association (NUGENIA) coordinates the implementation of R&D results to enhance the safety, reliability and competitiveness of Generation II & III NPPs across the EU. NUGENIA has highlighted many of these challenges and research gaps concerning the ageing mechanisms relevant to the safety of nuclear power plants (NPPs).
A number of research projects in previous Euratom programmes produced a greater understanding of ageing mechanism issues.
Projects that specifically addressed Reactor Pressure Vessel (RPV) embrittlement include PERFECT, PERFORM60, SOTERIA, NULIFE and LONGLIFE. The FP7 project LONGLIFE studied embrittlement mechanisms, and the H2020 Euratom project SOTERIA further expanded on this research while also investigating the influence of chemical and microstructural differences on embrittlement mechanisms. Ageing management programs and the implementation of regulator guidelines for extending the operating licenses of NPPs up to 60 years were significantly improved. However, there remain several issues that have not been fully addressed.
non-consensus on the influence of chemical elements causing rpv embrittlement
lack of surveillance tools and lifetime assessments to measure the validity of prediction tools assessing lto safety
need to validate or adapt existing prediction tools for lto beyond 60 years
Continuous research is essential to addressing these remaining issues, complying with safety standards and preparing decision makers for potential lifetime extensions of European NPPs beyond 60 years. STRUMAT-LTO presents itself as the missing puzzle piece in this field of knowledge and aims to fill the remaining gaps to ensure safe LTO of European NPPs.