Progress of EASICS Validation Experiments and Code Comparison of R5, RCC-MRX and ASME III Division V

The “Establishing AMR Structural Integrity Codes and Standards for UK GDA” (EASICS) project was established in 2019 to help support the acceptance of Advanced Modular Reactors, or AMRs, which are typically based on high temperature Generation IV reactors. The EASICS project is aiming to provide guidance on the requirements for codes and standards for the design of AMRs for use in the UK, to ensure that state-of-the art knowledge will be brought to bear on developing the required design and assessment methodologies. The EASICS project started in July 2019 and is looking to complete by December 2021. To support this aim, the work presented in this paper provides an overview of two interacting aspects of the programme. The first is to perform validation tests for high temperature creep-fatigue assessments of a plant relevant component. The second aspect is to use these results, to provide a comparison of internationally recognised approaches for the assessment of high temperature (creep regime) components. This approach will be repeated for two other case scenarios deemed to be plant relevant components. This paper builds upon the initial overview paper presented at the 2020 conference providing an update on progress. One of the cases presented herein, described as the Thin Walled Welded Pipe Test uses specialist testing of a plant relevant component under high temperature loading conditions is underway with some initial results available. The validation testing includes both fatigue tests and creep-fatigue tests on 316H welded thin section tubes. The tubes have been subjected to strain-controlled tension/compression (R-ratio of −1), with some including a displacement controlled dwell. The tests are being conducted at 525°C. An update to the progress of these tests is included herein. To help enhance interaction with the code bodies, and to understand the impact of differences in the approaches, comparative assessments have been performed when adopting R5, ASME Section III Div 5 and RCC-MRx. One comparison will be based around the tests detailed above (tube test). A further assessment comparison will consider the Evasion mock-up tests provided by CEA (sodium based thermal shock tests). The third assessment case is loosely based around a plant relevant assessment within one of the UK Advanced Gas Reactors (AGRs). This paper provides an overview of the results from all these cases using R5, ASME Section III Div 5 and RCC-MRx. The subsequent discussions covers results, differences and potential impact to the codes which will all help to inform a guidance document to support assessing AMRs within a UK regulatory framework.