Abstract
The UK government has committed to achieving “net-zero” carbon emissions by 2050. Advanced Modular Reactors (AMRs) are small Generation IV reactor that operate at high temperatures. These reactors could play a significant role in providing low carbon electricity generation and decarbonising other industrial processes by utilising heat directly. However the structural integrity challenges for such high temperature plant have been demonstrated in experimental Generation IV plant and the AGR fleet in the UK.
Ensuring the design codes are fit for purpose to satisfy the UK regulatory requirements, including Generic Design Assessment (GDA) and also producing a reliable design that results in a commercially viable plant, is essential. Therefore, the “Establishing AMR Structural Integrity Codes and Standards for UK GDA” (EASICS) project was established to identify the suitability and shortfalls of existing design codes and assessment procedures.
The headline deliverable from the EASICS project was a guidance document, aimed towards vendors looking to deploy AMRs in the UK. However many of the issues raised are relevant to AMR technology regardless of the regulatory regime. This paper provides a summary of the EASICS guidance document. This includes a review of the regulatory requirements for design substantiation in the UK (which unlike many other countries requires consideration of defect tolerance), status of existing design codes (i.e. ASME III Div. 5 and RCC-MRx) and assessment procedure (i.e. R5/R6), comment on the notable technical differences between the available design codes and assessment procedures, highlighting what has been learnt from previous operation of high temperature nuclear plant (including Generation IV reactors and the AGRs in the UK), and an overview of the conclusions.
The conclusions consider the strengths, weaknesses and gaps in the currently available design codes and assessment procedures for commercial deployment of AMRs. It also identifies the development required to address perceived shortfalls and how design codes and assessment procedures may have to be used congruently to provide a solution on a timescale consistent with the UKs ambition for AMR deployment.
