Approach to UK SMR Component Design

The United Kingdom (UK) Small Modular Reactor (SMR) is being developed by a Rolls-Royce led consortium to provide a market driven, affordable, low carbon energy, generation capability. The UK SMR is a Pressurised Water Reactor (PWR) design based on proven technology with a high level of safety achieved through multiple active and passive systems. This paper presents the approach that has been taken in the early design phases of the pressure vessels for the UK SMR. It considers the key design principles e.g. standardisation, simplification and design for manufacture, inspection and assembly which are being applied to enable the cost and lead-time reductions which are necessary for the UK SMR to be a viable alternative to larger conventional nuclear plants. The Reactor Pressure Vessel (RPV) is used as an example to illustrate some of the key design requirements which need to be addressed. Nuclear components are required to be designed and constructed to standards which are commensurate with the significance of the safety functions which they perform. This paper covers the practice established in the UK of designing to Incredibility of Failure for those components with catastrophic failure modes such as the RPV. It describes the additional features including more stringent materials specification and testing, additional defect tolerance studies and the qualification of manufacturing inspections which need to be addressed in the design to satisfy the high reliability claim.