SMR technology demonstration: are there major gaps in safety knowledge?

A comprehensive technology demonstration is an important component for establishing a novel technology, such as a Small Modular Reactor (SMR). The aim of such a program can be defined as providing objective and auditable evidence that the technology will meet or exceed the relevant requirements. Technology demonstration may have various aspects, such as those related to manufacturing of components, construction of the facility, operability, and safety. It is the last aspect that is explored to some depth in this paper, namely the need to demonstrate, to an appropriate level of confidence, that a novel technology will be safe. We will show how the need for such a demonstration is anchored in fundamental safety principles and can be achieved through a combination of methods. Then, an approach to identifying and prioritizing the focus areas for demonstration of a safety case is described. It is apparent that it is not always realistic to expect the same depth of the knowledge at the moment when a novel technology is brought up for licensing as we have come accustomed to expect for mature water cooled reactor designs. Potential lack of knowledge should not however lead to a weakness in a safety case. (author)