Speeding certification of an improved nuclear reactor design
Three of the six Generation IV (Gen IV) nuclear reactor designs are fast reactors, and in a unique position to meet relevant goals given that they can use minor actinides as fuel. Minor actinides are actinides other than uranium and plutonium, the two major ones, and they are present in abundance in nuclear waste. Thus, fast reactors cannot only generate their own fuel but also use actinides from legacy waste as well as from waste generated in the future by other (thermal) reactors. This significantly minimises the volume of hazardous radioactive waste. Scientists working on the EU-funded project 'European gas cooled fast reactor' (GOFASTR) are focusing on the gas-cooled fast reactor (GFR). Their goal is to address the main challenges to realising viability of the GFR system. Researchers have made tremendous progress in validating the overall system concept and are closing in on the experimental demonstration reactor ALLEGRO. Work on the reactor core has included activities related to neutron transport and core mechanics. Investigators also studied primary systems such as primary pressure boundary components, whose failure could lead to impaired cooling of the fuel and even loss of spent fuel confinement. Furthermore, they developed the concept for power conversion and identified potential materials for the ceramic-based ALLEGRO fuel design. Safety has been a key part of project research and scientists are employing probabilistic methods for reliability assessments and severe accident analyses. To date, studies have confirmed that current safety provisions are adequate in most accident scenarios and provided insight into design modifications to eliminate certain risks and to meet current licensing requirements. GOFASTR is validating the GFR Gen IV design concept with detailed experiments and modelling of the fuels, reactor core and primary systems, including a comprehensive safety analysis. The concept will be demonstrated in the ALLEGRO reactor, which will enable any operational problems to be solved. Getting the green light will speed the delivery of a sustainable, economic and safe carbon-free nuclear energy system.
