Safety Aspects of New Generation Nuclear Reactors

The current goal of many countries is to achieve carbon neutrality, and nuclear energy will form a major share in this objective. To this end, several new reactor systems are being designed with emphasis on enhanced safety, better fuel utilization, and more economic power generation. Safety in today’s nuclear reactors covers both process, plant, and radiological safety, and these are being improved by several orders of magnitude by design. Fuel utilization is being increased by using advanced fuels with significantly higher burnup and with better fuel and clad integrity to withstand longer residence times. From a neutronic standpoint, the feedback reactivity coefficients are being designed to be negative in all operating phases. These two aims are sometimes opposing, as changes in fuel compositions may lead to lower reactivity feedbacks. Radiological safety becomes extremely important as new energy systems are being considered close to human habitation. This paper will cover new design and safety features of current PHWRs, SMRs, and thorium-based reactors.