Safety justification for upgraded floating nuclear power plant reactors under external effects

Abstract

Object and purpose of research. This paper discusses an upgraded floating nuclear power plant (NPP) to justify its nuclear and radiation safety under external effects. Materials and methods. The authors follow the methods of system analysis. Main results. Following the requirements of Russian Maritime Register of Shipping (RS) and Federal Service for Ecological, Technological and Nuclear Supervision (Rostekhnadzor) to the safety of upgraded floating NPP reactors, this study explored the incidents related to external loads on floating NPPs, drawing up the list of initiating events and their respective probabilities of occurrence, as well as predicting final states of floating NPPs and their reactors as per the data on hull and equipment damage, with the assessment of corresponding radiation hazards. Conclusion. Nuclear and radiation safety justification of upgraded floating NPP was justified as per the regulations in force and Krylov State Research Centre procedures. If an icebreaker rams the reactor compartment of upgraded floating NPPs at the speed exceeding 6.5 knots, primary coolant circuit might leak, thus triggering a radioactive discharge into sea water that might create a contaminated spot up to 325 m in size. The worst-case scenario in terms of radiation hazard is a hypothetical (unlikely) off-design case of a medium-range airliner crash onto the upgraded floating NPP destroying all reactor protection barriers, so all humans within the range of 3.8 km might receive dangerous radiation doses and all population within the range of up to 20 km will have to be evacuated.