Adaption Of China's Safety Regulation Systems To Fusion Reactors

With the development of the International Thermonuclear Experimental Reactor(ITER),parties participating in ITER Project around the world have begun to plan the development and construction of the next generation of fusion reactors,such as EU-DMEO in Europe and CFETR in China,aiming to demonstrate the feasibility of fusion power station.Fusion reactor in the future has the characteristics of high neutron energy,high neutron yield,complex energy spectrum,complex reactor structure,extreme service environment and large storage of radioactive tritium.During its operation and service,it is possible to cause occupational radiation,radioactive release and other risks similar to fission reactors.Thus,how to carry out safety regulation of reactor-level fusion facilities has become one of key topics.Up to now,no country in the world has formally issued the requirements and licensing and regulation framework of nuclear safety for fusion reactors,which leads to the situation that nuclear safety regulation for fusion reactors lacks of legal basis.This work first conducts a comprehensive investigation of the nuclear safety laws and regulations at home and abroad,pointing out that the legalized management of nuclear energy began in developed countries and evolved in more and more countries in the world.The structrue of legal framework for nuclear safety in various countries are logically consistent.It is composed of a set of legal and normative documents formulated and issued by national legislatures and regulation bodies to instruct all sorts of nuclear actions.From the perspective of internal regulatory environment,China has attached great importance to nuclear safety since the beginning of the development of nuclear industry.After many years of development,the nuclear safety regulation of civil nuclear facilities has gradually clarified,and established a nuclear safety regulation framework of international level and keeps pace with the times.This regulatory framework would be the strong basis for the future development of fusion related regulations in China.This paper then further summarizes the relevant work and experience of nuclear safety for fusion worldwide,especially the practice of assessment and licensing for ITER.It is found that,through decades of efforts,the fusion community has initially formed a prototype of fusion safety concept based on the mature framework of the traditional fission safety concept.In this paper,the safety characteristics of future fusion reactor are further clarified systematically.Fusion safety concepts are analyzed and summarized in terms of safety objectives,safety functions,safety analysis and evaluation.The safety characteristics and safety concepts of fusion are compared with those of fission reactor in the aspects of basic principles,device attributes,radiation source terms,reactivity control,and accident mitigation.There are obvious differences in accident types,cooling methods and containment barriers,which lay a foundation for the subsequent analysis of the applicability of the existing legal nuclear safety regulatory framework for fusion.Based on the above mentioned differences,this paper investigates the current nuclear safety laws and regulation system in China comprehensively:firstly analyses the applicability to fusion reactors on each level of the system;second from the perspective of system and safety requirements,the applicability to the fusion reactors of the licensing system,radioactive waste safety management system,radiation protection and safety assessment system,as well as the safety requirements for the design of nuclear power plant are analyzed.On the basis of the relevant analysis results,the possible ways to realize the construction of laws and regulations system of fusion safety supervision in China are discussed.Finally,according to the possible ways to realize the construction of laws and regulations system,taking into account of the current stage of development of fusion reactor,this paper selected the nuclear power plant design safety regulations and safety classification framework of the fusion structure,system and components to conduct a case study on how to revise and establish the corresponding provisions.At the same time,this paper puts forward the supporting policy suggestions to ensure the implementation and promotion of the revision of laws and regulations,and summarizes the possible challenges in the construction of fusion nuclear safety laws and regulations system briefly.