Preliminary Analysis Of Physics And Safety Characteristics For Small Supercritical Water Cooled Reactor

Since the Fukushima Nuclear Power Station accident in 2011,China has temporarily suspended the approval of all nuclear power plant projects.The "13th Five-Year Plan" clarifies the direction of nuclear power development and we must follow right path,which is safe,efficient and independent.Recently,the ACP100 floating nuclear power plant has been successfully applied.The Hualong No.1 nuclear power plant has been stationed in units 5 and 6 of Fuqing.All of them indicat that the Chinese nuclear power project is being carried out in an orderly manner.Six fourth-generation reactor types were proposed at the GIF.Supercritical water cooled reactors were selected as the only light water reactor type of them.Combined with China’s nuclear power development planning and the development status of small reactors in China,small-power supercritical water reactors are of great significance to the development of China’s future energy.In order to meet China’s future energy demand and reactor miniaturization development trend,a conceptual design of a small supercritical water cooled reactor based on the supercritical water cooled reactor type is proposed in this paper.The supercritical water cooled reactor has the characteristics of simplified structure and high economicality,and it can be combined with a supercritical thermal power plant.Meanwhile the small reactor has the characteristics of flexible site selection,small construction period and small investment,and it can be used for heating and power generation.So combining the two advantages,a small modular supercritical water cooled reactor is designed.Physical analysis,thermal analysis and accident analysis are made based on the reactor.Under the premise of ensuring safety,optimize the program to obtain greater economic benefits,which will alleviate China’s future energy shortage trends.Firstly,physical analysis is made of the core,which decides that the reactor type is a supercritical water cooled reactor.Selecting a fuel component suitable for the supercritical water cooled reactor,then using the PIJ program in the SRAC code to calculate the parameters such as the small group microscopic section of the cell,and then getting the whole cross-section parameters of the components.Combined with the characteristics of the small pressurized water reactor and the boiling water reactor core,the core layout is designed,and the main parameters of the core are calculated by the CITATION program.Secondly,the reactor thermal analysis program is carried out.According to the requirements of the supercritical water cooled reactor and the small modular reactor,and according to the thermal hydraulic design principle of the reactor,the core structure and main thermal parameters of the reactor are determined.The core structure is selected as a dual-flow design.Using RELAP5 system analysis program for steady-state thermal hydraulic analysis.Dynamic analysis of feed water flow step,reactive step and pressure step is introduced on the basis of steady state,and a control system is designed according to the results and characteristics of dynamic analysis.The stability and controllability of the established supercritical water cooled reactor were confirmed.Finally,accident analysis is made for the reactor.And the conditions of the lost flow accident were selected,two sets of passive safety systems are designed,one passive safety injection system and one passive residual heat removal system.The core can be cooled and residual heat can be effectively discharged to ensure the safety of the reactor.The task of this paper lays a foundation for the design of future supercritical water reactors,and has certain academic value and engineering application value.