Development And Experimental Research On Thermal Hydraulic Simulation Test Bench Of Spent Fuel Pool Under Lost Coolant Condition

The fuel discharged after reactor radiation is called spent fuel.When the nuclear reactor stops operation,the chain type nuclear reaction also stops.However,due to the decay of the decay product,the spent fuel will still emit a large amount of heat.Spent nuclear fuel removed from a nuclear reactor is usually stored in a spent nuclear fuel tank filled with water and must be stored for a period of time before the heat is reduced to a certain level and then operated and processed.The widely used method is to store spent fuel from the reactor and temporarily store it in the spent fuel pool,so each nuclear power plant has its own spent fuel pool.A cooling system in the pool is used to bring out the decay heat of the spent fuel.In March 2011Japan's Fukushima nuclear power station unit 4 spent fuel pool water system failure,resulting in the spent fuel pool long time loss of circulating cooling water,the water level decline and boiling phenomenon appeared in the heating of spent fuel assemblies,types of accidents so the safety of nuclear power plants in the new design concept of the spent fuel pool water in super base accident in the condition can lead to the evaluation and analysis to get attentionAccording to the nuclear power plant in the spent fuel pool accident loss condition,the possible working conditions,such as heating,boiling,steaming phenomenon,and with the further study and analysis of elevated cladding tube oxidation,zirconium water reaction,direct oxidation of zircaloy cladding caused in fire are been studied.According to the above conditions designed simulated condition test bench spent pool water loss,and according to the analysis of the accident type,designed the simulation bench test and performance test of spent cladding;analysis of the spent fuel pool loss of cooling conditions of thermal hydraulic test-bed design and test scheme,considering the design principle test bench design,the main research contents and key technical problems are analyzed and solved.Through the physical model of the thermal hydraulic test-bed was developed and improved,and the use of unirradiated cladding materials are pre-processed to simulate method of spent fuel cladding,preparation of the spent fuel cladding performance of the required sample and tooling to meet the performance requirements of spent fuel testing needed cladding.Through the test and simulation test preparation and spent cladding,to obtain thermal hydraulic data and precast cladding and spent fuel cladding loss of cooling and dry bare,bare and regain therapid dehydration behavior data under the condition of cooling.Finally,through the analysis of the lack of pool accident conditions problem,designed and developed test bench that meet the performance parameters and the test requirements,using the test rig to carry out thermal hydraulic test,carried out a series of simulated tests,obtained the relevant test data and results,to obtain thermal hydraulic test data and the spent cladding performance test data.Some innovative achievements have been achieved and the contents of the report have been completed.