| In the research of Engineering Research Project of Liquid Radwaste Treatment Technology for PWR,the corresponding treatment process is designed for the pollution of Ag-110 m in radioactive waste liquid of nuclear power plant,and the problem of high Ag-110 m content in effluent discharge of active nuclear power plant is solved.Through the test and the result of the technical scheme and equipment design and the equipment in the nuclear power plant,the operation of the test device and the test result are analyzed,and the radioactive waste treatment scheme available for the PWR nuclear power plant is put forward.Two processes,each respectively using a distinctive pretreatment measure,have been designed via the analysis of the source terms of nuclear power plants and the investigation of main treatment technologies.Process I adopts the Ultrafiltration membrane technology as pretreatment while process II adopts flocculation injection combined with active carbon bed treatment.Fundamental researches of the flocculation and active carbon selection for process II have been conducted.Based on their results have the required technical features of flocculation and active carbon and parameters of flocculation injection been determined as follows.The cationic polymerization with a molecule weight,and cocoanut active charcoal with a mesh of 8-80 as the active carbon.In order to examine the performance of these two processes,three parts of experiments were performed.The combination of ultrafiltration unit and ion exchange unit under design flow rate(approximately 350L/h)was tested in Experiment part I,in which the ultrafiltration’s liquid radwaste radioactivity removal efficiency and inorganic ionic exchange bed’s Co removal efficiency were studied.The combination of the active carbon unit and the ion exchange unit was tested in Experiment part II,in which the flocculation injection’s liquid radwaste radioactivity removal efficiency was studied.In experiment part III,tests were conducted to compare the ultrafiltration unit’s removal efficiency with that of the active carbon unit.This Engineering Research Project shows that both process,the flocculation injection-ion exchange – reverse osmosis system process and the ultrafiltration-ion exchange – reverse osmosis system process,have undergone operational tests.The test results show that the radioactivity of normal operation and maintenance period liquid radwaste can be reduced to 20 Bq/L by both processes,which proves the good performance of the two processes.Both processes consist of devices which are not very complex.In the sense of treating the nuclear power plant process liquid radwaste of the same kind,if the radwaste of extreme low activity produced by reverse osmosis treatment is not counted,there will be a significant decrease in the total amount of radwaste with the removal performance not impacted.Both these processes could be recommended as liquid radwaste treatment process for maritime nuclear power plants. |
