Research On CPR1000 PWR Radiation Source

Since the 18 th Congress of the Communist Party of China,our country pays great attention to environmental protection and ecological management,and the development of clean energy has also become the inevitable choice.As a safe,clean and efficient energy,nuclear energy has naturally become one of the main option for the national policy of developing clean energy.The vigorous development of the nuclear power plant has brought us a huge energy supply.But at the same time,there is also a risk of nuclear radiation.That how to reduce the radiation level of nuclear power plants and reduce the exposure dose of workers is one of the safety goals of nuclear power plants.The fundamentally way to reduce the collectivity dose of nuclear power plant workers is to reduce the radiation level of the unit.In order to reduce the radiation level of the CPR1000 nuclear power units,we have finished this research and analyze of the radiation source.In combination with production practice,the main contents of this paper are as follows:1.The formation of radiation source of CPR1000 PWR nuclear power plant;2.Control method of radiation source of CPR1000 PWR nuclear power plant.Through the summary of the actual working experience of nuclear power plants and the study of relevant theoretical knowledge,the following conclusions are drawn:1.Radiation source of CPR1000 PWR nuclear power plant included fission products and neutron activation products.Fission product is the biggest source of radiation and is the first source of radiation,under normal operating conditions,due to the limitation of time and space,the fission products in the first circuit has little effect on the relative contribution of collective dose.Activation is the main radiation source in the first circuit and auxiliary system,and also the main contribution of the collectivity dose of CPR1000 PWR nuclear power plant.2.One of the most important ways to reduce the effect of fission products on the radiant source of the unit is to reduce the probability of breakage and bad damage.3.To control the production of activated products and to effectively remove the generated activation products are the main methods to reduce the radiation level of the unit.The main measures to control the activated products are as follows:1)Use the materials with low cobalt,nickel and silver as much as possible in the first circuit and auxiliary system to reduce the amount of activated substances from the source.2)By physical or chemical means,control high radioactive substances migrate from the first circuit(especially core)to other auxiliary systems,and through physical or chemical means(such as filtration,purification,p H optimization etc.)to removel the activation products in the first circuit and corrosion products that were not activated.Through the study of the radiation source of the nuclear power plant,the basic methods and work ideas for controlling the radiation source are mastered,but the research on the specific measures is not enough.There are two research directions in the future.1.Further studies on existing source control measures,such as the relationship between the output of primary loop corrosive products and p H,temperature and pressure;in-depth investigation of material components in primary circuit and auxiliary system,and research on alternative materials,etc.2.The study and application of advanced radiation source control technology at home and abroad,such as the ultrasonic decontamination technology of fuel assembly,etc.