Carrying out Calculations of Radiation Safety During Unloading and Disassembly of Cores of Spent Removable Parts of Reactors with Liquid Metal Coolant of Submarines
The results of calculations of radiation safety when treatment the spent removable part of reactors of nuclear submarines with a liquid metal coolant are presented in the article. The spent removable part of reactors of nuclear submarines with a liquid metal coolant are sources of intense neutron and gamma radiation. The shield should greatly reduce neutrons and gamma so that total dose rate from neutrons and gamma quanta should not exceed 2 mSv/h on the surface of the container and 0.1 mSv/h at a distance of 2 meter from the surface of the container.
A homogeneous core model was used for calculations. Sources from neutrons in spent fuel, sources of gamma from fission fuel products, from europium in control rods, from the reactor vessel and fuel grids were considered. The dose rates of neutrons and photons were calculated using the MCNP program.
Direct calculations of dose rate of neutrons and secondary gamma are generally reliable. Direct calculations of problems with a source of gamma quanta had large variance values. These problems were calculated with variance reduction methods: geometry splitting with Russian roulette and the MAGIC (Method of Automatic Generation of Importances by Calculation) method.
Values of dose rates were obtained with an acceptable error. The results of the calculations helped in the treatment of spent nuclear fuel. The results of the calculations were used in the design and making of the shield.
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Link for citing the article: Devkina E.V., Suslov I.R., Chernov V.A. Carrying out Calculations of Radiation Safety During Unloading and Disassembly of Cores of Spent Removable Parts of Reactors with Liquid Metal Coolant of Submarines. Izvestiya vuzov. Yadernaya Energetika. 2022, no. 2, pp. 73-80; DOI: https://doi.org/10.26583/npe.2022.2.07 (in Russian).