Search academic texts

Information × Registration Number 0225U002371, (0123U101904) , R & D reports Title Radiation safety during transportation of spent nuclear fuel and handling of radioactive waste at Ukrainian NPPs popup.stage_title Радіаційні захисти зі сплавів з Pb+Al Head Hirka Ihor O., Доктор фізико-математичних наук Registration Date 05-03-2025 Organization V.N. Karazin Kharkiv National University popup.description1 The objective of this work is to develope effective radiation protection of transport casks (TC) and options for modification of TC "HI-STAR 190 UA", the methodology of placement of spent fuel assembly (SFA) to ensure radiation safety and heat loads during the transportation of nuclear fuel, as well as the justification of radiation safety of temporary storage of conditioned radioactive waste (RAW) in light hangar storages on the territory nuclear power plant. a) Development of additional radiation protection and heat-conducting elements in the HI-STAR 190 UA TC model while minimizing their weight and maintaining dimensional characteristics. b) Study of the effectiveness of radiation shields made of Pb+Al alloy with boron addition for weakening the gamma-quantum and neutron radiation of spent nuclear fuel in MCNP and PHITS packages. c) Calculating the gamma and neutron radiation of spent fuel outside the TC "HI-STAR 190 UA" with additional radiation protection in the MCNP and PHITS packages. d) Calculations of heat release in the "HI-STAR 190 UA" TC model with heat-conducting elements and determination of the permissible time of spent fuel in the TC. e) Development of an engineering model of TC based on a Pb+Al alloy with boron addition and determination of permissible burnout and holding time of spent fuel (31 SFA) to ensure radiation safety and thermal regimes during transportation. f) Analysis of characteristics of RAW after processing: burning, pressing and vaporization at the Rivne, Khmelnytskyi and Pivdenno-Ukrainian NPPs. g) Justification of the radiation safety of storage of conditioned radioactive waste for light hangar storage options on the territory of the RNPP, KhNPP, PUNPP. popup.description2  Continuous and accident-free operation of nuclear power plants (NPPs) is accompanied by regular reloading: spent nuclear fuel (SNF) is replaced with fresh fuel. Now, SNF is transported to the constructed Centralized Dry Spent Fuel Storage Facility (DSFSF) in the Chornobyl exclusion zone using the technology of HOLTEC, USA. SNFl should be transported in special transport containers (TCs). We have previously shown that when SNF with design parameters is loaded into the TC, radiation safety conditions are not met and thermal loads are exceeded. A number of problems during SNF transportation are solved at this stage of the project. Namely, heat generation in the HOLTEC HI-STAR 190 UA model with additional heat conductive elements proposed by us is calculated and the permissible time for SNF to be in the cask is determined; radiation protection of the cask, which has no world analogues, based on Pb+Al alloy with boron addition and with high radiation safety and heat removal efficiency, is developed. The use of the new type of shielding proposed by us reduces the total weight of the TC by 4.6 tons and brings the dose level closer to the maximum permissible doses or even reduces it by more than half. It has been established that there are places on the surface of the TC where the dose rate exceeds the limit level established according to the calculations of the HOLTEC company. It is found that the required level of radiation safety can be ensured only if an additional layer of neutron shielding material of Holtite-B type is installed in the lower part of the fuel assembly. The studies of the thermal state of SNF during transportation in HI-STAR 190 TCs show the potential to improve thermal safety by optimizing the placement of fuel assemblies inside the TC. The proposed options reduce the maximum temperature level by more than 20 degrees compared to the initial mixed load arrangement. The option with centrifugal dispersion is proved to be more appropriate. Product Description popup.authors Azarenkov Mykola O. Alokhina Svitlana V. Berezhnoi Yurii A. Hakh Andrii H. Kalashnyk Nataliia V. Kovtun Volodymyr Ye. Lazuryk Valentyn T. Lazuryk Valentyna M. Mazilin Bohdan O. Makhnenko Halyna V. Okseniuk Ivan I. Popenko Nataliia V. Prokhorets Svitlana I. Rudychev Yehor V. popup.nrat_date 2025-03-05 Close