Radiation characteristics of reactor structures after the final shutdown of a nuclear power plant with VVER

Abstract

The results of computational studies of the radiation characteristics and mass of the structures in the VVER-1200 reactor facility in the AES-2006 design with respect to the activity group as a function of the holding period after final shutdown of the power-generating unit are presented. The three-dimensional program KATRIN was used to obtain the radiation characteristics. It is shown that after final shutdown all metal structures in VVER-1200 will remain radioactive wastes for up to 150 years and the concrete structures after a holding period of more than 60 years will remain in the radioactive materials category.

Composition and structure of simulation models for evaluating decommissioning costs for nuclear power plant units

“…Thus, calculations of the following radiation parameters of power-generating units in nuclear power plants with VVER-440, -1000, -1200, and RBMK-1000 [4,5] have been completed at the National Science Center Kurchatov Institute -the specific activity of the structural elements, the dose rate of ionizing radiation, the distribution of the structural elements over groups of wastes (low-, medium-, and high-level) according to SPORO-2002, the mass of each group of wastes as a function of the cooling time after the unit is finally shut down (to 150 yr). The calculations were performed using a modern computing tool (three-dimensional computing code together with multigroup libraries of neutron-physical constants).…”

Calculation researches for the formation of high-level and long-life medium-level radioactive waste of activation origin for the WWER-1200 reactor of Belarusian NPP

“…Расчетное прогнозирование объемов радиоактивных отходов, образующихся в результате нейтронной активации бетонов радиационной защиты при выводе из эксплуатации действую-щих ядерных установок, рассмотрено в [1,2]. В [3] применено расчетное моделирование активации элементов конструкций реактора при эксплуатации АЭС с ВВЭР-1200. В данной работе в соответствии с российскими санитарными правилами обращения с РАО все конструкции реактора были разделены на три группы твердых РАО (высоко-, средне-и низкоактивные).…”

Radwastes from disassembly of nuclear power plant reactor units

“…The final shutdown sequence for nuclear power plants and start of their decommissioning follows the program of [1]. The methods for calculating the activity of reactor facilities with RBMK and VVER are similar: first the neutron flux for each structure and then the activity and mass of the wastes are determined [2][3][4][5].The present research took account of the following basic activated elements of a reactor facility: VVER [4] -in-vessel facilities (compartment, in-vessel shaft, protective-tube block), vessel, heat-insulation of the reactor shaft, support beam, interior layers of serpentine and construction concrete; RBMK-1000 [3] -graphite masonry, pipes of process and special channels, case of the reactor, biological protection tank, metal constructions of scheme E and OR, support blocks and protective slabs, serpentine fill.The results of the computational investigations of the amount of the solid radwastes formed during decommissioning of a nuclear power plant are presented in Table 1 for currently active reactor units which exhausted their service life at nominal power, neglecting the Bilibino nuclear power plant [3,6].The investigations showed the following: 1) most of the wastes from reactor facilities with VVER are classified as metal structures and construction concrete, while for RBMK, approximately half is the graphite;2) wastes will accumulate to 2049, and their total mass will be ~50000 tons. One of the main factors determining the dynamics of decommissioning of a reactor unit is the presence of storage facilities for holding/disposing of conditioned wastes.…”

“…The final shutdown sequence for nuclear power plants and start of their decommissioning follows the program of [1]. The methods for calculating the activity of reactor facilities with RBMK and VVER are similar: first the neutron flux for each structure and then the activity and mass of the wastes are determined [2][3][4][5].…”