Induced Radioactivity and Waste Classification of Reactor Zone Components of the Chernobyl Nuclear Power Plant Unit 1 After Final Shutdown

Analysis of relative release rates of radionuclides from the RBMK-1500 reactor fuel elements

“…Secondly, modelling of activation is extremely sensitive to the impurity concentration, which is not well known for RBMK construction materials and differs due to various production sites. This knowledge is very important for 60 Co estimation, but from the available sources we know only approximate composition of the impurities both in Zr + Nb cladding material and fuel channel and neutron activation analysis was not performed for these Zr + Nb construction materials (Buchuev et al, 2002;Bylkin et al, 2001;Ancius et al, 2005).…”

Studies on pulsed Nd:YAG laser cutting of thick stainless steel in dry air and underwater environment for dismantling applications

“…In nuclear facilities, dismantling or decommissioning of these structures is essential after a certain number of years of operation depending on its structural conditions and radiological characteristics. Steel structures, which are required to be dismantled, mainly consist of the vessels of the nuclear reactor, reactor internals, cooling tubes, steel fittings, steel blocks, and different steel equipments of reactor reprocessing plants [1][2][3][4]. Since, most of these steel structures have a thickness in the range of 4-20 mm, studies have been performed on laser cutting for this range of thickness.…”

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].…”