[en] Report presents problems related to design of accelerator-driven transmutation system (ADTS). In particular, paper describes a design of 80 kW capacity demonstration ADTS consisting of an accelerator (two-step cyclotron), subcritical reactor and target module. Paper presents layout of the mentioned facility as a whole and characteristics of its basic components and modules

[en] One justifies selection of accelerator-driven system with a liquid-metal lead-bismuth target to be used as a new source of thermal neutrons in place of the aged research reactors. One describes the principal design approaches. The selected energy of a proton beam equal to 150-300 MeV is explained by low cost of accelerator and by reactor spectrum of produced neutrons. Design of a moderator is optimized to ensure the maximum flux of thermal neutrons. A combined moderator representing H₂O, Be and D₂O layers surrounding the target is shown to produce the maximum flux of thermal neutrons

[en] One analyzed the processes occurring in a lead-bismuth coolant. One analyzed nuclear reactions leading to production of polonium nuclides in a lead-bismuth target. One analyzed data on cross sections of production of polonium parent nuclides (Po-210, Po-209, Po-208). One investigated into polonium chemical modifications in coolant. One analyzed procedures to extract polonium using carriers, as well as, procedures of vacuum sublimation and alkaline extraction. One studies procedures of polonium confinement and conservation in some rare-earth metal polonides in solid alkali and in solid lead-bismuth or in solid lead

[en] To evaluate radiotoxicity of a cylindrical 100 cm length and 50 cm diameter lead- bismuth target of electronuclear plants at E_p = 800 MeV and I_p = 30 mA proton beam characteristics subsequent to one year operation of the target was the aim of the paper. One studied total long-lived radioactivity of the target and activity caused by lead and bismuth nuclei fission products and by products of their spallation. One calculated radiotoxicity of targets at different periods of post operation time. The results are compared with radiotoxicity of 500 MW thermal power BRUS-150 reactor facility

[en] The experimental data obtained by the authors on the production cross sections of residual nuclei in the 100-2600 MeV proton interactions with ⁵⁹Co, ^63,65Cu, ^{nat,206,207,208}Pb, ²⁰⁹Bi nuclei (thin targets) and with ^natW nucleus (thick target) are compared with the results of predictive simulation by ten codes. The reliability of the codes is estimated by quantitative ranking separately for a few combinations of proton energies and target materials making allowance for different generation channels of residual product nuclei. Despite quite satisfactory results of comparing between the experimental and simulated data in some cases, none of the simulation codes can be considered to show the required degree of applicability to all of the reactions studied

[en] On the basis of the KASKAD program one calculated spectra of protons and neutrons produced in a lead target irradiated by 1 and 1.6 GeV energy protons. Accumulation of radioactive nuclides is shown to depend on location within target. One made conclusion that from the point of activity and toxicity the lead target irradiated by 1.6 GeV protons was safer in contrast to commercial reactors

[en] Paper contains the report presented by Minister of Atomic Energy Eugenyl O. Adam ov at the plenary meeting of the Conference on Heavy Liquid-Metal Coolants in Nuclear Technologies (October 5-9, 1998, Obninsk, Russia). The key problem addressed in the report deals with ecological safety and efficiency to be ensured when designing and constructing reactors. Problems of reactor waste, nondissemination of nuclear materials and weapon plutonium conversion

[en] One analyzes the records of operation of lead-bismuth coolant (LBC) reactors at former USSR nuclear-powered submarines and the records of reactor accidents occurred when they were put in service. Just one of three accidents is shown to be linked with LBC application (corrosion of structural materials). Two accidents are caused by manufacturing defects and by operator errors. One worked out recommendations to prevent accidents caused by application of LBC at NPP or in accelerator-driven systems

[en] 27/VT bench was designed to serve as a full-scale land-based prototype of reactor for nuclear-powered submarine. The records of the bench operation provide support for selection of intermediate neutron reactor with lead-bismuth liquid- metal alloy used as a primary coolant. The bench tests are principally evidence in favour of good conformity of calculated and experimental values

[en] One discusses the experiment to justify safety of accelerator-driven systems to burn nuclear waste. The first experiment is conducted to measure heat losses caused by natural convection and to measure radiation heat losses. The experiment with Pb-Bi coolant is to be conducted in 4 m height vessel; electric heaters simulate reactor core. The second experiment is conducted using the same facility to intensify coolant natural circulation