Application of low-current accelerators for modeling ecologically acceptable utilization of plutonium

Abstract

For a long time electronuclear installations have been viewed as breeders of easy-fissioning 239pu and 233U in uranium and thorium targets, which can then be used in reactors (see, for example, [1][2][3][4]). This approach requires accelerators with currents = 100 mA, the construction of which is a complicated and in some respects still an unsolved problem. Although specialists assert that these difficulties are all of a purely technical character, the production and, especially, operation of such giant machines will encounter difficulties, and this will be the main argument against electronuclear technology.The next stage was the concept of a closed cycle of one accelerator --one reactor with burnup of long-lived wastes [5]. In this case, the intensity Of the accelerated-particle beams can be limited to values approximately 10 times lower and even to a current = 1 mA, if a system of several accelerators is used (this is also preferable from the technological standpoint [6]). The proposed approach has opened an avenue for producing already in the next few years electronuclear power plants based on uranium and thorium [7][8][9]. At the same time, there is also an important inverse problem --ecologically acceptable and economically advantageous utilization of the reserves of pure weapons plutonium and technical plutonium, contaminated with other nuclides, from nuclear power plants [7, 8].Electronuclear technology is promising for burning of plutonium, since the neutron high yield in the plutonium irradiated by protons, deuterons, or et particles even with an energy of only several hundreds of MeV makes it possible to use well-assimilated types of reactors for developing such a technology. Although a large portion of the energy of the primary beam is lost in ionization processes, the fission energy is many times greater than the losses, especially since the "ionization heat" released in the target can be utilized. Radiation safety, which substantially increases the complexity and operating costs of highenergy accelerators, also simplifies.As a first step in studying plutonium electronuclear systems, it is suggested that the core of an IBR-30 plutonium reactor (which is to be disassembled in connection with the development of the IREN neutron spectrometer) operating in the subcritical regime be combined with a 650 MeV proton cyclotron at the Joint Institute of Nuclear Research. Having placed the core on a mobile platform, it is also possible to use the 9 GeV beams of protons, deuterons, and c~ particles of the synchrocyclotron.An attractive aspect of such a design is its relatively low cost and the possibility of rapid implementation, since almost all required equipment and parts of the hybrid installation are already available. Moreover, morally obsolete reactors and accelerators obtain a second life. The proposed, quite powerful, electronuclear installation can be used to estimate the limits of the admissable coefficient Keff and to study its possible fluctuations,* and to investigate the different regimes of breed...