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It is shown that the concept of relativistic heavy-nuclear energy is untenable. Using a large group of different experiments in the proton energy range 0. it is demonstrated that the high-energy hadron transport program SHIELD, which is based on modern nuclear models, has predictive power. The interaction of protons with energy ranging from 0.1 to 100 GeV with a simple model system target + blanket, containing heavy elements (lead, thorium, depleted and enriched uranium), is examined. The energy release, neutron production, and production of fissile isotopes in the system are calculated. It is found that for all values of the proton energy which are considered the useful yield of energy in weakly fissile media is inadequate (thorium, depleted uranium) and is completely absent in non-fissile media (lead). A blanket containing enriched uranium will be necessary in order to use the scheme for useful production of energy. In this variant, the optimal proton energy is 1-3 GeV, which corresponds to the conventional concept of electronuclear facilities whose main purpose is to transmute nuclear wastes and produce electricity at the same time.The concept of commercial production of energy using accelerators to accelerate heavy charged particles has been discussed since the beginning of the 1950s. According to this concept, a beam of protons or ions with sufficiently high energy should generate a large number of neutrons on interacting with a heavy target. Facilities which function according to this principle are said to be electronuclear facilities. The accelerator must be a high-current accelerator in order to produce more neutrons, and for this reason the target is a complicated technical system. An advantage of electronuclear facilities over conventional nuclear reactors is that there is no possibility of reactivity accidents.

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Nuclear power production is not at present in need of the extensive breeding of nuclear fuel. There are sufficient reserves of natural uranium. In addition, at the beginning of the twenty first century use will be made of surplus weapons material being released, highly enriched uranium and plutonium. However nuclear power production, which lays claim to replacing a substantial fraction of organic fuel, cannot exist without the breeding of nuclear fuel. Wide-scale nuclear power production in the twenty first century will require all nuclear fuel reserves to be activated, both uranium and thorium. Aiming for this policy and taking account of the time required for work to develop and master a new technology in nuclear power production it is necessary even now to begin to assimilate new fuel cycles. Considerable experience has been accumulated to date on the uranium-plutonium cycle which, from the start, was based on military programs. In the early days, thorium was also considered in military programs, but did not find application in them. Nevertheless, interest in it for nuclear power production is constantly being restored. A wide range of uses for thorium is proposed when considering it for nuclear power production, from the direct replacement of the fuel in operating power reactors to fundamentally new nuclear power schemes with the introduction of a reactor-accelerator combination and a fuel cycle with the depletion of actinides. Various possibilities have been considered for using thorium in VVI~R, RBMK, VTGR, fast, liquid-salt, and other reactors. Recently, along with the advantages indicated, the possibility has been studied of utilizing thorium in operating reactors or reactors under development in order to solve the problem of the nonproliferation of fissile materials. A version of a VVI~R reactor has been developed at the Kurchatov Institute Russian Scientific Center in which it will very shortly be possible to test and provide for the economic efficiency of thorium technology. The implementation of this concept will lower the risk of the proliferation of fissile materials, reduce the accumulation of radioactive waste, improve the practical efficiency of the thorium cycle, increase safety, supplement the fuel base, and deliver the possibility of utilizing surplus stocks of plutonium and uranium. NEW APPROACH TO INCORPORATING THORIUM IN NUCLEAR POWER PRODUCTIONInterest in thorium as a nuclear raw material arose from the first steps of the atomic era in view of the possibility of using it in order to obtain weapons 233U. However preference was given to highly enriched 235U and plutonium for military purposes.The characteristic features of thorium constantly draw attention to incorporating it into nuclear power production. The considerable natural reserves of thorium broaden the fuel base for nuclear power production and reinforce the preconditions for its wide-scale development. One of the principal problems of nuclear power production is that of guaranteeing the safe burial of the long-lived components of ...