Light-water thorium reactor VVÉR-T

Abstract

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 ...

Preliminary results of calculations for heavy-water nuclear-power-plant reactors employing 235U, 233U, and 232Th as a fuel and meeting requirements of a nonproliferation of nuclear weapons

“…These results are presented along with the results of the respective calculation for a light-water reactor that employs the same fuel (VVER-Т) [5]. It should be noted that two types of fuel elements are assumed to be used in VVER-T reactors: seed and blanket ones.…”

“…Below we presented the results of preliminary calculations for a gas-cooled heavy-water reactor of this type and perform a comparison with a similar VVERbased reactor [5]. The calculations were carried out by B.P.…”

“…Reactors of this type have yet another advantage: 233 U fission leads to the appearance of substantially smaller amounts of transuranium isotopes and, hence, long-lived radioactivity in relation to the fission of 235 U or 239 Pu † Deceased. and 241 Pu, and this facilitates the transmutation of radioactive waste.As applied to PWR light-water reactors, reactors of this type were calculated by Radkowsky and Galperin [4], while, as applied to VVER reactors, this was done by Ponomarev-Stepnoi and his coauthors [5].Below we presented the results of preliminary calculations for a gas-cooled heavy-water reactor of this type and perform a comparison with a similar VVERbased reactor [5]. The calculations were carried out by B.P.…”

“…As applied to PWR light-water reactors, reactors of this type were calculated by Radkowsky and Galperin [4], while, as applied to VVER reactors, this was done by Ponomarev-Stepnoi and his coauthors [5].…”

Neutron-physical and heat-engineering aspects of uranium-graphite reactors loaded with enriched-uranium fuel elements

“…In the process channels which are loaded with the new-type fuel elements and where additional passive protection is not used, the minimum admissible coolant flow rate must be increased by at least 3% in order to maintain the time margins for reliable removal of heat during accidents. One solution [3] for increasing the safety of water-graphite channel reactors is to introduce thorium and make the appropriate changes in the fuel assemblies. This will make it possible to decrease the effect of a loss of water and will allow maintaining the required margin of reactivity during a run.…”