[en] Brief description of the concepts studied by partners; of the Molten Salt Fast Reactor Concept activities; of the activities on MOSART concept; and of activities on FHR concept.

[en] Feasibility study of an underground molten salt thorium reactor is presented. Fuel cycle and safety considerations are given. (TRA)

[en] In the last 5 years, there has been a rapid growth in interest in the use of high-temperature (700 to 1000 C degrees) molten and liquid fluoride salts as coolants and for other functions in nuclear systems. This interest is a consequence of new applications for high-temperature heat and the development of new reactor concepts. These salts have melting points between 350 and 500 C degrees; thus, they are of use only in high-temperature systems. Nitrate salts with a peak operating temperature of about 600 C degrees are the highest-temperature commercial liquid coolant available today; thus, the development of higher-temperature salts as coolants opens new nuclear and non-nuclear applications. These salts are being considered for intermediate heat transport loops between all types of high-temperature reactors (helium and salt cooled) and hydrogen production systems, oil refineries, and shale oil processing facilities. Historically, steam cycles with temperature limits of about 550 C degrees have been the only efficient method to convert heat to electricity. This limitation produced few incentives to develop high-temperature reactors for electricity production. However, recent advances in Brayton gas-turbine technology now make it possible to convert higher-temperature heat efficiently into electricity and thus have created the enabling technology for more efficient cost-effective high-temperature reactors. The near-term advanced high-temperature reactor (AHTR) uses a graphite-matrix coated-particle fuel and a liquid salt coolant. There is the longer-term potential of a liquid-salt-cooled fast reactor (LSFR) that uses metal-clad fuel and a liquid salt coolant. The molten salt reactor (MSR), with the fuel dissolved in the molten salt coolant, is receiving attention because of (1) the advancing salt-coolant technology and Brayton cycles that improve the economics, (2) advances in salt chemistry that enable the development of fast-spectrum MSRs with the safety advantages of large negative void coefficients, and (3) the interest in actinide burning where MSRs avoid the need to fabricate fuel of highly active actinides. Last, there is a developing interest in liquid-wall fusion machines with much higher power densities than solid-wall fusion machines. (authors)

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[en] Molten Salt Reactors represent one of promising future nuclear reactor concept included also in the Generation IV reactors family. This reactor type is distinguished by an extraordinarily close connection between the reactor physics and chemical technology, which is given by the specific features of the chemical form of fuel, representing by molten fluoride salt and circulating through the reactor core and also by the requirements of continuous 'on-line' reprocessing of the spent fuel. The history of Molten Salt Reactors reaches the period of fifties and sixties, when the first experimental Molten Salt Reactors were constructed and tested in ORNL (US). Several molten salt techniques dedicated to fresh molten salt fuel processing and spent fuel reprocessing were studied and developed in those days. Today, after nearly thirty years of discontinuance, a renewed interest in the Molten Salt Reactor technology is observed. Current experimental R and D activities in the area of Molten Salt Reactor technology are realized by a relatively small number of research institutions mainly in the EU, Russia and USA. The main effort is directed primarily to the development of separation processes suitable for the molten salt fuel processing and reprocessing technology. The techniques under development are molten salt/liquid metal extraction processes, electrochemical separation processes from the molten salt media, fused salt volatilization techniques and gas extraction from the molten salt medium

[en] The results of investigations on molten salt (MS) applications to problems of nuclear energy systems that have been conducted in Russian Research open-quotes Kurchatov Instituteclose quotes are presented and discussed. The spectrum of these investigations is rather broad and covers the following items: physical characteristics of molten salt nuclear energy systems (MSNES); nuclear and radiation safety of MSNES; construction materials compatible with MS of different compositions; technological aspects of MS loops; in-reactor loop testing. It is shown that main findings of completed program support the conclusion that there are no physical nor technological obstacles on way of MS application to different nuclear energy systems

[en] Now some conceptual projects of Molten-Salts Based Nuclear Reactors (MSBNR) exists and problem of creating of full-scale demonstration installation of such type is working up seriously enough. Wide researches, confirming reality of solving of the problem of MSBNR building, have already been carried out. At the same time engineer realization of the project needs tests of a whole number of technical and technological solutions, and obtaining of additional data in physics and chemistry of salts and compatibility of materials. Possessing powerful scientific and technical potential and developed experimental base RFNC-VNIITF would have a possibility to bring in adequate contribution to the problem of creating MSBNR

No abstract available

[en] Materials corrosion is a major challenge in the use of molten fluoride salt as a coolant in molten salt reactors (MSRs) in large part due to the removal of protective oxides by these salts and the requirement for inherent thermodynamic stability of the exposed metal. Depending on reactor operating conditions, there is a possibility that no nuclear-code approved structural alloy meets the combined requirements of high strength and corrosion resistance in fuel-bearing molten fluoride salt. Therefore, a promising approach is to clad structural alloys with a corrosion resistant material. This paper presents the status of research on cladding for corrosion protection in molten fluoride salts. (author)

No abstract available