Molten-salt reactor development

One molten-salt reactor system has been constructed, and although its experimental operations were successful, there have been no others. The interest has been largely academic, but conceptual designs of commercial plants have been developed. This technology would require the largest development and demonstration program, and with no licensing experience, could prove to be a difficult option to implement. 

Technology originally developed for Aircraft Nuciear Propulsion Program and Molten Salt Reactor Program (left) Potential Uses Include AHTR, Heat Transfer Loop Between Reactor and Hydrogen Production Piant, and Fusion Energy Plants)... 

Graphite technology and component designs developed for the HTGR and Molten Salt Reactor (MSR) designs. 

A representative application of the MSR concept is thorium reactor, and MSRE (Molten-Salt Reactor Experiment) with thermal output of 8 MW was developed by Oak Ridge National Laboratory in the USA and had been operated from 1966 to 1969. In the thorium reactor, the breeding of fissile nuclide, can be achieved through prevention of parasitic absorption by... 

This section includes a brief early history of the development of nuclear power, primarily in the United States. Individual chapters cover the pressurized water reactor (PVVR), boiling water reactor (BWR), and the CANDU Reactor. These three reactor types are used in nuclear power stations in North America, and represent more than 90% of reactors worldwide. Further, this section includes a chapter describing the gas cooled reactor, liquid metal cooled fast reactor, the molten salt reactor, and small modular reactors, and concludes with a discussion of the next generation of reactors, known as "Gen IV."... 

Rosenthal, M.W. et al. Aug 1972. Molten Salt Reactor Program—The Development Status of Molten Salt Breeder Reactors, ORNL 4812. 

Chapters 6 through 8 give an introductory look at the liquid metal cooled reactor system, the molten salt reactor, and also the small modular reactor systems. Chapter 9 introduces the Gen IV reactor design concepts that have been developed by the United States Department of Energy (USDOE). 

The MSR FUJI is a simplified molten salt reactor of 200 MW(e) intended to operate in a closed -Th fuel cycle. The operation cycle length is more than 30 years however, periodical fissile-fertile feeding from an internal reservoir is necessary. The design of MSR FUJI is based on previous molten salt reactor designs developed or operated in the molten salt reactor programme at the Oak Ridge National Laboratory (USA) between 1950 and 1976. Many results of the R D performed under that programme are therefore directly relevant to the development of the MSR- FUJI. 

Thorium was recently the focus of an environmental problem on extracting rare earths from ores, such as mon-azite. Actually thorium can be utilised for nuclear fertile material, thus the electrochemical process is one of the promising techniques of separation from rare earth elements. One of the systematic studies on the chemistry of the compounds containing thorium was the development of molten salt reactors [1]. To investigate the relationship between the electrochemical behaviour and physico-chemical properties of thorium is important for process design, but structural information of the related materials is still limited [2], Thus, EXAFS analysis of molten thorium fluoride in mono- and divalent cationic fluoride mixtures was systematically carried out to elucidate the variation in local structure of thorium cation in various melts. 

SouCek, R, LisJ, R, Uhlff, J. et al. (2005) Development of electrochemical separation methods in molten LiF-NaF-KF for the molten salt reactor fuel cycle. J. Nucl. Sci. Technol, 42, 1017. 

AHTR Molten Salt Reactor Technology Was Developed in the Aircraft Nuclear Propulsion Program with Test Reactor Operations to 860°C... 

For high-temperature operations, materials, and fuels are key technologies. There is a century of large-scale experience in the use of fluoride molten salts. Aluminum is made by electrolysis of a mixture of bauxite and sodium aluminum fluoride salts at 1000 C in large graphite baths. Fluoride salts are compatible with graphite fuels. A smaller nuclear experience base exists with molten fluoride salts in molten salt reactors. Nickel alloys such as modified Hastelloy-N have been qualified for service to 750 C. A number of metals and carbon-carbon composites have been identified for use at much higher temperatures however, these materials have not yet been fully developed or tested for such applications. 

Engel, J., Bauman, H., Dearing, J., Grimes, W., McCoy, H., 1979. Development Status and Potential Program Development of Proliferation Resistant Molten Salt Reactors. USAEC, Oak Ridge, USA. Report ORNl/TM-6415. 

The beginning of molten salt reactor (MSR) research in Korea dates back to 1998. A basic concept of an MSR that bums the DUPlC fuel was first developed in Ajou University. More studies on MSR, including a recent fluoride—salt-cooled high temperature reactor, are under progress in UNIST (Ulsan National Institute of Science and Technology) and other institutes. Described below is a summary of the progress so far and future research plans of the MSR research in Korea. 

In addition to HTR and SFR, the other Generation IV concepts are also supported by different government agencies. The supercritical water-cooled reactor (SCWR) was supported under the National Key Basic Research Program of China (973 project) by the China Ministry of Science. The studies of molten salt reactors (MSRs) and lead-cooled fast reactors (LFRs) are performed in the framework of the Chinese Academy of Sciences (CAS) pilot projects. In the following section, the current research and development (R D) on Generation IV reactors in China will be briefly introduced. 

Figure 14.14 Strategy of Chinese thorium molten salt reactor research and development. TMSR-SF, sohd-fueled thorium molten salt reactor TMSR-LF, liquid-fueled thorium molten...

Zhang, D., Qiu, S., Su, G.H., 2009a. Development of a safety analysis code for molten salt reactors. Nuclear Engineering and Design 239, 2778—2785. 

Zhuang, K., Cao, L., Zheng, Y., Wu, H., 2014. Studies on the molten salt reactor code development and neutronics analysis of MSRE-type design. Journal of Nuclear Science and Technology 1—13. 

India is developing two concepts of molten salt reactors. One of the concepts has a pebble-bed configuration with molten salt being used as the coolant. The pebbles are made of TRISO-coated particle fuel. This is explained in Section 13.3.8. The other configuration is the fluid-fueled MSBR. This portion of the chapter will describe Indian R D efforts for the development of the IMSBR. 

ORNL, in J.R. Engel, et al. (Eds.), Development Status and Potential Program for Development of Proliferation Resistance Molten Salt Reactor, ORNL-TM-6415, Oak Ridge, TN, USA, 1979. 

These reactors can tx either one or two rej> ioii and, depending on the size of the reactor core and the thorinra fluoride concentration, can cover a wide raiif e of fuel inventorie. i, hrex dinj ratios, and fuel reprocessing. schedules. The chief virtues of this class of molten-salt reactor are that the design is based on a well-developed technology and that the u. jo of a simple fuel cycle contributes to nnluced costs. 

The information gained in the testing of Hastclloj B and Inconel led to the development of an alloy, designated IXOR-8, which combines the better properties of both alloys for molten-salt reactor construction. The approximate compositions of the three alloys. Inconel, Hastclloy B, and IXOR-8, are given in Table 13-1. 

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