Abstract: Nuclear power still plays an important role for reducing CO₂ emission. At the same time, small scale and small capacity reactors, such called “small modular reactor (SMR)” is the recent trend of developing as new generation. On the other hand, molten salt reactor (MSR) is remarked as safe, high economy way as nuclear power. There are numbers of new proposals of MSR both for large and small capacity reactor in these just a few years. The author’s proposal named “UNOMI (Universally operable molten salt reactor integrated)” is also among such small capacity MSR. In this paper, these new designs of MSR are reviewed from a view of engineering feasibility.

Keyword: small modular reactor; molten salt reactor; thorium