China on track to build a first thorium-based molten-salt nuclear reactor

In its drive to seek different energy sources to meet its energy demand, China has officially approved the commissioning of a thorium-based molten salt nuclear reactor.

The reactor, known as "Thorium Molten Salt Reactor - Liquid Fuel 1 (TMSR-LF1)", began construction in 2018 in Wuwei City, Gansu Province, by the Hongshagan Industrial Cluster.

The TMSR-LF1 reactor is an experimental liquid fluorinated thorium reactor using a LiF-BeF2 -ZrF4 -UF4 [+ThF4] fuel salt mixture and a LiF-BeF2 coolant salt. It runs on a combination of thorium (about 50 kg) and uranium-235, enriched to 19.75%, and can operate at a maximum temperature of 650°C for up to 10 years. The liquid fuel design is based on the molten salt reactor experiment conducted in the 1960s by the Oak Ridge National Laboratory in Tennessee, USA.

With this authorization, China has become the first country to take a significant step towards harnessing the power of thorium for clean, large-scale energy generation.

While uranium has traditionally been the main fuel for nuclear reactors, thorium offers several advantages such as its abundance in nature (more than uranium) and the reduction of nuclear waste production. However, thorium is "fertile" rather than "fissile", which means that it can only be used as a fuel in combination with a fissile material such as recycled plutonium. Although the use of thorium as a primary energy source has long been tempting, cost-effective extraction of its potential energy value has proved difficult.

If successful, TMSR-LF1 would open the door to developing and constructing a demonstration facility with an output of 373 MWt by 2030 and could lead to the construction of a TMSR fuel salt batch pyroprocessing demonstration facility, which would enable the utilization of the thorium-uranium cycle in the early 2040s.