TMSR (Chinese reactor project)
TMSR is a long-term research and development project of the Chinese Academy of Sciences, begun in 2011 and assigned to its Shanghai Institute of Applied Physics, to design, test, and build nuclear reactors that incorporate molten salt as a fuel-carrier and/or coolant, and thorium as a fertile material. The TMSR facilities grew from the collaborative efforts of "nearly 100 domestic research institutions, universities and industrial companies", and are now "the world's only research platform dedicated to molten salt reactors and thorium-uranium fuel cycle studies".
Project 728
In the late 1960s, CAS had begun to contemplate the development of molten salt reactors using thorium. Project 728 was launched in 1970 to develop nuclear power in China to mitigate an energy crisis caused by industrial fossil fuel demand exceeding domestic supply. Its initial goal was to build a 25 MWe power plant based on the 1960s Molten-Salt Reactor Experiment at Oak Ridge National Laboratory in the US. A demonstration molten salt reactor was built that achieved criticality in 1971, but was not intended to produce power. Further progress was hampered by the technological, industrial, and economic conditions in 1970s China however, and a pragmatic decision was made to develop pressurized light water reactors instead; their first commercial reactor, CNP-300 at Qinshan Nuclear Power Plant, began operations in 1991.Revisiting 728
The construction of PWRs did not extinguish the interest in MSR technology and Thorium breeding in China however.Due to relatively limited domestic Uranium deposits, China's nuclear power production relies heavily on imported uranium, a strategic vulnerability in the event of e.g. economic sanctions. The use of coal in China since the 1970s had also dramatically increased, and with it came serious air pollution that affected the health of large numbers of citizens. Finding cleaner energy sources became a pressing political concern. Some locations also make installing PWRs difficult; the relative lack of water available for cooling them west of the Hu line is seen as a limiting factor for siting them there. The perceived need for non-PWR nuclear in China was thus only increasing.
In the 1970s, global Thorium reserves were estimated to be on the order of 1 Mt, and China was not considered to have especially rich deposits. In the 1980s, the rare-earth industry in China began in earnest; rare earths are required for numerous high-tech devices which China manufactures. By the early 1990s, China was producing a majority of the world's rare earths, and by the end of the decade had achieved a near-monopoly. As a byproduct of its mining and refining, it was also generating Thorium far in excess of any non-nuclear needs. By 2009 it was noted that Thorium was being stockpiled in China for future nuclear use.
Meanwhile, with the derailed attempt to make a Chinese MSRE clone still in living memory among their senior researchers, a treasure trove of information on how it was actually done unexpectedly appeared: Kirk Sorensen had obtained copies of numerous important historical ORNL research technical documents, and in an effort to raise awareness of Thorium and MSR technology, had them digitized, and then made publicly available on his website beginning in 2006.
These new conditions invited a revisit of Project 728's original plan. Following the successful 2009 startup of the Shanghai Synchrotron Radiation Facility, a big science project of national interest to China, Xu Hongjie, who headed its construction, was given a new assignment by CAS: in order to further China's energy policy and sustainable development goals, he should lay the groundwork for an advanced nuclear fission energy program. After a team was assembled, relevant literature reviewed, and topics for research identified, a plan focusing on reactors which use thorium and molten salt was submitted to CAS for approval.
Project launched
In January 2011, CAS began the TMSR research and development project to create reactors which, among other advances, would use air cooling. Its initial budget was reportedly ¥3 billion. and was led by Xu Hongjie through SINAP, which established MSR research facilities in Shanghai's Jiading District.In 2012 a thorium energy conference was held in Shanghai, in partnership with SINAP; speakers included Xu Hongie, and Jiang Mianheng. For the conference, The First Nuclear Era: The Life and Times of a Technological Fixer, the autobiography of Alvin M. Weinberg, who headed ORNL during the MSRE, was translated into Chinese, and copies made available to attendees.
By 2014 the smog in China from burning coal had worsened to a point where TMSR engineers were told to accelerate their efforts to bring a reactor online from 25 years to 10.
In 2015, SINAP signed a decade-long Cooperative Research and Development Agreement with ORNL for technology transfer related to the MSRE and associated nuclear innovations.
By 2019, the Bayan Obo Mining District was recognized as a major Thorium deposit, with China holding at least 0.1 Mt Recent exploration at Bayan Obo has identified additional, massive Thorium deposits: 220,000 tons proven as of 2025, with total reserves estimated in excess of 1 million tons. The total for all of China is now thought to be 1.4 Mt. By some estimates, this is enough to power China for 60,000 years.
SF0
The initial project completed in Shanghai, in 2019, with operation starting the following year, was the TMSR-SF0, an electrically-heated simulator to aid development of a proposed "SF" branch of TMSR, as well as to gain operational experience using molten salt more generally. The SF0 has two liquid FLiNaK heat transport loops.LF1
TMSR-LF1 is a 2 MWt MSR prototype operating in northwest China. The "LF" design is directly based on the 1960s MSRE. The site selected for the TMSR-LF1 is part of an industrial park for the chemical and energy sectors, in a sparsely populated, arid region. Site construction began in 2018. Installation of equipment was finished in 2022. Criticality was first achieved on 11 October 2023. On 17 June 2024, full power operation was achieved. Following the introduction of thorium into the reactor in late 2024, Protactinium-233 was detected, indicating successful nuclear breeding.SINAP deputy director Cai Xiangzhou emphasized China's ability to produce the technology without the involvement of foreign entities, stating that "Over 90 percent of the reactor's components are domestically produced, with 100 percent localization of key parts and a fully independent supply chain. This achievement marks the initial establishment of an industrial ecosystem for thorium molten salt reactor technologies in China". SINAP's director, Dai Zhimin, stated that SINAP will work with energy companies, including the State Power Investment Corporation, "to build a comprehensive industrial and supply chain ecosystem for the thorium molten salt reactors."
LF2
A pilot plant based on the LF1, as well as a fuel salt research facility, is planned for the same site. New reactor specifications include: core graphite 3 m tall x 2.2 m wide, 700 °C operating temperature, 60 MW thermal output, and an experimental supercritical carbon dioxide-based closed-cycle gas turbine to convert the thermal output to 10 MW of electricity. Construction was slated to start in 2025, and be completed by 2029. The reactor's output would be used to demonstrate hydrogen production by high-temperature water splitting. A report compiled by the Chinese credit rating agency CSCI Pengyuan confirmed that site construction for the 60 MWt reactor began in September 2025, and is expected to last 48 months. Criticality, and full power operation, are expected in 2030.Future plans
Following the completion of the 10 MW project, construction of a commercial small modular reactor of at least 100 MWe is scheduled to begin in 2030. A proposal, referring to it as the smTMSR-400, specifies 400 MWt to generate 168 MWe. Such reactors are likely to be sited in central and western China, and may also be built outside China in Belt and Road Initiative nations; as low-carbon power plants, they would help to achieve the Chinese government's 2060 goal of carbon neutrality.In 2023, Jiangnan Shipyard released a conceptual design for a container ship using a TMSR-based reactor, designated KUN-24AP. Jiangnan Shipyard Group Vice President Lin Qingshan stated in 2025 that it was planning to invest in shipyards for vessels employing nuclear marine propulsion, beginning with the aforementioned container ship. The ship's construction would begin as early as 2035, and feature a 200 MW reactor, cargo capacity of 25 thousand intermodal containers, and 40 year lifespan. Hu Keyi, a senior engineer at Jiangnan, stated that the reactor would power the vessel electrically, generating approximately 50 MWe. A 10 MW backup diesel generator would also be included in the design. The TMSR unit would be "built as a sealed modular unit with a 10-year lifespan. Instead of refuelling it, the whole unit will be replaced after a decade, reducing the risk of leaks or human errors during maintenance."
Future concepts
The 2025 CSCI Pengyuan report additionally listed two further potential applications for TMSR technology: a bulk tritium source for ITER-scale nuclear fusion projects, and "Deep Space and Planetary Surface Energy": 1 MWe nuclear power in space that also generates process heat above 700 C. For a mission to the Moon, the salt used would be made there from lunar regolith; harvested lunar water would be split using the sulfur–iodine cycle, generating hydrogen and oxygen to be used as rocket propellant for a return trip.Location notes
The most recently published official Gansu site plan map is Figure 2.1-2 inThe LF1 reactor is sited within an industrial park located in Hongshagang, Minqin, Wuwei, Gansu, China. The area is a semi-desert just south of the Badain Jaran section of the Gobi. As per official documentation, the TMSR-LF1 site is located at 38°57′31″ N, 102°36′55″ E. However, due to the China GPS shift problem, the reactor location using Western GPS coordinates is approximately .
The LF2 reactor building is planned for approximately .