TMSR-LF1


TMSR-LF1 is a 2 MWt molten salt reactor prototype operating in northwest China.
The TMSR facility grew from the collaborative efforts of "nearly 100 domestic research institutions, universities and industrial companies", and is now "the world's only research platform dedicated to molten salt reactors and thorium-uranium fuel cycle studies".

History

The "LF" design is directly based on the 1960s Molten-Salt Reactor Experiment. 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. At the groundbreaking, a Taoist ceremony was held; after images of it went viral in China, CAS disciplined staff members, and issued a public apology.
A reactor construction permit was issued by the Chinese National Nuclear Safety Administration in January 2020. Unforeseen delays were caused by the COVID-19 pandemic in China. Installation of equipment was finished in 2022. 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".
Testing followed; in August 2022, the Chinese Ministry of Ecology and Environment informed SINAP that its commissioning plan for the LF1 had been approved. A ten-year operating license was issued in June 2023. For the first 5–8 years, it is to be run in batch mode, before converting to continuous mode.
Criticality was first achieved on 11 October 2023. On 17 June 2024, full power operation was achieved. In September, it received a license to load thorium into the molten salt, the initial loading of which happened the following month, and on 8 October, it operated at full power for 10 days with thorium in the molten salt; Protactinium-233 was detected, indicating successful nuclear breeding.

Specifications

The TMSR-LF1 is a Generation IV reactor constructed with the following specifications:
  • Thermal power: 2 MW
  • Fuel salt: FLiBe with fluorides of zirconium, uranium, and thorium
  • * inlet temperature: 630 °C
  • * outlet temperature: 650 °C
  • * volume: 1.68 m3
  • * flow rate: ~50 kg/s
  • Coolant salt: FLiBe
  • * inlet temperature: 560 °C
  • * outlet temperature: 580 °C
  • * flow rate: ~42 kg/s
  • Cover gas: Argon
  • * volume: 1.6 m3
  • Moderator: nuclear graphite
  • Structural Material: UNS N10003 superalloy
  • Lifetime: 10 years
  • * equivalent full power days: 300
  • * maximum full power days per year: 60
The reactor is located underground, seated at the bottom of a 14m deep dry well, which is capped at ground level, and above which rises a 20m tall roofed atrium.