Background: As one of the six candidates recommended by the fourth generation reactor forum

Molten Salt Reactor (MSR) owns many features such as high outlet temperature

high energy density

and anhydrous cooling. In the core of the first Thorium Molten Salt Reactor with Solid Fuel (TMSR-SF1)

most of the structure materials are graphite. 13C in graphite and the impurities N and O in coolant can be activated to produce 14C. 14C has long half-life

it can be involved in various complex biological cycle with other stable nuclides 12C and 13C. In TMSR-SF1

14C is widely distributed in the coolant

the active core and the structure materials. Purpose: The aim is to study the production and release of 14C in TMSR-SF1. Methods: According to the design parameters of TMSR-SF1

TRITON (Transport Rigor Implemented with Time-dependent Operation for Neutronic depletion) of SCALE6.1 (Standardized Computer Analyses for Licensing Evaluation) was applied for the transport burnup coupled calculation. Results: Computational results show that the radioactivity of 14C in main loop mainly comes from the activation of N

and the total amount of radioactivity of 14C in the main loop is 0.34 TBq each year. Conclusion: TMSR-SF1 could meet the current emissions standards of 14C according to current design parameters. Abstract