Thorcon is a nuclear engineering company that is designing the ThorCon Reactor, a small modular reactor (SMR) that employs molten salt technology. The reactor design is based on the Denatured molten salt reactor (DMSR) design from Oak Ridge National Laboratory and employs liquid fuel, rather than a conventional solid fuel. The liquid contains the nuclear fuel and also serves as primary coolant. ThorCon plans to manufacture the reactors cheaply in shipyards employing modern ship building construction techniques.
A 2017 study included ThorCon and seven other designs. The study concludes that "if power plants featuring these technologies are able to produce electricity at the average LCOE price projected here (much less the low-end estimate), it would have a significant impact on electricity markets."
ThorCon uses modular shipbuilding production processes except the blocks are barged to the site and dropped into place. Thorcon plans to build its reactors in shipyards, It requires as much steel as a medium size, 125,000 dwt Suezmax tanker. The reactor consists of two main components, steam/electrical and nuclear. The steam/electrical component features the same design and cost ($700/kw) of a 500 MWe coal plant. A 1 GWe nuclear component requires less than 400 tons of supercritical alloys and other exotic materials.
Passive cooling is needed only in the event of overheating, which first stops the reaction, and then triggers freeze valves to drain the reactor. Fluoride salt reacts with hazardous fission products iodine-131, cesium-137 and strontium-90, preventing their release. Each reactor unit operates for four years, cools for four years, and then is replaced. All recycling occurs offsite. Each power module has two siloed reactor units generating 557 MW (thermal) yielding 250 MW (electric).
In addition to (low cost) thorium, a 1 GWe reactor initially requires 3,156 kg of 20% low enriched uranium along with 11 kg per day of operation. Every 8 years the fuel must be changed out. At a yellowcake cost of $66/kg, a $7.50 UF
6 conversion cost and $90 per separative work unit, the levelized fuel cost is 0.53 cents per kilowatt-hour.
Every 8 years 160 tons of spent fuel travel to the recycling facility, consisting of about 75% thorium, with 95% of the balance uranium. Without separation (other than removing the salt), the total fuel waste stream averages about 2 m3 per year.