ThorCon nuclear reactor
- See also: Nuclear_power_reconsidered
These are molten salt reactors with a graphite moderator These reactors (and the entire power plant) are to be manufactured on an assembly line in a shipyard, and delivered via barge to any ocean or major waterway shoreline. The reactors are delivered as a sealed unit and never opened on site. All reactor maintenance and refueling is done at a secure location.
This article is a brief summary. For more details see the ThorCon documents.[1]
Safety
Accidental overheating. There is a plug at the bottom of the reactor vessel that melts if the reactor gets too hot, and allows the fuel to flow out of the reactor and into some drain tanks, where the fission reaction stops, and the decay heat is absorbed by a "cold wall" [2]. No operator action is required, and there is nothing an operator can do to stop the safe shutdown. There are no electronic or electrical safety-critical systems or valves.[3] The reactor is "walk-away safe".
Leakage of Radioactivity The molten salt is at low pressure, and any leakage to the environment is blocked by three gas-tight barriers - the Can, the Silo, and the Hull. The most troublesome fission products, including iodine-131, strontium-90 and cesium-137, are chemically bound to the salt.[4]
Sabotage The hull is a 10ft thick wall of sand with an inch of steel on each side, capable of blocking a jumbo jet with nine-ton engines. Reactivity can be increased only by adding fuel slowly through an orifice inside the silo, out of reach of any rogue operator. The maximum rate of increase in reactivity is enough for load following, but never enough that the reactor can go prompt critical.[5]
Waste Management
All reactor maintenance and fuel processing is done at a secure location.
Average per year for a 500MW plant:[6]
High Level Waste: 13,400kg to dry-cask storage
Medium and Low Level Waste:
Recycled Fuel: 650kg of 19.7% U-235 (33% of total U consumption)
Other: (Medical isotopes, etc.)
The "waste" in the ThorCon fuel cycle is actually valuable fuel for future fast neutron reactors capable of efficiently burning thorium and depleted uranium. This will extend proven resources from centuries to millennia.
Weapons Proliferation
The sealed cans are inside a silo under a heavy concrete lid. Any attempt to get inside the silo can be easily detected and stopped by local police or military.
All fissile material is in inaccessible high-radiation areas. Uranium is always low-enriched. Plutonium is always diluted with thorium, in fuel salt with hazardous fission products.[7]
Cost
The expected cost of a complete power plant will be less than a coal plant of equal power.[8]
Specs for a 500MW plant:[9]
Plant cost per kW: $1200
Operating cost per kWh: $0.03
Fuel consumption per day: 15.3kg of 19.7% enriched uranium plus 9.0kg of thorium.[10]
Notes and References
- ↑ ThorCon Isle
- ↑ The wall is kept "cold" by water that is replenished from a storage tank above the reactor. Circulation is maintained without pumps, because the hot water (or steam) rises in the space around the cold wall.
- ↑ https://thorconpower.com/wp-content/uploads/2019/03/ThorConSpecSheet7.pdf
- ↑ https://thorconpower.com/safety/
- ↑ https://thorconpower.com/wp-content/uploads/2019/03/ThorConSpecSheet7.pdf
- ↑ https://thorconpower.com/fuel/
- ↑ https://thorconpower.com/wp-content/uploads/2019/03/ThorConSpecSheet7.pdf
- ↑ See sections 6 and 7 of https://thorconpower.com/docs/docs_v130_isle20190315.pdf
- ↑ https://thorconpower.com/wp-content/uploads/2019/03/ThorConSpecSheet7.pdf
- ↑ https://thorconpower.com/fuel/