Lithium Enrichment Facility
Natural lithium has two isotopes, mass number 6 and mass number 7. Lithium-7 is the most common, comprising about 90% of natural lithium. Lithium-6 is only about 10% of natural lithium. From the perspective of a neutron, they couldn’t be more different. Lithium-6 has a huge appetite for neutrons, whereas lithium-7 has almost none. Liquid-fluoride reactors that use lithium fluoride in their salt need lithium that is isotopically enriched in lithium-7 to about 99.999%. This will require a lithium enrichment facility.
Inputs: natural lithium.
Outputs: Highly enriched lithium-7 and the depleted tails with elevated lithium 6 levels.
Liquid-Fluoride Thorium Reactor
The LFTR is the backbone of the plan. It is a two-fluid reactor, with a fuel salt of 7LiF-BeF2-233UF4 surrounded by a blanket salt of 7LiF-BeF2-ThF4. Heat generated from fission in the fuel salt is transferred to a coolant salt and then to the working fluid of a closed-cycle gas turbine, which turns an electrical generator. It can generate electricity at about 50% thermal efficiency, and its waste heat can be productively utilized for district heating or desalination. It is designed to be started on about 1000 kg of 233U per GWe of electrical generation capability and will operate at a conversion ratio of 1.0. Once started on 233U, it does not require additional fissile input. At the end of its useful life, both fuel and blanket salts can be recycled into the next generation of LFTR.
Inputs: Highly enriched lithium-7, beryllium, fluorine, thorium, and uranium-233 for startup, thorium for refueling.
Outputs: Electricity, waste heat, fission product fluorides.
Chlorine Enrichment Facility
Natural chlorine has two isotopes, mass number 35 and mass number 37. Chlorine-35 is the most common, comprising about 75% of natural chlorine. Chlorine-37 is only about 25% of natural lithium. Chlorine-35 has a healthy appetite for neutrons, forming chlorine-36 with is a long-lived radionuclide that is very mobile in the environment. Using chlorine-37 avoids this problem. Liquid-chloride reactors need enriched chlorine-37, and this will require a chlorine enrichment facility.
Inputs: natural chlorine (extremely common).
Outputs: Highly enriched chlorine-37 and the depleted tails with elevated chlorine-35 levels.
This reactor is a cousin to the LFTR, but uses chloride salts to achieve a fast-neutron spectrum needed to destroy long-lived transuranic waste that has already been produced by light-water reactor operation on uranium fuel. The chloride reactor is also a two-fluid reactor design, with a fuel salt of NaCl-(TRU)Cl3, where (TRU) is a mixture of predominantly plutonium, americium, curium, and neptunium in mixtures typical of that found in spent nuclear fuel from light-water reactors. The blanket salt is NaCl-ThCl3, intended to generate uranium-233 from neutron absorption in the blanket. All of the chlorine used is isotopically enriched chlorine-37 in order to prevent formation of long-lived Cl-36. Heat generated from fission in the fuel salt is transferred to a coolant salt and then to the working fluid of a closed-cycle gas turbine, which turns an electrical generator. It can generate electricity at about 50% thermal efficiency, and its waste heat can be productively utilized for district heating or desalination. It is designed to be started on about 10-15 tonnes of TRU per GWe of electrical generation capability. Uranium-233 produced in the blanket will be immediately removed and used to start LFTRs, while the fuel salt will be continuously refueled with additional TRU. When all the TRU has been consumed and a sufficient amount of 233U generated, the chloride reactors will mostly be shut down.
Inputs: Sodium chloride, transuranic chlorides, thorium chloride (all chlorides use enriched chlorine-37).
Outputs: Electricity, uranium-233, waste heat, fission product chlorides.
Spent-Nuclear-Fuel Fluorination Facility
This facility will receive the spent nuclear fuel, in the form of irradiated uranium oxide, that is produced by the hundreds of light-water reactors in operation around the world today. The oxide fuel will be fluorinated, first by hydrofluoric acid, and then by fluorine gas, in order to convert the oxides in the fuel into fluorides. About 96% of the spent nuclear fuel is uranium oxide, which will be converted to uranium hexafluoride, the suitable chemical form for an enrichment plant. Fission product oxides will be converted to fission product fluorides. Transuranic oxides (Pu, Am, Cm, Np) will be converted to fluorides as well. These TRU-fluorides will then be extracted from the overall mixture by contact with metallic aluminum, which will reduce the TRU to metal and fluoridize the aluminum. TRU-metal can then be combined with isotopically-enriched chlorine-37 to produce chloride fuel appropriate for introduction into the fuel salt of a chloride reactors, in order to destroy the TRU through fission and generate heat and neutrons.
Inputs: Spent nuclear fuel from light-water reactors, fluorine gas (F2), hydrofluoric acid (HF), isotopically-enriched chlorine gas (37Cl2).
Outputs: Uranium hexafluoride, fission product fluorides, transuranic chlorides suitable for a chloride reactor.
LFTR Manufacturing Facility
To mass-produce the thousands of LFTRs that will be needed, manufacturing facilities will be required.
Inputs: Hastelloy-N, steel, gas turbines, high-temperature piping, insulation, instrumentation, electrical generators, highly-enriched lithium-7, beryllium, fluorine, thorium, and uranium-233.
Outputs: Manufactured LFTRs.