Fission of 1000 kg U-233 produces several chemicals essential for industry, readily extracted from a LFTR, including 150kg xenon, 125kg neodymium (high-strength magnets), 20kg medical molybdenum-99, 20kg radiostrontium, zirconium, rhodium, ruthenium, and palladium.
LFTRs also produce non-fissile Pu-238, that conventional reactors can’t produce isolated from highly fissile Plutonium-239; Pu-238 is needed for radioisotope power such as for NASA deep space exploration vehicles (none left, only Th to U-233 makes Pu-238 w/o Pu-239).
(Extracting these from fuel rods in a solid fuel reactor would be extremely difficult.)
Radioactive isotopes are needed for medical treatment, including highly-targeted cancer treatments. These are currently very rare, since they have half-lives of a few days. LFTRs would produce these as part of the decay of U-233, and they would be easy to remove from the fuel salt.
Iodine-131 is used to treat cancers of the thyroid.
Thorium-229 for cancer treatments, decays to Bismuth-213, which decays through alpha emission (unlike most of the fission products that decay through beta emission). By binding Bi-213 to an antibody, it can be directed swiftly to a cancerous cell. The alpha decay of the Bi-213 then has a high probability of killing the cancer cell. (Very small amount/treatment, but decays fast to Bi-209.)
With molten fuel, a LFTR would generate 4,000 times less mining waste and up to 10,000 times less nuclear waste than any solid fueled reactor. The fission byproducts can be easily extracted, so the fuel can fission completely.
The uranium (or plutonium or other transuranic elements) are completely fissioned in a LFTR. 83% of the waste (fission byproducts) from a LFTR are safely stabilized within 10 years. The remaining 17% (135kg for a GigaWatt-year) are elements that need to be stored less than 350 years to become completely benign. 135kg vs 250 tons (250,000kg) from a solid-fueled reactor.
A 40-megawatt test reactor running for 10 years would “burn” 141 Kg. U-233, and produce less than 1 milligram of plutonium or other transuranic elements. Leave these inside the reactor, where neutron bombardment will cause them to fission. Charles Holden, TEAC 2011
The traditional “waste problem” includes storing all the uranium with the fission byproducts. However, separating the uranium (and plutonium) is easy; we don’t because of the “reprocessing is bad” conversations, but storing uranium in low density so chain reaction is impossible is simple and produces low levels of radiation. Many fission byproducts are very short-lived (half lives in seconds to months), and therefore highly radioactive.
As the separated fission products have much smaller volume, they can be left as salts and allowed to solidify and decay in short-term storage. (Other storage can work, in vitrified glass, for example.)
“FS-MSRs can be employed to consume actinides from light-water reactor (LWR) fuel or, alternatively, to extend fissile resource availability through uranium-to-plutonium breeding. FS-MSR reactors are highly flexible and can be configured into modified open or full-recycle configuration. The modified open FS-MSR fuel cycle options do not include chemical processing of the fuel salt. … The conversion ratio of an FS-MSR is largely determined by the fissile-to-fertile-material ratio in its fuel salt. Thus, a single reactor core design may be capable of performing both fissile resource extension and waste disposition missions.” Fast Spectrum Molten Salt Reactor Options, Oak Ridge National Laboratory, July 2011