Thorium is also radioactive, but has a halflife of about 14 billion years, so it’s pretty mild as far as radioactive shit goes. It can also be used as a fuel in reactors, but through a slightly different process. Thorium itself isn’t fissile like U-235, if one were so inclined, you could bombard it with neutrons, and convert it into U-233, which is quite eager to engage in fission. U-233 is radioactive as fuck though, with a halflife in the 130,000 year range, as opposed to 700 million for U-235, 4 billion for U-238, and 14 billion for Th-232.
They used to use this shit as a contrast agent in CT scans, but it’s been replaced by iodine/barium compounds, when it was discovered that using Thorium as a contrast agent reduces your median life expectancy by about 15 years.
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