Plutonium-238

Pu-238 is an Plutonium isotope primarily obtained by breeding. It is mostly used as Radioisotope Thermoelectric Generator fuel pellets. It is very hot and visibly glows. They become easier to obtain as time goes on in your game, although many of its uses have been removed to nerf it.

It is naturally pyrophoric and hot, so be careful handling it.

Uses
(In RTG form) fueling RTG Furnaces, powering RT Generators, and a crafting recipe for a Minigun. Each RTG pellet provides 10 power. If RTG decay is enabled, each will have a lifespan of 631,440,000 ticks, computing to a bit over 1 IRL year, with a stated in-game lifespan of 131 years and 55 days (assuming a 100 day year). They decay to Lead pellets. This also means it will make 6,314,400,000 power in total over that time.

Right-clicking nothing with a pellet will cause it to spit out random nuclear science facts.

Pu238Be RBMK neutron sources.

It can be used in the Radio Isotope Cell, which is basically a weak but more portable RTG.

A tier in Self-Charging Batteries, providing 100 HE/tick.

"AWESOME" injection

Breeding Pu-239.

Can be used in the Custom Nuke. It contributes a 1.15 multiplier to its nuclear stage, the same as unenriched Plutonium.

Trivia

 * As of recent updates, Pu-238 pellets have unfortunately been nerfed to the point of them having almost no use outside of RTGs and some other areas.
 * Pu-238 blocks emit small amounts of visible light.
 * Light level of 5