Crizznik t1_jc30n4k wrote on March 13, 2023 at 5:54 PM

Reply to comment by Accelerator231 in Why were the control rods in the reactor featured in the HBO series 'Chernobyl' (2019) tipped with graphite? by Figorama

There are natural nuclear reactors in the world. Pits of natural uranium that get super hot from fission reactions.

echawkes t1_jc3uari wrote on March 13, 2023 at 9:03 PM

There aren't been any natural nuclear reactors any more. Over a billion years ago, the natural enrichment of uranium was much higher, because U-235 and U-238 have different half-lives.

The only place a natural reactor was ever thought to have operated was at Oklo, and it can't happen anywhere now.