A nuclear chain reaction can only be sustained through very specific molecules that have the ability to undergo fission and release neutrons while they do. Those released neutrons then need to interact with new fissile molecules that surround the first one.
The chain reaction also requires that there are enough of those molecules and that they are packed closely enough together, so the reaction doesn’t fizzle (no pun intended) out.
That only happens in an environment like enriched uranium, which is uranium with an artificially high percentage of U-235 that doesn’t occur naturally –at least not anymore.
A nuclear chain reaction can only be sustained through very specific molecules that have the ability to undergo fission and release neutrons while they do. Those released neutrons then need to interact with new fissile molecules that surround the first one.
The chain reaction also requires that there are enough of those molecules and that they are packed closely enough together, so the reaction doesn’t fizzle (no pun intended) out.
That only happens in an environment like enriched uranium, which is uranium with an artificially high percentage of U-235 that doesn’t occur naturally –at least not anymore.