Question

Is it possible for a nuclear power plant to experience a nuclear explosion?

Answer 1

Not a traditional nuclear fission explosion

Explanation:

As far as I understand it, the level of enrichment that is needed for a bomb is something like 95% (Uranium exists as U238 and U235...U238 goes fizzle fizzle....U235 goes boom....you have to get your sample of uranium up to 95% U235 to go boom). The fuel used in a nuclear reactor is something like 20% enriched (U-235).

You can get explosions in a nuclear reactor (like steam explosions, `H_2` explosions), but I don't think you can get fission chain reaction explosions, since you don't have enough enriched material.