The reactors on aircraft carriers have a similar thermal output to many commercial power reactors. The ones on submarines are around a third of that size, about the size of SMRs like NuScale VOYGR or the Xe-100 reactors proposed to be built at Long Mott in Texas.

Chernobyl was supposed to turn low enrichment uranium into plutonium for Soviet bombs. They made design choices that compromised safety to make plutonium production more efficient.