You're comparing a one-use device to a trillion-use device. I think
Tell me when you find an atom splitter that works a trillion times.
Then tell me what it's efficiency is, because it's not nearly 0.1%.
Nuclear bombs may only get used once, but nuclear reactors get used
continuously for years or decades, and like I already said, their
efficiency is around 0.1% (mass converted to energy). There are also
various types of atomic batteries, such as radioisotope thermoelectric
generators, which convert the radiation given off by radioactive
substances to electricity. They are typically expected to have an
effective working life of a decade or more.