In a gun-type bomb, Uranium-235 is the fuel. In an implosion bomb, Plutonium-239 is the fuel. A fusion-boosted atomic bomb uses the implosion design, with the addition of gaseous tritium (Hydrogen-3). Producing the appropriate amounts of fuel for bombs is expensive, time-consuming, and difficult.
What does an inhibitor switch do? An inhibitor switch basically tells your vehicle whether its in motion or in park. It can tell the car to park or to go into first gear etc.
That's why automatic transmission cars are equipped with a neutral safety switch. This is intended to keep you from starting up the engine with the transmission in gear.The switch comes with electric contacts that open or become disconnected when you try to crank the engine with the transmission engaged.