Why can’t a nuclear gauge explode like a bomb?
A gauge does not have enough radioactive material — or the right kind of material — to cause an explosion. It does not have the capability to produce a burst of energy that one would associate with a bomb. Even a nuclear reactor does not explode. The material in a reactor is distributed in such a way that it does not release energy instantaneously; rather, it is a controlled reaction that sustains energy production for beneficial purposes.