It is only instruments like Geiger counters which can do this and no-one carries Geiger counters around with them. So we're suspicious of anything which we know contains radioactivity - like nuclear power stations. You expect it to glow blue or something, but it just lies there looking boring and grey. Not a hint that if you were to pick it up in your hand for a second or two, you'd get a lethal radiation dose which would kill you in hours. Scary, as I said.
Risk Being alive is a risk.
But our perception of what is risky is, to say the least, quirky. The nuclear industry claims that the risk from nuclear power is vanishingly small. People are generally more scared of flying too and yet only 45 died in that same year. There is no shortage of examples of how illogical we are about danger and risk. By careful design using material like uranium, engineers ensure that neutrons collide with uranium atoms, breaking them apart into unequal-sized halves.