That's why the ceramic form of the plutonium is an important safety feature. The ceramic fractures into chunks and large particles, which are not breathable and can be cleaned up.

In a way, you can think of it as a nuclear battery. It's very rugged and has no moving parts.

Once you get a probability of an accident occurring, the question is what's the impact to people? That's where the risk is low.

Surely, sport is not fundamentally about the safety of athletes. If it were, we'd probably have to ban professional football, right after boxing.

The safety argument against steroids may be a good one, but let's be honest. It isn't the one that motivates most officials and fans to frown on steroids. Steroid use does not just seem risky or unnatural, it seems to disrupt the level playing field.

There may be times when we have to rescue pilots and the less said the better for the safety of the pilots.