Hi, just to point out a hole in your reasoning, if these reactors are so safe then why even a small portion of the radioactivity escaping the containment shell can cause such a big disaster like Fukushima or Chernobyl?

Now, I understand there are differences in size and the level of radioactivity used (they won't be driven as close to prompt criticality as the power reactors) and they may be designed to be less reliant on active protection (pushing a lot of water as required means to prevent disaster).

But still, this is radioactive material in Earth orbit where stuff tends to fall back after some time and we don't always control when and where it reaches us.