Re: "super-heated plasma that turns the Earth into another star"
A "broken" fusion reactor is cold, and has very low levels of radioactivity - certainly compared to a fission reactor at least. The problem with fusion is not that it's a runaway process (like fission) but that it's so damn hard to initiate and maintain. The tiniest fluctuation is enough to cool and/or disperse the plasma beyond the fusible region - any accident, even in the worst possible case, is highly unlikely to cause any significant damage beyond the immediate vicinity. This is one of the main reasons why we're investing all this time and money in trying to perfect them:
1) No radioactive waste (well, nearly)
2) No need to mine/transport/process/store fissible material
3) No risk of runaway processes
Biting the hand that feeds IT
