The Fukushima incident had a cost of at least a trillion Dollars, with the estimate rising. Yes, there were lower estimates, those are old. Tschernobyl is still

The Fukushima incident had a cost of at least a trillion Dollars, with the estimate rising. Yes, there were lower estimates, those are old. Tschernobyl is still a hazard. You could argue it was a benefit that Russian soldiers irradiated themselves by digging trenches in contaminated dirt, but that's about it. And you probably underestimate the probability of such things happening. Bad intent is unpredictable. Bad intentions plus negligence plus accidents usually turns out to be worse than imagined, especially on this timeframe.