Five years ago, Anthony Sarrack, an engineer at a Minnesota nuclear plant, warned the US government that their common emergency vents wouldn't work in a disaster. He was ignored. Two months ago, Fukushima exploded because of those same vents.
The vents at Sarrack's plant require electricity to open—which is exactly what workers at Fukushima didn't have when the plant was smashed by a quake and tsunami. No juice and no vents means a buildup of dangerous gasses—and then your plant explodes. Twice. Sarrack foresaw this happening in the US, the New York Times reports, and turned to the Nuclear Regulatory Commission. They didn't agree with his (correct) critique, prompting him to flee the industry altogether in dismay.
So what does Sarrack think would avert a Fukushima repeat? How do we replace the GE-manufactured vents with something safer? Take the human element out of the equation. He believes
"A passive system, like one using a rupture disk, would work better and could be set to rupture at a pressure just slightly less than the pressure at which the containment would rupture. In those cases, he said, venting is always preferable; the releases of radioactive materials during deliberate venting are expected to be lower than those resulting from explosions."
At any rate, the lesson here is to listen to your engineers. I doubt there can be such a thing as too much consideration when it comes to keeping nuclear plants from exploding. [NYT]