If just one rod breaks, or comes into contact with air, it could trigger an explosive reaction, releasing the combined radioactivity of the rods into the atmosphere. Result? Apart from the effect on Asia, the entire Western seaboard of America - from Alaska to Panama - would become uninhabitable.
Bear in mind the plant has, officially, zero chance of surviving another seismic event.
And here's the really chilling bit: the Japanese, so anxious to save face, have ignored repeated calls from the International Atomic Energy Agency to permit them to get the world's top nuclear engineers to handle the task, and instead are trusting TEPCO, the company which built the inherently-flawed plant, to undertake this crucial work.
Given TEPCO has repeatedly underplayed the problem and dismally failed to prevent further degradation and accidental leakage, if I were living in, say, San Francisco, I'd be moving.
Such a disaster may not come to pass, leaving only a 30-40 year disposal and decontamination process to go through before the crisis is finally averted. Plus several thousand years intact containment until the spent fuel stops being lethal.
But that's not the worst bit. The worst bit is the radiation that has already leaked - and continues to leak - into the Pacific Ocean, via the thousands of cubic metres per day of ground-water being contaminated as it flows in under and around the crippled facility.
Fancy a four-eyed fish for dinner? And it's not about to stop - the "best" Japanese plan is to build an underground wall of ice around the plant, but even if this works, it may be five more years until the site is effectively sealed.
Then there is the problem of the melted reactor cores. So far, no one seems to know what to do about those, except to try to stop them sinking into the earth and causing more mayhem.
All this from one nuclear plant affected by one natural event.
Sure, the Japanese may have been stupid enough to build nuclear reactors on a flat tsunami-prone coast - bit like building a dam on a major fault-line, eh? - but if Chernobyl was the warning, this is the main event. The one that proves, once and for all, that nuclear fission is a mad pursuit for the human race.
There are all sorts of alternatives, from the mundane to the fantastical - a bunch of theoretical scientists are working out how to get power from black holes - and more power-generating and power-saving inventions daily.
So we do not need "clean green" (yeah, right) nuclear power. We should ban not just the bomb, but the reactors.
Bruce Bisset is a freelance writer and poet
