Fukushima reactor 1 back to square 1
Any hope of bringing wayward Fukushima Daiichi reactor unit 1 under control has been dashed with the news that the radiation level on the ground floor of the reactor building is 2 sieverts an hour. The current worker dose limit being used by the Japanese government -- and it's lax by international standards -- is 0.25 sieverts a year. Do the math: Any worker going into that building will get a year's maximum dose in 7 minutes and 30 seconds. They're not going to rebuild the cooling system for that reactor under those conditions, or probably ever.
This is the same reactor that Tokyo Electric was making a big show about a week or two ago when they set up an air filtration system in the turbine building that was supposed to make that part of the plant less lethal to occupy. The usefulness of that effort now seems much diminished.
Coupled with this week's news that the fuel rod section of the unit 1 reactor core has been completely without cooling water for nearly two months, the situation is not only completely uncharted territory, but also a challenge beyond the current limits of human engineering. The containment has been breached, and there's a blob of deadly, superheated, melted fuel sitting on the bottom of the reactor, covered at least to some extent by water. There's a good chance that some radioactive lava has oozed out past the steel shell of the reactor and onto the concrete pad below it. Even if it just wallows there, it has to be doused constantly with water, which has become highly contaminated and leaked into the building basement and beyond, into the groundwater and the ocean.
The groundwater under the plant has not been tested, or if it has, the results have been kept secret by Tokyo Electric and the Japanese government. But all sorts of radioactivity has clearly been detected in the ocean near the plant, and the contaminated leakage is relentless.
And that's just unit 1. Reactors 2, 3, and 4 also have serious problems -- perhaps even more serious than no. 1. Knowledgeable observers continue to fret about more hydrogen explosions like the ones that have already ruined the countryside and sent radioactive clouds around the globe -- giant dirty bombs, in effect.
The evacuation zone due to the airborne releases keeps getting bigger, but children attending school just outside the zone are being subjected to radiation exposure that is unconscionable. Meanwhile, they found radioactive cesium in tea leaves grown south of Tokyo, at Minamiashigara, which is more than 170 miles away from the meltdown. The Japanese powers would like to ignore what's happened and what's continuing to happen, but the laws of nature that have been violated aren't going to let them do that forever.
The nucle-heads in the United States are also feeling a bit uncomfortable these days, as they don't have answers for some obvious questions. There are 35 boiling water reactors currently operating in our country -- 23 of them are GE Mark I reactors like the ones that have gone kerblooey in Japan. Current U.S. rules require plant operators to have at least four hours' worth of battery power on hand to run cooling pumps in case of a disaster that causes a complete blackout of the reactor plant and wipes out the on-site diesel generators. Is four hours enough? It wasn't at Fukushima.
And however sturdy the Mark I reactor vessels might be -- they weren't strong enough at Fukushima -- the spent fuel pools in the reactor buildings are incredibly vulnerable. They keep telling us that the reactor vessel can withstand a direct hit from a fully loaded 747. The same assertion cannot be made of the spent fuel pools, and as we now know from Fukushima Daiichi no. 4, those can be a colossal headache even if the reactor isn't running when the disaster hits. Let's hope all those heavy cockpit doors work.