Normally, we get 3.65 millisieverts of radiation a year. Increased cancer risk is associated with 100 millisieverts per year. Nuclear workers are only meant to get 100 millisieverts even in an emergency with protective clothing.
Previously, radiation at Fukushima has hit 100 millisieverts per hour. A few days ago, three workers were hospitalised after exposure to water emitting 750 millisievert water.
Today, water in No 2 reactor was detected emitting 1 sievert per hour, ten million times the normal level – and they’re not sure of the source.
There’s been no explosions, there’s no more smoke or steam, the electricity is reconnected, yet the situation seems to be worsening.
No 2 reactor, you’ll remember, had that mysterious internal explosion, that they feared had created a leak in the suppression chamber and possibly damaged the core reactor chamber. The new radiation may be a sign that the chamber is breached, possibly due to damage from that explosion and/or the corrosive seawater that they’re using to cool the fuel rods with the normal fresh water pumping system still broken.
A lot of ‘possibly’s and ‘maybe’s. And a hell of a lot of radiation. Exposure to 1 sievert carries a small risk of death, 8 sieverts or more has a 100% fatality rate.
Of course, these radiation intensities drop off rapidly the further away you get from the Fukushima plant but radioactive iodine has been distributed over a wide area, including Tokyo. The quantities are very small but the danger of radioactive iodine is that it gets absorbed by the thyroid gland, which potentially causes thyroid cancer . It’s particularly dangerous babies.
It’s important to realise this when some dismiss the low radiation levels further away from the Fukushima plant. The immediate dose that is not the danger to the broader public as it is for the workers, the threat to the public is the absorption of minute quantities radioactive materials through the air, food, and water. Fortunately, the current levels of radiation over the wider area, while breaching safety regulations probably aren’t going to hurt anyone.
Funnily enough, I’m still a supporter of nuclear energy for countries where the scale works and where the alternative is coal – neither of which apply to New Zealand. Like George Monbiot says: “On every measure (climate change, mining impact, local pollution, industrial injury and death, even radioactive discharges) coal is 100 times worse than nuclear power”. Nuclear kills when it goes wrong, coal kills when it goes right.
But make no mistake, the situation in Fukushima is extremely serious and the fact that it’s still not under control is very worrying.
And let us not forget the real human toll of the Tohoku Earthquake disaster, thus far, has not been from radiation but the tsunami. Nearly 11,000 bodies have been recovered and a further 17,000 are missing. Many will never be recovered, swept out to sea with the retreating waters. Entire towns are destroyed. With and aging, declining population (and an ailing economy as a result) those communities may never be rebuilt.
(*cheers to Lanth for corrections to iodine paragraphs)