Cole wrote:I'm doing my best not to beat a dead horse here, but please be careful about putting fallout from nuclear reactors in the same category as x-rays and "background radiation."
It's apparently not much of a dead horse since it keeps kicking. Background radiation like medical x-rays and such take the same form, and cause the same effects as fallout from nuclear reactors. Those are alpha, beta, gamma and neutron radiation. Muon and proton radiation aren't present in nuclear fallout, but have similar effects to beta and alpha radiation, respectively.
Cole wrote:Background radiation doesn't contain volatile isotopes of plutonium such as neptunium and americium; or xenon, strontium, and other byproducts of nuclear fission that are still being found in "hotspots" hundreds of miles away (and later blamed on archaic "Radon canisters" by TEPCO/Japan).
Plutonium, neptunium, and americium aren't volatile, and won't be present unless they are physically ejected from nuclear material (as happened in Chernobyl as well as the dozens of atmospheric nuclear tests). All of these are present in minute, but detectable, quantities around the world as fallout from atmospheric nuclear tests, and no reliable reports have shown elevated levels of these elements in Japan after the Fukushima disaster.
Plutonium (and other Transuranic isotopes and decay products) are primarily alpha emitters. The primary source of natural background radiation exposure is radon, which is an alpha emitter (radon is present all over as a decay product of natural uranium 238). All alpha radiation is pretty much the same, it is extremely damaging to tissue but unable to penetrate deeply. Alpha radiation from transuranic metals tends to cause leukemia, as the transuranic metals are bio-accumulated in bone tissue. Alpha radiation from radon tends to cause lung cancer, as radon doesn't bio-accumulate in the body.
The primary fallout from a nuclear disaster consists of strontium-90 and caesium-137. Neither a volatile, they are present in large amounts (radioactively speaking) because they are the decay products of krypton-90 and xenon-137, which, as noble gases are volatile and escape from the fuel cladding easily. Cesium-137 is a beta-gamma emitter and strontium-90 is a beta emitter. Both have radiation spectra similar to naturally occurring isotopes such as potassium-40 (which is a major component of the natural background radiation your are normally exposed to).
Cole wrote:While its true that 100 rem (aka acute radiation syndrome) is the only way to see a 100% cancer causality rate from radiation, cancer has a curious way of following fallout 5-10 years down the road. Especially when they're just now detecting up to 1600millisievert/hr (160 REM/hr) on the floor of Reactor 3 -- the highest levels to date.
An acute (not chronic) radiation dose of 100 REM will often cause radiation sickness, but only extremely
rarely results in death. It will only result in slightly increased cancer rates long term, not 100% casualty rates. Chronic radiation doses are less dangerous than acute doses because the body's repair mechanisms have more time to work in between damage events in chronic doses. People in places with high background radiation, such as Ramsar, Iran (where the yearly dose is 250 mSv), typically do not experience elevated rates of cancer.
They are detecting radiation rates of 1600 mSv/hr (maximum, not everywhere) inside the reactor containment buildings, where nobody is going (because they are detecting those high radiation rates), not on tea (which is why they build big, expensive reactor containment buildings). Cleaning up Fukushima Daiichi is going to be an expensive, dangerous mess (hey, don't put your backup generators below the level where they'll be swamped by a tsunami). It's not an expensive, dangerous mess that's present in your tea.
And since you accused me of being careless in talking about radiation, I'm a Physicist working for the US Dept. of Energy in radioactive cleanup (and any opinions presented are solely mine, and not those of the Dept. of Energy).