TOKYO: Tests of seawater near Japan's Fukushima nuclear power plant have not detected any radioactivity, the environment ministry said on Sunday (Aug 27), days after authorities began discharging into the sea treated water used to cool damaged reactors. Japan
Tests of seawater near Japan's Fukushima nuclear power plant have not detected any radioactivity, the environment ministry said on Sunday (Aug 27), days after authorities began discharging into the sea treated water used to cool damaged reactors.
Japan started releasing water from the wrecked Fukushima plant into the Pacific Ocean on Thursday, sparking protests within Japan and neighbouring countries, in particular China, which banned aquatic product imports from Japan.
Japan and scientific organisations say the water is safe after being filtered to remove most radioactive elements except for tritium, a radioactive isotope of hydrogen.
UV radiation is quite damaging (although part of the popular "summer tan" culture) on its own. However, we also receive higher energy photons (above UV: xray, gamma) as well as some energetic muons from the sun. You get a 4x of a daily dose of radiation if you grab a flight. Around that of an xray. All of which is mostly ignored by people.
You are correct that gamma ray radiation is by far the most damaging radiation. Beta and alpha radiation can be stopped by pieces of paper (or your skin), gamma radiation will go through your house, your car, your wife, hit a dna molecule in your hair follicle, and make that hair follicle permanently gray.
More interestingly, putting the "radioactive" seawater in perspective: tritium fizzles into some beta radiation, of 18kev energy. Assuming, magically, all this (beta radiation) energy was deposited perfectly into your DNA (nearly impossible because it is beta radiation), resulting in maximal damage, in somewhere important and not the dead layer of your skin, doing a tiny calculation we can compute this damage to be that of a photon of 0.07nm wavelength (18 kev), of similar energy used in simple xray imaging (CT imaging uses 5x higher energy). With 10 becquerels / liter, 100 liters of water surrounding you, could inflict a horrible dose of 24 (hours) * 3600 (sec / hour) * 10 x 100 x 18 kev * 1.60218e-16 (Joule / kev) / 70 (kilograms per human) = 3.55958619e-9 Sv in a day
That is a terrifying amount of 3.6 nSv. Almost close to 1/20 that of a banana you eat (I am not joking, just smiling heavily).
On one hand it's weird how people are so upset about this, on the other these morons were talking about radioactive fallout hitting the US right after the tsunami hit. They aren't the brightest bulbs.
Like you ca. swim at the top of a pool in a tractor coolant tank. Water is very cool at diffusing radioactivity (if that’s the right term, it’s probably not).
Heck we have legit crashed nuclear subs at the bottom of the ocean, and places we have just straight dumped waste much more potent than this water.
The sea floor will have a lot of thorium and uranium, because every inch of the ocean floor does. This is because uranium oxide is water-soluble, and billions of years of erosion have led to the oceans being full of the stuff.
Thorium does not have a natural water-soluble oxide, but can end up in suspension, to participate out to the ocean floor.
Now, we're not actually talking about uranium or thorium in this water discharge, instead we're talking about deuterium and tritium, both of with can naturally be found in seawater, but natural tritium is vanishingly rare. It's usually created via cosmic ray, and has a half life of 12 years.
Anyway, the point is, all this radioactive material, both natural, and discharge, will be so diluted that it's not an issue.
Because no human activity could ever have effects that accumulate at the macro scale. All that plastic has been successfully diluted and SO2, CO, CFCs and CO2 are all harmless once released.