Nuke Plant != Hydrogen Bomb?

March 14, 2011 7:30 PM

Is there any meaningful way to compare the possible radiation releases due to the damaged Japanese nuke plant with the radiation released by the air and sea bursts of the U.S. nuclear weapons testing in the 40s, 50s, and 60s?

I am well aware that the plants will not explode like our A and H bombs did, but they will produce a great deal of radioactivity, and that is what I am interested in knowing. How will the radiation production of these plants match those weapons tests?

posted by hwestiii to Technology (11 answers total)

I am well aware that the plants will not explode like our A and H bombs did, but they will produce a great deal of radioactivity

Well it's not clear that the plants will produce "a great deal of radioactivity."

And the amount of radiation exposure is measured in roentgens.
posted by dfriedman at 7:32 PM on March 14, 2011

There's no meaningful way to compare the radiation released until it's done being released.
posted by devbrain at 7:32 PM on March 14, 2011

Actually, according to the wiki link, roentgens are no longer the accepted measurement of radiation exposure; it's now something calculated as charge / kg.
posted by dfriedman at 7:35 PM on March 14, 2011

Sieverts are the biological/dose equivalent unit for radiation.
posted by gramcracker at 7:40 PM on March 14, 2011

Response by poster: With at least one containment evidently breached, I think there is a pretty good likelihood that there will be a release.

I'm not really interested in units of measure. I'm wondering about total output.
posted by hwestiii at 8:04 PM on March 14, 2011

You have to be careful with words like "containment" because most news article are not using them in their technical sense. There has been no serious breach of containment.

It's worth reading this article, even if you don't agree with the conclusion, for the solid grounding in exactly what these terms mean, what's going on, and how it all works (From MIT's Dept of Nuclear engineering.)

http://mitnse.com/2011/03/13/why-i-am-not-worried-about-japans-nuclear-reactors/
posted by Nothing at 8:25 PM on March 14, 2011 [3 favorites]

Also, the answer is probably not easy. Radioactivity is not a thing on it's own. There is radiation, which is energy, and there are radioactive isotopes, which are bits of matter that emit radiation as they undergo radioactive decay. Different isotopes decay at different rates, releasing energy faster or slower. Some last only minutes, and are terribly radioactive. Some last millions of years, and are only really dangerous over prolonged exposure. In general, the isotopes produced in power generation are more dangerous and in larger quantities than those produced in bombs, or so I have read. I suppose this is because they are created by controlled fission, instead of a release of as much energy at once as possible.

But the point is this: there are many things to compare: the types of isotopes released into the environment and the amounts and where they ended up for a start.
posted by Nothing at 8:36 PM on March 14, 2011

This is what I do for a living, well, I model radioactive waste repositories. There might be meaningful ways to compare the effects of each, but you need a better defined question.

As far as what they produce, the radioisotopes will be somewhat similar. Though the fission yield curves differ a bit from uranium to plutonium and isotope to isotope.

The location of the tests/reactors play a role too. Atmospheric tests will spread much more evenly over the surface of the earth than an undersea or ground based scenario. The quantities and nature of activation products (things made radioactive by neutrons created by the bomb/reactor vs. fission products, things that are radioactive because the splitting of uranium/plutonium created unstable elements) could be different depending on the surroundings. Undersea tests activate a fair amount of Cl-36 for example as ~2% of the mass of seawater is chlorine.

As far as how much is released, you could count how many Becquerels of each isotope were released from the Japan reactors and compare that to the total amount released over the course of atmospheric testing or on a per test basis.
posted by pseudonick at 9:28 PM on March 14, 2011 [1 favorite]

Is there any meaningful way to compare the possible radiation releases due to the damaged Japanese nuke plant with the radiation released by the air and sea bursts of the U.S. nuclear weapons testing in the 40s, 50s, and 60s?

A great deal of what is known about health physics (the biological effects of ionizing radiation) has been derived from studies of the two nuclear bombs dropped on Japan in 1945. Early benchmarks for "safe" exposure to different forms of radiation came directly from the studies of the Japanese population in and around Nagasaki and Hiroshima.
posted by three blind mice at 2:43 AM on March 15, 2011

The best study of the effects of aboveground testing in the US that I have come across is this one:Estimated Exposures and Thyroid Doses Received by the American People from Iodine-131 in Fallout Following Nevada Atmospheric Nuclear Bomb Tests You'll have to do some conversion of measurements, as we have changed some of the standards (1 rad = 0.01 sieverts). Location is important in comparing the data. Have fun digging through this!
posted by davismbagpiper at 2:08 PM on March 15, 2011

This is worth reading too (brief ad before content displays) for a discussion of what's happening which is significantly more useful than most mainstream news outlets.
posted by southof40 at 2:10 PM on March 15, 2011