Wednesday, March 16, 2011

Hanging in There at Fukushima

I closed down my computer last night to news that another fire had started up at Fukushima #4. It's been put out now, and none of the fires seem to have been in the fuel pond, despite some reports.

In other confusing reports, the bottom line appears to be that the workers are still on the job at Fukushima, despite reports that they were removed because of too-high radiation readings. What has happened in other nuclear incidents is that workers have been willing to take high radiation doses that sometimes meant their death. So far, only one worker at Fukushima has been reported to have taken a high dose, and that dose is at the "you'll probably get sick but won't die" level. I'm guessing that he went close to the reactor to fix something that wasn't responding to controls or to check that a reading was right. If his exposure had been from a release, it would have been several people rather than just one.

I probably should have said yesterday that I don't expect that things will be smooth at Fukushima now. The news since I've read that post is consistent with what I expected: things are far from normal, but the operators are coping.

A few things to think about; I may write more about them later.

Radiation is very easily detected at very low levels. The fact that you can detect it doesn't necessarily mean it's harmful. At some point, there is likely to be a report that radiation from Fukushima has been detected on the West Coast of the United States. That will be a few atoms' worth. No, you don't need potassium iodide if you live in California.

Two things are being poorly understood: the concepts of concentration and rate. Whether something can harm you depends on its concentration. If you eat a tablespoon of common salt, your heart might stop from a sodium-potassium imbalance. Lower levels, over time, can contribute to high blood pressure. Low levels are essential for life. How much of a substance is present in a volume or weight of air, water, or food is important in understanding how it's likely to affect you. Unfortunately, this point is often missed in reporting.

I'd like to see more numbers for radiation levels in various places in Japan, like Tokyo. I'd also like to see them done right, namely expressed in rates, like so many microSieverts per hour. Or day. Both are likely to be how the rates are given. But reporters leave off the unit of time. Like concentration, rate of exposure to radiation makes a big difference in the likely effects. And a pet peeve that goes beyond this story: the word spike has meant, until recently, a quantity that goes up and quickly falls, not just the going-up part. Please use it correctly, reporters! And readers, keep in mind that they often don't.

Fukushima reactor #2 has had some noises coming from inside it that could have damaged it. We don't know that they're explosions - steam and water in confined circumstances can make noise. And we don't know that the reactor is damaged, much less that it's leaking. So reports that say the containment on reactor #2 may have ruptured, or that there are fears that it may have, aren't wrong, but it's easy - too easy IMHO - to read them quickly as saying that this has happened. They could have equally said that the containment may not have ruptured, but that wouldn't be as exciting. When the radiation levels around it rise, we'll know it's ruptured.

Update: Nice photo of an American contingent headed for Japan to help out.

I have the feeling I haven't said enough times how much credit those tending the reactors deserve.

Further Update: Ezra Klein presents a chart and proves he doesn't realize the difference between dose and dose rate. Dose rates coming out of Japan can't simply be compared to this table. Dose rate multiplied by the time spent in an area with that rate can. And the WaPo rebuild isn't letting me comment.

3 comments:

Robert K said...

i share you pet-peave, another one (of mine) is how reporters fail to differentiate radiation and radioactivity.

MT said...

Or how they fail to correct nuclear experts who misleadingly say "nuclear reaction" to mean chain reaction, as with regard to what insertion of the control rods shuts down.

Cheryl Rofer said...

Ah, you caught that too, MT!

I almost blogged about it yesterday. I think it was the New York Times, and the quote was something like "All nuclear reactions were shut down at the site when the earthquake struck."

That's sort of like saying that the laws of physics were suspended. It would have been nice if they could have done it.