Slashdot Mirror
16 US Ships That Aided In Operation Tomodachi Still Contaminated With Radiation (stripes.com)
mdsolar writes: Sixteen U.S. ships that participated in relief efforts after Japan's nuclear disaster five years ago remain contaminated with low levels of radiation from the crippled Fukushima Dai-ichi nuclear power plant, top Navy officials told Stars and Stripes. In all, 25 ships took part in Operation Tomadachi, the name given for the U.S. humanitarian aid operations after the magnitude-9.0 earthquake and subsequent tsunami on March 11, 2011. The tsunami, whose waves reached runup heights of 130 feet, crippled the Fukushima plant, causing a nuclear meltdown. In the years since the crisis, the ships have undergone cleanup efforts, the Navy said, and 13 Navy and three Military Sealift Command vessels still have some signs of contamination, mostly to ventilation systems, main engines and generators. "The low levels of radioactivity that remain are in normally inaccessible areas that are controlled in accordance with stringent procedures," the Navy said in an email to Stars and Stripes. "Work in these areas occurs mainly during major maintenance availabilities and requires workers to follow strict safety procedures."
If you mean "half life", then it all depends. Half life of U-238 is on the order of 4 billion years; C-14, 5730 years; I guess I won't live that long. But half life of Pb-211 is just over half an hour. I'd like to think I have at least that long to live...
Of course, maybe your sig line is for real.
Which basically makes it clear that there IS NO ISSUE.
A few quotes for those who cannot bother reading the article:
'The low levels of radioactivity that remain are in normally inaccessible areas that are controlled in accordance with stringent procedures'
'The radioactive contamination found on the ships involved in Operation Tomodachi is at such low levels that it does not pose a health concern to the crews, their families, or maintenance personnel'
' the Reagan’s ventilation system was contaminated with 0.01 millirems of radiation per hour, according to the Navy. Nuclear Regulatory Commission guidelines advise no more than 2 millirems of radiation in one hour in any unrestricted area'
'“Personnel working on potentially contaminated systems were monitored with sensitive dosimeters, and no abnormal radiation exposures were identified'
'Of the 1,360 individuals aboard the Reagan who were monitored by the Navy following the incident, more than 96 percent were found not to have detectable internal contamination, the Navy said. The highest measured dose was less than 10 percent of the average annual exposure to someone living in the United States'
And the whole article wraps up, after showing quite clearly that there is NO ISSUE, by pointing out that a bunch of money-grabbing US navy staff are trying to push a baseless lawsuit for such things as 'genetic immune system diseases, headaches, difficulty concentrating, thyroid problems, bloody noses, rectal and gynecological bleeding, weakness in sides of the body accompanied by the shrinking of muscle mass, memory loss, leukemia, testicular cancer, problems with vision, high-pitch ringing in the ears and anxiety', from doses that are fractions of quite normal background exposure.In other worse for anything they could dream of that has happened since then.
Their may reasoning seems to be 'Well, the Navy cleaned the decks after, it must have been dangerous!', so they appear to be suing on the basis that due care was taken!
The real news here is how ridiculously out of perspective many people are about radiation risks.
Lets hope none of those sailors like bananas! they better sue Ecuador!
Well, sorry to disappoint you, but a dose of 4 Sv will kill you, while the same amount of energy (it's just a couple of Joules per kg) won't even heat your coffee to "lukewarm".
tl;dr: Ionizing radiation becomes a hazard long before its emission will generate significant, useful amounts of heat.
Well, it's not so simple as that. What you're really interested in is the interaction of radioactive materials with a complex biological entity -- your body. The rate and type of decay is only one parameter in that interaction; the chemistry and physical form also matter, along with the chemistry and stability of the daughter products.
For example strontium is in the same periodic table column as calcium -- which obviously is a major component of our bodies. Therefore strontium is digested and metabolized the same way calcium is. This make Strontium-90 a much higher concern than other isotopes with similar half lives (roughly 29 years). An intact block of metallic strontium is moderately hazardous. An aerosol suspension of colloidal Sr-90 particles is extremely hazardous.
The Radium 226 in old watch pigments has a half-life of 1600 years, and is perfectly safe to wear inside a sealed case on your wrist. But you don't want to ingest it. It's probably best to avoid working on old radium watches because the pigment breaks down into a very fine powder. Would I panic if I had a single exposure to an opened radium watch? No. I just wouldn't make a habit of it.
The "duck-and-cover" era advice about avoiding atomic fallout tries to balance survival priorities against each other. You're supposed to stay in your shelter for several weeks, which allows the levels of the most radioactive isotopes to fall. But the reason you come out after several weeks is not that it's perfectly safe to do so; it's that you can't live for years or even decades in a shelter. So the compromise is to stay in the shelter long only enough to avoid dying quickly of acute radiation sickness. After two or three weeks the levels of highly radioactive Sr-91 and Sr-92 are negligible; the levels of Sr-90 are hazardous and will remain so for decades.
Depending on the degree, form, and nature of the contamination of these ships, it could prove a serious handicap to their ongoing operation. Not because the sailors will come down with acute radiation sickness, but because of the laborious precautions needed to avoid chronically exposing sailors. TFA doesn't say much about specifics, but I do know Fukushima released a great deal of Cesium-137, which has a half-life of 30 years and is in the same periodic table column as potassium, which is obviously biologically very active. It's also readily water soluble and can enter the body that way. Less Sr-90 was released, but depending on exactly where and when the ships were contaminated that could also pose an operational handicap because calcium remains in the body much longer than potassium.
As for Hiroshima and Nagasaki, it's important to realize that they were high altitude detonations. That both reduced the levels of contamination and spread the contamination widely throughout the region. It'd serve little purpose to abandon the city centers. Compared to, say, Chernobyl with its burning radioactive graphite, the detonations were relatively clean radiological disasters.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.