I hope this comment doesn't cause the thread to be locked. I've been delaying posting my reply because I was busy with work. I'll try not to continue this discussion, but I'd like to post it before it's no longer possible to reply to M Paquette's comments.
One radioactive decay, releasing one gamma ray, which intersects and interacts with the P52 gene in one reproducing cell can cause cancer. Whether that one decay comes from an atom from a nuclear power plant, or from that banana you had with lunch is, of course, also a matter of chance.
Maybe someone should inform the Japanese that what's happening there isn't bad when you compare it to bananas.
If you had absorbed significant Iodine-131 from a reactor accident or atomic testing, there might be an increased chance of thyroid cancer. A dose of 10 nanograms adds roughly a chance of one in one million to the baseline incidence rate of roughly one in ten thousand over a lifetime. Compare and contrast with a typical medical dosage to treat hyperthyroidism of roughly 1000 nanograms of I-131.
Thanks for the numbers, I appreciate.
But Iodine-131 has a very short half life (8 days) and is just one part of the puzzle. Half life is much longer for Uranium, Cesium, Plutonium, etc. A number of
fuel rods have been damaged, which increases risk of such things being released, and the huge quantities of spent fuel on the site could also lead to spreading quite a bit of nasty stuff if things should turn for the worst. I just read that minute amounts of radioactive strontium have been detected in soil and plants in Fukushima Prefecture beyond the 30-kilometer zone. It is the first time that
radioactive strontium has been detected since the Fukushima plant began leaking radioactive substances.
UPDATE: some amount of nuclear fission seems to be
going on in open air!
Also, how reliable is the information we have on the risks of these substances?
The nuclear establishment doesn't exactly encourage researchers who challenge it with unwelcome findings.
An excerpt from
“The Nuclear industry: A History of Misleading Claims”, by Dr Sue Wareham OAM:
Dr Alice Stewart’s discovery that children who had been exposed in the uterus to X-rays had double the risk of developing leukemia and other cancers, was of great significance and is now undisputed in medical practice. And yet her findings were aggressively rejected by the nuclear lobby,14 both within and outside government, and by the ICRP.
Subsequently, Stewart worked with Professor Thomas Mancuso, Professor of Occupational Medicine at the University of Pittsburgh in the US, on the health of workers at the Hanford plutonium production facility. When their results showed cancer incidence roughly ten times that predicted by A-bomb survivor studies, Mancuso’s research funding ceased, and the US Government attempted to destroy data that he had collected.15
Other scientists who suffered the consequences of raising concerns about the effects of radiation exposure include John Gofman, who died in August 2007, and his colleague Arthur R Tamplin. Gofman was the chief medical researcher for the Atomic Energy Commission in the US, which both regulated and promoted the US nuclear industry. After he and Tamplin published data in 1969 showing that the risks from low dose radiation were much greater than that stated by the government (despite strong attempts by others at censorship), the two lost virtually all of their research funding.16
Dhirendra Sharma was a leading figure in science policy research at India’s Jawaharlal Nehru University, and was an outspoken critic of the Indian nuclear power program and its links to nuclear weapons. He alleged secrecy, lack of accountability, mismanagement and corruption. His book India’s Nuclear Estate was published in mid 1983. In December 1983 he was suddenly transferred out of the Centre for Studies of Science Policy, with no satisfactory official explanation being given, and thus his ability to further engage officially in science policy studies was diminished.17
In Belarus in 1999, more than a decade after the 1986 Chernobyl accident, Professor Yuri Bandashevsky, head of the Gomel State Medical Centre in one of the most contaminated regions, also paid a heavy personal price for his work. He was arrested and sentenced to 8 years imprisonment, allegedly for his work on the health effects of the accident and his criticism of lack of government resources for medical investigation of the disaster.
A final obstacle in the way of research on the health effects of radiation exposure relates to funding. Rudi Nussbaum, Professor Emeritus of Physics and Environmental Sciences at Portland State University in the US, reports that “Practically all such research has relied on funding by agencies that were created to promote, facilitate and regulate military and civilian uses of ionising radiation, to allay concerns about health effects from occupational and public
exposure, and to fend off litigation for workers’ compensation claims”.18 This situation indicates a clear conflict of interest for those bodies that purport to, on the one hand, protect public health, and, on the other hand, promote an industry that undermines public health.
The figures include Chernobyl, a worst case of an absurdly bad reactor design, a stack of carbon blocks with fuel pellets tucked into holes in the blocks. The damaged reactor actually blew apart. There was no containment whatsoever, and no mechanism to limit dispersion.
Chernobyl may have been the worst case as far as design is concerned, and also the worst case so far. But that doesn't mean future accidents can't be much worse.
A lack of precedents didn’t keep the Titanic and the Hindenburg disasters from happening.
Chernobyl was bad and it lasted ten days. The Fukushima disaster is in its second month now, is not under control, and
officials have warned it will be several months before the situation at the nuclear facility is brought fully under control.
What if you run out of "heroes"? What if radiation becomes so strong that you can't send in men or even dump water from helicopters anymore? What if all reactors on the site and the spent fuel that still needs cooling, aren't being cooled anymore and nobody can approach the site anymore? I have no idea, but one "Dr. Tom Burnett" (I don't know if he has any qualifications in this matter) writes: " If reactor 3 is in meltdown, the concrete under the containment looks like lava. But Fukushima is not far off the water table. When that molten mass of self-sustaining nuclear material gets to the water table it won’t simply cool down.
It will explode – not a nuclear explosion, but probably enough to involve the rest of the reactors and fuel rods at the facility." And there's much more nuclear fuel in Fukushima than there was in Chernobyl… From the same article: " Making matters worse is the MOX in reactor 3. MOX is the street name for ‘mixed oxide fuel‘ which uses ~9% plutonium along with a uranium compound to fuel reactors."
It did not render a whole country uninhabitable.
Indeed. Chernobyl was a bad case, but no worst case.
Official data on the scope and
health effects of the Chernobyl disaster seem to have been understated though.
News from Japan: “Chief Cabinet Secretary Yukio Edano said Friday that the new bans would apply to areas beyond the current 30 kilometer exclusion zone around the stricken Fukushima No. 1 nuclear power plant. Rice production within the 30-km zone is already effectively banned.” “Rice will also be inspected at the time of harvest. If cesium figures exceed safety standards, farmers will be instructed not to ship their rice.
The half-life of cesium is 30 years, so the problem is likely to persist.
The agriculture ministry will look at whether replacing soil in banned farmland is a feasible option or whether alternative crops that absorb fewer radioactive substances than rice might be allowed.”
And a prof. Christopher Busby has somewhat
worrying estimates of the potential number of victims. I don't know how well supported his views are, but his
Wikipedia page looks legit.
Note that the higher the radioactivity a given amount of material exhibits, the faster it goes away.
In Fukushima there are also dangerous products that don't go away fast. Plutonium has a very long half life. Plutonium gives off alpha radiation, which has a relative biological effectiveness about 20 times larger than that of the most radioactive beta and gamma radiation.
Alpha radiation can be blocked easily, unless you ingest the particles. And humans have to eat and drink. “Consuming food containing radionuclides is particularly dangerous. If an individual ingests or inhales a radioactive particle, it continues to irradiate the body as long as it remains radioactive and stays in the body.”
(Alan H. Lockwood, MD, a member of the Board of Physicians for Social Responsibility)
(Note: The calculations took me an hour or so, between reference books and running them a couple of ways. I'd appreciate it if any responses also used hard data, rather than the media copout of 'possibly', 'could', 'perhaps as much as', etc. Innumeracy when doing risk assessment is just bad, M'kay?
You seem to have a scientific education. Scientists assure us that nuclear plants are theoretically safe.
My education is in Law (though I work in an entirely different domain). I tend to worry more about things going wrong, because in real life, they do.
On the subject of nuclear energy, I share the feelings of Hirose Takashi, who told this story in an
interview:
"Waste plutonium, he said, was buried in pits dug deep into the ground, and then carefully monitored to make sure there was no leakage.
I asked him, “But didn’t you tell us just now that plutonium has a half-life of 24,000 years? Who is going to monitor it for that long?” “The US Government, of course.” “In all of human history, has there ever been a government that lasted for 24,000 years?” He did not answer, but only looked at me with contempt. Evidently he thought I was lacking in patriotism.
This was the moment I realized that a very intelligent, highly trained nuclear engineer can be a fool.
My field, political science, has produced probably only one scientific law: Power corrupts, and absolute power corrupts absolutely. But few political scientists have noticed that the closest thing we have to absolute power is nuclear power. Nuclear power corrupts the thinking of its believers in a peculiar way. It seems to tempt them to imagine that they have been raised to a higher level, where common sense judgments don’t apply. Common sense judgments like, it’s very dumb to produce a substance that will continue to radiate death, and will therefore require “monitoring”, for tens of thousands of years."
The US also has a serious
problem with spent fuel pools, by the way. There too, earthquakes or other issues can lead to big problems. The industry tends not to mention these things when informing the public about nuclear safety.
Most of the really nasty stuff around Chernobyl is gone now, decayed into stable isotopes.
And spread over many countries, blown around by the wind and spread by contaminated animals. How many people can prove what their cancer has been caused by?
The areas designated as 'contaminated' (as opposed to the worst areas designated 'strict radiation control') originally had radiation levels averaging 9 milliSieverts/year above the background of 50 milliSieverts/year. These areas now have levels of 0.1 to 1 milliSievert/year above background.
Radiation going down is good news. Thanks.
Ok. I'm going to try stop writing in this thread.
I would like to leave you with this thought of Ran Prieur:
"Why do geeks love nuclear power? More precisely, using Howard Gardner's theory of multiple intelligences, why do people with high logical-mathematical intelligence like nuclear power so much more than people with high intelligence in other areas? Framed this way, it's an easy question. In the world of logic and numbers and predictable machines, nuclear power is totally safe. Chernobyl doesn't count because, for political reasons, the plant was not designed, regulated, or run correctly. Fukushima doesn't count because, for economic reasons, the plant was not built to withstand an 8.9 earthquake and tsunami.
Nuclear power would be perfect if only you stinky primates would obey our beautiful science!" 
