2012/08/22

Adequate Design?




Looking back more than a year after the event, it is clear that the Fukushima reactor complex, though nowhere close to state-of-the-art, was adequately designed to contain radiation.”                   
- Dr. Richard Muller, physicist, University of California Berkeley, August 2012.

Take your time. Go back and read that again: “The Fukushima reactor complexwas adequately designed to contain radiation.”
While a recent official Japanese report on the Fukushima Daiichi disaster confirms the view that it was a tragedy with enormous environmental, social and economic effects, there is still commentary appearing in the media claiming that the real danger was minor, while all the harm it did was caused by irrational panic. Sadly, the event is said to have needlessly caused nuclear power to fall out of favor at a time when we need it as an alternative to carbon-based energy. This week, The Wall Street Journal published The Panic Over Fukushima, the latest example of such an essay, by University of California Berkeley physicist Richard Muller.
While Dr. Muller is chosen to speak on this issue in the mass media because of his expertise as a physicist, his opinion piece has an unfortunately narrow view of the issue from the viewpoint of medicine, engineering and ethics. Most of what he writes is correct, but his conclusions are doubtful if what he omits is taken into consideration.
All scientists who have tried to downplay the seriousness of nuclear accidents choose to discuss only cancer and external radiation exposures. However, people who are concerned about environmental contamination in Fukushima are mostly worried about the effects of particles that will get into their bodies, and other ailments that are not as frightening as cancer but a serious concern. The earliest studies of the health effects of radiation were focused on internal contamination, and the hazards were well known before there was a nuclear power industry that preferred not to talk about them. Every health physicist knows that cesium in living organisms is absorbed in the same way as potassium, and strontium fills the role of calcium. The former goes to muscles and the latter goes to bones. Dr. Muller’s argument doesn’t mention internal contamination, but it seems to rest on the assumption that the levels of these toxins in the environment around Fukushima will have a negligible impact, whether they are inside or outside living things. Yet considering the complexity of the problem, how could anyone know with any certainty what the health effects will be?
Other omissions are the topic of non-cancerous health effects, and the greater vulnerability of fetuses and children. These are conveniently not discussed. One reason might be the common assertion that no official support has ever been given to the claim that radiation causes non-cancerous health effects. Indeed it is difficult to find any government compensation or any legal decision that has favored claimants who said they suffered non-cancerous health effects from exposure to radiation. But there is one little-known precedent from a forgotten corner of nuclear history. The U.S. government has awarded Marshall Islanders, who were exposed to nuclear weapons test fallout, with compensation for several non-cancerous diseases and benign tumors, among them non-malignant nodular thyroid disease, hypothyroidism, autoimmune thyroiditis, severe mental retardation, and unexplained bone marrow failure. Internal exposure is implicitly admitted in the recognition of these conditions.
One quarter of the 36 conditions listed for compensation are non-cancerous or include benign tumors. It was not easy to get these conditions recognized, but when they were added to the list they were described as being “medical conditions which are irrebuttably presumed to be the result of the Nuclear Testing Program.” Skeptics would probably say that it was all just sympathy money, politicking and liberal guilt caving in to pressure from victims. There is no convincing some people.
Many of the admitted conditions are related to thyroid malfunction, which can be a primary cause of other health conditions such as diabetes, obesity, heart disease and hypertension. Furthermore, research by Bandazhevskaya et al has shown that heart disease later in life can be caused by the absorption of the radioisotope cesium 134 and 137 by heart muscle during embryonic development and during childhood. The Marshall Islands has some very poor statistics in world rankings for death caused by ailments related to heart disease (listed in the table below.) If they have never been recognized as effects of radiation it is because the world authorities in health physics (WHO, UNSCEAR, IAEA, ICRP) refuse to acknowledge Bandazhevskaya’s work on heart muscle absorption of cesium, even though they also seem reluctant to conduct research that would settle the matter. Also, the diseases in the table are all secondary effects of thyroid malfunction, and they are parts of a single condition known as metabolic syndrome which is caused by a combination of environmental, dietary and cultural factors. It would be impossible to determine precisely how much nuclear weapons testing contributed to the present health condition of Marshall Islanders, but undoubtedly it is a factor in the dismal statistics of a place that should be a tropical paradise full of healthy people. The list below shows world ranking for rate of death for various diseases, along with the rate of death within the Marshall Islands. Since these five causes of death are problematically inter-related, they could be totaled as one cause labeled metabolic disease. In this way, we can say that 52.35% of Marshall Islanders are dying from this preventable condition, with radiation exposure being a highly probable contributing factor.

cause of death
world ranking
% of deaths in the Marshall Islands
stroke
1
17.69
endocrine disorders
2
2.35
diabetes
4
7.22
hypertension
5
6.68
heart disease
13
18.41
TOTAL

52.35

But this is medicine, not physics. Perhaps it is too much to expect a physicist to learn this information that is outside his area of expertise. This is a job that can only be done, apparently, by amateurs who take the time to read research papers from various fields in their free time.
Dr. Muller wrote in his conclusion, “Looking back more than a year after the event, it is clear that the Fukushima reactor complex, though nowhere close to state-of-the-art, was adequately designed to contain radiation.” I doubt there are many nuclear engineers who would agree with this statement because most of them, even ones who are still staunchly pro-nuclear, must be ashamed and appalled by how badly this complex was maintained and how badly it failed to contain radiation. To take just one example of inadequate design, TEPCO workers on the site found it impossible to vent the pressure that caused the explosions and led to the catastrophic release of radiation. It is peculiar that anyone could call this “adequately designed to contain radiation.”
Of course, if you believe there are no serious environmental or health consequences from the massive releases of radiation that occurred, then the complex was adequately designed. There will be no problems if other reactors of the same design fail in the same way because there are no health effects. Don't worry. Be happy.
Furthermore, this statement about “adequate design” shows no awareness of the ongoing dangers posed by the melted cores and the spent fuel pools – the main reasons people are reluctant to re-inhabit the area.
In his discussion of the risks of nuclear power, Dr. Muller declares the obvious in stating, “Nothing can be made absolutely safe.” Then he asks a question that actually gives his opponents a clear reason to not change their minds. He asks, Must we design nuclear reactors to withstand everything imaginable? What about an asteroid or comet impact? Or a nuclear war? No, of course not; the damage from the asteroid or the war would far exceed the tiny added damage from the radioactivity released by a damaged nuclear power plant.” Well, actually, these are good reasons not to build nuclear power plants in the first place. There are other crises less severe than nuclear war that could be worsened by the involvement of nuclear power plants and spent fuel pools. If nuclear power plants had existed at the time of WWII, their destruction by conventional bombing would have left Europe uninhabitable. A small war or terrorist attack with non-nuclear explosives aimed at nuclear power plants would be enough to cause widespread damage.
Most of Dr. Muller’s essay is devoted to a discussion of how the risks of cancer are calculated for a radiological emergency, and how these risks compare with natural sources of radiation and other risks we face from nature or from other man-made threats. The long mathematical explanation becomes a condescending lecture to the non-specialist who, it is presumed, is too dimwitted to understand the simple point that radiation exposure produces relatively few additional cancers compared to all the cancers that occur in a population. We get it, but those who dwell on this point fail to address the ethical issues of the discussion.
If the extra cancer cases caused by a radiological accident amount to only a 1% increase, the crime of imposing this burden on people is the same no matter what the risk is. If, in addition to the cancers that will be caused by radiation from Fukushima, there are 99 known carcinogens sold legally and scattered throughout the environment, the producer of each one can say that his product contributes only an additional 1% lifetime risk of getting cancer. And he’ll say that this is, of course, an acceptable trade-off considering the benefits the product brings to society (sterile toilet bowls, perhaps). But, of course, the net result of everyone using this rationale is a 100% chance for everyone of an untimely death by cancer.
For some reason, the moral outrage is easier to perceive if you consider the risk of harm by criminal activity. If a sociopathic killer is paroled, the murder rate will increase only incrementally, while there is a benefit to society in the saved cost of incarceration. My overall risk of dying by violence hasn’t changed too much by the release of this one criminal. High-income people, such as university professors, choose to not live in neighborhoods with higher crime rates, even if living there would only increase their lifetime risk of dying by violence by less than 1%. Their “irrational” fear and discomfort with living with the uncertainty would be the deciding factor, and most people find this to be natural value system. Psychological comfort matters.
To take another example, if a real estate agent knowingly sells someone a house that was used as a methamphetamine lab, he can rationalize his action in the same way the criminal rationalized making the drug. He can say that there is only a small increase in the risk to the health of the sucker who buys the house. If he already has poor health and some bad habits, so much the better. In these cases, the answer to the moral question seems clear: risks can only be imposed with informed consent, and individuals have the right to decline risks for reasons that may seem irrational to others. This will all become much clearer to you when it is the radionuclides falling on your property and not on the homes of abstract strangers on the other side of the world. In my neighborhood, soil deposition of cesium went from a few hundred Bq/m2 to about 20,000, but this, we are told, is nothing to worry about because in the exclusion zone 200 kilometers away the figure is 500,000 ~ 1,000,000, or more. And the optimists say even that will have a negligible impact. I didn’t panic and I haven’t evacuated because the doctor is right, lifetime risks of cancer haven’t increased much at all, and quitting my job at the age of 53 would have a serious downside. But I still claim my right to be rationally outraged.
Furthermore, it does not matter whether the person declining the risk agrees with others about how dangerous it is. If my wife has a phobia about butterflies, it would be sadistic of me to mount framed specimens of them on the wall and tell her to just get over it. In contrast, the fear of radiation is not completely irrational. It is a known poison. Radioactive particles should not be in the human body, but to some degree people are, admittedly, irrational about the risks, sometimes. But so what? If they choose not to live on land contaminated with 500,000 Bq/m2, that’s their prerogative. If the land becomes economically depressed and depopulated, too bad. If the electorate no longer wants nuclear power, that’s democracy in action. If the insurance liabilities of nuclear power make it too expensive to finance with private money, again, too bad. The market has spoken. This is the consequence of badly managing nuclear safety, not of the general population’s panic and irrationality.
In spite of these moral arguments, I regret to say that Dr. Muller is probably right about the numbers and the long-term effects of Fukushima. It amounts to just an incremental addition to the health disasters that have been unfolding for a long time, and, as a civilization, we appear to be too dumb to understand why people are dropping all around us. Rates of metabolic diseases and cancer have been increasing steadily, and the increase in cancer is not occurring just because life expectancy has increased. According to Samuel S. Epstein, M.D., the chairman of the Cancer Prevention Coalition,

 [Since 1971] … childhood cancers have increased by 26% overall, while the incidence of particular cancers has increased still more: acute lymphocytic leukemia, 62%; brain cancer, 50%; and bone cancer, 40%. The federal National Cancer Institute (NCI) and the charitable American Cancer Society (ACS), the cancer establishment, have failed to inform the public, let alone Congress and regulatory agencies, of this alarming information. As importantly, they have failed to publicize well-documented scientific information on avoidable causes responsible for the increased incidence of childhood cancer.

If society doesn’t wake up to the causes of cancer and start preventing it, then nuclear accidents like Fukushima, occurring amid all the other causes of disease, will continue to be wrongly perceived as inconsequential.
Dr. Muller makes a couple additional assertions that are worthy of attention. Invited to write for a major media company as an expert, he is allowed to make assertions that don’t need to be supported by as much as a hyperlink to a credible source. Nor does he have to admit that his assertions are controversial within the scientific community.
He claims that nuclear power is an abundant resource, but doesn’t explain that there are many uncertainties about the world supply of uranium. Specialists who have looked into the question admit that the supply of uranium depends on many factors that can’t be predicted. The World Nuclear Association is optimistic about a technological solution in a post-carbon world in which nuclear energy produces hydrogen fuel which powers the heavy machinery to mine and transport uranium. This presumption conveniently avoids the fact that global warming will do catastrophic damage before carbon energy supplies are depleted. Other experts are not so sure, regardless of the recently exploited deposits in Kazakhstan that have temporarily dampened talk of  a shortage of uranium. An article in Live Science described the situation this way:

Now it seems that mining uranium, which nuclear power depends on, could be even less environmentally friendly and more costly than critics say, according to a new analysis led by Gavin Mudd, an environmental engineer at Monash University in Australia.
On average, supplies of high-quality uranium ore have been steadily declining worldwide for the past 50 years, and will likely to continue to wane in the mid-to long-term, Mudd said. Any new uranium deposit is likely to be deeper and harder to extract, and getting uranium from lower-quality deposits involves digging up and refining more ore, according to their analysis of government and industry reports.
"I have often found that the numbers used by many in industry, government or green groups are guesses rather than extensive, measured data sets," Mudd said. "The main thing is to understand the environmental costs of mineral production in terms of land disturbance, energy and water inputs, greenhouse outputs and that this will gradually climb up over time."

Another questionable claim of Dr. Muller is in his reference to the gold standard of radiation studies – the studies of Hiroshima and Nagasaki victims – to make conclusions that may be flawed. Critics of the official studies of Hiroshima and Nagasaki have pointed out for a long time that their basis is questionable. For one thing, a very important group of radiation victims died in the instant the bombs detonated, or shortly afterward from burns. That takes about 200,000 people out of the studies from the start. Another problem is that the official studies left out people who were living at a distance of more than 2.5 kilometers, and people who entered the cities after the detonations. These groups received significant internal doses and low-level external doses. Another physicist, Inge Schmitz-Feuerhake, studied these groups and said in a recent interview, “What I found was that the death rate from leukemia and respiratory and gastrointestinal cancers was above the national average, and that the incidence of thyroid cancer, leukemia, and breast cancer among women were 1.5 times to 4.1 times higher.” That’s a higher rate than just a few cancers added to the millions that occur “naturally,” but Dr. Schmitz-Feuerhake is just a member of the European Committee on Radiation Risk (ECRR), a group accused by the nuclear establishment (the IAEA, ICRP, UNSCEAR and industry organizations) of being politically motivated and fringe – not to be taken seriously. It is interesting that these groups of scientists and engineers always see these traits in those who disagree with them, but view themselves as rational, neutral Dr. Spocks who have no skin in the game.
Dr. Schmitz-Feuerhake goes on to say,

Meanwhile, in the past several decades, various studies on nuclear accidents, nuclear facility workers, medical x-rays, and natural radiation have shown the effects of low-level radiation exposure on health. However, the research has been largely ignored, primarily because they contradict data from Hiroshima and Nagasaki. The ICRP's risk assessment, in particular, underestimates the effects of long-term low-level radiation exposure, and also lacks awareness of its effects on illnesses other than cancer… Similar things [official denial of the effects of internal exposure] are happening in many other countries. It's because once a public organization acknowledges internal radiation exposure, they would be forced to acknowledge their responsibility for the risks to the health of nuclear plant workers. Nuclear plant workers are burdened with the same problems as the people of Fukushima who have been exposed to radiation.

I hope that Dr. Schmitz-Feuerhake and others in the ECRR might find that the above-mentioned recognition of Marshall Islanders constitutes a rare official acknowledgement of non-cancerous diseases and internal exposure. As for commentators such as Dr. Muller, I am reminded of something I was told by a friend who took the Trans-Siberian Railway in 1989. A few times he saw graffiti on dilapidated buildings that screamed out, “Eat here, Gorbachev.” This is food for thought for anyone who thinks the exclusion zone in Fukushima is fit for human habitation.

References and Other Resources

2012/08/19

Corporate Responsibility


With this post I have a rare occasion to make use of the French that I studied three decades ago as an undergrad. This post is mostly a translation of an article that appeared in Le Monde and other French language media this week, but it seems like it was not picked up for translation into other languages.
The story highlights one more example of the bad stuff that happens when we trust corporations to do the right thing. This story shows, in a strange way, that the American right wing nuts are correct when they say “regulations are killing us.” Yes, the way government regulation is done these days, it certainly will kill us. Even if you believe that corporations will act responsibly in most cases, when it comes to the safe handling of medical isotopes, it only takes one bad actor to ruin the show for everyone.

Le Monde, August 14, 2012
Virginie Lefour

A Belgian corporation that produces material for nuclear medicine has gone bankrupt and has abandoned several cubic meters of nuclear waste, according to statements by Belgian authorities on August 14. The announcement comes one week after the discovery of possible fissures in a Belgian nuclear reactor.
Best Medical Belgium, part of an American group of companies located in Fleurus, close to Charleroi in the south of the country, declared bankruptcy in May and was placed under judicial administration. On July 17, L’Institut belge des radioelements (IRE), owner of the local facilities rented by Best Medical, inspected these sites accompanied by specialists from l’Organisme national des dechets radioactive (ONDRAF) and from l’Agence federal de controle nucleaire (AFCN).
In a letter addressed to the judicial administrators, made public by the daily news organizations Le Soir and De Standaard, the director of the IRE, Jean-Michel Vanderhofstadt, gives a frightening account of the state of the facilities. The director writes, “We observed in many places not only a general state of disrepair of the installations and equipment, but also, in an indescribable disorder, a mass not only of metal pieces, cases, files, papers, tools, tubes, electric cables, solvent bottles, hardware… but also radioactive waste consisting, for the most part, of combustible material.”

Necessary to “intervene rapidly”

Mr. Vanderhofstadt continued by saying the situation described constitutes a “risk to the safety of other nuclear installations on the site, and, as a consequence, for the environment and the population nearby.” He describes seven cubic meters of plastic bags and fifteen containers of strontium 90 that were found among the debris. “There is no danger for the nearby area,” but it is necessary “to intervene rapidly,” declared the head of the AFCN, Willy De Roovere. The Belgian Minister of the Interior, Joelle Milquet, said the situation was unacceptable and has ordered ONDRAF to handle the materials as fast as possible.
ONDRAF has already placed the substances of most concern in containers. The organization added that the treatment of waste material and decontamination of the site will begin in September and could last five to seven years. The question of the safety of nuclear installations came to the surface last week in Belgium with the announcement that “possible fissures” have been discovered in the containment structure of the Doel 3 reactor, near Anvers. The operator of this reactor, Electrabel, announced that it has been shut down since early June, is not to be restarted before the end of September.

Readers can note that the reporter avoided giving any background information on the American parent company, or any explanation of why the facilities were left in such disarray.
With a few moments of internet searching, I was able to find that the parent company is Best Medical International, of Springfield, Virginia, USA. The Belgian operation had been in a deteriorating relationship with its union, and Belgium in general, according to a letter it posted to its employees earlier this year.
It seems that the international business world has turned very sour on Belgium. The head of the multinational human resources company, Adecco, advised corporations bluntly in April this year, “If you can leave Belgium, run!” Well, it looks like Best Medical took the advice a little too seriously.
One thing that is easy to overlook in this story is that although Best Medical Belgium is bankrupt, the parent company Best Medical will carry on. In fact, it can, in theory, increase future revenue because of the radioactive waste it left behind in its Belgian location. More isotopes spread around means more future cancer cases. People working in health care wish to prevent cancer and they have genuine concern for patients, but the medical industrial complex itself has no structural incentive to prevent cancer. It has more revenue when there are more cancer patients to offer the hope of prolonged life.

2012/08/14

Curiosity about Plutonium in Spacecraft


"You may leave here for four days in space
But when you return, it's the same old place"
Barry McGuire, Eve of Destruction


 The landing of the NASA Mars rover, Curiosity, was big news on August 6, 2012, but in the media fanfare there was scant discussion of the implications of it being powered by 4.8 kilograms of plutonium-238. When it was launched last November, NASA was not keen to inform the public about the risks involved, what the nation needs to do to maintain the supply, or the disturbing history of failed launches of and crash landings of other rockets and satellites loaded with nuclear materials.
In fact, NASA is in a public relations bind right now because the continued exploration of deep space requires nuclear-fueled probes, but supplies of plutonium-238 are soon to be depleted, as reported by NPR last year when the Mars rover was launched. The only way to get more is to lobby for a new program of plutonium production, but NASA knows the American public has little appetite for the expense, nor for revisiting the dark times of the Cold War when plutonium production left a legacy of damaged health of nuclear workers and environmental pollution at numerous sites. Furthermore, the public is conscious of the odds of launch failures and disasters, and so it is not a good thing to remind them that the rocket on the launch pad has a payload of plutonium that could melt and fall back to earth if the launch fails. Thus NASA’s strategy is to mention the plutonium shortage as little as possible, and not lobby for funding too loudly. Instead, NASA, and other space agencies, play up the romance of boldly going to new frontiers and the importance of new endeavors. It is unthinkable that the space program could be halted just because of the public’s reluctance to produce the required plutonium.
One can suggest at this point the unthinkable, that the space program is just not worth it if it involves the costs and dangers of making and handling plutonium. Space will always be there. What’s the hurry? Let’s wait until we figure out a safe way to do it, or not do it at all. The physicist Michio Kaku has said NASA's renewed interest in not only nuclear powered probes, but the more dangerous nuclear propulsion "… is not only dangerous but politically unwise. The only thing that can kill the U.S. space program is a nuclear disaster. The American people will not tolerate a Chernobyl in the sky."
The drawback to arguing against space exploration is that whoever makes it is immediately on the defensive, accused of being against progress, or the type who would shoot down a child’s dream to be an astronaut. Here in Japan, my children are exposed to a steady stream of news features and documentaries about JAXA (Japan Aerospace Exploration Agency) and Japanese astronauts on NASA missions. The JAXA headquarters in nearby Tsukuba holds tours and events for children every summer. There is a popular manga and anime series called Space Brothers (Uchuu Kyoudai) about two young men living their childhood dream of joining a NASA mission. My children are all hooked. This is how space agencies, and the associated military, chemical and nuclear industries behind them, cynically play the public relations game. It is all packaged as benevolent scientific progress for mankind, and it takes advantage of the child’s desire to transcend the ordinary and engage in imaginative play. Through these education programs and works of fiction, children all know the amusing factoids about food in tubes and what happens to farts on the space shuttle, but no one teaches them about the Radioisotope Heater Unit and what is required to make one.
One can stand up to this onslaught and suggest that progress might lie in learning how to clean up our planet and live on it within its ability to sustain us, but the brilliance of this propaganda system is that whoever does so will be seen as a cynic who just wants to deprive children of their dreams. It’s less cynical than building those dreams on concealed truths, but this point will also go unmentioned along with some facts about what is needed to produce a few kilograms of plutonium-238 for a single space mission.
Plutonium can exist in several isotopes, all of which vary in the length of their half-lives, the intensity of the life-damaging radiation they emit, and in their applications. The number of protons in an atom’s nucleus defines the atom, but the number of neutrons can vary to make different isotopes of the same atom. Plutonium-244 (the number being the total number of neutrons and protons in the nucleus of the isotope) is found in trace amounts in nature, but almost all plutonium now on earth was created by human activity over the last seventy years. In this sense, it is said to be something that no life form has evolved with. Since it damages chromosomes, there is a good argument to be made that it should never be created or used, no matter how well we imagine that its contact with living things can be managed safely.
Various isotopes of plutonium can be created by bombarding other radioisotopes with neutrons. For example, the fissile isotope plutonium-239 used in nuclear weapons is made by bombarding uranium-238. In this way, plutonium for weapons is inextricably linked to the “peaceful” uses of the atom because nuclear fuel in in light water reactors (enriched uranium) used for generating electricity is bombarded with neutrons, leaving behind nuclear waste containing plutonium that can be used to make bombs. The isotope required for space missions is plutonium-238, which emits higher radioactive energy and has a shorter half-life than plutonium-239.  Nuclear waste contains only small amounts of plutonium-238, so it can’t be obtained directly from this source. However, spent nuclear fuel contains neptunium-237, and this can be separated from the spent fuel and irradiated to create plutonium-238. A 100-kg sample of spent fuel can yield 700 grams of neptunium-237.
Once you understand what is involved in obtaining a small quantity of plutonium-238, you understand why space agencies are so reluctant to talk about it, even though they need to play politics to get more funding. Production involves numerous problems such as cost, safety, security, and the ongoing problem of cleaning up contaminated environments and storing the plutonium waste already in existence. Space Daily reported in 2003, Historically DoE has a bad track record when it comes to protecting workers and local water systems from radioactive contaminants… During the Cassini RTG fabrication process at Los Alamos 244 cases of worker contamination were reported to the DoE.”
A nation that wants to send a probe deep into space where the sun don’t shine on solar panels (i.e. Jupiter, Uranus and beyond) needs the entire infrastructure of a large nuclear industry. Spacecraft require a small amount of plutonium-238, which requires the production of enriched uranium, which requires a fleet of civilian nuclear reactors that will provide the nuclear waste from which to make the plutonium-238. The nuclear waste has to be moved around to various facilities, with tight security and all the associated risks. And of course, only a few self-anointed countries are allowed to engage in this production process. The Soviets used polonium 210 (the same isotope that was used to murder the Russian spy Alexander Litvinenko in 2006) on many satellites and the Lunokhod series of moon rovers, one of which exploded on the launch pad in 1969. A country needs to be a major nuclear power to be in the space exploration business, so if you’re a child in Iran, which the major nuclear powers won’t allow to produce enriched uranium, or just a country without the resources for (or the wisdom not to spend resources on) space exploration, the dream of being an astronaut has been denied to you.

So what are the risks?

There is a lot of controversy over the risks involved in sending payloads of plutonium into space. NASA says that the fuel is packed into ceramic and graphite-coated pellets that have been tested to resist impact and melting in the event of an explosion on launch or a fall from orbit. Critics point out that the risk is not easily understood because the small amount of plutonium-238 involved is very radioactive compared to other isotopes of plutonium.
Not all radioisotopes release, by mass, equal amounts of radiation. Plutonium-239 has a long half-life of 24,110 years, but 277 times less energy that plutonium-238, which has a half-life of 87.7 years. Wired Magazine, that consistent cheerleader of all technological progress, commented about this isotope being aboard rockets:

The plutonium (which is, not to worry, non-weapons-grade Pu-238) undergoes nuclear decay, providing heat to warm MSL’s electronics and keep it churning out data even at night.

It may not be weapons-grade, but the writer is gullible to NASA PR saying that it is safe, and he fails to notice the glaring omission in this quote:

They [NASA] point out that NASA has reliably used nuclear generators for 26 missions over the last 50 years.

Yes, reliably in 26, but unreliably in the two mishaps mentioned below that NASA neglected to point out to the Wired journalist. This would amount to 28 missions, with a record of 1 failure for every 14 successes. NASA’s recent estimates of failure probability give much more favorable odds than the actual record, especially if you include the Challenger and Columbia disasters which, fortunately, did not carry radioactive payloads (as far as we know).  
If you think of a rocket exploding high in the atmosphere and scattering 4.8 kilograms of material throughout the vast expanse of the earth’s atmosphere, that may seem insignificant. But, in fact, it is a massive release of radioactive energy, and some experts say the impact has been significant.

Not all radioisotopes are created equal.
Plutonium-238 is 277 times as radioactive as plutonium-239, so…
plutonium-238 on the Mars rover Curiosity
4.8 kilograms
plutonium-239 used in the bombing of Nagasaki
6.4 kilograms
amount of plutonium-238 that has the same radioactive energy as the plutonium-239 used in the Nagasaki bomb
6.4 ÷ 277 = 0.0231 kilograms
energy equivalence of 4.8 kilograms of plutonium-238
4.8 x 277 = 1,329 kilograms of plutonium-239
Curiosity radioactivity payload equals how many Nagasaki bombs?
1,329 ÷ 6.4 = 208

In spite of the invention of ways to contain plutonium within ceramic pellets and graphite, NASA’s own Final Environmental Impact Statement for the Mars Science Laboratory Mission finds there is still a chance of environmental release of plutonium in various accident scenarios. It might be foolish to spend much time on a discussion of the probabilities of various scenarios because the methodologies and assumptions involved render the undertaking an absurd game. Nonetheless, NASA concludes “… there is an overall probability of 4 in 1,000 that the MSL mission would result in an accident with a release of PuO2 [plutonium dioxide] into the environment.” About a less likely scenario it states, “The risk assessment also indicates that in at least one very unlikely ground impact configuration, FSII with a total probability of release of 9.2 x 10-5 (or 1 in 11,000), a mean area of 86 km2 could be contaminated above 0.2 microcuries/m2… Land areas contaminated at levels above 0.2 microcuries/m2 (or 7,440 becquerels/m2 ) would potentially need further action, such as monitoring and cleanup.” For mixed use urban areas, this cost is estimated to be $562 million per km2. These estimates include no guess about how far above 0.2 the levels could go. But note that when a radiological disaster does occur, this level of 0.2, or 7,440 becquerels/m2 is suddenly deemed too low to require action. By the standards set for Chernobyl, places with less than 37,000 becquerels/m2 were considered weakly contaminated. Recommended evacuation (that included permission to leave in the old system of Soviet restrictions on movement) began at 555,000 becquerels/m2. Compulsory, compensated evacuation began at 1,480,000 becquerels/m2. The Japanese authorities have been similarly complacent since the Fukushima disaster.
In addition, the NASA report mentions, but finds incalculable, the costs of relocation, loss of employment, damage to fishing and agriculture, and health care. Finally, the report concludes with an interesting rationalization for the risks imposed on the public. “The individual risk estimates are small compared to other risks… in [the year] 2000 the average individual risk of accidental death was about 1 in 3,000 per year, while the average individual risk of death due to any disease, including cancer, was about 1 in 130.”
Consider how this logic appears when a drug dealer in your neighborhood turns his house into a methamphetamine lab and contaminates the area. He is likely to rationalize the imposition of risk, which you were not able to have a say in, as only a negligible increase in the risks you already face in your life. It would be better if official agencies of government did not sink to this level of reasoning.
As mentioned above, earlier NASA missions loaded with plutonium failed. The worst one occurred in 1964 with the SNAP-9A Radioisotopic Thermo Generator (RTG). 950 grams of plutonium-238 was widely dispersed over the earth when the satellite containing the RTG fell back to earth. Comparative data on this event can be found in the FEIS of the Mars Science Laboratory Mission.


Global releases of plutonium (Curies)
Pu 239
Pu -238
weapons tests
444,000
9,000
SNAP-9A accident*
*
17,000
(25% fell on Northern Hemisphere, 75% on Southern)
Chernobyl accident**
Plutonium-239, 241: 2,351
400
Plutonium-240:     194,594

plutonium reprocessing (1952-1992)
discharged into oceans
100,000
3,400
TOTAL
740,945
29,800
Total fallout from all isotopes
740,945 + 29,800 = 770,745
Percentage of total fallout from SNAP-9A accident
770,745 ÷ 29,800 = 4%

NASA states the following equivalence:
Plutonium-238 is 17.12 Curies/gram, Plutonium-239 is 0.0620 Curies/gram
* NASA considered the inventory of plutonium-239 on SNAP-9A too small to include.
** NASA did not consider the releases of plutonium-239, 240 and 241 from Chernobyl to be worth mentioning or looking up, but the author calculated them from the data in becquerels given in Zhang et. al. According to this source, the plutonium releases from the Fukushima disaster are estimated to be five orders of magnitude less than the Chernobyl disaster, making them too small to include here. The conversion factor is 1 Curie = 3.7 x 1010 becquerels.

Plutonium released from Chernobyl (converted to Curies in the table above):
plutonium 239 and 240
8.7 x 1013 becquerels
plutonium 241
7.2 x 1015 becquerels
         
This single mishap of the SNAP-9A unit, involving less than a kilogram of plutonium, accounts for 4% of the plutonium-derived radioactivity released into the environment since the start of the nuclear age. Another part of NASA’s website, not the FEIS, explains these failures with great understatement and typical omission of inconvenient facts. The failure of the satellite in 1964, involving the SNAP-9A Radioisotope Thermal Generator (RTG) is described this way:

Status: Mission was aborted because of launch vehicle failure. RTG burned up on re-entry as designed.

On the other hand, the loss of the Apollo 13 lunar module in 1970 was described differently. People familiar with the story of this failed mission know that the astronauts survived by staying in the lunar module as long as possible, but it was discarded from the main capsule just before re-entry. The lunar module crashed into the South Pacific along with its payload of plutonium-238 in the SNAP-27 RTG. In this case, NASA describes the loss this way:

Status: Mission aborted on the way to the moon. RTG re-entered earth's atmosphere and landed in South Pacific Ocean. No radiation was released.

In the latter case, NASA specifies that no radiation was released, but in the former case there is no mention of whether radiation was released. In fact, the failure of the SNAP-9A was one of many “lessons learned” in the history of nuclear technology. NASA admitted that a large volume of plutonium was released into the earth’s atmosphere, and they subsequently developed solar energy technology, as well as the ceramic and graphite casings for plutonium pellets which, presumably, meant that the plutonium aboard the Apollo 13 lunar module went to the bottom of the sea encased in its protective shells to safely decay through several half-lives of 87.7 years. The same presumption of safety holds for numerous other payloads of plutonium that have been launched into space since 1970. The Cassini space probe, for example, launched in 1997, carries 36.2 kilograms of plutonium-238.
The health effects of the 1964 accident, and the potential effects of future accidents, have  become controversial. According to a study titled Emergency Preparedness for Nuclear-Powered Satellites, the 2.1 pounds [950 grams] of Plutonium-238 in the SNAP-9A dispersed widely over the Earth. “A worldwide soil sampling program carried out in 1970 showed SNAP-9A debris present at all continents and at all latitudes.” (cited in Grossman, K.)
Dr. John Gofman, a scientist on the Manhattan Project who later broke ranks with the nuclear establishment, claimed the 1964 accident, on its own and added to the effects of fallout from weapons testing, contributed to a rise in global lung cancer cases. Yet his findings were contested by Snipes et. al. Gofman claimed that most of the lung cancer cases would occur in smokers because they clear particles from their lungs much more slowly than non-smokers. These critics claimed that an assessment of the risk of plutonium would have to be based on healthy individuals. Nonetheless, Gofman still found there is a substantial risk for non-smokers, well-known because of American government studies of non-smoking dogs and rats sacrificed for research (Bair & Thompson). The risk is more acute for the “plutonium workers” who have to handle and transport the nuclear material produced for the civilian and military nuclear complex. When it comes to the general population, proponents on either side of the controversy could never agree on how much plutonium people have ingested and what the effects could be. Regardless, one can make a value judgment and question the wisdom of introducing into the world a known toxic primordial nuclide that has not been present during the evolution of life.

Other great moments in space exploration

The 1978 crash of the Soviet satellite Cosmos 954 spread uranium-235 debris over 77,000 square miles of Northern Canada. There was a media uproar at the time (like there never was about the American SNAP-9A accident), and debates in parliament about the assault on Canadian sovereignty, but the incident was quickly resolved and brushed out of public awareness. There was a joint Canadian and American cleanup, Operation Morning Light, that lasted one year, and the discovery of some highly radioactive debris, but also official assurances that the accident would have no health effects, that all the dangerous material had “harmlessly” disintegrated, melted, vaporized, neutralized or dispersed in such dilute amounts as to not be a concern. During the cleanup, only an estimated 0.1% of the radioactive fuel was recovered, and the fragments of the satellite that were found gave off a deadly 1.1 sieverts per hour. The rest of the radioactive fragments are still out there over the Great White North, at the bottom of Great Slave Lake, or the remainder of the uranium dispersed high in the atmosphere to have its controversial and unknown effects on human health. This is how it was described six years later in the journal Health Physics:

It was estimated that about one-quarter of the reactor core descended over Canada's Northwest Territories in the form of sub-millimeter particles. The other three-quarters apparently remained as fine dust in the upper atmosphere. Each particle contained megabecquerel quantities of the fission products 95Zr, 95Nb, 103Ru, 106Ru, 141Ce and 144Ce, as well as traces of other fission and activation products. Laboratory tests indicated that these radionuclides would not dissolve significantly in drinking water supplies or in dilute acids. Contamination of air, drinking water, soil and food supplies was not detected. The dose equivalent to the GI tract for an individual who might have inhaled or ingested a particle could have been as high as 140 mSv.

Gary Bennett, an American expert on nuclear power and propulsion, described how the Cosmos accident disrupted the consensus on nuclear power in space that existed in the UN Committee on the Peaceful Uses of Outer Space (COPUOS). In a paper tellingly entitled Reaching the Outer Planets – with or without the UN, he states that the agreement at the time “...represented not only a consensus of international technical experts but also a succinct statement of the US position.” But then for the Canadian delegation, and other concerned countries, the Cosmos accident had changed everything. If such a crash had occurred over a populated area, the effects could have been horrendous. By 1981, Bennett says, “…several delegations, led by the Canadian contingent, had introduced working papers proposing new or different technical principles.” Bennett laments, “To a number of people on the US side, it appeared almost as if the Canadian delegation had decided to punish the US rather than the Soviet Union for the accidental reentry of the Soviet Cosmos 954 reactor.”
Bennett notes that differences within different US departments and agencies led to the State department signing on to principles that banned nuclear power in space. They essentially prohibited the nuclear devices now in use on Curiosity and Cassini. He blames this sorry state on the lack of technical expertise on UN committees and the lack of resolve of US negotiators. The result occurred because “… beliefs and wishes and ideology seem to count for more than technical reality.” This is the blind spot of career scientists in institutions such as NASA. Whenever the outcome is unsatisfactory, it is the other side that has been emotional and ideological, while their own self-interests and emotions are not acknowledged - they are believed to be a neutral “technical reality.” There is no acknowledgement here that the UN principles were a value judgment that simply said no to the risks involved in putting nuclear materials in space.
 However, we know that the US went ahead with its program and continued to launch nuclear devices into space. Bennett is disappointed that the US chose a passive aggressive approach by voting for the UN principles while intending to ignore them because they were deemed to be non-binding. “In short, the US may have voted for the principles, but it does not intend to abide by them.” He quotes from a Clinton administration memorandum (not cited):

… the proposed position does not confer US approval of any specific provisions of the Principles, but only declares that US policy and practice is consistent with their overall objective and intent, which is the safe use of NPS in outer space.

Nuclear Propulsion Rockets


It is risky enough that we launch small amounts of plutonium into space in order to give a little heat and electricity to long-lasting probes and Mars rovers, but a truly awesome risk is posed by the temptation of using nuclear reactors to launch the rocket itself, or propel a spacecraft to Mars at high speed. This was seriously attempted in the 1960s in Project Orion (for more detail see the BBC documentary To Mars by A-Bomb: The Secret History of Project Orion), but it was scrapped because of the hazards and the frightening radiological accidents that happened beyond public awareness, and the because it would accelerate the arms race with the Soviets. However, the fact that this dream was abandoned once is no guarantee that it won’t be taken up again. In fact, the renewal of nuclear propulsion was behind George Bush’s attempt to dream big, aping Kennedy’s initiative to put Americans on the moon, in announcing that he wanted a manned mission to Mars. Furthermore, nuclear devices in space have not only peaceful purposes. They would be an essential part of any space-based defense system, and this is further reason why other states are suspicious of American plans and why the United Nations, through COPUOS, has tried to downplay the dangers of a space-based arms race.
The history of nuclear propulsion research is still not fully known because many of the files are still classified. In the book Area 51, journalist Annie Jacobsen focuses less on the speculation about freaky aliens at the secret Nevada Test Site and more on what is known about the real events that happened there. These are frightening enough without having any UFOs in the picture. The Kiwi test, which actually occurred in Area 25, was a test to see how badly the environment would be affected by a failure of a nuclear propelled rocket. Engineers designed a small-scale deliberate failure, then watched what happened when they blew up the small reactor core in the rocket. Here is how it is described in Jacobsen’s book (pages 309-310):

On January 12, 1965, a nuclear rocket engine, code-named Kiwi, was allowed to overheat. High-speed cameras recorded the event. The temperature rose to "over 4,000 degrees C until it burst, sending fuel hurtling skyward, glowing every color of the rainbow," Dewar wrote. Deadly radioactive fuel chunks as large as 148 pounds shot up into the sky. One ninety-eight-pound piece of radioactive fuel landed more than a quarter mile away.
Once the explosion subsided, a radioactive cloud rose up from the desert floor and "stabilized at 2,600 feet" where it was met by an EG&G aircraft "equipped with samplers mounted on its wings." The cloud hung in the sky and began to drift east then west. "IT blew over Los Angeles and out to sea," Dewar explained. The full data on the EG&G radiation measurement remains classified.
The test, made public as a "safety-test," caused an international incident. The Soviet Union said it violated the Limited Test Ban Treaty of 1963, which of course it did.

The one other occasion when witnesses to a nuclear explosion described fuel going skyward in “every color of the rainbow” is the explosion of the Chernobyl reactor (see The True Battle of Chernobyl, 0:01:20-0:02:10). The Kiwi test, like the unplanned Rocketdyne meltdown near Los Angeles in 1959, suggests that Three Mile Island is on record as the most serious American nuclear accident only because it is the accident that the public has information about.
The controversy of nuclear power in space is not something that can be resolved by pursuing the correct data on risk assessment, or looking for a way to quantify the harm done by the global population’s inhalation of plutonium particles. These numbers are unknowable. What is clear is that further space exploration will not happen by known methods without the continued processing of plutonium and launching of it into space. For those whose careers are invested in space exploration, and the millions of dreamers and enthusiasts of space travel, it is unthinkable that space exploration could just stop because we are afraid to live with the risks of plutonium processing.
I suspect, however, that most of the 7 billion people on earth don’t even think about space exploration, and wouldn’t care much about it if they did. For others who are informed and primarily concerned about taking care of the planet we inhabit, space exploration has little to offer, especially if it worsens ecological problems. I haven't discussed here the additional harm done by CO2 emissions of rocket launches and rocket fuel chemicals. Certainly, we obtain valuable data from satellites about the minute details of what we are doing to the ecosystem, but they really only confirm simple truths that we already know.
Supporters of space exploration tell us constantly of the necessity of breaking new frontiers, of constantly going beyond, but most of the talk is vague and the logic is circular. We need to keep going farther to develop STEM (education in science, technology, engineering and mathematics), and we need STEM in order to keep going boldly to the next frontier.
People like Peter Diamandis typify the views of what has come to be called the techno-optimists – wealthy high-tech entrepreneurs who get juiced up annually on mutual self-adoration and wonderment at the TED conference. He effuses, with the redundant adjective in the title, Curiosity’s Successful, Glorious Triumph on Mars:

What the success of Curiosity highlights is the importance of our being bold and audacious. It takes big risks to drive breakthroughs. Financial risks, technical risks, and when it comes to funding billion dollar programs - political risks….

He fails to mention the risks taken by the low-level workers who actually handle the plutonium and get contaminated in the process. When you are at the lofty heights of the technological elite who get to stare off into the distance of humanity’s glorious future, the gritty details of how humanity gets there are of no import. The techno-optimists are the conquistadors of the modern age. They are optimists in the same way the Hernan Cortes had a positive view about the conquest of Mexico. It goes without mentioning that most of humanity will be used, abused or ignored in the great march of progress. Yet at least the Spanish conquistadors had the sense to covet places that could sustain life, something which we can’t say about people who want to go to lifeless planets.
 Diamandis goes on to say:

I spend much of my time as Executive Chairman of Singularity University and as CEO of the X PRIZE Foundation.  At SU we teach attending graduate students and executives about exponentially growing technology. More importantly, we speak about the importance of taking risk to truly create breakthroughs and the importance of failing early and failing often - the Silicon Valley formulation for innovation.

What is not mentioned here is that humanity actually has not been afraid to take risks, and we seem to be adept at failing spectacularly. In truth, we are quite reckless. While the ecosystem we depend on collapses, Diamandis and his kind have their heads in the clouds envisioning a melding of human minds with robots. Our energy problem is not that fossil fuel supplies will soon be depleted but that catastrophic climate change will occur first. There is nothing more urgent than facing the escalating disasters caused by climate change and the unresolved problem of nuclear waste storage. Outer space can wait. If it seems too sad to tell our children to put this dream on hold, that’s unfortunate, but the unavoidably mature thing for adults to do. Instead of asking our children if they want to be astronauts when they grow up, it is time for the human race to ask itself what it wants to be when it grows up.

References and Other Resources


Bair, W.J., Thompson, R.C. “Plutonium: Biomedical Research.” Science. Vol. 22. February 1974: 715 722. DOI:10.1126/science.183.4126.715 http://www.sciencemag.org/content/183/4126/715.short

Bennett, Gary L. “Reaching the Outer Planets – with or without the UN.” Aerospace America. The American Institute of Aeronautics and Astronautics. July, 1996. http://www.fas.org/nuke/space/aeroamer.pdf

Gofman, John D., “The Plutonium Controversy.” The Journal of the American Medical Association (JAMA). July 19, 1976 vol. 236, No. 3 pp. 284-288. http://jama.jamanetwork.com/article.aspx?articleid=346814

Jacobsen, Annie. Area 51: An Uncensored History of America’s Top Secret Military Base. Back Bay Books, 2012. The passage cited here quotes Dewar, James, To the End of the Solar System: The Story of the Nuclear Rocket, University Press of Kentucky, 2004.

Johnson, Thomas (Dir.). The Battle of Chernobyl. Icarus Films. 2006.

Newman, Lee S., Mroz, Margaret M., Ruttenber, James A. “Lung Fibrosis in Plutonium Workers.” Radiation Research 164, pp. 123-135.  2005. http://www.cdc.gov/niosh/oerp/pdfs/2001-133g25-1.pdf

Nuclear Energy Agency, and Jan-Olof Snihs. Emergency Preparedness for Nuclear Powered Satellites. Organization for Economic Co-operation and Development (OECD), 1990. Cited in Grossman, K. Nukes in Space in the Wake of the Columbia Tragedy. http://www.21stcenturyradio.com/articles/03/0224176.html

David F.S. Portree. "The Last Days of the Nuclear Shuttle." Wired Magazine. September 20, 2012. http://www.wired.com/wiredscience/2012/09/nuclear-flight-system-definition-studies-1971/

Sykes, Christopher (Dir.). To Mars by A-Bomb: The Secret History of Project Orion. BBC. 2003.

Tracy BL, Prantl FA, Quinn JM. “Health impact of radioactive debris from the satellite Cosmos.” 954. Health Physics. 1984 Aug;47(2):225-33. http://www.ncbi.nlm.nih.gov/pubmed/6480350