God’s good green earth was created out of the radioactive waste products of the great nuclear reactions that spawned the galaxies and the planets. Life arose out of, and adapted to, a much higher level of natural radiation than exists today. Nuclear radiation (ionizing radiation: alpha, beta and gamma radiation) is essential to Life; without it, organisms wither and die.
Despite all the radioactive material we create, this radioactivity is nowhere near enough to keep up with the decay of the earth’s natural radioactivity, which becomes inexorably smaller every day. Thus, most populations today are “under-dosed” and would benefit from more irradiation in the range of interest. The argument that humanity can only be harmed in some way by such radiation is simply untrue. There is no scientific basis for such a claim.
Just as we no longer have to wait for lightning to strike a tree in order to make use of fire, we have learned to produce some types of nuclear radiation “artificially.” The claim that “human-made” radiation is somehow more harmful, or should be minimized because it can be, is also an argument without merit. Neither the organism being irradiated, nor the instrument measuring the amount of radiation, can distinguish between “natural” and “human-made” radiation.
This brings us to the acronym “LNT,” which stands for “linear, no threshold.” This term was invented to describe what was intended to be a conservative model of radiation damage that could be used for regulation of radiation protection. It was observed that at high radiation levels, the damage to organisms was linear: double the radiation dose and you double the damage to the irradiated organism. So, the argument went, if we assume for regulatory purposes, that this linear relationship of radiation dose to organism damage continues all the way down to zero radiation dose, then we should have a conservative premise for radiation protection.
No one claimed the LNT model represented scientific reality; in fact, its defenders called that possibility “vanishingly small.” It was merely said to be “conservative.” So we must examine what “conservative” means in this context. Consider an example: Werner Heisenberg, arguably one of the best analytical minds in human history, reportedly did a calculation in his head shortly after he learned about the discovery of nuclear fission. He concluded, conservatively, that to make a single fission bomb would require a large number of tons of pure U-235, and therefore a program like the US Manhattan Project could not be successful. That answer is not “conservative.” It is simply wrong. As a result, Nazi Germany never undertook a serious atomic bomb program.
In a world in which natural radiation was a large and highly variable reality, how did phobic fear of radiation become such an overwhelming issue? That is a subject involving many overlapping stories, each with its own organizations, incentives and problems. And there are other forces at work that continue to play a part. I will touch on several of them.
First, the weapon. The desire to characterize any new weapon as uniquely and unprecedentedly fearful is natural and understandable. In the A-bomb case, both sides had an additional incentive to give the Japanese, who had sworn to fight to the last man, an excuse to surrender. No mere mortal could be expected to fight bare-handed against the force that held together the very fabric of the universe. And so, the Emperor stepped in, and the idea of nuclear being uniquely fearsome was promoted.
Then, MAD: Mutually Assured Destruction. The fragile peace was sustained by repeatedly scaling up the hypothetical scenarios of destruction of civilization and desolation of cities and farmlands that would supposedly result if either side dared initiate military action against the other. The fear of radiation, and its postulated potential for irrevocably fouling the human gene pool – and perhaps of all Life itself! – was repeatedly nurtured and expanded.
Fallout from weapons tests threatened the environment. Could power plants do the same? Earth Day became an anti-nuclear focus. Fear of spreading nuclear weapons technology became an anti-nuclear-power argument. In 1982, U.S. nuclear weapons labs developed scenarios for hundreds of thousands of deaths from hypothetical meltdown accidents in nuclear power plants, even though TMI had shown that meltdown presented negligible public hazard. Anti-war arguments led to anti-nuclear power concerns. The nuclear community itself did little to refute these fears; in fact, the anti-nuke rhetoric was answered by description of the many PRAs (probabilistic risk assessments) being undertaken, which had the understandable effect of strengthening the concerns that led to such studies. Thus, the nuclear community contributed significantly to its own fearsome image.
While all these terrible problems were being studied in the analytical laboratories, what was happening to the real nuclear power plants out in the hard and unpredictable world? Let us look at some examples:
1. Naval Reactors Radiological Data: 1954-Present. The Director, Naval Nuclear Propulsion, four-star Admiral Kirkland H. Donald (USN), has made available for the first time, all relevant radiological data on the more than 200,000 persons exposed to radiation and handling radioactivity in connection with their duty in various aspects of the naval nuclear propulsion program. Each year’s reports accumulate and update the data from previous reports, so there is a continuous record from initial operations in 1954 of the Nautilus prototype reactor, to the date of the latest report, March 2011. This information has always been available to the Congress and other organizations with demonstrated need to know, but was tightly controlled by Naval Reactors. It is now available on a virtually unrestricted basis.
The annual Naval Reactors Reports summarize the history and current status of the various components of the NR Program, its submarines, surface ships, R&D and support labs, nuclear component procurement, nuclear equipment suppliers, shipyards, support facilities and tenders, schools and training facilities, and headquarters. It lists the basic data for each of the 231 nuclear powered ships authorized by Congress, and adds some interesting statistics. The Navy has built 220 of these ships so far, and they have steamed over 145,000,000 miles, with no significant radiological incidents, no radiation deaths or injuries, and no detrimental environmental impact. The 103 naval reactors currently in operation make about 45% of the combat fleet nuclear-powered.
With refuelings, the Navy has operated 528 reactor cores, but current reactors are designed to operate for a lifetime of 30 years or a million miles, without refueling, retaining the “nuclear waste” in the interstices of the fuel (giving an indication of the trivial magnitude of the much-touted “nuclear waste problem” in existing pressurized water reactors.)
One of the Naval Reactors’ series of unclassified handbooks on nuclear technology of interest is the Reactor Shielding Design Manual, published in 1956 by the Office of Technology Services, Department of Commerce, U.S. Government. Commerial editions were then published by McGraw-Hill and VanNostrand, and a Russian language edition by the USSR Ministry of Culture. After several printings of each, these editions all sold out, and poor photo-copies of the American edition were selling for up to several hundred dollars each. So the U.S. Nuclear Regulatory Commission has now made down-loadable copies available free at: http://www.osti.gov/bridge/purl.cover.jsp?purl=/4360248-Cr40J8/
This 465-page basic textbook shows how permissible radiation levels were determined and how they were applied to design; how the designs were tested; properties of different shielding materials, including stability under irradiation; and other information of use to radiation protection technology.
2. Fukushima Nuclear Power Plants. A case can be made that if the Fukushima operators had focused on protecting the reactor and the fuel pools, rather than trying to minimize collective radiation dose, they might have been able to prevent the release of significant quantities of radioactivity. But that question is moot, and it is more useful to examine the events that did in fact occur. Even with all the radioactivity released, not a single lasting radiation injury occurred. Not one! This includes the dedicated operators who worked in the dark to get the plants shut down and secured in a safe condition. These operators were characterized as a “suicide squad” and are under a cancer scrutiny that might actually worry them into a medical problem. But the fact is, that the radiation doses they received are well within the beneficial range.
The radiation levels in the business and living areas around Fukushima are not particularly high. There are many areas of the world where people live happily and healthily in natural radiation levels many times higher. If radiation protection policy had been set as other protection standards are set – as high as safely tolerable – then radiation would hardly be mentioned in connection with recovery efforts. In fact, the lack of electricity to provide light and heat, run elevators, pump gasoline for cars, and perform countless other functions was a more real problem than radiation during the first weeks and months after the tsunami struck. Yet radiation is still cited as the reason workers and their families can’t return to their homes and productive life.
The measured radiation levels are not the controlling factor. Many of the radiation protection criteria are set far below any reasonable limit. The extra factor of 100 set for children defies the data showing that children are more resistant than adults to radiation damage, not less so. And children are more damaged by forced, unwilling separation from home, friends, and school.
With regard to decontamination, can the soil safely remain as radioactive as, say the soil in Colorado, India, Brazil, or Iran, where the uranium and its decay products run high, and the cancer rates are well below average?
3. U.S. Commercial Nuclear Power Plants
We don’t have to speculate about health effects from possible slight increases in radiation levels around nuclear power plants. The Naval Reactors Reports describe a closely monitored population of nearly a quarter of a million people, over a period of two human generations, who live for years within 100 meters of a nuclear power plant. These people wear individual personal radiation dosimeters and have follow-up physical exams and detailed record-keeping. There is no longer any excuse for basing U.S. radiation policy for commercial nuclear power plants on the “Gold Standard” of estimated exposures of unmonitored Japanese A-bomb survivors – a demographically different population exposed to a radically different radiation experience. The best nuclear worker study is the Department of Energy’s Nuclear Shipyard Workers Study, This thirteen-year occupational study of the health effects of low-dose radiation was performed by the Johns Hopkins Department of Epidemiology, School of Public Health and Hygiene, reported to the Department of Energy in 1991 and in UNSCEAR 1994. Professor Arthur C. Upton, former Director, National Cancer Institute, chaired the Technical Advisory Panel that advised on the research and reviewed results.
The results of the study contradict the LNT hypothesis. From the database of almost 700,000 shipyard workers, including about 107,000 nuclear workers, two closely matched study groups were selected, consisting of 28,542 nuclear workers with working lifetime doses over 5 mSv (many received doses well in excess of 50 mSv), and 33,352 non-nuclear workers. The data showed that the nuclear workers had a significantly lower death rate from “all malignant neoplasms” though this fact was omitted from the Summary of Findings and not reported in UNSCEAR 1994.
These risk decrements are inconsistent with the LNT hypothesis and do not appear to be explainable by the constantly invoked “healthy worker effect.” The nuclear and the non-nuclear workers were similarly selected for employment, were afforded the same health care thereafter, and except for exposure to shipyard radiation, performed the identical type of work, with a similar median age of entry into employment of about 34 years. This provides evidence with extremely high statistical power that low levels of ionizing radiation are associated with decreased risks.
The 10 million dollar 437 page report was not published. An inquiry to DOE elicited the response, “It wasn’t in the contract.” The report was never submitted to a scientific journal for peer review and publication, as is usual for such reports, though the unpublished report is now in the public domain. This study with internal comparison of nuclear workers with carefully matched non-nuclear workers was designed by the technical advisory panel to eliminate any “healthy worker effect” from the comparison. The non-nuclear workers did not demonstrate “healthy worker effect.”
Nevertheless, the September 1991 DOE press release misleadingly states, “The results of this study indicate that the risk of death from all causes for radiation-exposed workers was much lower than that for U.S. males. These results are consistent with other [sic] studies showing that worker populations tend to have lower mortality rates than the general population because workers must be healthy to be hired, and must remain healthy to continue their employment."
4. Conclusion These are but a few examples of the nuclear community’s repeated efforts to exaggerate the dangers associated with any form of nuclear technology. Some of these efforts originate outside the nuclear community, and can be explained as “bad-mouthing the competition.” But most of the stories follow the tone set by Alvin Weinberg’s characterization of nuclear technology as “a Faustian bargain,” a basically diabolical enterprise. Weinberg justified this model as necessary to scare people into upholding a level of quality control otherwise unattainable. But I find that its main consequence has been to hold off applying engineering solutions as inadequate by definition, allowing scientists more time to think of wholly new, untried solutions.
That is just the opposite of the Rickover approach of setting highly conservative radiation specifications, then starting to build reactor plants, tackling each problem as it arises. That is a primary difference between science and engineering.
For over 100 years, the science has been clear and unambiguous: Low-dose radiation in the range of interest is beneficial, not harmful, and repeated attempts by regulators to hide or deny this fact are indefensible scientifically. The relevant scientific organizations have made this position part of their public policy. The extensive report published in connection with the 2012 ANS President’s Special Plenary summarizes the scientific knowledge on low-dose radiation effects. Regulators owe deference to this fact. Distortion of the science for political purposes is not only harmful to the advancement of nuclear technology; it is harmful to the public health and should no longer be tolerated.