PARIS: As concern over global warming grows, the nuclear industry is stepping up efforts to portray itself as a viable source of clean energy. Governments are increasingly receptive, including the British government, which last year backed the construction of a new generation of nuclear power plants.
Antinuclear environmentalists say that approach is like avoiding an oncoming truck by driving off a precipice.
Worldwide, there are about 440 nuclear reactors in operation.
Leaving aside the unresolved issue of disposing of the 12,000 tons of radioactive waste that are produced annually and remain dangerous for millions of years, nuclear power presents other drawbacks: Atomic power plants routinely release radioactivity into the air and into the water used in their cooling and waste treatment systems.
Industry lobbyists say that only "safe" levels of radiation are emitted. "Scientific evidence does not indicate any cancer risk or immediate effects at doses below 100 millisieverts per year," according to the Web site of the World Nuclear Association, an industry group.
The millisievert is a measure of the biological effect of radiation exposure. The average exposure of people to background radiation is two millisieverts a year, according to the International Atomic Energy Agency, an arm of the United Nations.
But the International Commission on Radiological Protection, a scientific advisory body that provides guidance to national authorities on radiation risks, says that safe radiation is, at best, a relative concept.
"Any exposure is capable of causing an effect, with no threshold," the commission said in a 2005 report on the health risks of radiation. "Exposure limits are set to limit their occurrence to an acceptable frequency."
Antinuclear and public health advocates contest the right of the commission, a nonrepresentative, self-electing body, to judge what may be "acceptable."
The commission "has no moral or representative authority for making assumptions about the acceptability of risks," said Diane D'Arrigo, radioactive waste project director at the Nuclear Information and Resource Service, an antinuclear networking center in the United States.
One issue in judging the danger of radiation from nuclear plants is the lack of reliable data, said Rosalie Bertell, a specialist in biometrics and environmental epidemiology.
Most information about the effects of low-dose radiation is extrapolated from flawed studies of Japanese atomic bombs victims, said Bertell, who has studied radiation effects for over 50 years. Bertell said the studies focused on survivors of high-dose radiation, using lower-dose survivors mainly as a control group.
These studies, in assessing the reproductive effects, looked only at live births, ignoring miscarriages and stillbirths despite their own findings that the most vulnerable to radiation are children and fetuses. A further flaw of thresholds set by regulatory bodies, Bertell said, is that they are determined in relation to healthy, young males rather than for the most vulnerable, pregnant women.
Referring to the International Commission on Radiological Protection, Bertell said: "The ICRP assumes that the public is unconcerned about nonfatal cancers and reproductive problems. They should be setting the levels to protect those most at risk - pregnant women."
Well founded or not, the commission's recommendations are nonbinding. In the United States, for example, the Nuclear Regulatory Commission "is a little slow" in applying them, said Jack Valentin, scientific secretary of the International Commission on Radiological Protection.
And in 1997, Ramona Trovato, as director of the Office of Radiation and Indoor Air at the U.S. Environmental Protection Agency, faulted the agency over its lax regulations for returning decommissioned nuclear installations to unrestricted public use. "To put it bluntly," she said, "radiation should not be treated as a privileged pollutant."
Beyond the potential health hazard of low-level radiation exposure looms the ever-present fear of cataclysmic accidents.
Since the 1950s, the industry and its regulators have argued that nuclear power is inherently safe. Yet the March 1979 accident at Three Mile Island, in the United States, and the 1986 disaster at Chernobyl, in Ukraine, are grim reminders of the limits of that safety.
An inquiry ordered by President Jimmy Carter after the Three Mile Island accident found that the plant's owner, operator and designer "failed to acquire enough information about safety problems, failed to analyze adequately what information they did acquire, or failed to act on that information." Less than 10 years later, Chernobyl sent an irradiated plume across Europe. A study of Chernobyl by the UN atomic agency's international nuclear safety advisory group concluded that "the need to create and maintain a 'safety culture' is a precondition for ensuring nuclear power plant safety."
In the 22 years since Chernobyl, there have been 22 significant accidents at nuclear power plants worldwide, including 15 that caused abnormal radioactive releases, according to a French antinuclear organization, Sortir du Nucléaire.
Yet the industry plays down the possibility of another serious accident. "No mistakes are allowed - the consequences in terms of public confidence are too great," said Jeremy Gordon, an analyst for the World Nuclear Association.
But insurance companies are unconvinced.
Complex international mechanisms provide compensation for nuclear accidents. Conventions signed in the 1960s by most Western countries with nuclear power - although not the United States, which has its own arrangements - provide for compensation of up to 300 million International Monetary Fund Special Drawing Rights - equivalent to about € 300 million, or $474 million.
The agreement shares liability between the operator, the host government and, if necessary, all parties to the convention.
After Chernobyl, a decision was made to increase coverage, said Julia Schwartz, head of legal affairs at the Nuclear Energy Agency, which is based in Paris and advises industrialized countries on nuclear power.
"The signatory parties realized that the amounts provided were simply not enough," she said.
A 2004 agreement raised the total liability to €1.5 billion and extended the scope of the convention to cover a wider range of damage, including environmental.
But the agreement has yet to take effect. It requires the operators to buy insurance to cover their share of the liabilities, and the insurers are balking.
"The market," Schwartz said, "doesn't have the capacity or refuses to cover these risks because, in the case of environmental risks, these are unquantifiable and they don't know how to assess the risk."