Two days ago, Japan’s nuclear regulatory agency disclosed estimates of the volume of radioactive material that has escaped from the Fukushima reactor complex since the March earthquake and tsunami. The agency estimates that the emitted volume of radioactive cesium is approximately 168 times higher than that of the atomic bomb dropped on Hiroshima at the end of WWII, and that the volumes of radioactive iodine and strontium are approximately 2.5 times higher. All are linked to cancer, and the cesium and strontium isotopes can persist in the environment for decades.
The estimates are truly alarming. Some have argued that the impact on humans will be limited because the vast majority of the material has fallen or leaked into the ocean, where it will disperse and substantially dilute. But dilution is not a great reassurance. Given the extended half-lives of some of these materials, there is reasonable concern that radiation from Fukushima will damage marine habitats for years and, in turn, harm the citizens of Japan and other proximate countries.
Although not discussed in the media, the radiation leak may also violate international law. The United Nations Convention on the Law of the Sea, which entered into force in 1994, requires states-parties such as Japan to take steps to prevent and control pollution into the oceans. One of its provisions mandates that states take measures necessary “to prevent, reduce and control pollution of the marine environment,” including pollution involving the “release of toxic, harmful or noxious substances, especially those which are persistent, from land-based sources.” Another provision mandates that states-parties “take all measures necessary to prevent, reduce and control pollution of the marine environment resulting from the use of technologies under their jurisdiction or control.”
The Convention seems to cover the type of pollution coming from Fukushima. Radiation leaking from Japanese nuclear reactors into the ocean is a “toxic, harmful or noxious substance” from a “land-based source.” It is also pollution that “result[s] from the use of technologies” under the jurisdiction and control of a state-party.
Whether the Japanese government took “all measures necessary to prevent, reduce and control” the Fukushima pollution is less clear. With the benefit of hindsight, it is obvious that the government did not do enough to prevent radiation from leaking from the nuclear plants into the ocean—if it had, the leaks would not have occurred. But the Convention does not itemize the specific measures that are deemed “necessary,” and there is often a difference between the necessary and the sufficient. The government could theoretically complete “all measures necessary to prevent” radiation leaks and yet still fail to do enough to completely preclude any possibility of a leak. The mere occurrence of pollution, in other words, may not demonstrate a violation, at least as a matter of textual interpretation.
One way to think about the problem is normatively, by asking simply whether there should be a difference between the necessary and the sufficient in this area. In the United States, tort law imposes strict liability for certain ultra-hazardous activities, and in doing so effectively closes the gap between necessity and sufficiency for purposes of liability determinations. But other areas of tort law leave a gap, and thus permit actors to avoid liability by meeting certain minimum standards of conduct even if harm still follows. What is your view? Is strict liability for environmental harms from accidents at nuclear plants the appropriate standard? Or should international law utilize some other standard?