03/21/2011 - 12:35

Reflections on Fukushima: A time to mourn, to learn, and to teach

Robert Socolow

Robert Socolow

Socolow is chair of the Bulletin's Science and Security Board and the codirector of Princeton University...

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As a physicist, I have spent my life hoping that nuclear power could realize its potential. My teachers were scientists who had penetrated the nuclear world for the first time. They told those of us who were studying physics in the pre-1960s era that we could have all the fun they had had, as the domain of analysis moved down in scale from the nucleus to the hadrons and leptons of the sub-nuclear zoo. But, with that fun, came a second assignment: Our generation had to ensure there was no further use of nuclear weapons. My contemporaries and I were socialized to believe that nuclear physics could bring humankind amazing insights into our past via precise dating and powerful tools of diagnostic and therapeutic medicine -- but nuclear physics, we were taught, also could bring attractive energy sources. The triad of nuclear power weaknesses -- safety, waste management, and couplings to weapons -- was a surmountable challenge. The decoupling of nuclear power from nuclear weapons, in particular, seemed to generate an agenda that would compel stronger international governance and a path toward non-reliance on nuclear war.

The accident at Fukushima Daiichi on March 11 implicates me, somehow, much more than did either Three Mile Island in 1979 or Chernobyl in 1986, both well-etched into my memory. Three Mile Island, I convinced myself, was a teething accident: An industry had pretended that nuclear power was just another way to boil water, and the accident resulted from appalling deficiencies in worker training and "the man-machine interface." In the months after Three Mile Island, the nuclear industry overhauled its instrument panels, introduced job training via simulators, and communicated, somehow, that it had been chastened and was implementing reforms. Chernobyl, I could pigeon-hole, as well: The Chernobyl RBMK (Russian acronym for "high power, channel-type reactor"), whose fateful design permitted prompt criticality, was a manifestation of the isolation of Russia and its obsession with self-reliance. The unwillingness of nuclear experts in the West to strong-arm the Soviets not to build RBMKs, despite their awareness that an actual nuclear explosion at any power plant could sink the whole global industry, was yet another disastrous outcome of the East-West divide.

I can find no escape from Fukushima Daiichi. Words I hoped never to read in a news report, like loss of coolant accident (LOCA), exposed core, hydrogen explosion: Here they are. Except for those who can identify ways to contribute directly to the management of the disaster, we scientists have only one job right now -- to help governments, journalists, students, and the man and woman on the street understand in what strange ways we have changed their world.

We must explain, over and over, the concept of "afterheat," the fire that you can't put out, the generation of heat from fission fragments now and weeks from now and months from now, heat that must be removed. Journalists are having such a hard time communicating this concept because it is so unfamiliar to them and nearly everyone they are writing for. Every layman feels that every fire can be put out.

We must also explain the strange temporal features of radioactive spent fuel. Hour by hour, week by week, year by year, one isotope passes grief to a second and the second passes grief to a third. As the tragedy emerges at Fukushima, the moral complexity is overwhelming. The radiation is coming primarily from short-lived isotopes, and it is lethal in hours for anyone who is near the plant. We are watching a civilized society facing Sophie's Choice writ large, as the Japanese government decides how to use workers and soldiers and volunteers at the site, trading their large doses of radiation against an outcome where far more people will face the statistical risks of a shortened life. Evacuation is another part of the agony. So, too, is distribution of iodide tablets to limit thyroid cancer.

Already, however, the next form of grief is emerging: grief that results from ambiguity. Small quantities of radioactivity are being detected in food. Unless a large dread-to-risk ratio is assigned to choices such as whether to eat or not to eat, the experts' models of risk will not match the choices. Inevitably, much more of the same lies ahead, with immense human costs, as measurements on fields and city streets and in buildings confirm contamination with radioactivity. Notably, two rogue isotopes with 30-year half-lives, Cesium 137 and Strontium 90, will be found everywhere, both of them unmistakably attributable to the accident. They will be measurable throughout the lifetimes of everyone alive today. Throughout this century, the poor will live on the contaminated land, eat the contaminated food, and live in the contaminated buildings.

All aspects of the suffering that has come -- and will continue to come -- from the succession of dominating isotopes are familiar to philosophers and economists, to the nuclear power community and its civil defense counterparts.

Finally, the accident itself demands our best efforts as teachers. My first impression is that we are too focused on the onslaught from the natural world. The release of radioactivity from the Fukushima Daiichi plants may not have been an inexorable consequence of either the earthquake or the tsunami. The three operating nuclear power plants at that site shut down successfully, and all the other nuclear power plants in Japan that shut down that day progressed, in most cases with back-up power, to the stable condition called "cold shutdown." Perhaps damage to the primary systems at the Fukushima Daiichi plants had made the back-up system ineffective. We should prepare ourselves, however, for news that only a relatively conventional back-up system failed.

There are so many urgent questions related to the resilience of the back-up system. I want to know why the back-up diesel engines were on low ground where they could be flooded and whether it is true that fuel tanks were washed away. How much less potent a source of damage could have knocked out the back-up system: a terrorist bomb? Why weren't the back-up engines and their fuel a few miles away at higher altitude at a hardened site? Were the engines and fuel tanks located on low ground because they were right behind a seawall, in which case are the seawalls of Japan a Maginot Line, providing Japan's citizens illusory protection? What nearby back-up systems didn't fail -- at banks, at airports, in posh homes?

I think it may well emerge that the most important lesson that should be learned from this accident is to revisit the resilience of back-up systems. Power blackouts are a given; perhaps failures of back-up systems during power blackouts must also become a given. Should much greater public and private effort be devoted to the assurance of proper performance by the back-ups to the back-ups? The earthquake and tsunami may have brought a message as critically important to hospitals and data centers as to the nuclear industry.