The worst case. These three words have been at the back of everyone’s mind ever since the Fukushima nuclear reactors began malfunctioning after being swamped by a tsunami. Remarkably, these words have been at the front of few experts’ mouths.
Many experts have shied away from describing worst-case outcomes, which are terrifying to contemplate and risky to mention. The risk isn’t just panicking the public. Crying wolf can threaten one’s expert status.
The bias toward calm, cool expression has been on full display in the crisis. The Japanese are especially good at this. The authorities have repeatedly said that exploding reactor housing is not a big problem, that released radioactive steam is not a big problem, that the significant cracks in containment vessels are not a big problem, that burning spent fuel ponds are not a big problem, and that the contamination of food and water is not a big problem. To top off all this, Tokyo Electric Power Co.’s president, Masataka Shimizu, made a formal apology “for causing such a great concern and nuisance.”
Earth to Shimizu: This isn’t just a nuisance.
What’s already occurred is horrible enough, what with death and severe injury to plant workers and the contamination of local milk, spinach, beans, and, presumably, fish. But the worst-case scenario at Fukushima is far beyond this. It entails six reactors melting down and all 4,277 tons of spent fuel stored at the plant burning out of control. And this at a site just 150 miles from Tokyo’s 14 million inhabitants, whose water is already showing traces of radiation.
But let’s just imagine how we might end up in this scenario. Another quake and tsunami could certainly get us there. Sound crazy? Maybe not. Maybe last week’s quake was a foreshock to an even larger one that’s coming.
If this thought makes you queasy, you are feeling the bias we humans have against considering terrible tail events, or outcomes that are at the far end of the probability distribution. If we haven’t seen it, and it hurts to think about it, we ignore it. But equating what has happened with what will happen is folly. When it comes to quakes, we’ve only recorded a minute span of geological history.
Nor can we count on future geological processes following past patterns. Four of the nine largest earthquakes since 1900 have occurred in the last seven years.
The US Geological Survey states emphatically that no one can predict earthquakes. What it doesn’t say is that neither the survey nor anyone else knows the statistical distribution governing earthquakes of different magnitudes.
Hence, the probability of extremely powerful quakes and their attendant tsunamis may be much higher than we think. Case in point — the 9.0 magnitude earthquake off the northeast coast of Japan was 10 times bigger than the maximum quake the builders of the Fukushima plant considered possible.
Japan has 55 nuclear reactors. It’s in the process of developing another 11. That’s 66 “nuisances” waiting to happen, if not by earthquake and tsunami, then by terrorism, or by human error — the cause of the Chernobyl meltdown.
Thanks to Chernobyl, an area the size of Switzerland, or 41,000 square kilometers, is uninhabitable for the next 300 years. Japan is about nine times bigger than Switzerland. If Japan has nine Chernobyls, it’s game over.
Is this unthinkable? It depends on your time frame. A lot can happen in 700 million years, which is the half-life of uranium-235, or 24,000 years, which is the half-life of plutonium-239, or even 30 years, which is the half-life of cesium-137. Japan’s spent fuel is full of these ingredients.
Since we care about our kids, who will care about their kids, who will care about their kids, we effectively care about all our future descendents. Therefore we must worry not just about the likely effects of nuclear energy, but the tail events, which are potentially so catastrophic to our progeny that economics tells us to place all the weight in our planning on the worst-case scenario.
Were Nobel physicist Enrico Fermi alive today, he would be appalled by the nuclear tail risk we are manufacturing for ourselves and our descendents. Fermi, would have no hesitation in telling Japan to shut the reactors. He developed the first nuclear reactor and had grave doubts about their net benefit, wondering when mankind will “grow sufficiently adult to make good use of the powers that he acquires over nature.”
Bloomberg News
Laurence Kotlikoff is professor of economics at Boston University. Eugene Stanley is professor of physics at Boston University, and a member of the National Academy of Sciences.
Many experts have shied away from describing worst-case outcomes, which are terrifying to contemplate and risky to mention. The risk isn’t just panicking the public. Crying wolf can threaten one’s expert status.
The bias toward calm, cool expression has been on full display in the crisis. The Japanese are especially good at this. The authorities have repeatedly said that exploding reactor housing is not a big problem, that released radioactive steam is not a big problem, that the significant cracks in containment vessels are not a big problem, that burning spent fuel ponds are not a big problem, and that the contamination of food and water is not a big problem. To top off all this, Tokyo Electric Power Co.’s president, Masataka Shimizu, made a formal apology “for causing such a great concern and nuisance.”
Earth to Shimizu: This isn’t just a nuisance.
What’s already occurred is horrible enough, what with death and severe injury to plant workers and the contamination of local milk, spinach, beans, and, presumably, fish. But the worst-case scenario at Fukushima is far beyond this. It entails six reactors melting down and all 4,277 tons of spent fuel stored at the plant burning out of control. And this at a site just 150 miles from Tokyo’s 14 million inhabitants, whose water is already showing traces of radiation.
But let’s just imagine how we might end up in this scenario. Another quake and tsunami could certainly get us there. Sound crazy? Maybe not. Maybe last week’s quake was a foreshock to an even larger one that’s coming.
If this thought makes you queasy, you are feeling the bias we humans have against considering terrible tail events, or outcomes that are at the far end of the probability distribution. If we haven’t seen it, and it hurts to think about it, we ignore it. But equating what has happened with what will happen is folly. When it comes to quakes, we’ve only recorded a minute span of geological history.
Nor can we count on future geological processes following past patterns. Four of the nine largest earthquakes since 1900 have occurred in the last seven years.
The US Geological Survey states emphatically that no one can predict earthquakes. What it doesn’t say is that neither the survey nor anyone else knows the statistical distribution governing earthquakes of different magnitudes.
Hence, the probability of extremely powerful quakes and their attendant tsunamis may be much higher than we think. Case in point — the 9.0 magnitude earthquake off the northeast coast of Japan was 10 times bigger than the maximum quake the builders of the Fukushima plant considered possible.
Japan has 55 nuclear reactors. It’s in the process of developing another 11. That’s 66 “nuisances” waiting to happen, if not by earthquake and tsunami, then by terrorism, or by human error — the cause of the Chernobyl meltdown.
Thanks to Chernobyl, an area the size of Switzerland, or 41,000 square kilometers, is uninhabitable for the next 300 years. Japan is about nine times bigger than Switzerland. If Japan has nine Chernobyls, it’s game over.
Is this unthinkable? It depends on your time frame. A lot can happen in 700 million years, which is the half-life of uranium-235, or 24,000 years, which is the half-life of plutonium-239, or even 30 years, which is the half-life of cesium-137. Japan’s spent fuel is full of these ingredients.
Since we care about our kids, who will care about their kids, who will care about their kids, we effectively care about all our future descendents. Therefore we must worry not just about the likely effects of nuclear energy, but the tail events, which are potentially so catastrophic to our progeny that economics tells us to place all the weight in our planning on the worst-case scenario.
Were Nobel physicist Enrico Fermi alive today, he would be appalled by the nuclear tail risk we are manufacturing for ourselves and our descendents. Fermi, would have no hesitation in telling Japan to shut the reactors. He developed the first nuclear reactor and had grave doubts about their net benefit, wondering when mankind will “grow sufficiently adult to make good use of the powers that he acquires over nature.”
Bloomberg News
Laurence Kotlikoff is professor of economics at Boston University. Eugene Stanley is professor of physics at Boston University, and a member of the National Academy of Sciences.
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