Fukushima nuclear accident
The Fukushima Daiichi nuclear disaster was a series of equipment failures, nuclear meltdowns and releases of radioactive materials at the Fukushima nuclear power plant in northeastern Japan, following a devastating earthquake and tsunami on 11 March 2011 which claimed nearly 19,000 lives. It is the largest nuclear disaster since Chernobyl in 1986 and only the second disaster to measure Level 7 on the International Nuclear Event Scale.
Abe must act now to seal Fukushima reactors, before it's too late
Julian Gresser, Ernst Frankel and Jerome A. Cohen say complacency is putting the world at risk
Dear Prime Minister Abe, the Fukushima crisis is getting worse. Yet you have an option at your disposal to resolve it. But first you must begin by challenging a chain of untested and dangerous assumptions that have lulled you and your administration into apparent complacency.
The key assumption, the root of all the others, is that you still have a safe window of time, at least two or three more years, and possibly longer, to deal with Fukushima's four damaged nuclear reactors. Indeed, you have assured the Olympic Committee that the situation at Fukushima is under control and will remain so, certainly until after the Games in Tokyo scheduled for 2020, although your government has recently estimated it may take another 30 years for the radioactive contamination emanating from Fukushima to be abated.
What if this assessment is unrealistically optimistic? What if the safe window of time is less than a year? What if the very concept of a safe window is inappropriate for Fukushima? The fact is, we really don't know what might happen.
According to the Tokyo Electric Power Company's published engineering reports, the most severely damaged reactors (one to four) are only secure to the level of a magnitude 7.9 earthquake. But the mega earthquake that caused the greatest damage at Fukushima was measured at magnitude 9.0. What will happen at reactors one to four when the next earthquake of 7.9 magnitude or greater strikes? Or what if the cumulative effects of a series of smaller earthquakes exceed this threshold? In order to compromise any or all the reactors at Fukushima, the next earthquake, tsunami or volcanic eruption need not even occur within Japan.
The crucial question is: how secure is the facility against any number of dark scenarios?
There is a high probability that, if a quake of magnitude 7.9 or above, or some other serious event, strikes Fukushima, a "criticality" will occur. The least dangerous would be the local release of strontium-90, caesium 134/137, or nano-plutonium. Far more dangerous would be an explosion, or a series of explosions - a chain reaction, engulfing reactors one to four - that would spew this contamination over much broader areas of helpless populations. Three previous explosions have released radioactive material over Fukushima and Tokyo.
The next criticality may be far more serious. If you look at a three-dimensional topographical map, you will see that greater Tokyo virtually touches Fukushima. But no one is immune. The jet stream will transport airborne contamination to the United States and other parts of the world. In 2005, the US National Academy of Sciences reported that there were no safe dosages of strontium-90, caesium 134/137, nano-plutonium or other long-lived radioactive isotopes, and the risks to human health increase cumulatively with continuing exposure.
Some Russian scientists estimate that 985,000 people died, mainly of cancer, as a result of the Chernobyl accident. Fukushima may be far more dangerous because the risks are continuing, and the situation is dynamically degrading and unstable. Moreover, unlike Three Mile Island or even Chernobyl, the formidable problems of access to reactors one to three make accurate assessment of the true extent of the damage, hence the level of risk and vulnerability, extremely challenging.
We urge that you commission a 30-day independent assessment by a multidisciplinary international team of experts on the feasibility of entombment of reactors one to four, addressing the following specific scenario among others:
Use helicopters mounted with telescopic nozzles, and, after reinforcing the spent fuel pool in the target reactor, spray it with special lighter-than-water concrete, dissolved in water solution; let the pool harden, along with the remainder of the facility, which is also sprayed until it becomes impervious to radiation or explosion. The independent commission should advise which reactor is the best initial candidate.
The special materials are currently being used in construction in Israel, the US, and other countries and can easily be made available in Japan, if they are not already in use.
Hundreds of tonnes of material will probably be required for each nuclear reactor, and preliminary estimates suggest that each operation should cost well under US$10 million. Reactors one to four can probably be entombed within six months.
This plan obviously requires you to recognise that reactors one to four are probably not salvageable. Entomb them. Then commission pilot studies for improving earthquake prediction and early warning and monitoring systems at any nuclear plants you can responsibly contemplate operating.
Julian Gresser is chairman of Alliances for Discovery. Ernst G. Frankel is emeritus professor of ocean engineering at MIT. Jerome A. Cohen is co-director of the US-Asia Law Institute at NYU Law School. Dick Wullaert also contributed to the article