The March 11 earthquake off the coast of Japan has been an unprecedented disaster. Now estimated to have been a magnitude 9 earthquake — one of the top five earthquakes measured since reporting started in 1900 — it was the result of a “megathrust” in which an area of sea floor bigger than the state of Connecticut broke free and moved under the force of colliding tectonic plates. It was so strong that it literally moved the entire island of Honshu eight feet to the east. The earthquake was then followed by a tsunami comparable to the Boxing Day tsunami of 2004 — but since the epicenter of the quake was only a few miles off the coast of Japan, the tsunami struck the heavily populated coast of Honshu with almost no warning, basically washing many coastal villages off the face of the earth.
The earthquake and tsunami seriously damaged reactors at the Fukushima Daiichi (“number one”) and Daini (“number two”) in Okuma, in Fukushima Prefecture, and also damaged the Onagawa plant in Miyagi Prefecture. In total, of the 55 nuclear power generation plants in Japan, 11 have been forced to shut down, cutting power generation capacity in Japan dramatically and forcing the country to adopt a series of rolling blackouts. It would seem impossible to overstate the severity of the crisis.
The media, however, has risen to the challenge, with a combination of poor information, ignorance, and alarmism, along with antinuclear activists passing themselves off as unbiased experts.
Let’s try to make some sense of it all.
Basics of How Reactors Work
The Fukushima plants have several reactors built on the same basic design, either by GE or by Japanese companies licensed by GE. These are all “boiling water” reactors, which means just what it sounds like: the heat of the nuclear reaction boils water; the steam generated is used to drive turbines and thereby generate power. The water in direct contact with the reactor core known as “coolant” is nothing particularly special, just demineralized; water itself isn’t very susceptible to becoming radioactive, but minerals and contaminants in the water can be. If the water is purified, there’s less radioactive waste to deal with.
The cooling water is pumped past the reactor core in normal operation to get the energy with which power is generated, and of course to cool the core. If there’s an accident, the reactor is shut down by inserting the “control rods,” made of some material that absorbs neutrons and so slows the nuclear fission from which the reactor gets its power. Even a shut down reactor continues to need cooling, however; there’s an immense amount of residual heat still left in the reactor core. This means continuing to run the pumps, and of course with the reactor shut down they can’t be run from the reactor’s power, so there are diesel generators as a backup, and batteries as a further backup to the generator.
If all the cooling fails for some reason, the accumulated heat can’t escape; the water boils away, and once it’s gone, the materials that make up the reactor core break down. This is a Bad Thing, because the controls on the reactor fuel also break down; it starts to heat up again. This is what’s called a meltdown. When this happened at Chernobyl, the reactor core quickly became hot enough to vaporize the reactor’s fuel and a good part of the other material around it, leading to an explosion that destroyed the building that housed the reactor.
To prevent that from happening in commercial reactors in the capitalist bloc, the reactor is inside three concentric safety vessels: first, the “boiler” itself; second, a massive steel bottle; and third, an even larger and more massive reinforced steel, concrete, and graphite outer containment vessel. In case of a meltdown, the whole reactor should be contained within the steel secondary containment vessel, but if it’s not, the molten reactor core drops to the graphite floor of the third vessel, where it spreads out across the floor. This causes the reactor to stop, and it can cool naturally. Eventually the pieces can be cleaned up.
This whole structure is then inside a big conventional steel building that is the outside wall of the reactor complex.
What happened at Fukushima Daiichi
The original earthquake hit. Three of the six reactors were in operation, the other three were shut down for scheduled maintenance. The reactors were designed to sustain an earthquake of magnitude 8.2; at magnitude 9, the Honshu quake was 16 times more powerful. This caused the plant to automatically shut down; this was apparently successful, but …
About an hour later, the tsunami hit. The tsunami did two significant things: it destroyed the backup generators that kept the pumps running, and it apparently so contaminated the reserve coolant that it was not only no longer pure, but was so mucked up with the scourings of the tsunami that it couldn’t be safely pumped. At this point, the reactor was in some trouble.
As the reactor heated up, water began to react with the zirconium fuel-rod containers, liberating hydrogen, which started to build up in the boiler. The operators began to vent gases from the reactor to reduce the pressure, liberating the hydrogen into the outer façade building. These gases are mildly radioactive, mainly with nitrogen-16 and several isotopes of xenon, all products of the fission reaction that powers the reactor; apparently they were vented into the outer building in order to slow their dispersion and give them a chance to lose radioactivity.
Hydrogen in combination with the oxygen in the air can be explosive, and at some time after the venting started in reactor 3, the hydrogen in the outer façade exploded, blowing off the walls of upper half of the building and leaving the steel structure exposed. This explosion put six workers in hospital, with various injuries and one apparent heart attack. This was the first spectacular explosion that raised great clouds of white smoke.
This was reported in the New York Times as “radiation poisoning.” No other source has reported this, including the IAEA. Apparently, according to the Times, radiation poisoning breaks arms.
The second explosion was another hydrogen explosion; as before, apparently what was destroyed was the outer building that surrounds the containment, not the containment itself.
This is the point at which the media confusion starts. Many stories concentrating on the reactor accidents were illustrated with blazing pictures of a natural gas plant explosion and a burning oil refinery, much more visually impressive than a building with the façade stripped off, but giving the false impression of a blazing inferno at the reactors.
Several headlines said “nuclear explosion,” which is something very different from “an explosion in a nuclear power plant.”
Anti-nuclear politicians like Congressman Ed Markey and anti-nuclear activists from groups like the Institute for Policy Studies warned ominously of “another Chernobyl” — which this isn’t and never will be; the reactors are wildly, radically, different in design. (More on this below.)
Television talking heads talked about the “containment building.” Which is strictly true, since the building in which the containment is housed would be the “containment building” — but misleading and confusing, because the containment for all three reactors remained intact.
So there’s the first bottom-line point: at least so far, the inner, steel, containment vessel on all three Fukushima reactors remains intact.
When the gases started to be released from the containment vessels, that meant there was some release of radiation. With their usual nuance, the media reported only that there was radiation released; since there was detectable radioactivity on the clothes and bodies of the men injured in the explosion, this apparently turned into “radiation poisoning,” even for the poor guy who had the heart attack.