You've got to hand it to the Greens -- 6,000+ people dead or missing, but that's not worth mentioning. That can't be blamed on anyone (except maybe Mother Gaia). But a series of nuclear breakdowns that have killed a reported one person and with little further chance of harming anyone? That's worth screaming about. That can be dropped on somebody.
There are plenty of questions concerning the Fukushima reactor breakdowns. For one, if I were living in Japan, I would like to think that reactors would be isolated from subduction zones. But that's not the kind of question the Greens and associated media are asking. The rhetoric they're using is designed to make the disaster seem much worse than it is, to find someone to pin things on, and to shift public opinion in the direction of shutting down all nuclear plants no matter what the circumstances. (Germany has already shut down seven of its reactors for the next four months, just in case there's a magnitude 9 earthquake in Stuttgart.) Anybody who was around for Three Mile Island back in 1979 or Chernobyl in 1986 will recognize the cycle: first hysteria, then accusations, then more hysteria, then demands to return to the pre-modern era.
First, let's put the accidents in context: the Fukushima reactors survived one of the worst earthquakes in the historical record without breaking down catastrophically. This is a compliment to the designers (GE, in case anyone was wondering), the construction crews, and the operational teams. If the same had been true of Three Mile Island and Chernobyl, the accidents that occurred at those sites would have been of interest only to specialists. (Remember that TMI had a critical set of coolant valves put in backwards, while the Chernobyl reactor had no containment structure and was deliberately red-lined with all the safety features shut down, for reasons never adequately explained.)
"The reactors in question were all shut down four days ago. The control rods have been inserted, and the cores have been salted with boron. It is physically impossible for them to sustain a fission reaction of any kind at this point, let alone cause another Chernobyl. Only the fission-byproduct decay heat remains, and it is fading fast as the short half-life material... performs its decay reactions and ceases to exist." It is at this point as likely that the reactors could melt down as a car with an empty tank and all four tires stripped could win the Indy.
A major point being missed is that the Mark 1s at Fukushima are high-pressure light-water reactors of an obsolete design. They operate at extremely high temperature and pressure -- needless to say, this is where things go wrong. The GE Mark 1s were designed in the 1960s and most of them went into operation during the 70s. They are all nearing the end of their operational lives and due for replacement. Despite news reports intended to work up a scandal, they have compiled a pretty good record regarding safety and reliability. Modern designs are quite a bit different, operating on different principles. For one thing, they're much safer, particularly as regards the nightmare scenario of a meltdown. Despite what everyone has been told, it's possible to construct a reactor that can't melt down. This was demonstrated by the TRIGA reactor (Training, Research, Isotopes, General Atomics) built by a team that included America's greatest living physicist, Freeman Dyson, and designed in large part by Edward Teller. TRIGA reactors are fueled with uranium zirconium hydride, a compound that acts as its own moderator. Since the fuel loses efficiency as it heats up, it is next to impossible for a TRIGA reactor to melt down. (Dyson has a hair-raising passage in his memoir, Disturbing the Universe, in which he describes deliberately overloading the prototype TRIGA reactor only to have it immediately settle down to standard operating level.)
Seventy TRIGA reactors are in operation, 35 in the U.S. and the same number overseas. Unfortunately, the TRIGA design can't be scaled up to an economical power reactor due to critical mass characteristics of uranium zirconium hydride. Equivalent power reactor designs were slow in coming. Dyson complained that the "truly efficient reactors haven't been designed yet." (Largely due to interference by Greens.) But that has changed.
The oldest ultrasafe reactor is, as one might expect, a Canadian design, the CANDU (Canadian Deuterium-Uranium) reactor. The CANDU reactor utilizes deuterium, or heavy water, as both coolant and moderator. The trick is that heavy water is nearly transparent to neutrons, meaning that low-purity and even unrefined Uranium can be used as a fuel. The reactor simply doesn't get hot enough for a meltdown to happen. If a coolant leak occurs, loss of heavy water stops the reaction. CANDU reactors are so safe they don't even feature standard containment vessels. (I once had the pleasure of bouncing Cory Doctorow, who was waxing hysterical over the fact that Canada had not checked its reactors for Y2K problems. "But they're CANDU reactors," I told him. "They can't melt down." Doctorow was subdued for the rest of the discussion, a rare event, I was assured.)
CANDU reactors comprise Canada's entire nuclear reactor inventory. They've also been sold overseas, particularly to India, which has developed its own variants. The sole drawback of the CANDU design lies in the expense of the Deuterium. Even using cheaper unrefined Uranium, CANDU reactors are more expensive to operate than light-water reactors.
Moving on to newer designs we have the Generation III+ reactors. These feature passive safety features, that is, safety systems that don't require power to work. These include double containment vessels, expanded cooling areas, and large water reservoirs placed on top on the reactor. The first such design is the EPR, which stands variously for European Pressure Reactor and Evolutionary Power Reactor, now under construction in Finland and France. Beyond those we have the Generation IV reactors, such as the NGNP (Next Generation Nuclear Plant), being developed under sponsorship of the Department of Energy. These reactors will be constructed with inherent safety features utilizing basic physical properties to provide safeguards. For instance, cooling the core through convection currents created by heat to assure that a meltdown cannot occur. One example of a design based on totally new tech is the Pebble-bed reactor, in which "pebbles" -- graphite-covered Uranium nodules -- are fed through a reactor by means of gravity. There's never enough fissile material in the reactor chamber to achieve meltdown. If a problem develops, you simply stop the feed, dump the pebbles already inside, and halt the reaction. The pebble-bed reactor was originally developed in Germany. A South Africa research program ran out of funds last year, but development is continuing in China. Over the long term the Thorium reactor, which uses a Thorium-Uranium cycle to create a fission reaction, is the surest bet. Thorium reactors are inherently safer than LWRs -- Thorium does not create high-level nuclear waste, curtailing any possibility of a meltdown. Thorium reactors were successfully operated in the U.S. before being abandoned in favor of LWRs. India is the center of current Thorium power research, with one experimental reactor currently operating and five more in the construction stage. India hopes to see its nuclear power system running completely on Thorium by 2030. Japan, interestingly enough, has a High-Temperature Gas-cooled Reactor (HTGR) under construction that can burn Thorium and possesses Generation IV safety features. Look for a large-scale shift toward Thorium in the near future. A rather boosterish analysis of Thorium power appeared under Ambrose Evans-Pritchard's byline in the Telegraph last year. A more measured treatment comes from designer Ratan Kumar Sinha.
Clearly, to imply that the Fukushima accidents are representative of current developments in nuclear power is similar to claiming that car safety has remained unchanged since the Model A. This is how the Greens want it -- keep in mind that goal of the environmental movement is not to develop new sources of power, but to accustom Americans to far lower levels of energy use than prevail today. Unfortunately, it's up to conservatives to get the information across, and conservatives are not very good at tech. (A mystery, when you consider how many engineering types conservatism attracts. Maybe we need to develop a tech debate squad to handle these matters.)
The point is that we're not going to be using GE Mark 1s in the future any more than we'll be driving Stutz Bearcats or flying around in DC-3s. We'll be using pebble-bed reactors (that we'll probably buy from China) or Thorium reactors (that we'll probably buy from India -- see how this works?), or our own IVth or Vth generation designs, any of which will be safer than what's online today. The one thing we can sure of is that we're not going back. So let's stop the nonsense and help the Japanese clean up.