Out of options: A surprising culprit in the nuclear crisis

From The Boston Globe:

As the nuclear crisis in Japan unfolded last week, experts scrambled to understand why things were going so horribly wrong. While no one was surprised that a 9.0 earthquake and a massive tsunami had caused severe and complicated problems, critics charged that various aspects of the Fukushima Daiichi plant’s design had made the catastrophe more perilous than it had to be. Some considered the particulars: Why had the cooling system’s backup generators been installed in a way that left them vulnerable to the tsunami? Why did the reactors use a cost-saving containment vessel whose disaster-worthiness had been repeatedly questioned by scientists? Why had the pool of spent fuel rods overheated?

For those taking a longer view, however, there is a larger question looming over the disaster: Why was Japan, a nation at high risk for earthquakes and natural disasters, using a type of reactor that needed such active cooling to stay safe? And the answer to that doesn’t lie with Japan, or the way the plant was built. The problem lies deeper, and concerns the entire nuclear industry. Japan’s reactors are “light water” reactors, whose safety depends on an uninterrupted power supply to circulate water quickly around the hot core. A light water system is not the only way to design a nuclear reactor. But because of the way the commercial nuclear power industry developed in its early years, it’s virtually the only type of reactor used in nuclear power plants today. Even though there might be better technologies out there, light water is the one that utility companies know how to build, and that governments have historically been willing to fund.

More here.