All weekend, I'm checking the stories of radiation leaks from the damaged reactors in Japan. The science of what constitutes a partial meltdown is complicated, and it's clear that reporters, even those who specialize in nuclear energy issues and who are interviewing experts with Ph.D.s and top-of-the-line credentials, are unsure of the extent of the damage and danger..

As I read Thomas H. Maugh’s excellent Q-and-A in this morning’s Los Angeles Times, I wondered, Why didn't anyone think to stockpile charged batteries — in multiple facilities to keep them safe and dry — to be used as a tertiary power backup, to keep the reactors cool.

Maugh explains that engineers "are pumping seawater laced with boron into two nuclear reactors at Japan's Fukushima No. 1 power plant ... to stave off a meltdown that could release dangerous amounts of radioactivity into the environment." The reactors have to be cooled, he writes, because the tsunami that followed the earthquake knocked out the electrical grid "that supplied power to the pumps that circulate cooling water" at the 11 nuclear reactors. At six of those reactors, the tsunami also damaged the backup power source: diesel generators.

So engineers went to batteries to keep things cool. The problem, Maugh explains, is that the batteries "had a life of only several hours." And so a partial meltdown ensued.

My question is why couldn't off-site charged batteries be changed and changed again until the fuel rods were cooled to the point that the danger of meltdown ended? According to news reports as early as Friday, officials of Japan's Nuclear and Industrial Safety Agency were considering using Japanese military helicopters to airlift batteries to the reactor sites. As it turned out, it was too late to prevent damage and some, at this point, low-level radiation leakage.