Thank heavens the Japanese tsunami did not hit a solar-panel facility: If it had, it could have caused a flood of potentially deadly toxins to be washed over the island and into the Sea of Japan. The risks would have included the discharge of silicon tetrachloride, the irresponsible use of which by solar-panel makers already has led to severe environmental damage.

Instead, the earthquake and subsequent tsunami struck a country heavily reliant upon nuclear power for the generation of electricity, and three generators were damaged. Malfunctions at nuclear-power plants practically define the term “grave concern,” but it is possible to exaggerate the danger of even so grave a matter — which is precisely what is happening in the case of the damaged reactors at Fukushima Daiichi.

Nuclear reactors get hot — very, very hot. They require robust cooling systems. In the case of Fukushima Daiichi, the tsunami shut down the electricity grid and washed away the backup diesel generators. The backup to the backup was batteries, the first set of which worked. When those had run down their charges, a second backup set of batteries was discovered to be defective. And thus the backup to the backup backup was deployed: flooding the reactor cores with sea water to cool them down.

It is worth noting, as National Review contributor William Tucker does, this particular cooling-system problem belongs only to outdated facilities: The Generation II plants use pumps, which require power; the new Generation III plants use passive cooling systems that require no pumps.

This makes the Japanese situation, worrisome as it is, precisely the wrong example to bear in mind when considering the future of nuclear power in the United States: American utilities do not propose to build outmoded, 40-year-old plants based on discarded designs. They propose to build new plants. Rep. Ed Markey of Maine, a Democrat, is therefore wrong to call for a moratorium on new U.S. nuclear power in reaction to the situation in Japan.

No doubt any new U.S. nuclear-power plants will have their limitations — everything does — but the modest and manageable risks of nuclear power must be weighed against the costs and risks of forgoing it. In the United States, the absence of new nuclear power means that electricity generation remains heavily reliant upon coal. One need not be in Al Gore’s orbit to appreciate that the environmental costs of coal — not just of burning it, but of digging it up in the first place — can be very high. Nuclear power has a limited role to play in our other major national energy concern — the predominance of imported oil and the unsavory entanglements sometimes associated with that — but it is not insignificant: If some automotive genius were to invent an electric car that Americans actually wanted to buy and drive tomorrow, we’d only be moving from petroleum-powered cars to, in effect, coal-powered ones.

The question of nuclear power is largely one of balancing the remote possibility of a dangerous nuclear event against the virtual guarantee of continuous lower-impact environmental costs associated with other sources. Natural-gas lines explode, coal-fired plants release small amounts of radiation into the environment daily, oil rigs sometimes spill vast amounts of crude into coastal waters. Hydropower dams collapse and cause floods, and it takes a lot of poison to make a solar panel. Every form of energy production entails risks and tradeoffs. Nuclear-power plants cannot explode like atomic bombs; they use the wrong kind of fuel for that. The worst nuclear disaster in American history, Three Mile Island, produced no casualties and no environmental damage of any consequence. The Japanese, unhappily, have not been so fortunate: Explosions at the nuclear plants, caused by the buildup of gases in the cooling system, injured workers. And the damage they have done to the facilities is unknown. Of critical concern is the state of the containment structures, which wall off the melting reactor cores.

The situation is bad, and it could get worse. And the move from bad to worse can be sure to draw the attention of opportunistic politicians, as this disaster already has. The campaign against nuclear power has always been particularly politicized in that it was linked to the Cold War Left’s campaign against nuclear weapons — against American nuclear weapons, anyway. The “China Syndrome” is a fanciful movie plot from the 1970s, not a nuclear-power reality. (A nation’s energy policy should not be set by Jane Fonda.) Japan’s experience should be studied and learned from, not used as a totem to cut the nation off from seeking out the best mix of power sources.