The following editorial first appeared in the Chicago Tribune:

A few days ago, Japanese officials declared that the accident at the Fukushima Daiichi power complex rated a “7” on a ranking with a scary name: the International Nuclear and Radiological Event Scale. That’s the same rating as the Chernobyl accident of 1986.

Some experts convincingly disputed that dire evaluation, arguing that the release of radiation from Chernobyl was much worse than the situation in Japan — which to date has killed no one. But there’s no denying that the ongoing disaster has shaken the nuclear industry worldwide. Six in 10 Americans oppose building nuclear power plants, a recent AP-GfK poll says. That’s up from 48 percent in November 2009. Overshadowing an earthquake and tsunami with a death toll approaching 14,000 — with a like number missing — is no easy feat. But such is the level of public fear of nuclear energy.

It’s urgent that governments and power providers take a fresh look at nuclear power in light of this crisis. Example: The Tennessee Valley Authority said Thursday it is considering millions of dollars in improvements to protect its six nuclear reactors from earthquakes and floods.

But curbing or abandoning nuclear power plants, as some reinvigorated critics are proposing, is shortsighted. Nuclear power supplies about 20 percent of this nation’s electricity. Renewable energy sources such as wind and solar are gaining importance, but nuclear remains a key component in electrical generation that releases minimal carbon emissions.

For the industry, the timing of the Japanese disaster couldn’t be worse. In recent years, nuclear energy started to gain momentum, even among some environmentalists, as a viable alternative to fossil fuel generation. Now Fukushima raises the specter of earlier nuclear accidents: not only Chernobyl but the less severe Three Mile Island. That 1979 accident similarly occurred at a time when nuclear power was gaining popularity in the aftermath of the Arab oil embargo. A cooling malfunction at that plant in Pennsylvania led to a partial evacuation — and screaming headlines about a potential meltdown. In the end, the main casualty was America’s faith in nuclear energy. Planning for new plants stopped. Then came Chernobyl. “Nuclear power equals high risk” was entrenched in the American psyche.

That legacy is reflected in America’s aging nuclear fleet. More than half the 104 operating power reactors in the United States are at least 30 years old. Only three have been built in the past 20 years, the last coming online in 1996. As a way to boost output, utilities are turning to a technique called “uprating,” in which existing plants are run at higher capacity to produce more power. Retrofitting existing plants is a more cost-effective alternative to building new ones. But it carries added safety concerns.

Even before Fukushima, the cost of building new nuclear plants had become all but prohibitive. The price tag for a new 1,000-megawatt facility: around $6 billion, and now likelier to rise than to decline.

Nuclear power is not risk free. But we need to weigh those risks against the known costs associated with fossil fuel use. Among them: environmental accidents such as last year’s Gulf of Mexico oil spill and lethal industrial accidents in coal extraction — not to mention the carbon impact of burning fossil fuels.

As emotions cool and acceptance of nuclear power re-emerges, power providers and regulators will focus intently on modern designs for future plants. This we know: No one will be building any more plants from 40-year-old engineering plans like those used at Fukushima.