Day by day, the news from the stricken nuclear reactors in Japan has grown worse. Reports this week raise the possibility that large amounts of radiation could be released into the air and water. If you, like we, have been hoping that the long-touted renaissance of American nuclear power would finally materialize, then post-earthquake events in Japan are likely to shake your optimism and your confidence.

Yes, obituaries are being written this week for the prospects of nuclear expansion. But we think and hope those obits are premature. Much depends on what happens in Japan. If the Japanese avert a full-scale meltdown, the scare fades. If, on the other hand, escaping radiation creates an even greater public health crisis, then the chances for a reinvigorated nuclear industry plummet.

But let’s step back. At the end of this scary episode, all of us still want the same thing: to be able to turn on the lights, juice a cell phone or recharge a Chevy Volt.

Nuke plants generate 20 percent of U.S. electricity — including half of Commonwealth Edison’s.

Let’s also remember that other mega-sources of power plant fuel — oil, coal, natural gas — carry their own proven dangers. That’s not only for workers who drill and mine, but for all of us who breathe air, drink water and eat food.

Coal? The 2010 explosion in the Upper Big Branch mine in West Virginia killed 29 miners. Coal plants spew pollution that causes lung disease and heart attacks. The Nuclear Energy Institute calculates that from 1995 to 2009, generating power from atoms instead of coal kept 20 million tons of nitrogen oxides and 51 million tons of sulfur dioxide out of the nation’s air. Ditto 10 billion metric tons of global-warming carbon dioxide.

Oil and natural gas? Last spring’s Deepwater Horizon oil disaster in the Gulf of Mexico killed 11 workers and spilled millions of barrels, snuffing out wildlife and livelihoods all along the coast. Around the globe, extraction workers often die in oil and gas accidents.

Renewable energy sources such as wind and solar hold great future promise. But scaling them up to power cities and factories is a costly prospect.

The best power source for the future, today as always, is human ingenuity driving scientific discovery. We hope for the day when our editorials on power generation lean heavily on such words as “geothermal,” “hydrogen” and “fusion” . . . or marvels we can’t imagine today.

Right now, there’s a nuclear accident to tamp down and clean up. And after that? There will be global skepticism about building nuclear plants — particularly in regions near seacoasts or seismic faults.

Good. That’s how we avoid preventable accidents. Plants under construction today are 1,600 times safer than the 40-year-old generation of reactors like those disabled at Fukushima, according to a study last year by an arm of the Paris-based Organization for Economic Co-operation and Development. Nuclear plants of the future will be even safer. But they will never be foolproof. Only generating no power is absolutely safe.

Nuclear accidents are scary. But not as scary as a world starved for electricity. Before we dismiss a thriving future for nuclear reactors, we need to weigh the risks of every alternative. More humans have died because of power generation from fossil fuels — some by accidents in extraction industries, others by breathing combustion pollutants in the air — than by all nuclear incidents worldwide.