Scientists at the National Ignition Facility, a huge federal nuclear laboratory about 45 miles east of San Francisco, have announced a breakthrough in the decades of research devoted to taming nuclear fusion for peaceful uses. One of their massive experiments has, if only briefly, for the first time reportedly produced more energy than it consumed.

That remarkable outcome serves as another reminder that our national government must keep investing in scientific advances to reap vast dividends in decades to come.

Ponder the implications of that positive energy-produced result.

"For the first time anywhere, we've gotten more energy out of the fuel than what was put into the fuel" when using this technique, said Omar Hurricane, a physicist at the Lawrence Livermore National Laboratory and lead author of a report in the scientific journal Nature.

The reaction did not "ignite" the sustained reaction required for the practical use of the fusion process in the generation of electricity.

Nevertheless, it does "represent a significant step forward in fusion research," wrote Mark Herrmann of Sandia National Laboratories in a related article.

However, this achievement, using the world's most powerful lasers, is still a long way from proof that fusion can be sustained by the methods used in the experiment.

Still, proponents of nuclear fusion say that, like the fission process used in today's nuclear power industry, fusion will produce no greenhouse gases.

And unlike today's nuclear power plants, the fusion process would not generate long-lived nuclear waste and would present no danger of a meltdown.

Fusion plants are not on the horizon today, but continued research makes sense as another rising alternative to fossil fuels.

Meanwhile, policy makers seeking renewable energy sources might turn their attention to a new development in the nuclear power industry that is said to be a lot closer at hand than fusion.

This is the invention of the so-called "fast" fission reactor that can burn nuclear waste as fuel, is resistant to meltdown and produces relatively benign wastes of its own that require storage for hundreds rather than millions of years.

According to Forbes magazine, fast fission reactors have been installed in submarines and are ready to enter service in the electrical power industry.

If they live up to their advance billing, fast reactors deserve a policy fast track to becoming operational.

And if America is to meet its future energy needs, it must keep developing new energy sources.