The last nuclear power plant built in the US was way back in 1977. But after a regulatory approval yesterday, work could begin as soon as next month on the next generation of nuclear plants.

The Nuclear Regulatory Commission unanimously approved a radical new reactor design on Thursday, clearing away a major obstacle for two utilities to begin construction on projects in South Carolina and Georgia.

The decision, a milestone in the much-delayed revival of plant construction sought by the nuclear industry, involves the Westinghouse AP1000, a 1,154-megawatt reactor with a so-called advanced passive design. It relies more heavily on forces like gravity and natural heat convection and less on pumps, valves and operator actions than other models do, in theory diminishing the probability of an accident.

Two reactors are planned for the Southern Company’s plant near Augusta, Ga., and another two at the Summer plant of South Carolina Electric and Gas in Fairfield County, S.C.

In an unusual step, the commission waived the usual 30-day waiting period before its approval becomes official, so its decision will be effective in about a week. That moves the utilities closer to the point where they can start pouring concrete for safety-related parts of the plant.

Gregg Levine points out that there’s nothing that radical about the new design from Westinghouse, other than the fact that it’s cheaper to build, what with the relying on gravity rather than parts and all.

Ed Markey calls it a holiday gift to the nuclear industry. Gregg obviously has been following this closely and will have a more detailed report. I just think it’s unconscionable to move forward on what was clearly the plan for speeding nuclear plants to construction before Fukushima, given the disaster there and the still-unknown consequences. It’s not like natural disasters are somehow foreign to the United States. Every single state in the Union has been declared a disaster area at some point this year. Safety should be the primary question for all working nuclear plants, before we even get around to approving new construction. But in this case, of course, the barriers to construction are being toppled as fast as possible.

Aside from safety, my biggest problem with nuclear power is the enormous cost of construction and insurance. The loan guarantees held by the federal government means every taxpayer is on the hook if something goes wrong. That subsidy is all that makes nuclear competitive as a fuel source. Even now, natural gas has become much cheaper than nuclear, so these plants may not get built right away. But the NRC certainly gave the industry a boost with this ruling.