The sun didn’t set on chances for a new nuclear plant in Mississippi with the election of Barack Obama, but the skies became far more cloudy.

As a candidate, Obama set two preconditions for any new approvals that may be impossible for energy companies to meet.

One was no federal subsidy of the cost.

The other was that an approved facility for storage of nuclear waste must be in operation — and Obama doesn’t support the repository at Yucca Mountain, the Nevada site proposed by the U.S. Department of Energy for spent fuel many years ago and a political football since.

Neither of those preconditions will be welcomed by Entergy Nuclear, which now operates the state’s only nuclear-fired power plant at Grand Gulf in Claiborne County, or by utility consortiums that have been taking steps toward new plants in Mississippi, Louisiana and Alabama.

In a story reported by Reuters news service earlier this year, Obama said that because nuclear power does not emit greenhouse gases, the United States should consider — not commit to — research dollars into whether nuclear waste can be stored safely pending reuse. France, for example, reprocesses spent fuel — a practice now illegal in the United States. Obama has also accepted campaign donations from Exelon, which sells power made by nuclear plants in his home state of Illinois.

Otherwise, he’s a no-nuker.

“I don’t think that nuclear power is a panacea,” Obama said, contrasting his position with that of John McCain, the Republican nominee, who repeatedly pledged a big nuclear push, putting the country on a course to build 45 new nuclear reactors by 2030 as part of an energy independence effort.

On the campaign trail answering questions from citizens, Obama responded with, “I am not a nuclear energy proponent.” His preference, he said, is for solar, wind and other alternatives to replace the dwindling global supply of fossil fuels.

His position matters to Mississippi because steps taken so far toward adding a second reactor at Grand Gulf would culminate in the largest single private economic development project in state history — larger than the Nissan and Toyota plants combined.

Planners are about halfway through a 15-year process, divided into three equal increments.

The first five years led to what’s called early site approval for land on the Mississippi River near the existing power plant. As an initiative of the current administration, federal dollars were made available to supplement the costs private firms faced in studying and clearing any and all environmental hurdles. Without the tax dollars, the companies said they couldn’t afford the expense of meeting regulators’ demands.

With a final declaration that Grand Gulf is fully suitable, planners began the second phase — applying for construction and operating licensure — about two years ago. Although Entergy, based in New Orleans, says a decision to build at Grand Gulf or at an equally eligible site in St. Francisville, La., has not been made, components for a new boiling water reactor have been preordered from General Electric.

According to the timetable, if a federal license was OK’d in the next two years or so, a decision would be made on whether a five-year construction period would start on a $5 billion plant.

Since the state’s only nuclear plant fired up 23 years ago, power companies have been learning from automakers and other corporate heavyweights. Grand Gulf was built with company dollars, most of them borrowed. That was then. Now utilities expect inducements — public-private partnerships at least as generous as those provided to Nissan and Toyota. Job-hungry governors, including Haley Barbour in Mississippi and Bobby Jindal in Louisiana, both Republicans, have pledged whatever it takes to lure an economic development prize such as a new nuclear plant would be. Lawmakers in both states have already passed new laws to allow utilities to “frontload” their construction costs. Customers would pay for plants as they are built instead of afterward.

There is always a lot of curiosity about which statements from a campaign will be remembered by winners after taking their oaths of office, but there was very little nuance room in Obama’s position on nuclear plants. He didn’t say “never.” That may prove important.

Claiborne County has 12,000 residents and is often at or near the top of joblessness charts. Voters there, who pinned lots of hopes on new jobs and tax revenue from a second nuclear plant, also voted overwhelmingly (85 percent) for Obama. Perhaps he will gin up other ideas to help that county and all of Southwest Mississippi see economic gains.

There may yet be another reactor at Grand Gulf, but last week’s election made it a lot less likely.

(Charlie Mitchell is executive editor of The Vicksburg Post. Write to him at Box 821668, Vicksburg, MS 39182, or e-mail cmitchell@vicksburgpost.com.)