Talk about a nuclear tale of two cities.

In Washington, D.C., Duke Energy's deposed CEO-for-a-moment Bill Johnson, now head of the Tennessee Valley Authority power company, stood at the podium of this week's Nuclear Energy Institute conference to unveil the industry's secret weapon.

It's a video of the North American Young Generation in Nuclear, the nuclear power industry's organization of youthful engineers and others who work at nuclear power plants. Some 300 of them, including a half dozen or so from a Duke nuclear plant in North Carolina, descended this week on Capitol Hill to spread the nuclear gospel to 200 members of Congress.

"It is very important that these people see that there are young people interested in nuclear science and technology and are advocating for a positive future," says the group's young chairwoman.

The organization delivers a compelling appeal to Congress to support nuclear power. And the video boosts morale at the Nuclear Energy Institute meeting where an industry gathered to celebrate the nation's few new nuclear power plant projects — in Georgia, South Carolina and Tennessee. Says NEI: Nuclear is "well positioned to expand" as the economy rebounds.

But in St. Petersburg, Duke Energy finds itself once again defending its caviar-priced $25 billion plan to build a two-reactor nuclear power plant in Levy County. A Tampa Bay Times analysis published Sunday concluded a natural gas plant would be cheaper to ratepayers in the long run.

The Times analysis found a gas plant could be built for a fraction of a nuclear power plant, and that its natural gas costs still would not equal those of a nuclear plant over the course of 60 years.

In response, Duke Energy Florida president Alex Glenn repeated the utility's claim that nuclear is cheaper. "To compare the long-term costs of a new nuclear plant versus a natural gas plant requires the assumption of many unknown variables," he said.

No doubt. But that comment suggests figuring the long-term cost of any power plant — including nuclear — requires some guesswork.

Regulated by Florida's subservient Public Service Commission and our gullible Legislature, Duke rarely finds itself challenged on matters of cost involving Florida power plants.

Maybe that's why Glenn suggests in his May 14 letter to the Times that an analysis is too complex for a 2,000-word news article.

In November 2011, a column ran in the Times about whether to fix the Crystal River nuclear power plant broken by a botched in-house repair. Written by Vincent Dolan, Glenn's predecessor, the column insisted that repairing Crystal River was the best solution — and quite beyond the grasp of a newspaper.

"This is a complex issue in a complex industry and not one that can be sufficiently addressed through the media," Dolan wrote, echoing Glenn's letter this week.

A year later, Duke closed the plant.

Now Duke is already collecting $1.5 billion in customer money without officially saying it will actually build the Levy County nuclear facility. The utility insists spending $25 billion is the cost effective thing to do.

Should we believe them this time?

Robert Trigaux can be reached at trigaux@tampabay.com.