“The resurgence of nuclear energy is underway,” says Steve Kerekes of the Nuclear Energy Institute, an industry trade group. Whether it will yield a flood of new reactors or a trickle will largely depend on the success — or failure — of the initial wave. The industry believes it can avoid the billions in cost overruns and years of delays that marred nuclear construction in the 1970s and 1980s. Licensing has been streamlined. Utilities are seeking firmer costs and schedules. And designs are more detailed. Still, some hurdles are emerging. Some companies are submitting incomplete applications or seeking design changes at the Nuclear Regulatory Commission (NRC), possibly delaying approval. At least two utilities recently said they’re switching to different reactor models because they couldn’t receive assurances on costs and the timetable. And since several models are new, problems could emerge as they’re built in the USA for the first time. The type of reactor planned for Maryland is being built in Finland, where it’s three years behind schedule and $2 billion over budget.

Today, 104 reactors supply 20% of the nation’s electricity. Just to hold that share, all 26 proposed reactors would have to be completed by 2030. And to meet global-warming goals, 42 reactors should be built the next two decades, according to the Electric Power Research Institute. Reed says that’s possible if the first wave goes well. A new Gallup Poll shows a record 59% of Americans favor nuclear energy. Here’s the rub: Nuclear reactor costs have doubled in the past three years to as much as about $8 billion, Moody’s Investors Service says. They’re twice as expensive as coal-fired plants and triple the cost of natural-gas plants. Reactors also are far more complex, taking up to 10 years to license and build vs. a couple of years for gas-fired plants.

The industry is recovering from a harrowing past. After the Three Mile Island accident in central Pennsylvania — which led to no deaths or known injuries, but caused a small radiation leak from the plant — the NRC passed sweeping new safety rules. Inspectors forced utilities to rip out pipes and install back-up pumps or generators midconstruction. Since utilities didn’t submit designs before building, each reactor was custom built, further burdening the NRC. Companies built plants so quickly to meet rising power demand that blueprints were only about 20% complete when construction began. Contractors redid work on the fly, causing delays. Double-digit interest rates drove up already swollen costs.

•Elusive financing. With lenders hesitant to take chances on nuclear energy, 10 companies seek a total of $93 billion in federal loan guarantees for new nuclear plants. But only $18.5 billion is available — enough to finance three or four projects. NEI President Marvin Fertel told Congress this month that independent power producers would likely abandon projects if the entire $93 billion is not funded, slowing the nuclear revival. Bill Wicker, spokesman for the Senate Energy committee, says guarantees are meant to bankroll only the maiden versions of new models. No more than another $18 billion is likely to be funded, he says. “It’s not like a bottomless cup of coffee.”

•Avoiding construction snafus. Manufacturers are trying to avoid the missteps of the first construction era. Three-dimensional computer images tell engineers precisely where pipes should go. GE and Westinghouse say 70% to 80% of their designs will be done before they break ground. And makers are increasingly building modular parts in the factory, cutting costs and minimizing mistakes on site. Westinghouse says 30% of its AP1000 reactor is modular. Still, “When you’re building (a new model) for the first time, yes, there’s risk,” says Jone-Lin Wang of Cambridge Energy Research Associates.

Tight supplies. Only one company, Japan Steel Works, builds the 600-ton steel forgings used to make reactor vessels. It can make only five or six a year. Southern, SCE&G, NRG and Constellation have spent tens of millions of dollars reserving such items. Those building reactors after the front-runners could face bottlenecks, Standard & Poor’s says. But Japan Steel Works has said it’s expanding its capacity by about a third, while others are entering the market. In the U.S., factories to make nuclear parts are being built in Virginia, Louisiana, Indiana and Tennessee.

•Fewer workers. New reactors are likely to strain a pool of nuclear workers depleted by the construction hiatus. About 100,000 new workers would be needed to build and staff the 26 proposed reactors. Meantime, 35% of the current workforce is eligible to retire in five years. The NEI notes utilities have teamed with community colleges to train workers. Still, a likely shortage of specialized workers, such as nuclear welders, could drive up wages and construction costs, says consultant Steve Rus of Black & Veatch.