Customers of Florida's two largest power companies will have paid $772 million by the end of 2011 to produce more nuclear power - before any concrete has been poured.
    The money has been plowed into planning the expansions. Florida Power & Light has applied for state and federal approval to build two reactors and expand four generators. Progress Energy Florida wants to build two reactors in Levy County. Florida has five reactors.
    With the approvals, there's no guarantee the projects will be built. Uncertainty is growing over whether the new reactors and expanded generators will be cost-effective in light of lower natural gas prices and new safety measures that may be required after Japan's nuclear disaster at the Fukushima Daiichi plant.
    "Ultimately the decision to build will be based on a number of factors: the economic situation, the cost of nuclear [power] relative to other sources of generation, and what's going to deliver the greatest positive return for our customers," FPL spokesman Mike Waldron said. He said FPL expects to decide after it secures the required approvals, which is likely in 2014.
    The approval process for nuclear power generators can take five or more years. In today's Money section, see details of the power companies' plans, the issues that regulators will consider, and timetables for approval and construction.

A guide to Florida's proposed nuclear expansions

What will they cost you, and what hurdles remain?

Construction of Florida's newest nuclear reactors could start in 2013.
    Progress Energy Florida could win all federal and state approvals for its two nuclear reactors in time to start construction then. Florida Power & Light could begin construction of two reactors at Turkey Point a year later.
    Customers of these utilities would then begin paying financing costs for the new reactors, which are projected to cost up to $41 billion combined. They would start paying for the construction about eight years later, when the plants are running.
    FPL also wants to expand energy production at its four existing nuclear generators in the next couple of years at a cost of up to $2.5 billion.
    Supporters of nuclear power say the plants, once built, would be cheap, reliable, clean sources of energy that would help diversify the state's power supply.
    Until then, customers of these two power companies are paying to plan and win approvals of the new reactors and expansions of four existing generators. In Florida, companies can charge customers for nuclear planning as costs are incurred. Economists have said it's a no-brainer for companies to move forward with plans because they don't have to pay for them.
    FPL began seeking approval for its projects in 2007; Progress in 2008. Here is what's on the table for both companies.
Proposed expansions
    FPL, the state's largest electrical utility, wants to build two reactors at its Turkey Point plant near Miami, expand by 15 percent two existing generators at Turkey Point and expand by 12 percent two generators in St. Lucie County. FPL operates two reactors at Turkey Point and two in St. Lucie County.
    Progress, the state's second-largest utility, plans two reactors in Levy County. It has completed part of an expansion at its plant near Crystal River. That reactor has been shut down since late 2009, when expansion work triggered a crack in the concrete and steel building around the reactor. Progress fixed the damage but is investigating other possible smaller cracks.
Project costs
    Planning: FPL will spend $314 million, including $31 million this year.
    Progress will spend $457 million, including $60 million this year.
    Construction: $13 billion to $18 billion to build two reactors at Turkey Point, including new pipelines to transport cooling water and 89 miles of new transmission lines.
    $2.3 billion to $2.5 billion to expand FPL's four existing reactors.
    $17 billion to $23 billion to build two reactors in Levy County. The cost includes interest, fuel and the price of building 200 miles of transmission lines.
    Energy to be generated: About 4,440 megawatts by the four new reactors, enough energy to power about 2 million homes.