Lawmakers and consumer advocates on Monday called for investigations into whether the St. Lucie nuclear plant in South Florida is safe and whether ratepayer money was used appropriately to boost the reactor's power.

The questions came a day after a Tampa Bay Times story detailed how tubes inside the steam generators that help cool the reactor had abnormal amounts of wear.

The Times report also prompted a former U.S. Nuclear Regulatory Commission engineer to say that federal regulators aren't using the right criteria to measure the damage. Until they do, the plant cannot be declared safe, he said.

"There is damage there and quite a lot. How do you account for it?" said Joe Hopenfeld, an expert in degraded steam generator tubes who still consults on nuclear plant cases.

St. Lucie's owner, Florida Power & Light, the state's largest utility, replaced the steam generators at its St. Lucie 2 plant in 2007, intending them to last until the plant's license expired in 2043. Since then, more and more wear has developed on the thousands of thin alloy tubes inside the two steam generators.

By the last inspection in November 2012, the number grew to 3,745 tubes with 11,518 dents and wear indications. Almost all the active nuclear plants with replaced steam generators have less than a few hundred worn tubes.

St. Lucie, about 50 miles north of West Palm Beach, is set for another inspection next month.

The Southern Alliance for Clean Energy, which intervenes in utility cases before the state Public Service Commission, called on the NRC to keep the St. Lucie plant from coming back online until after the tube inspection is complete and publicly reviewed.

The Southern Alliance also wanted state lawmakers to review FPL's use of a law passed in 2006 to charge customers in advance for adding any nuclear power to the state's energy mix. FPL used the nuclear advance fee to increase St. Lucie 2's power.

"Our first concern is for the more than one million people that live within a 50-mile radius of the St. Lucie Unit 2 reactor," said Stephen Smith, Southern Alliance executive director. "While I appreciate that FPL is highly motivated to return the reactor to service for financial reasons, safety must be their highest priority."

State lawmakers, led by Rep. Dwight Dudley, D-St. Petersburg, and Rep. Michelle Rehwinkel Vasilinda, D-Tallahassee, also said Florida needs to re-evaluate the policy that led to billions in spending around the state on new nuclear projects that either failed or are troubled. The so-called nuclear advance fee was used by Duke Energy at the now closed Crystal River plant and for the now scuttled Levy project.

If St. Lucie's tube wear problem leads to repairs, another steam generator replacement or even closure, consumers could get hit in the pocket book, again.

"It's a story we will hear again and again as long as we have advance nuclear cost recovery, the utility tax," Dudley said

U.S. Rep. Kathy Castor, a member of the House Energy and Commerce Committee, said she plans to question the NRC about St. Lucie. Castor, D-Tampa, also said she will contact California Sen. Barbara Boxer, because she has been grilling the regulatory body about a tube wear problem at the San Onofre nuclear facility south of Los Angeles.

In 2012, a tube inside a steam generator at one of those two plants burst, spewing radioactive fluid. Both plants shut down forever after owner Southern California Edison concluded it would cost too much to bring them back online.

FPL spokesman Michael Waldron said the utility would never compromise safety.

"When the outage is complete, we fully intend to follow our startup procedures, with oversight from our federal regulator, to ensure the highest levels of safety at all times," he said.

Scott Burnell, an NRC spokesman, said Monday that St. Lucie does not have a tube wear problem. The problems that led to the permanent closure of the two California reactors, he said, resulted from tubes rubbing against each other. At the St. Lucie plant, the tubes are rubbing against antivibration bars.

"The St. Lucie steam generator wear comes from existing, well-understood causes," Burnell said. "There is no steam generator safety issue, nor tube integrity safety concern, at St. Lucie."

Hopenfeld, the nuclear engineer, isn't so sure.

The guidelines the NRC and FPL are using to assess the severity of the tube damage are the same ones used to measure a different type of wear, he said. The current inspection criteria are for wear caused by stress corrosion cracking, he said. St. Lucie's tube wear comes from the tubes vibrating too much, which caused them to rub and bang against the antivibration bars.

Those are different problems, Hopenfeld said, which call for different types of evaluations.

"This is not black and white as being presented by the NRC," Hopenfeld said. "There's some sickness. I don't know the degree, but there is some sickness. It's getting sicker, sicker and sicker."

Federal regulators need to come up with guidelines to thoroughly assess vibration damage, he said. After that, the steam generator tubes need a "serious independent assessment."

It's too soon to declare the plant safe, he said. St. Lucie's weakened condition could be exacerbated by unrelated problems, like a person with an autoimmune deficiency who seems fine but is then hit with a cold.

"If you have a good steam generator, good solid tubes, there's almost 100 percent chance nothing is going to happen," he said. "But when those tubes are sick, you don't know what's going to happen. You certainly don't tell the public nothing is going to happen."

Ivan Penn can be reached at ipenn@tampabay.com or (727) 892-2332.