Indiana has never built a nuclear power plant. In the late 1970s, an alliance of environmentalists, blue-collar workers and trade unions thwarted Northern Indiana Public Service Co.'s plans to build a power plant on Lake Michigan. And another proposed nuclear plant was abandoned midway through construction in 1984.

But Indiana put itself back on a path to nuclear power last month, when its state Senate passed a measure aimed at encouraging nuclear developers with "clean energy" incentives.

The Indiana Senate joined lawmakers in Iowa, Illinois, Iowa, Minnesota and Wisconsin who have also considered measures to boost nuclear energy, drop nuclear-plant moratoriums and allow power companies to charge ratepayers for building new reactors.

Then came the March 11 earthquake and tsunami that crippled the Fukushima Daiichi nuclear plant in northeast Japan. Workers are struggling there to limit radiation releases from damaged reactors and spent fuel rods.

The Japan disaster invigorated Midwestern foes of nuclear power.

"More and more legislators are taking a second look, and clearly public opinion is swinging against developing nuclear," said Nathaniel Baer, who directs the energy program for the nonprofit Iowa Environmental Council. His group opposes two pro-nuclear bills in Iowa that give information on how rates would be set if a utility decides to build a nuclear plant.

Even some legislators who proposed pro-nuclear measures are backing off a bit.

"It probably is wise to step back -- and I would say temporarily -- step back for now on the nuclear provision but move forward with some of the other proposals with the bill," said state Sen. Beverly Gard (R), who introduced the Indiana clean-energy measure.

In Iowa, which has a nuclear plant near Cedar Rapids, nine state senators opposed two pro-nuclear bills in a letter to colleagues. "There is very little known about how much a new nuclear plant would cost. ... There are significant safety and financial liability concerns, especially after the nuclear disaster in Japan," they wrote last week.

An Illinois state senator who has tried several times to lift a 1987 ban on building new nuclear plants in the state, which has 11 reactors at six sites, said last week she intends to lie low this year. State Sen. JoAnn Osmond (R) said, though, that that was the case even before the Japan crisis began because of questions of nuclear-waste storage.

Some state legislators, however, say they intend to keep pushing for a nuclear expansion.

"I'm not ready to say we should give up a potential nuclear future because there was a tragedy in Japan," said Minnesota state Rep. Joyce Peppin (R), who introduced a bill that would end a 1994 moratorium on new nuclear plants. That legislature has passed that measure.

Minnesota

But it may be difficult to get Peppin's bill and a companion Senate measure signed into law. Coincidentally, on the day of the Japan earthquake, Gov. Mark Dayton (D) laid out three conditions that need to be met before he agrees to lift the moratorium.

Dayton's conditions: The question of nuclear waste storage must be answered at the federal level, there needs to be a guarantee that ratepayers won't pay for reactor construction, and spent fuel should be prevented from being turned into weapons-grade plutonium.

It would be "virtually impossible" to remove the ban under those conditions, Peppin said, adding that the bills already partially address those conditions. The state House bill, for example, addresses nuclear proliferation.

Ken Bradley, program director at Environment Minnesota, praised the governor's stance.

"The governor, I think, has shown bold leadership," Bradley said. "And I think the governor is going to stand by his position, which is essentially pretty logical. You need to figure out how to deal with waste issues and make sure customers are not stuck with the cost."

Dayton is not the only Midwestern governor to oppose attempts to open states to nuclear expansion as the Japan crisis unfolds.

Illinois

When President Obama urged a safety review of U.S. nuclear plants last week, Illinois Gov. Pat Quinn (D) echoed his words. Quinn called for Exelon Corp., which operates the state's 11 reactors, to pay higher fees for inspections by the state Emergency Management Agency.

Illinois is easily the nation's most pro-nuclear state.

Reactors supplied 48.7 percent of the state's electricity in 2009, according to the U.S. Energy Information Administration. The state was home during World War II to the Manhattan Project, the effort to develop the atomic bomb, and in the 1950s, the federal government offered "sweeteners" to spur the industry, including offering to buy back nuclear waste for weapons manufacturing, according to Dave Kraft, director of the nonprofit Nuclear Energy Information Service.

There's no "rational basis" to explore nuclear power in states that have renewable portfolio standards because those laws already lay out what the next round of renewable energy is going to be, Kraft said.

Instead, states should phase out older plants and those that contain the General Electric Mark 1 boiling water reactor containment design used in Fukushima Daiichi, Kraft said.

"You methodically phase out nuclear because you have the luxury of doing it where it won't hurt," Kraft said. "If suddenly somebody passed the magic wand after Japan and then said all the Mark I's in the country have to be closed, that's hugely disruptive and chaotic."

Iowa

Iowa's lone nuclear plant supplied 9.7 percent of the state's electricity in 2009, but an energy company is actively pursuing plans to build another nuclear plant in the state.

The state Legislature is considering broad House and Senate bills that would address technicalities in setting electric rates and make nuclear more attractive for investors.

Last year, state lawmakers passed a bill that allowed MidAmerican Energy Co., which is proposing the construction of a new nuclear plant in Iowa, to charge ratepayers $15 million for a three-year feasibility study.

Late last week, MidAmerican announced that utility bills would rise 10 percent over 10 years for its proposed plant, which may be sited near the Duane Arnold Energy Center in Linn County. MidAmerican didn't return phone calls requesting comment.

Baer of the Iowa Environmental Council said the legislation being considered by state lawmakers would fast-track a new plant.

"It really limits oversight from regulators, it limits judicial review," Baer said, and it "ties the hands of regulators so a plant would be much more likely to be built regardless of the cost and the risk."

Legislators' views are mixed.

Iowa Republicans urged the continued study of nuclear, while Democrats signed onto a letter opposing expansion.

Such division is also seen in the Wisconsin Legislature, where Republican Rep. Mark Honadel has said he still plans to co-sponsor a bill that would repeal a 1983 moratorium on new reactors. Two Democrats, meanwhile, released a statement calling nuclear "dangerous" and "expensive."

Indiana

Opinions on nuclear energy, though, aren't split along party lines in Indiana.

Indiana Senate President David Long (R), for instance, told a local radio station, "We need to take a step back, try to understand how this happened" in Japan.

Jack Weinberg, a retired environmentalist who helped form the 1970s alliance that opposed nuclear power in Indiana, said that at the time of the 1979 Three Mile Island accident in Pennsylvania, the majority sentiment was strongly anti-nuclear in Indiana. The alliance and others filed one lawsuit after another, he said, on construction issues, emergency evacuation routes for nearby residents and other concerns.

"The reason for the economic problems [at the plant] was that every time a new safety concern was raised, they attempted to address it, and that adds to the cost," Weinberg said. "So the high cost of nuclear power was by a large measure a consequence of them trying to make an inherently unsafe technology safe."

While the disaster in Japan is also spurring anti-nuclear sentiment, Weinberg said he sees some big differences between now and the 1970s. Arguments over climate change -- and the low emissions of heat-trapping gases from nuclear plants -- are dividing supporters and opponents now, he said.

"I don't think nuclear power has a bright future, but I think that the forces who are supporting it have not thrown in the towel yet," Weinberg said. "They're going to do everything they can to turn this disaster into proof that nuclear is not so bad after all" by calling it merely a worst-case scenario.