The potential nuclear disaster in Japan is prompting fresh anxiety at the Minnesota Capitol about a push to lift a moratorium on new nuclear power plants in the state.

Minnesota has power plants at Prairie Island and Monticello that went online 40 years ago. The Monticello plant has the same kind of General Electric reactor that exploded at Japan's Fukushima Dai-ichi nuclear plant when an earthquake knocked out power, crippling the reactor's cooling systems.

Now Minnesota and states nationwide are looking anew at their aging nuclear generating plants, reminded of the danger that accompanies nuclear power. Some states have considered new reactors. But on Monday several European countries imposed temporary moratoriums on building new ones, and at least one Massachusetts congressman is calling for a similar ban.

But in St. Paul, GOP legislators say they intend to push forward with their efforts to repeal Minnesota's 1994 moratorium, which arose over concerns about nuclear waste storage.

Senate Majority Leader Amy Koch, R-Buffalo, who is sponsoring the bill, said a repeal should not be affected by events in Japan. "This doesn't build a nuclear plant, this just puts it on the table for discussion," she said.

The Senate and House have already approved the repeal. They had been working out some differences in a conference committee on Friday when news of the quake hit.

Koch noted that Minnesota is not at risk from earthquakes or tsunamis.

But DFL opponents said the disaster unfolding across the Pacific is evidence the ban should be kept in place.

"I think what the situation in Japan shows is that this would be the absolute worst time to lift a moratorium," said Rep. Frank Hornstein, DFL-Minneapolis.

Gov. Mark Dayton, who had said he would consider the bill, is now requiring conditions that could prove to be the bill's undoing.

Lethal objections

As TV sets throughout the Capitol broadcast events unfolding in Japan on Friday, a panel of legislators reviewing the bill learned that Dayton would not approve it without language protecting ratepayers and a requirement that the federal government find a place for nuclear waste before new plants are built.

Sen. Julie Rosen, R-Fairmont, said Dayton's storage provision "basically ... just shuts the whole bill down."

But the meetings to reconcile the Senate and House bills will likely continue next week, said bill sponsor Rep. Joyce Peppin. "Our situation is a little different than in Japan," Peppin said.

U.S. Reps. Tim Walz and Erik Paulsen, who have voiced bipartisan support for lifting the ban, maintained that support in separate statements Monday.

Support for lifting the ban, though more prevalent among Republicans, has never fallen strictly along party lines at the Legislature partly because some trade unions support building new plants. Rep. Tom Anzelc, DFL-Balsam Township, said Monday that there has been a lot of e-mail chatter among DFL lawmakers about events in Japan.

"At a minimum, this will cause legislators who are undecided on the issue, it will cause them to pause and reflect a little bit more on the perils of nuclear power," Anzelc said.

Steve Morse, executive director of the Minnesota Environmental Partnership, called the aftermath "a tremendous human tragedy" that "does change the landscape on our issues here."

Opponents note that Minnesota regularly faces its own natural disasters, such as flooding and tornadoes. Both plants sit near the Mississippi River and nuclear waste has been stored on a flood plain outside the Prairie Island plant for nearly two decades.

Rep. Linda Higgins, DFL-Minneapolis, said the Japanese disaster should be a wakeup call to legislators who will have to take another vote on the bill. "The timing couldn't be more startling," she said.

Are our plants safe?

U.S. nuclear power plants, like those in Japan, are built with multiple backup systems to cool reactors in an emergency. Last year the Nuclear Regulatory Commission (NRC) ordered Xcel Energy to remedy such a risk at Prairie Island Unit 2.

The flaw, which had existed since the unit opened in 1974, could have allowed flooding of backup generators and other safety systems needed to cool the reactor in an accident, the NRC says. Xcel made modifications to avoid such an event.

Whether Japan's disaster will reveal safety issues that need attention in U.S. nuclear plants won't be known until the crisis is over, the NRC says.

"Right now there is not enough clarity about what is happening today, let alone about the causes and possible lessons learned," said Viktoria Mitlyng, a spokeswoman for the NRC in Chicago. "The whole world, including the United States, will be looking at, assessing what happened and whether there are issues to be considered."

The disaster comes as Xcel awaits NRC approval for a 20-year extension on licenses of the two Prairie Island units, set to expire in 2013 and 2014.

Xcel's Monticello nuclear plant, which like the Japanese plants is a boiling water reactor, began operations in 1971. Its operating license has been extended to 2030. It currently is down for refueling and replacement of four control rod blades that are considered a risk because that blade model has cracked in other plants.

Eric Roper • eric.roper@startribune.com

David Shaffer • shaffer@startribune.com