People wait to be screened by a technician in protective gear for signs of possible radiation in Nihonmatsu, northern Japan, on Monday. [Yuriko Nakao/Agencies]

WASHINGTON - The fragile bipartisan consensus that nuclear power offers a big piece of the answer to the US' energy and global warming challenges may have evaporated as quickly as confidence in Japan's crippled nuclear reactors.

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Until this weekend, President Barack Obama, mainstream environmental groups and large numbers of Republicans and Democrats in Congress agreed that nuclear power offered a steady energy source and part of the solution to climate change, even as they disagreed on virtually every other aspect of energy policy. Obama is seeking tens of billions of dollars in government insurance for new nuclear construction, and the nuclear industry in the United States, all but paralyzed for decades after the Three Mile Island accident in 1979, was poised for a comeback.

Now, that is all in question as the world watches the unfolding crisis in Japan's nuclear reactors and the widespread terror it has spawned.

"I think it calls on us here in the US, naturally, not to stop building nuclear power plants but to put the brakes on right now until we understand the ramifications of what's happened in Japan," Senator Joseph I. Lieberman, independent of Connecticut and one of the Senate's leading voices on energy, said on CBS' Face the Nation.

Nuclear power, which still suffers from huge economic uncertainties and local concerns about safety, had been growing in acceptance as what appeared to many to be a relatively benign, proven and - if safe and permanent storage for wastes could be arranged - non-polluting source of energy for the United States' future growth.

But even staunch supporters of nuclear power are now advocating a pause in licensing and building new reactors in the United States to make sure that proper safety and evacuation measures are in place. Environmental groups are reassessing their willingness to see nuclear power as a linchpin of any future climate change legislation. Obama still sees nuclear power as a major element of future US energy policy, but he is injecting a new tone of caution into his endorsement.

"The president believes that meeting our energy needs means relying on a diverse set of energy sources that includes renewables like wind and solar, natural gas, clean coal and nuclear power," said Clark Stevens, a White House spokesman.

European Energy Commissioner Guenther Oettinger said on Monday that safety at older German nuclear power stations must be checked rigorously, and he refused to rule out closures if necessary.

He told Deutschlandfunk radio that the crisis at a Japanese nuclear plant had changed the world and put into question what had been regarded as safe and manageable.

Oettinger, Germany's member of the European Commission, made the comments as Chancellor Angela Merkel faces a backlash due to Japan's nuclear crisis against Berlin's decision to extend the life of the nation's atomic plants.

Oettinger said safety questions were primarily the responsibility of the 14 European Union states which used atomic energy, and added that safety at Germany's older plants was constantly being upgraded.

But asked if the older plants could be shut down following the Japanese nuclear crisis, he said: "If we take it seriously and say the incident has changed the world - and much that we as an industrial society have regarded as safe and manageable is now in question - then we can't exclude anything."

New York Times-Reuters