But Prime Minister Naoto Kan said alternative new energy would become "a major pillar" after the Fukushima accident.
"Taking this as a lesson, we will lead the world in clean energy such as solar and biomass, as we take a step toward resurrection," he told lawmakers last week.
China, the world's no. 1 emitter of greenhouse gases, has ambitious plans to move away from coal plants that provide 70 percent of its energy and go toward clean alternatives. It may also scale back its nuclear program in light of the Japan emergency, Chinese climate envoy Xie Zhenhua said.
"I believe this accident will have some impact on the development of nuclear power not only in China, but also the rest of the world," he told reporters in Australia last week.
U.S. President Barack Obama has defended nuclear energy, but also strongly supports development of solar cells, clean coal and biofuel technology.
The most dramatic developments are likely to occur in Western Europe. Germany had planned to phase out nuclear power over 25 years. But the Fukushima crisis — which Chancellor Angela Merkel called a "catastrophe of apocalyptic dimensions" — has accelerated those plans.
The government almost immediately took seven of its 17 reactors offline for three months of safety checks. Most of Germany's leaders now seem determined to swiftly abolish nuclear power, possibly by 2020, and are willing to pay for intensive development of renewable energy, already a major industry in Germany.
The country currently gets 23 percent of its energy from nuclear power — about as much as the U.S. Germany's Environment Ministry says that in 10 years, renewable energy will account for 40 percent.
That kind of plan would not work for countries such as France, which relies on nuclear for 70 percent of its power and has no intention of shifting, but could provide a map for other countries, activists say.