Japan is planning a move to shutter all nuclear plants by the 2030s, Japanese media reported Thursday, a major policy shift for a resource-poor nation that once depended on atomic power for a third of its energy.

The nuclear phaseout, reported by both the Kyodo News agency and broadcaster NHK based on a draft of the policy, comes amid fierce political debate about this country’s 50 operable reactors, which are both prone to disaster and vital to the economy.

The gradual turn away from nuclear power over the next two decades represents a major concession from Japan’s traditionally pro-nuclear leaders to a largely anti-nuclear public, whose fears were stoked by the March 2011 triple meltdown at the Fukushima Daiichi plant.

But it also prompts new worries about how Japan will make up for a gaping energy deficit, and whether it can eventually grow renewable energy into a cheap alternative. In the short term, Japan will have to rely on increased imports of fossil fuels, raising the nation’s energy prices as well as its greenhouse-gas emissions.

An official announcement about the phaseout could come by the end of the week, Japanese media said.

“We will devote all policy resources to achieving zero nuclear power generation in the 2030s,” Kyodo News said, quoting a draft of the policy.

The new policy still faces some major obstacles and could be revised if Prime Minister Yoshihiko Noda loses his job, as expected, sometime in the coming months. Political analysts here predict that Noda’s ruling Democratic Party of Japan will be handed a landslide defeat in an upcoming parliamentary election, opening the door for the Liberal Democratic Party to return to power.

Until 2009, the LDP ruled almost uninterrupted for half a century, engineering Japan’s rise into one of the world’s most nuclear-dependent nations.

Japan’s government, under Noda, had been considering three potential long-term energy policies, along with the nuclear phaseout. Other options called for Japan to depend on nuclear power for either 15 percent or 20 to 25 percent of its energy by 2030.

Noda himself hinted at the new strategy Wednesday during a debate with other candidates for the party leadership. Noda acknowledged that most Japanese want a non-nuclear country, and he mentioned that his own party favored the phaseout by 2030.

“There could be different views about how we can achieve that goal, and by factoring those into consideration our party last week proposed we should aim for a nuclear-free society. I must take this seriously,” Noda said, according to the Associated Press.

The government’s previous energy strategy, mapped out in 2010, called on Japan to boost its nuclear reliance to about 50 percent by 2030. But last year’s accident at the Fukushima plant — the worst nuclear crisis in a quarter-century — forced a rethink of that plan, which required the construction of nearly a dozen new reactors.

More than 100,000 people were displaced from their homes because of the Fukushima accident, which spread radiation across wide tracts of the region. Some will not be able to return home for years, the government has said.

Noda has promised recently that Japan will not build additional reactors, nor will it allow existing reactors to operate for more than 40 years.

Japan is now operating just two of its 50 usable reactors. Those two units, at the Ohi nuclear facility on the country’s west coast, came online in July after Noda made a public plea, saying the economy would wither in the short term without nuclear power.

But Japan’s powerful business lobby, Keidanren, has made a case that Japan’s economy, even in the long term, will be damaged by a shift away from nuclear power. Keidanren Chairman Hiromasa Yonekura said earlier this week that a nuclear phaseout was “unrealistic and unreachable.”

According to Keidanren estimates, Japan’s unemployment rate in 2030 will be 7.2 or 7.3 percent without nuclear power, as opposed to 6.0 or 6.1 percent with 20 or 25 percent nuclear reliance. (The current unemployment rate is roughly 4.4 percent.)