About once a month, the same group of two dozen Japanese government officials, company executives and professors file into a bland white and beige conference room at the nation’s economy, trade and industry ministry to plot its long-term energy future. Each has a printed agenda, tablet computer and carton of green tea neatly laid out before them, and politely flips over a rectangular name card to request a turn to speak. Beneath the rigid formality, there’s an increasingly divisive debate: what’s the role of nuclear energy a decade after the Fukushima disaster.

Since Japan pledged in October to become carbon neutral by 2050, many among the advisory group have reached the same conclusion. To meet its global climate commitments, the country will need to restart almost every nuclear reactor it shuttered in the aftermath of the 2011 meltdowns, and then build more.

“We had better hurry and rebuild trust in nuclear power,” said Masakazu Toyoda, a member of the 24-strong government panel that’s devising new policies. “This is a matter of energy security.”

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Nuclear now accounts for about 6% of Japan’s energy mix, down from roughly 30% of the Fukushima disaster. In the immediate aftermath, Japan closed all its 54 reactors, around a third of which were permanently scrapped.

More than 160,000 people were evacuated from the region surrounding the Fukushima Dai-Ichi plant after a magnitude 9 earthquake in March 2011, the biggest ever recorded to hit Japan, caused a massive tsunami that overwhelmed the facility, shut off power to cooling systems and led to meltdowns of three reactor cores.

The incident convinced some governments that nuclear power’s risks far outweighed its benefits, and prompted some including Germany and Taiwan to set deadlines to close down their fleets of plants.  Mammoth costs of building new facilities, and frequent delays, have since served as other deterrents to the fuel’s revival.

Still, China plans to have 70 gigawatts of nuclear generation capacity by 2025 as it aims to zero out emissions by 2060. That’s the equivalent of adding about 20 new reactors.

Read More: The Global Debate on Nuclear Power

Nuclear energy produces about 10% of the world’s electricity, down from a peak of 18% in the mid-1990s, and the construction of new plants lags far behind the pace of closures, according to the International Energy Agency.

Yet some 39% of Japanese people want all nuclear plants closed, according to a February survey. Many local, prefecture-level governments—which must sign off on reactor restart plans—have been reluctant to wave through approvals, while courts have supported requests to temporarily shut some operating reactors.

That opposition is problematic for a Japanese government that’s promised to lower emissions 26% by 2030 from 2013 levels under its Paris commitments, and is slated to review those targets this year and potentially make them stricter. “Japan will change its attitude toward nuclear builds somewhere on the road toward net-zero emissions,” said Frank Yu, an analyst at Wood Mackenzie.