Since achieving the ambitious emissions-reduction targets laid out in the Paris Accords will require developed nations to revive their nuclear plans (something that climate activists have increasingly supported despite the continuing fallout from the disaster at Fukushima) Japan on Wednesday decided to revive three long-idled reactors, marking the first time that Japan has restarted a reactor that's more than 40 years old.

After Prime Minister Yoshihide Suga last week announced a new goal of cutting the country's greenhouse gas emissions 46% by fiscal 2030 (an announcement that coincided with President Biden's virtual climate summit) Nikkei reports that Gov. Tatsuji Sugimoto of Fukui Prefecture (located about 300 km, about 186 miles, west of Tokyo) gave the green light on Wednesday to restart the Kansai Electric Power reactor units 1 and 2 at the Takahama nuclear power plant, and unit 3 at the utility's Mihama plant. Japan's plans for building new reactors have been frozen for years, leaving its aging nuclear infrastructure largely intact.

Achieving the emissions goals laid out by Suga last week will require generating 20% of Japan's power via nuclear energy in the coming decades, experts said.

Currently, Japanese regulations imposed after the 2011 Fukushima meltdown set the operating life of Japanese reactors at 40 years, while leaving open the possibility of extending that to 60 years. No reactors older than 40 years are currently operating in Japan - but that's about to change.

Industry Minister Hiroshi Kajiyama on Tuesday told Sugimoto that Japan "will use nuclear power sustainably into the future" and promised up to 2.5 billion yen ($23.1 million) in federal grants to help restart older reactors. Sugimoto told reporters that Kajiyama's remarks were "something we hadn't heard before."

Japan had about 50 nuclear reactors when Tokyo Electric Power's Fukushima Daiichi plant was struck by a tsunami in 2011 that knocked out its emergency power, leading to a historic meltdown. 

Since then, more than 20 reactors in Japan have been marked for decommissioning. By 2030, nearly half of the country's remaining reactors will be over 40 years old.

Still, as Fukushima fades into history, support for nuclear power is growing within Japan's ruling Liberal Democratic Party. To open the door to reviving more reactors, more lawmakers favor a different rubric for counting a reactor's operating age that will subtract the years they spent idled.

Unfortunately for the nuclear industry in Japan, other obstacles remain aside from environmental concerns. For example, the outlook for restarting Tokyo Electric's workhorse Kashiwazaki-Kariwa plant has been dimmed by a report that finds insufficient safeguards against terrorist attacks. In the US, nuclear has remained out of favor ever since that incident at the Three Mile Island plant in Pennsylvania.

As we pointed out on Earth Day, proponents of lower emissions are starting to accept that nuclear is the only practical strategy that wouldn't involve massive reductions in energy use, while still maintaining robust systems that won't seize up when wind turbines freeze.