Japan's pro-nuclear lobby pledged Monday that 2015 would be the year reactors are restarted, despite public wariness that has lingered since the Fukushima disaster.
Industry officials and supporters said the country desperately needs atomic power to play its part in cutting greenhouse gas emissions and to ensure a stable electricity supply.
"This year marks the exit from zero nuclear power," Takashi Imai, chairman of the Japan Atomic Industrial Forum, told an audience of around 900 people, including industry officials and global policymakers.
"It is self-evident that nuclear power plants that have passed safety tests should be restarted as soon as possible," he said, citing the need for a stable power supply.
Japan's atomic watchdog last year gave the green light to restarts for four reactors -- a move welcomed by pro-nuclear Prime Minister Shinzo Abe.
The push from the nuclear industry comes as the public remains deeply concerned about safety, more than four years after a tsunami sparked meltdowns at Fukushima, spreading radiation over a large area and forcing tens of thousands of people from their homes.
It also comes as Japan prepares to decide its new energy policy -- how much electricity will come from renewables, nuclear and fossil fuels -- and readies to make a new international pledge on cutting greenhouse gas emissions before a global summit on climate change this year.
Yukiya Amano, director general of the International Atomic Energy Agency (IAEA), said the atom could not be forsaken.
"Despite the Fukushima Dai-ichi accident, nuclear power has continued to play an important part in the global energy mix," he said.
"Nuclear power can make countries more competitive by delivering the steady supply of base-load electricity which is needed to power the modern economy. It also helps to reduce emissions of greenhouse gas," Amano said.
While the earthquake and tsunami killed more than 18,000 people, the disaster it caused at Fukushima is not officially recorded as having directly cost any lives.
However, it displaced a sizeable population and has made some areas uninhabitable, with warnings certain settlements may have to be abandoned forever.
The complicated decommissioning of the crippled reactors is expected to take up to 40 years and may need technology not yet invented.
Anti-nuclear activists are trying to block moves to restart four reactors at two plants by seeking court injunctions.
A ruling for the Takahama nuclear plant in central Japan, one of two ongoing cases, is expected on Tuesday while another ruling for the Sendai plant in southern Japan is expected on April 22, according to plaintiffs.