Hundreds of Japanese demonstrators have been marching to celebrate the last of the country's 54 nuclear reactors being switched off.
The crowd gathered at a Tokyo park on Saturday said that they were not concerned about government warnings that the reactor shutdowns will lead to electricity shortages.
One of three reactors at the Tomari nuclear plant, on the northern island of Hokkaido, has gone offline for routine maintenance checks, meaning that for the first time in decades there is not a single active nuclear reactor in the country.
After the earthquake and tsunami on March 11 last year set off meltdowns at reactors at the Fukushima Daiichi plant, no reactors that have been stopped for maintenance have gone back online.
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The government requires that new tests on withstanding earthquakes and tsunamis be carried out on all reactors.
It also requires that local residents' approval be sought before reactors are restarted.
The Hokkaido Electric Power company, which runs the Tomari plant, said that control rods would be inserted to halt the chain reaction in the reactor on Saturday, and that a "cold shutdown" would occur on Monday.
It is the first time since the 1970s that the resource-poor country has been without any form nuclear power. Until the meltdowns at Fukushima, Japan was generating a third of its electricity at nuclear power plants.
Last month, Kansai Electric Power, which supplies mid-western Japan, including the commercial hubs of Osaka, Kyoto and Kobe, said a hot summer could see supply fall nearly 20 per cent short of demand after the shutdowns.
Kyushu Electric Power, covering an area further west, as well as Hokkaido Electric Power, also said they will struggle as air conditioning gets cranked up in Japan's sweltering summer.
The country's nuclear disaster forced tens of thousands of people from their homes in an area around the Fukushima plant - some of whom may never be allowed to return.
"A new Japan with no nuclear power has begun," said Gyoshu Otsu, a 56-year-old monk who joined a Tokyo protest against nuclear power held in front of the industry ministry, which supervises the nation's power utilities.
"Generating nuclear power is like a criminal act as a lot of people are still suffering," said Otsu wearing white Buddhist clothes. "If we allow the situation as it is now, another accident will occur."
Protest organiser Masao Kimura said: "It's a symbolic day today. Now we can prove that we will be able to live without nuclear power."
Supporters of nuclear power could also be seen at Tokyo demonstrations.
Prime Minister Yoshihiko Noda's government has given the green signal for the resumption of operations at the the Oi nuclear plant, but regulators have been unable to convince those living near the station.
George Dracoulis, the head of the nuclear physics department at Australian National University, told Al Jazeera that the loss of nuclear power was "a serious issue for Japan".
"At the moment they're surviving by increasing imports of gas, coal and oil, currently at the cost of about $40bn a year," said Dracoulis
"One of the results of this is that greenhouse gas emissions will rise by about 16 per cent."
He said that if Japan was not able to make up the energy shortfall from losing 30 per cent of its generating capacity, it could have a long-term effect on industrial competitiveness, citizens' standard of living and energy security.