Japan has restarted its nuclear-power programme four years after a tsunami caused a meltdown at its Fukushima plant, resulting in the evacuation of tens of thousands of people. That led to all the country’s reactors being shutdown in September 2013.

Much more rigorous safety standards have now been introduced, including extra back-up prevention measures and higher tsunami-blocking walls in areas most susceptible to them. An Energy Ministry spokesman said: “It is important for our energy policy to restart reactors, once they are confirmed as safe.”

Reactor No 1 at the Sendai nuclear plant (nearly 620 miles south of Tokyo) was ‘fired up’ again on the morning of 11 August and was said to have reached full capacity later that day. In an interview with the Nikkei newspaper, Nuclear Regulation Authority chairman Shunichi Tanaka said: “A disaster like that at Tokyo Electric Power’s Fukushima nuclear plant will not occur again — not under the new rules, which are incomparably stricter.”

However, he acknowledged that “there is no such thing as absolute safety”, before adding: “Any future crisis will be contained before it reaches a scale anywhere near what happened in Fukushima.”

His comments did little to reassure some 400 protesters who gathered in front of the Sendai plant on the island of Kyushu. Ai Kashiwagi from Greenpeace Japan said: “The Government still remains committed to an economy based on nuclear power and fossil fuels, but the reality is that Japan has the potential to generate 56% of its electricity from renewable resources by 2030.”

In July, the Government announced that the evacuation order imposed on Naraha (a town in the Fukushima region) has been lifted, allowing more than 7,000 people to return to their homes.

However, many of them are said to be wary of going back, due to concerns about radiation.