The chief of Japan's Fukushima atomic plant at the time of the quake-tsunami disaster has said he never considered withdrawing from the escalating crisis despite fearing for his life, reports said Sunday.

"I thought my fellow workers and I could die when huge amounts of debris flew off" the plant after an explosion, Masao Yoshida said in rare public comments in a video message released Saturday, according to local media.

The 57-year-old, whose message was played to an event in northeast Fukushima prefecture that discussed recovery from the disaster, described the scene as "hell".

But he added: "I did not suggest to headquarters that (we should) retreat and never thought about it."

"If we had left there and could not have poured water (into the reactors), there would have been more serious radiation leaks. It would have been a dire calamity," he said. His comments were recorded early July in Tokyo.

In one of their desperate attempts to stop the disaster in March last year, workers poured water into the plant to try and cool down the overheating reactors.

The deadly tsunami knocked out the atomic plant's cooling system and sent some of its reactors into meltdown, spewing radiation into the air, sea and food chain in the worst nuclear accident since the 1986 Chernobyl disaster.

At the start of the message, Yoshida offered an apology to people around the plant. "We are doing our best for restoration," he said.

Last week, TEPCO released video footage that showed Yoshida shouting "We have a big problem, a big problem!" to bosses at the operator's Tokyo headquarters as a reactor exploded.

It was among 150 hours of footage released by the operator.

Yoshida, who stepped down from the job of plant chief in December after being diagnosed with esophagus cancer, has spoken little to the media, saying investigation into the accident is still under way.

At the time of his cancer diagnosis, a TEPCO spokeswoman said it was "extremely unlikely that his disease was caused by radiation exposure".

No one is officially recorded as having died directly as a result of the power plant accident, but many who fled the area and those who remain, including workers decommissioning the crippled plant, worry about the long-term effects.

The quake-tsunami killed more than 19,000 people.