The operator of Japan's crippled Fukushima nuclear plant faced a fresh lawsuit Wednesday from the family of a 102-year-old man who killed himself because he was depressed at having to leave his home.

Fumio Okubo was the oldest resident of Iitate village 40 kilometres (25 miles) from the Fukushima Daiichi plant.

He took his own life reportedly by hanging after the government ordered area residents to flee in April 2011, a month after tsunami waves sent the plant's reactors into meltdown.

Okubo's daughter-in-law Mieko said his family members sued Tokyo Electric Power Co (TEPCO) for 60 million yen ($485,000) compensation.

"I want them to realise the gravity of what happened. A person who lived to become 102 had chosen to kill himself. We want them to know the pains that we as his family have to suffer," she told a press conference in Fukushima.

"We will use this opportunity to speak about our feelings."

Iitate was one of a number of areas the central government declared off-limits due to concerns at the effect of long-term exposure to radiation.

The killer tsunami, triggered by a 9.0-magnitude offshore earthquake on March 11, 2011, swamped the emergency power supplies at the Fukushima power plant, sending its reactors to meltdown as cooling systems failed.

Many of the tens of thousands of people who evacuated their homes and farms are unlikely to return to their ancestral properties due to radiation dangers.

While the quake and tsunami killed nearly 18,000 people, no one is officially recorded as having died as a direct result of the atomic catastrophe.