TO reduce radiation across Japan's northern Fukushima region after the 2011 nuclear disaster, authorities scraped a layer of contaminated soil from swathes of land.

Now, as young farmers seek to bring life back to the region once known for its delicious fruit, authorities are deliberating what to do with the mass of removed soil — enough to fill more than 10 baseball stadiums.

Topsoil was collected as part of largescale decontamination efforts that also included blasting buildings and roads with high-pressure jets of water.

Almost all areas of Fukushima have gradually been declared safe, but many evacuees have been reluctant to return because they remain worried about radiation, or have fully resettled elsewhere.

Fukushima has, however, welcomed new residents such as 25-year-old kiwi farmer Takuya Haraguchi. "I want people to become interested in and learn about what Fukushima is really like these days," he said.

A vast quantity of soil — 14 million cubic metres — is being stored at interim storage facilities near the Fukushima Daiichi plant.

The huge mounds are kept inside guarded grounds, protected by layers of clean soil and man-made sheets to prevent runoff into the environment.

The government wants to use the soil for building road and railway embankments, among other projects. It has vowed to do this outside Fukushima to avoid further burdening the region.

Around 75 per cent of the stored soil has a radioactivity level equivalent to or less than one X-ray per year for people who directly stand on or work with it, according to the Environment Ministry.

Asphalt, farm soil or layers of other materials should be used to seal in the radioactivity, said Akira Asakawa, a ministry official working on the Fukushima soil project.

In a test, the government has con- structed roads and fields in Fukushima by using the contaminated soil as filling material.

Those locations did not show elevated levels of radioactivity, and there was no runoff of radioactive material to surrounding areas, Asakawa said.