Temporary disposal sites for incinerated ash containing radioactive cesium are rapidly filling up, and no alternative landfills are available. Many of 32 municipal governments and wider-area administrative organizations in seven eastern prefectures that operate waste incinerators are at their wits' end, an Asahi Shimbun survey has found.

In total, these local authorities store more than 35,000 tons of incinerator ash, a legacy of the disaster that struck the Fukushima No. 1 nuclear power plant a year ago. Tons of radioactive substances were released after the facility was crippled by the March 11 Great East Japan Earthquake and tsunami.

The problem is that the amount of radioactive ash keeps increasing, and some of the temporary depots are operating at near-capacity levels.

The lack of protected storage space poses a huge problem for the central government, which has responsibility for sorting out the mess. Radioactive ash is generated because incineration condenses the cesium, which is absorbed by tree cuttings and other waste.

Measures to be taken by the central government include using cement to contain the radioactive ash and burying it in landfill. But that final step, permanent disposal, has so far eluded official efforts to tackle the problem.

That is partly because residents living near disposal facilities are opposed to accepting anything other than regular waste in landfills in their areas.

In late February, the newspaper contacted 35 municipal governments and administrative organizations in eastern Japan, where radioactive cesium in excess of the central government's landfill safety standard of 8,000 becquerels per kilogram has been detected in incinerator ash, to ascertain the state of waste disposal.

Questions were put to two local authorities in Iwate Prefecture, 12 in Fukushima Prefecture, nine in Ibaraki Prefecture, three in Tochigi Prefecture, two in Gunma Prefecture, six in Chiba Prefecture and one in Tokyo. Of these 35 local authorities, all but three operate temporary depots.

The sites are all located on the grounds of waste disposal facilities, including incineration plants and final disposal plants.

Radioactive ash that cannot be taken elsewhere continued piling up at 20 sites. Five temporary depots either had reached capacity or were expected to hit full capacity within three months.

Fifteen administrative offices, including 11 in Fukushima Prefecture, where the nuclear disaster occurred, said they either continued to produce ash in excess of 8,000 becquerels per kilogram or had not been able to confirm that radioactive levels had fallen below that level.

As a result, they are legally forbidden from burying ash. Five administrative offices in Ibaraki, Tochigi and Chiba prefectures said they had not been able to obtain the approval of residents to create landfill, even though radioactive levels had fallen below 8,000 becquerels per kilogram.

In the city of Kashiwa, Chiba Prefecture, authorities said the temporary radioactive ash depot had reached full capacity. In the meantime, the city of Nagareyama, Chiba Prefecture, has had to resort to using disposal plants in another prefecture.

Although radioactive concentrations have fallen to just over 3,000 becquerels per kilogram, the city is accumulating ash on a daily basis that cannot be removed from its incineration plant because of strong opposition by residents in the area where the final disposal plants are located. The city said its depot could run out of capacity by the end of March.

The city of Iwaki in Fukushima Prefecture, along with an administrative organization made up of Toride and three other cities in Ibaraki Prefecture, and the city of Matsudo in Chiba Prefecture, also said their temporary depots could soon reach full capacity.

Case reports: Chiba Prefecture
The lack of an alternative storage site has forced an incinerator in northwestern Chiba Prefecture, home to a number of radiation "hot spots," to suspend operations. This is beginning to have a social impact with less frequent waste collection.

"The more we incinerate, the more ash we produce," said an official at the Nanbu (South) waste disposal plant in Kashiwa, Chiba Prefecture. "There are limits to what we can do to create depots."

The basement of the plant was packed with 1,049 oil drums, each containing 200 kilograms of radioactive ash, up to the stairway and the space beneath conveyor belts. Stainless steel wire was used to bundle many dozens of drums to prevent them from toppling over.

The plant shut down its incinerator on two occasions in September and January because it ran short of space to store the oil drums. It stopped incinerating tree cuttings and other waste that gave off high radiation readings and began transporting it to another storage facility in the city. But that site is also coming close to hitting full capacity.

Its hands tied, Kashiwa was compelled to restart the incinerator in March. The Nanbu waste disposal plant is one of the only two disposal facilities in the city.

"We would lose all capacity of waste disposal if the other plant broke down," said one worker. "That's why I feel so anxious every day."

The crisis is beginning to affect waste collection timetables. The city of Matsudo re-categorized tree cuttings as recyclable waste, not flammable waste, and began storing it rather than incinerating the stuff. Recyclable waste is collected only one day per week, whereas flammable waste is collected three days a week.

Residents near the storage depot for tree cuttings, which was installed outside the waste disposal facility, have complained that they cannot open windows because of a bad smell.

Officials said 1,963 tons of radioactive ash remains at waste disposal plants in Kashiwa and five neighboring municipalities because it has nowhere to go. The Chiba prefectural government has come up with a plan to store that ash temporarily at the Teganuma final disposal plant operated by the Chiba Prefectural Sewerage Management Public Corp.

However, senior officials of Abiko and Inzai cities, where the Teganuma disposal plant is located, snubbed that proposal when it was presented Feb. 6 by Morio Sakamoto, a vice governor of the prefecture, during a meeting of the Chiba prefectural government and other cities. Sakamoto was told that a city assembly has passed a resolution against the plan.

The ash in Abiko contains less than 8,000 becquerels of radioactive cesium per kilogram. "That being the case, why do we have to accommodate ash from elsewhere?" asked a member of the Abiko city assembly that passed the resolution.

A senior official of the Inzai city government, citing public sentiment, said the city could not approve of the plan. The city is due to hold a mayoral election in July.

Situation outside Chiba
The situation outside Chiba Prefecture is not much brighter. According to the Ibaraki prefectural government, 2,200 tons of ash with readings of more than 8,000 becquerels per kilogram are temporarily stored at nine waste disposal plants in the prefecture.

One plant in southern Ibaraki Prefecture had planned to begin burying ash at a final disposal site on its premises in September, but the plan was thwarted by local residents. The plant had expanded the temporary depot because ash kept building up.

The city of Kawasaki in Kanagawa Prefecture has been burying ash off reclaimed land in Ukishima, which is part of Tokyo Bay. The city government has repeatedly called on the central government to draw up safety standards for disposal at sea.

(By Tateki Iwai, Yoshitaka Sumida, Shigenori Komatsu and Kiyotaka Sato, The Asahi Shimbun, 29/02/2012)