– Sludge from contaminated water would be packed with radioactive substances: TEPCO (Mainichi, June 10, 2011):
Sludge that will be generated in the process of treating radioactive water at the tsunami-hit Fukushima No. 1 Nuclear Power Plant is estimated to contain 100 million becquerels of radioactive substances per cubic centimeter, the plant operator said.
Tokyo Electric Power Co. (TEPCO) made the estimation in a report on the water treatment system submitted to the government’s Nuclear and Industrial Safety Agency (NISA).
While trying to begin treating the increasing volumes of radioactive water at an early date, TEPCO has failed to indicate how it will store the toxic sludge or a final disposal site in its road map to bring the crippled plant under control.
TEPCO will launch treatment of the radioactive water on June 15 at the earliest. Specifically, it will use special equipment produced by Kurion Inc. of the United States and France-based Areva — which have broad experience removing radioactive substances — to separate sludge contaminated with radioactive substances from the water. The sludge is expected to contain such high levels of radiation because radioactive substances in it will be condensed.
TEPCO estimates that about 2,000 cubic meters of sludge will be generated through the treatment of radioactive water at the plant by the end of this year, and intends to keep the toxic substance in the plant’s intensive radioactive waste disposal facility.
However, the facility can only hold 1,200 cubic meters of the sludge because radioactive waste generated in the plant’s ordinary operations is already kept there, forcing the utility to build a new facility to keep the sludge on the plant premises.
However, because it is so highly radioactive, the sludge is extremely difficult to manage. Areva acknowledges that it has never handled sludge generated through the treatment of water emitting more than 1,000 millisieverts of radiation per hour.
While radioactive waste generated in the plant’s ordinary operations is regularly transferred to a reprocessing plant in Rokkasho, Aomori Prefecture, the final disposal site for the sludge and other waste generated as a result of the Fukushima nuclear disaster has not been determined.
NISA councillor Hidehiko Nishiyama fears it will take a long time to establish the radioactive sludge treatment process.
“Since such sludge has never been generated in Japan, the treatment technology must be created from scratch, from the research and development phase,” he says. “It will likely take a long time, considering the safety regulations need to be enforced, development of an actual treatment method, and legal procedures.”
Junichi Matsumoto, a high-ranking TEPCO official, also admitted that it will need to develop treatment methods. “We haven’t decided how to produce containers for the sludge, or how to treat it,” he said.