follow up

The Science and Technology Agency of Japan has decided to establish a committee of experts to examine the extent to which residents living near the uranium-processing facility in Tokaimura, Ibaraki Prefecture were affected in the nation's worst nuclear accident that occurred on September 30 ( Down To Earth , Vol 8, No 11).

In a previous survey the agency revealed, 49 people including company employees were exposed to radiation in the accident. However, it plans to conduct a full-scale survey to examine the extent of the exposure and analyse its possible effects, as it is highly likely that more residents were exposed to the radiation, the officials added.

Unlike normal exposure to gamma or alpha rays that are often associated with nuclear plant accidents, the victims of this accident were exposed to large amount of neutrons. But, the neutron levels were not measured until more than six hours after the incident, the officials said. Besides three plant operators, 36 staff affiliated to the company, three ambulance workers, who tried to rescue the operators, and seven people -- five men and two women -- including neighbourhood residents and company employees, were exposed to radiation. But the activities of residents, who live near the facility immediately after the accident are not known, the officials said, adding that they "cannot deny the possibility of exposure to more people."

Officials said that the committee plans to locate other possible victims of the accident, examine types and amount of radiation and study nuclear fission reaction records from the time of the accident. It also hopes to calculate how far radioactive materials dispersed using wind direction data and other meteorological information from the time of the accident. The committee will include experts from the agency's National Institute of Radiological Sciences and the Japan Atomic Energy Research Institute.