TOKYO -- Radioactive materials that appear to be uranium were sold and bought on an internet auction website, people close to a police investigation into the case told the Mainichi Shimbun on Jan. 30.
The materials have been confiscated by the Tokyo Metropolitan Police Department (MPD) consumer and environment protection division and passed on for identification to the Japan Atomic Energy Agency (JAEA) officials. The JAEA judged that the materials are extremely likely to be depleted uranium and yellowcake uranium concentrate powder.
Police have identified the sellers and buyers of the materials, and will launch a full-fledged investigation into the case shortly as a possible violation of the Act on the Regulation of Nuclear Source Material, Nuclear Fuel Material and Reactors. The law regulates unauthorized transfer of nuclear fuel material in the country. Violators face an imprisonment of up to 1 year or 1 million yen in fine.
According to individuals close to the investigation, the secretariat of the Nuclear Regulation Authority first spotted materials dubbed as "uranium" were placed on an auction website, and reported the issue to the MPD. Investigators identified the seller and several buyers and confiscated the materials in question. The items were either powdered or solid and radioactive. They were placed in glass casings and weighed several grams in total. The seller agreed to voluntary questioning by police, saying that he had bought the goods on an overseas website.
The MPD requested that the JAEA identify the items in mid-December last year. The materials are likely to include depleted uranium that was produced during uranium enrichment and yellowcake, according to the people close to the investigation. The final results of the agency examination are expected to be released soon. Depleted uranium contains the fissile uranium 235 isotope at a concentration less than the natural concentration of 0.7 percent.
Experts worry that such radioactive materials could be abused in "dirty bombs" designed to disperse such materials as a form of terrorism. Professor Mitsuru Fukuda of the Nihon University College of Risk Management says the use of such explosives could result in sealing off the detonation area so that residents can evacuate and the area can be decontaminated.
"People's concerns would rise and economic activities could stop. Even a tiny amount of material with low radioactivity could have a major impact on society," he said.
(Japanese original by Ikuko Ando, City News Department, and Toshiyuki Suzuki and Riki Iwama, Science & Environment News Department)