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TEPCO sources said they were considering asking an outside agency to conduct a detailed analysis, citing limitations on what the utility could investigate

Mystery objects with high radiation found on Fukushima coast Asahi Shimbun, By SHUNSUKE KIMURA/ Staff Writer August 03, 2013 In a coastal area long silent due to the Fukushima nuclear accident, the only sounds of human activity on June 18 were from workers removing rubble and continuing their decontamination efforts. But soon, their supervisor discovered something that broke up the monotony of the work and added to the eeriness of the atmosphere.

After a call to the Environment Ministry, Takeshi Kato, 55, a ministry specialist, immediately headed to the location about 15 kilometers south of the crippled Fukushima No. 1 nuclear power plant.

As he slowly walked around with a dosimeter, he reached a hot spot where radiation levels nearly doubled those of the surrounding areas. Using a fallen branch to clear away dirt, Kato uncovered a grayish pile about 3 centimeters long, about 1.5 cm wide and about 0.5 cm thick.

The surface of the pile, which looked like soil, had gamma ray readings of about 85 microsieverts per hour. The total reading, including beta rays, came to 1 millisievert per hour.

It was the first of four mysterious objects with high radiation levels found near the mouth of the Idegawa river in Naraha, Fukushima Prefecture.

Officials at the government and Tokyo Electric Power Co., the plant’s operator, do not know where these objects came from or why they have high radiation levels. In fact, they are not sure what these objects actually are or were used for…….

TEPCO officials are studying the four objects at the Fukushima No. 1 plant.

The gray pile appears to be made of rubber.

The fragile object that looked like part of a black plastic sheet had an extremely high radiation reading of 36 millisieverts per hour when combining beta and gamma rays, TEPCO officials said.

Its ratio of radioactive cesium-134 and -137 was close to 1:2, leading TEPCO officials to conclude that cesium generated by the Fukushima nuclear accident likely attached to the object. However, it is still unclear where and how the objects were contaminated by radiation. A further study will be required to determine what the materials were originally used for.

Tetsuji Imanaka, assistant professor of nuclear engineering at the Kyoto University Research Reactor Institute, said reliable experts should handle the study.

“Rather than leave the investigation up to TEPCO, which has lost the public’s trust, a more appropriate agency, such as the Japan Atomic Energy Agency, should conduct a thorough investigation,” Imanaka said.

TEPCO sources said they were considering asking an outside agency to conduct a detailed analysis, citing limitations on what the utility could investigate. http://ajw.asahi.com/article/0311disaster/fukushima/AJ201308030015