Perilous
Times
Highly Radioactive ash found in Tokyo sewage plant: reports
by Staff Writers
Tokyo (AFP) May 14, 2011A highly radioactive substance was
detected in ash from an incinerator at a sewage works in Tokyo in
late March following the nation's worst nuclear accident in
Fukushima, newspapers reported Saturday.
The ash, containing an unidentified substance with a radioactive
density of 170,000 Becquerel per kilogramme, was collected from a
plant in Koto Ward, eastern Tokyo, the Nikkei and Sankei dailies
said, quoting metropolitan government sources.
The ash in sewage plants is formed by the incineration of
inorganic constituents in waste materials.
Much of the ash from the Koto batch had already been recycled into
construction materials, including cement, the unnamed sources
said. The volume of the ash was not reported.
A radioactive substance of 100,000-140,000 Becquerel per
kilogramme was also detected in ash at two other sewage plants in
Ota and Itabashi wards, eastern Tokyo, in late March, the sources
said.
The substance has yet to be identified and researchers are
currently looking into whether it is radioactive caesium, they
said.
The March 11 quake and tsunami crippled the Fukushima Daiichi
nuclear power plant, some 220 kilometres (136 miles) northeast of
Tokyo, causing leaks of high levels of radiation.