Although authorities had confirmed that caesium-137 contamination was safely contained at a foundry in Prachin Buri province, facts indicate that related health risks remain, according to Greenpeace Thailand.
Greenpeace Thailand and the Ecological Alert and Recovery - Thailand (Earth) Foundation have raised their concern about the disappearance of a 25-kilogramme tube of caesium-137 from the National Power Plant 5A Co facility in 304 Industrial Park in tambon Tha Tum of Si Maha Phot district.
The two organisations said on Tuesday that although authorities announced they found caesium-137 contamination at a metal foundry in Kabin Buri and had safely contained it at the closed plant, they could not confirm the contamination came from the missing radioactive tube.
The disappearance of the container of caesium-137 and the delay in it being reported to authorities showed recklessness by the management which prevented the government from handling the matter swiftly and efficiently, and the public had to live with the fear and the risk, the joint statement said.
They said the tube's disappearance was irrational because a power plant was a restricted area.
"The caesium-137 tube is a necessary component of the production process. It should not have fallen off and gone missing without trace," the statement said.
They referred to earlier speculation that the tube, which was attached high up in the machinery, had just fallen off. The caesium-137 device was reportedly used in ash measurement at the coal-fired plant.
"Failure to closely monitor the radioactive component is a grave mistake," they said.
The two environmental agencies said no one knew how far the impact of the missing caesium-137 had reached because the Office of Atoms for Peace could not confirm if the contaminated furnace dust they found at the foundry in Kabin Buri district really came from the missing tube.
"The lack of the confirmation raises the question about the real source of the contaminated furnace dust. This requires additional investigation," the statement said.
Police suspect the missing tube was stolen, sold as metal scrap and later melted down.
Police spokesman Archayon Kraithong said National Power Plant 5A Co was aware of the disappearance on March 7 and reported it to Sri Maha Phot police station on March 10.
The company would be charged with failure to swiftly respond to a hazardous radioaction incident and report it to authorities, he said.