Investigators probing the radiation contamination of a drinking water cooler unit in Kaiga atomic plant in Karnataka have zeroed in on five employees from whose department the heavy water could have been smuggled out.
Sources privy to the investigations said today the contamination incident described as an "internal sabotage" had links to the department from where moderator heavy water is supplied for the nuclear reactor.
The laboratory examination of the water from the cooler showed only presence of tritium--a radioactive isotope of Hydrogen-- and no other chemical.
Tritium is used in a type of heavy water which is used to moderate the high temperatures of the nuclear reactor while the coolant comprises tritium and other chemicals to cool temperatures in the reactor.
The sources said that on November 23, things were normal but some radiation effects in some employees were noted only on the night of November 24.
The sampling of the moderate heavy water is done everyday whereas for coolant it is done once a week, the sources added.
