|
|
A new polymer has been developed by a team of Indian scientists that will help in reducing radioactive wastes in nuclear reactors. This will make the decontamination process less costly.
The new polymer that has been named 'Cobalt Imprinted Polymer’ is a compound that selects the radioactive cobalt ions in the nuclear coolants. It then dissolves and removes them without changing their properties.
Narasimhan V Sevilimedu, a scientist with the Indira Gandhi Centre for Atomic Research said,"The polymer is imprinted with a memory for cobalt ions, source of radioactivity in most nuclear plant coolant channels. By doing this, the radioactive ions will be trapped in very small volume of this special polymer.”
"So, the amount of radioactive waste volume which is subjected to immobilisation will be very small."
He added that the compound had been synthesised in such a way that they have pre-designed "holes" to selectively recognise and trap cobalt ions. The main characteristic of this imprinted polymer is its pre-designed selectivity.
Conventionally, by circulating a solution of mild chemicals in the coolant circuits the corrosion products, metal oxides, are removed. The solution contains both radioactive and non-radioactive ions, namely cobalt and iron respectively.
These conventional resins do not have the ability to distinguish between cobalt and iron ions which have very similar chemical properties.
"This synthesized polymer has been designed to differentiate and selectively absorb the cobalt ions (both radioactive and non-radioactive) while rejecting iron ions," Narasimhan said.
The polymer can also be used for cleaning of decommissioned reactors for separating the active waste and concentrating them in a small volume, he added.
"It (polymer) is able to separate two metal ions effectively and absorb, thereby net volume required for trapping the cobalt ions (radioactive and non-radioactive) is reduced. Hence the subsequent processing cost also will be reduced," Narasimhan said.
Narasimhan and his colleague Anupkumar Bhaskarapillai conceptualized, initiated and tested this technology in India at Water and Steam Chemistry Division, BARC Facilities, Kalpakkam.
A journal of the American Chemical Society named 'Industrial and Engineering Chemistry Research’ has published an article on this new polymer.
