Many of us think that nuclear power is very dangerous even if we only speak about energy production, as the process creates a lot of radioactive byproducts. The disposal of the old core rods and also the reactor operation results in a large amount of low-level waste, especially contaminated cooling water. But nuclear power could solve our energy problem if only we could find a way to make it clean.
The chemist PD Dr. Bi¶rje Sellergren from the Institute of Environmental Research at Technische Universität Dortmund has developed together with his colleague Sevilimendu Narasimhan from the Bhabha Atomic Research Center in Kalpakkam, India, a new method to considerably reduce the amount of radioactive waste. Their central idea was to destroy the radioactive waste from water with small beads made of a special polymer.
In a normal pressurized-water reactor, the hot water circulates through high pressure steel pipes. Metal ions are removed from these pipes and when they get to the reactor’s core, they are bombarded with neutrons. Most of the removed ions are iron-isotopes (Fe56) which don’t become radioactive while bombarded with neutrons. But the problem is that most of the steel pipes contain also cobalt. While the cobalt absorbs neutrons, it becomes radioactive and unstable (cobalt-isotope- Co60) and has a half-live of more that five years. Water cleaning is made with ion exchangers, but this technique has its disadvantages as well: there is no difference made between non-radioactive iron-ions and radioactive cobalt-ions.
In order to bind only the cobalt ions, Sellergren and Narasimhan developed a special polymer made through a procedure called “molecular imprinting”. As the polymer is made in an environment containing cobalt, the cobalt-ions are extracted with hydrochloric acid, being “washed out” in the end. The imprinting process is able to trap only cobalt radioactive isotopes. The two scientists are now concentrated to making a polymer into small beads that can pass through the cooling system of a nuclear-power station.
As radioactivity will be concentrated into these beads instead of disposal of large amounts of low-level waste, Sellergren and Narasimhan expect this to be a more economically and environment-friendly process. Today, around 40 new nuclear-power plants are built in the U.S. and it is estimated that 70 more will be built in the next 15 years. As there is obviously a demand for nuclear power, why not research for it to become more friendly on the environment?