Russian scientists have developed a new technique for disposing of radioactive wastes, which turns them into chemical compounds similar to natural minerals and friendly for an environment.
Common and widely used technique for disposing of radioactive wastes is putting them into a lead container and burying them deeply in the ground. However, lead containers provide protection for only several tens of years, and after that, no one is able to guarantee absence of leakage.
Researchers from the Institute of Volcanology and Seismology (Far Eastern branch of Russian academy of sciences) had a fruitful cooperation with several geological companies, which resulted in an innovative suggestion to bury radioactive wastes in natural high-temperature (up to 350 degrees Centigrade) hydrothermal systems. Authors of the innovation believe that natural geochemical processes would turn dangerous radioactive wastes into harmless geological complex compounds. In other words, geological ore deposits of hydrothermal origin are formed.
First “playground” for this technology may appear in the hydrothermal system of Kamchatka and the Kuril Islands. This region is unique for a combination of factors (rock pressure, high temperatures and etc), essential for transforming radioactive wastes into stable and harmless substances. However, a theory of hydrothermal burial can also be effective in other regions, for instance, North Caucasus, individual Kuril islands, or Pecheneg deep system.
Hot springs can be found anywhere on our planet, however, they hide at various depths, authors of the research say. Deep boreholes unearthed high-temperature springs in Moscow, at the Kola Peninsula, in the Ural region, at Kamchatka, deep in seas and oceans, and etc. Studies of chemical composition of these revealed absorbing agents, able to immobilize heavy metals. After natural hydrothermal absorbing agents are neutralized, siliceous substances form, which safely lock radionuclides or other dangerous materials deeply inside our planet for millions and billions of years.
New technology has three stages. First one is adsorption of radioactive chemical elements by clay minerals and gels of natural colloidal solutions, and formation of hydrogel, a jelly-like substance. Second stage consist of precipitation of just formed “radioactive” hydrogels on geochemical barriers, which are zones of abrupt reduction of migration ability of chemical elements. During the last, but not the least stage an insoluble colloidal quartz (chalcedony) forms.
Authors of the new technology of radioactive waste utilization consider their development to be ecologically perfect and economically sound. They believe that the innovation would help significantly reduce expenditures on constructing new temporary storages and nuclear waste repositories. The innovation will remove radioactive wastes from natural turnovers and keep them safe for millions of years, at the same time returning wastes in their initial condition.
Source: Science & Life
Kizilova Anna