The Yakutian town of Mirny gets drinking water from the Irelyakh water reservoir enclosed with a dam with permafrost in foundation. The frost has started thawing out, and water began to infiltrate near the foundation. Due to the dam slump, a many-meter gap appeared, through which the water reservoir lost up to 4,000 tons of water an hour.
Alrosa, a company producing diamonds in Yakutia, turned to the Oil Chemistry Institute in the West Siberian city of Tomsk, which specializes in resolution of problems in the field of prospecting, extracting and processing hydrocarbons. One of the most important and promising directions dealt with here for about 20 years is creation of technologies to increase oil recovery of layers. Different gel-forming mixtures are used for this.
For the dam of the Irelyakh hydrosystem, scientists suggested using cryo-gel. This is a chemical solution that becomes a gel when being frozen. In two years of tense work, ecologically pure solutions of polymers with electrolyte additions which form a gel with temperatures from 0 to -20 Celsius were created. With cyclic processes "freezing-thawing" the gel becomes a cryo-gel, which possesses high elasticity and a perfect cohesion with the rock. It blocks the stream and creates a screen. The more often the cycle repeats, the firmer it becomes.
Cryo-gels have never been used before for hydro-technical facilities. To build a barrier to water along the perimeter of the whole dam, whose length is 300 meters, it's necessary to inject 1,700 tons of gel to 117 holes. Scientists hope to fill with it only 20-25 before the year end.
The next facility is likely to be the Vilyuiskaya hydroelectric power plant (on the left tributary of the Lena river in Central Yakutia) - the first hydropower plant in Russia built in the zone of permafrost. In the future, the new technology may serve not only for maintenance and elimination of emergencies, but to strengthen soils in the permafrost area.
