Adhesive to Close up the Defects of Natural Rocks
Development and Research on an Adhesive to Close up the Defects of Natural Rocks to Improve Reliability of the Repositories of Nuclear Wastes
Tech Area / Field
- CHE-POL/Polymer Chemistry/Chemistry
- ENV-WDS/Waste Disposal/Environment
8 Project completed
Senior Project Manager
Genisaretskaya S V
VNIIEF, Russia, N. Novgorod reg., Sarov
- St Petersburg Technological Institute, Russia, St Petersburg
- International Safety Research, Canada, ON, Ottawa\nSandia National Laboratories, USA, NM, Albuquerque
Project summaryUrgency of the problem of safe operation of repositories of nuclear wastes comes from the fact that crack zones of rocks at the repositories, that are formed as a result of industrial activity of a person or tectonic loosening, create a threat of leakage of the ecologically dangerous products. The leakage process is out of control.
A possible way to solve this problem is implementation of the materials introduced into the defective zones to restore the solidity of the rocks and to resist successfully possible leakage caused by water filtration for example. Complexity of the problem comes from severe constraints of formation of compositions directly in defective zones at low temperatures (up to 4°С), as well as the pressure of water, significant extent of the defects and little disclosing of cracks.
The leading role abroad in solution of a similar task of repairing large hydraulic engineering constructions belongs to the French company called “Solitange”, which uses “Rodur” epoxy compositions (Germany) as repair compounds. Domestic development was carried out basically in the field of creation of cement screens using polymer materials. Implementation of compositions on the basis of polyurethane, furfural-acetone and carbamide bindings is well-known; however under conditions of the pressure head filtration during forcing into the water-sated environments they get mixed up with the water and are taken out from the cracks and cavities of the rock mass being strengthened.
Recently there have been developed compositions on the basis of thermosetting resins and caoutchouc that are widely implemented now and have shown good results in repairs of basements and bearing constructions of the industrial and civil buildings; for example, there were repair works at Bureyskaya hydro-electric station, repair works at the Memorial to the Motherland at the Mamayev-Kurgan Complex, Volgograd, repair works at Sayano-Shyshenskaya hydro-electric station to restore the solidity of the concrete dams and reduce filtration in their basements.
The main goal of the Project is the development of polymer thermoreactive materials that would ensure reliable restoration of solidity and water resistance of natural rock mass in places of repositories of nuclear wastes. It is planned to develop the materials with various viscosity (for various geometry of defective zones) that would be polymer compositions on the basis of the modified epoxy and rubber bindings and would provide the solidified structures with the following level of properties:
- Possible hardening on wet surfaces under conditions of excessive pressure of water at the temperatures up to 4С.
- Destroying pressure at compression (at 20 oС) – not less than 60 Mpa.
- Destroying pressure at detachment (at 20 С) – not less than 11 Mpa.
- Water absorption of hardened compositions – not more than 0.1 %.
- Preservation of properties of the compositions under operating conditions - 50-60 years.
Scientific and practical value of this work lies in possible production of the materials of polymer compositions that would provide safe operation of repositories of radioactive wastes and in the technologies of their implementation for restoration of solidity and water resistance of rock mass and basements of the repositories of radioactive wastes.
Technical approach and methodology. To reach the goals of the Project the authors have necessary methods and equipment, highly qualified personnel in the area of polymer chemistry, physical and mechanical research. There are experimental bases for realization of the goals of the Project in RFNC-VNIIEF and StPSTI (TU).
It is also important to note that employees of StPSTI (TU) have positive experience in repairs of large-scale constructions. Implementation of the developed materials for restoration of the solidity of the basement of the dam at the Sayano-Shushenskaya Hydroelectric Power Station in 1999 allowed them to low down water filtration by 81 % in average.
On the basis of theoretical and experimental bases of RFNC-VNIIEF and StPSTI (TU) it is supposed to work out some kinds of compounding of polymeric compositions and to research on their physical and mechanical properties, to make predictions and to study the adhesive capacity of the composition at long storage.
Then this work may proceed in the following areas:
- Development of the equipment to mix and pump the composition into the well under high pressure;
- Development of techniques:
- To evaluate the condition of a rock mass.
- To evaluate the results of injection.
A potential role of foreign collaborators. As the Project is aimed at solving acute problems of environmental protection from the hazardous effects of radioactive wastes it may promote establishment of business relations with foreign partners. Participation of foreign collaborators in the work will promote perfection of plans of the project and their realization. It is supposed to have an exchange with techniques, joint participation in seminars and publications, participation of the collaborators in technical control of the work within the project and partnership in realization of its outcomes. All thrusts of the activity can be described in more details in joint programs.