Confinement of Radioactive Waste
Developing Confinement Techniques for Radioactive Matters within Topsoil to Prevent their Spread with Water and Wind from the Sites on Nuclear Fuel Cycle Sites.
Tech Area / Field
- ENV-RWT/Radioactive Waste Treatment/Environment
8 Project completed
Senior Project Manager
Bunyatov K S
All-Russian Scientific Research Institute of Non-Organic Materials named after A. Bochvar, Russia, Moscow
- Moscow State University / Department of Chemistry, Russia, Moscow
- JAERI, Japan, Tokyo
Project summaryThe objective is to develop ecologically safe polymers for protecting soils against weathering by wind and rain and spread of high-toxic and radioactive matters, for better vegetation and structure-formers powder matters and hard soils.
Nuclear fuel cycle activity and accidents result in radioactive contamination of topsoils which contributes to further spread of contamination to adjacent areas. Air and water flows are responsible for the mass transfer of finely dispersed soil particulates with radioactive matters absorbed. Soluble radionuclides are underground - and rain - water-borne. The carryover of radioactivity can be prevented by coating soils with protective polymers stable to the action of air and water flows. Underground water-borne contamination can be reduced by means of polymer-based antifiltering barriers.
Experience with the elimination of consequences of the Chernobyl accident since 1986 is unambiguously indicative of a high efficiency and durability of interpolyelectrolite complexes (IPEC) - based protective composites developed and tested by joint efforts of the VNIINM and the Moscow State University. Later the complexes were found to be effective dust and wind erosion suppressing agents contributing to vegetation. The experience and findings on the IPEC properties open up the way to the development of new compounds promoting environmental protection.
IPEC are the products of interaction of the two oppositely charged polyelectrolites - polyanione and polycatione and form a water-insoluble but moisture-and gas-permeable protective crust containing as much as 98% of soil. The treated soil holds its natural structure. The protective crust provides not only reliable confinement but better vegetation as well due to a greenhouse microeffect and limited moisture-retention.
As a part of the program, the following problems will be studied:
- fundamentals of confinement technology;
- laboratory research units;
- IPEC formation in water-salt media;
- interaction between IPEC constituents and inorganic disperse fillers;
- IPEC-radionuclide interaction in water-salt media;
- aggregation of soil exposed to IPEC;
- soluble radionuclide migration in imitated media with and without IPEC;
- polymer-surfactant complexing;
- effect of polymers on the water permeability in imitated media;
- a technique for applying polymers on topsoil;
- IPEC and protective coat resistance;
- recommendations for soil protection.
These polymers can be used:
- as effective dust suppressing compounds;
- to localize small-dispersed high-toxic substances, including radioactive ones;
- to immobilize powder materials;
- as effective means against the wind and water soil erosion;
- as agents for better vegetation.
- new polymer soil-stabilizers providing a confinement efficiency of 98 %, when added at a concentration of 2-5 % in amounts of no more than 1.5 1/m2, the stabilizer endurance being no less than a year; ternary polymer-metal complexes with radioactive ions will further decrease their spread with water flows;
- environmental safety;
- better vegetation;
- lower reclamation intensity;
- lower community dosage to the personnel;
- description of the IPEC formation process;
- an experimental lot (50 kg) of polymers;
- test procedure;
- description of polymer properties;
- technique for applying polymers on topsoil.
The end effect of the project would be a new polymer and technique for long-term confining contaminated soils to minimize the spread of radioactivity. These polymers are useful not only for radioactive applications but for aggregation of heavy soils, better vegetation, specially in arid districts, and dust setting in open-out mines and waste piles.