Rehabilitation of Degelen Mountain Massif Water
Development of a Sorption Method for Decontamination of Radioactive Water Streams Resulted from Nuclear Weapon Tests at the Degelen Mountain Massif of the Semipalatinsk Test Site
Tech Area / Field
- ENV-EHS/Environmental Health and Safety/Environment
- ENV-RED/Remediation and Decontamination/Environment
3 Approved without Funding
National Nuclear Center of the Republic of Kazakstan / Institute of Radiation Security and Ecology, Kazakstan, Kurchatov
- Claremont McKenna College, USA, CA, Claremont
Project summaryA significant part of CIS countries’ lands including several streams and water bodies is continuously affected by operation of nuclear industry and power engineering facilities. Nuclear weapon tests, imperfect technologies and contingency situations caused the radioactive contamination of both large and small water ways. As a result, a necessity arose to perform detailed radioecological studies of and develop rehabilitation methods for areas and water bodies affected. The present project proposes to use water streams of the Degelen Mountain Massif (DMM) to test methods, based on natural sorbents, for ecological rehabilitation of water bodies using natural sorbents.
The Degelen Mountain Massif was one of the technical fields of the former Semipalatinsk Test Site (STS) used to test nuclear devices in horizontal workings – tunnels. Over 200 nuclear devices have been detonated in DMM tunnels in 1961-1989. As a result, a huge amount of radioactive products accumulated within a relatively small area, posing a threat to the environment. They are mainly contained within underground cavities produced by nuclear explosions and seem to be tightly sealed by concrete plugs. However, monitoring results show that water streams running out of 30 tunnels transport radioactive products to the day surface. Small areas with values of radiation parameters highly above those measured inside the tunnels were found within beds and flood-lands of these streams. The laboratory analysis of water samples show that the radionuclide transport is still proceeding. Ground waters percolating through explosion cavities wash off radioactive products and carry them out to the day surface. The radionuclide sorption by soil of stream banks and flood-lands results in activity accumulation at certain locations. In the lower course, tunnel water streams flood relatively large areas which become water-logged. These water-logged areas are now highly radioactive due to the many-year accumulation of the radioactivity. Contaminated water can possibly get into the Chagan River which is a left tributary of the Irtysh River. Thus, there is every likelihood that radionuclides transported from the former Degelen Technical Field could get into the Irtysh River recharge basin.
Rehabilitation issues associated with the radionuclide transport by tunnel water streams into the general hydrographic network of the Degelen Mountain Massif are primary related to search for effective and non-expensive sorbents capable of absorbing radionuclides (137Cs, 90Sr, 239,240Pu) from water. Obviously, natural or modified natural sorbents are mostly promising as they are commonly available and cheap. The Institute of Nuclear Physics (INP) in Almaty studied cesium and strontium absorption by zeolite (clinoptiolite) from the Chaikanai deposit.
The Institute of Radiation Safety and Ecology is currently studying sorption properties of local clays and clay-based compounds to use them for absorption of underground explosion radioactive products from ground and surface waters of the Semipalatinsk Test Site.
Studies conducted show that local natural sorbents (white clays confined to weathering crust) are mostly promising for application in various filtering facilities absorbing radionuclides from water flowing out of tunnels. Clays absorb over 90% of 137Cs dissolved in water and require no preliminary treatment. STS abounds in these clays. Clay sediments often come out to the day surface and are easy to mine. We believe that natural sorbents should be used in water clean-up systems which designing has only started.
The present Project objective is to develop a method for water decontamination using natural sorbents (clays), conduct experimental field trials and elaborate recommendations on industrial decontamination of radioactive water streams of the Degelen Mountain Massif.
To construct a decontamination facility, a dam will be erected in the most appropriate part of the streambed to create a water storage pond. Locks will be provided in the dam body to drain water from the water storage pond. Containers filled with sorbents will be placed in the dam body and along the pond banks. The sorption facility design is primarily aimed at maximum convenience and easiness of operation and quick replacement of used containers by fresh ones.
The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.
ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.