Examination and Remediation of Toxic Waste Storage
Over-all Examination of Ecological Situation at the Toxic Wastes Storage "Koshkar-Ata" and Development of Rehabilitation Actions
Tech Area / Field
- ENV-MIN/Monitoring and Instrumentation/Environment
- ENV-RED/Remediation and Decontamination/Environment
8 Project completed
Senior Project Manager
Rudneva V Ya
National Nuclear Center of the Republic of Kazakstan / Institute of Nuclear Physics, Kazakstan, Almaty
- Williams College, USA, MA, Williamstown
Project summaryThe ecological situation in the Mangystau province (Kazakstan) became aggravated in 1960’s, at start of exploration of the deposits of uranium ores, oils, and raw minerals and the creation of a chemical industry in Mangyshlak, in neglect of environmental problems. The KOSHKAR-ATA tailing pond is the most hazardous place among all objects, making a considerable contribution to atmospheric contamination with powder radioactive and toxic wastes of chemical and mining metallurgic industries. KOSHKAR-ATA represents a serious hazard for habitants of Aktau and adjacent inhabited localities.
The purpose of the Project is to investigate the current ecological situation in the territories, adjacent to the KOSHKAR-ATA tailing pond and to develop rehabilitation measures, taking into consideration local soil/climatic peculiarities.
The KOSHKAR-ATA tailing pond, a drain-free settling pool for industrial, toxic, chemical and radioactive wastes, and for ordinary domestic drains, is 5km north of Aktau (Mangystau province), which is situated on the shore of the Caspian Sea. Industrial, toxic and radioactive wastes, solid sediments of unpurified ordinary domestic drains from a part of the Aktau residential region have been placed in the tailing pond since 1965 and have been stored there up to this day.
Solid radioactive wastes of the chemical mining metallurgic plant, where uranium ores were processed, were buried without control or official account in a trench-type burial without hydro-isolation. According to the data of the Mangystau Provincial Ecology Department (Aktau), the real mass of radioactive wastes (RAW), disposed in the tailing pond, is about 360 million tons with 11000Ci total activity.
Industrial wastes are represented, mainly, by phosphogince, phosphomel and pyrite cinders that contain such stable elements as: iron, silicon, sulfur, zinc, lead, silver, selenium, cobalt, arsenic, etc., and enhanced concentrations of natural radionuclides.
Results of works, which were carried out by the Institute of Nuclear Physics in 1999, showed that the exposure dose rate (EDR) at shallow zone equaled 80-150mkR/h. Some places were revealed, where EDR was 1500mkR/h and radionuclide content was up to 548-5000bk/kg. According to preliminary experimental data on samples from KOSHKAR-ATA, which were obtained by using a certified EPR-dosimetry method, dose load measured 15-25kGy. That is similar or even exceeds the dose value of soil samples from the South-East trace of the Semipalatinsk test site.
As a result of a steady reduction in the water phase level, the area covered by just bed sediments, which are a source of toxic dust, has recently increased.
Under existing hydrogeological conditions of the tailing pond region, there is potential for penetration of liquid waste to aquifers and to the Caspian Sea.
The inhabited locality of Kora is situated on the western shore of the settling pool. Owing to an enhanced radiation background, its inhabitants suffer from permanent enhanced irradiation and poisoning by chemical toxicants.
Thus, permanent and long-term contamination of the land around the KOSHKAR-ATA tailing pond and its plant unambiguously forces us to consider the regional ecological situation as critical. That is why it is very important to take immediate measures in order to reduce sequences, eliminate the reasons and sources of contamination and to restore the natural characteristics of the environment.
The highly qualified personnel and technical resources at the Institute of Nuclear Physics will help to solve the above problem. At the KNNC INP, under the sponsorship of such international institutions as the IAEA, the ISTC and others, a modern instrumental and methodical base has been created to determine the radionuclide/element composition of an environmental object. For investigation of the radiological situation, instrumental/radiochemical techniques, certified by Kazakstan standardisation bodies, have been developed and are in use at INP. A technique based on EPR dosimetry has been developed, which allows the reconstruction of dose loads on the population and various areas of the territory concerned. The Institute has been granted State license GLA 0000017 (dated January 11, 1999), on conducting radiological investigations and radiation situation monitoring in Kazakstan.
As a result of Project implementation, the following outcomes are expected:
– Quantitative data will be obtained on contamination of the KOSHKAR-ATA tailing pond toxic/radioactive wastes and adjacent lands by radioactive isotopes and toxic metals, that characterise current ecological conditions of air/water/soil medium in that territory and adjacent land (in particular, toward the Caspian Sea);
– On the basis of the obtained experimental data, dose loads on the local population throughout studied lands will be determined;
– Actions will be developed for rehabilitation of the shallow zone of the tailing pond, taking into consideration local soil/climate conditions and, then, the efficiency of these actions will be estimated;
– Potential ways of migration for contaminating and dose-forming elements will be analyzed before and after rehabilitation actions and forecasting of ecological situation evolution;
– Recommendations concerning implementation of rehabilitation actions will be developed and submitted to local executive bodies.
The experience gained during radiological investigations and rehabilitation actions conducted on the storage of KOSHKAR-ATA toxic/radioactive wastes can be applied for investigation of similar lands in other countries.
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