(Editor's note: The format of scientific notations in this electronic presentation is being standardized.)
The Agency's activities in the area of the industrial applications of radiation and radioisotopes have focused on methods for minimizing industry related environmental pollution, non-destructive testing (NDT), and nucleonic control systems for on-line mineral analysis and tracer applications. Industrial radiation sterilization is now established as a major technology with hitherto unattainable environmental, technical and economic benefits. A pilot scale demonstration model technical co-operation project was initiated using radiation technology for the removal of toxic flue gases from coal fired power stations. Personnel development in Member States in the area of NDT and other aspects of industrial radiography continued to be stressed.
The following subject areas were emphasized in the hydrology programme: development and management of water resources, focusing on arid and semi-arid regions; environmental investigations, including the evaluation of contamination processes and contaminant transport in water bodies; geothermal resources assessment, with emphasis on high enthalpy fields; studies of sediment transport and related problems; and analytical and intercalibration services.
A regional co-operation project, focusing on isotope field investigations at ten different aquifer systems in countries in the Middle East, including the Islamic Republic of Iran, Jordan, Kuwait, Lebanon, Saudi Arabia, the Syrian Arab Republic, Turkey and the United Arab Emirates, was completed. Another regional project on the use of nuclear and related techniques for the study of leakages in dams and reservoirs was started in five Latin American countries (Brazil, Costa Rica, Cuba, Mexico and Venezuela).
Assessment and transfer of radiation technology
Two CRPs have been concerned with the applications of radiation technology in bioengineering and the synthesis of biomaterials. In one CRP on the synthesis of biomaterials, which was completed in 1994, techniques were developed for the production of air permeable burn and wound dressings, and for the controlled release of drugs. Some of these applications are already in commercial use. The other CRP, on the applications of radiation technology, resulted in the development of new radiation techniques for the immobilization of bioactive materials for use as diagnostic reagents in the early detection of communicable diseases.
Nuclear methods for reducing industry related environmental pollution
A CRP on nuclear methods for assessing healing pathways of pollutant damage in the environment, particularly for the bulk analysis of coal and estimation of pollutants in coal and coke, resulted in a new technique based on the inelastic scattering of neutrons in carbon. This makes it possible to evaluate the calorific value and the ash content of Polish coal. Techniques based on dual gamma, natural radiation, prompt gamma and X ray fluorescence methods were successfully demonstrated for the determination of the ash content of coals from several countries. Furthermore, a number of on-line nucleonic measurement systems for use in coal fired power stations have been developed. Similarly, low coal ash gauges based on the attenuation of soft gamma radiation have been developed in Viet Nam and China, and their performance has been evaluated.
CRPs in progress
|Year of start||Subject||Year of completion||Participating institutions|
|1988||Development of diagnostic reagents for communicable diseases using radiation||1994||6|
|1988||Radiation processing technology applications in bioengineering||1994||10|
|1989||Nuclear techniques in the exploration and exploitation of coal: On-line and bulk evaluation of potential environmental pollutions in coal and coke||1994||12|
|1992||Application of nuclear techniques for environmental preservation in resource extraction and processing||1995||7|
|1992||Nuclear methods in the monitoring of wear and corrosion in industry||1996||5|
|1992||Nuclear techniques for advanced ceramics and semiconductors||1995||9|
|1992||Nuclear techniques for the evaluation of healing pathways of pollutant damage in the environment||1995||10|
|1993||Stability and stabilization of polymers under irradiation||1996||11|
Development of new methods for the assessment of water resources with isotope techniques
A CRP on mathematical models for the quantitative evaluation of isotope data in hydrology was completed. The results of the programme were published as an IAEA-TECDOC. Various quantitative evaluation methodologies for natural isotope data in groundwater systems were successfully assessed in this programme. A manual on mathematical models for isotope hydrogeology is being prepared as another product of the CRP.
A CRP on isotope techniques in lake dynamics investigations was started. The emphasis is on the water dynamics of large lakes and related problems, such as solute dynamics, sedimentation processes and isotopic effects due to evaporation. The programme is expected to help elucidate the potential of environmental isotope techniques for such studies.
A regional project was started in five Latin American countries (Brazil, Costa Rica, Cuba, Mexico and Venezuela) with the aim of using nuclear and related techniques for the study of leakages in dams and reservoirs. These leakages endanger the stability of the dam and could also give rise to significant water losses. A workshop was held in S. Luis Potosi, Mexico, to provide training in the application of tracer techniques for the identification of leakages, as well as the flow paths of the water from leakages.
In Venezuela, a model technical co-operation project was initiated with reserve funds. The increasing water deficit in the city of Caracas made it necessary to search for new water sources to complement the existing distribution system, which basically is fed by reservoirs. The rational exploitation of groundwater resources is expected to help supply drinking water to peripheral areas of the city. The hydrogeological investigations will be complemented by geochemical and isotopic techniques for characterizing quality and the amount of water to be pumped from the Valle de Caracas aquifer.
Geothermal projects with Agency technical assistance to El Salvador, Mexico and Greece were completed. In these projects, isotope techniques were used to study the occurrence of geothermal water. The origin and flow directions of geothermal waters could be identified and, to some extent, the temperature of geothermal reservoirs determined. Assistance was given for the development of water, gas and isotope laboratories in China, El Salvador, Ethiopia, Guatemala, Indonesia, Nicaragua and the Philippines.
To promote research on water-rock interaction by means of isotope techniques, co-operation was started with the Russian Federation and the Philippines. The investigations are expected to extend the applicability of isotope geothermometry to depths in geothermal systems where chemical indicators may fail. The research based on sulphur isotopes will, similarly, provide a better understanding of the sources of acid fluids in geothermal systems.
Water resources evaluation in arid and semi-arid regions
A regional technical co-operation project on isotope hydrology in the Middle East was completed after four years. The aquifer systems investigated include coastal aquifers in Lebanon and the Syrian Arab Republic, a karst aquifer in the Islamic Republic of Iran, aquifers with different characteristics in Jordan and in Turkey, overexploited karst aquifers in the United Arab Emirates, and water movement in the unsaturated zone in Saudi Arabia, the Syrian Arab Republic and Kuwait. A core of well trained staff was created in each of the participating countries, capable of planning, implementing and evaluating isotope studies.
In the Peruvian Altiplano, isotope techniques have contributed to identifying groundwater origin and altitude of recharge and characterizing the hydrogeological parameters of the aquifers. These results help to make available additional sources of drinking water which are badly needed in the water scarce coastal areas of Peru. In Brazil, tritium is being used as a tracer to investigate the dynamics of the surface reservoir supplying potable water for the city of Sna during August, in co-operation with the International Association of Hydrological Sciences. Presentations were made on six main topics related to tracer applications in arid zone hydrology.
Environmental investigations with isotope techniques
A CRP on the application of isotope techniques to investigate groundwater pollution was started. It aims at the use of isotope techniques to identify groundwater pollution sources, characterize the level of pollution, predict the movement of pollutants and help prevent or mitigate contamination. Isotopes such as 2H, 3H, 18O, 13C, 14C, 15N and 34S address specific pollution sources and provide information which complements chemical and hydrological data. The CRP addresses issues related to urban groundwater pollution by domestic wastes and sewage disposal, landfill performance and hazard assessment, seawater intrusion and pollution from agricultural practices. The results of these investigations will help develop methodologies for monitoring so that management of water resource utilization can be more effective.
An Advisory Group meeting on the use of isotope techniques in the hydrological appraisal of radioactive waste disposal sites was held in June. Scientific presentations illustrated the investigations of residence times in low permeability rocks, the origin of waters, fluidrock interaction and transport of radionuclides in groundwater that affect the performance of radioactive waste disposal sites. The meeting emphasized that isotope techniques are indispensable for the assessment of the performance of potential geological repositories for nuclear wastes from the standpoint of understanding groundwater flow and radioactive migration under low permeability conditions.
A CRP on isotope variations of carbon dioxide and other trace gases in the atmo-sphere was concluded. The CRP made a significant contribution towards solving the missing CO2 sink' problem: the data on 14C concentration in atmospheric CO2 point to an oceanic carbon sink smaller than previously believed; and the 13C data for atmospheric CO2 being gathered under programmes run by the United States National Oceanic and Atmospheric Administration and Australias Commonwealth Scientific and Industrial Research Organization suggest a large CO2 sink at temperate northern latitudes, mostly of terrestrial origin. The achievements of the CRP with regard to methodological developments include revised data acquisition procedures for high precision 13C and 18O analysis of atmospheric CO2, and an intercomparison exercise between laboratories engaged in high precision isotope analyses of atmospheric trace gases, based on whole air samples.
In pursuance of the recommendations made by consultants in 1993 on the Caspian Sea environmental crisis, a proposal was prepared for a regional project to be implemented within the Agency's technical co-operation programme. In order to assess the commitments of the Governments of the riparian countries to the implementation of this project and the extent of local infrastructural support available to execute the project, Agency staff, an Agency recruited expert and a UNESCO representative visited the countries in August and September. The mission reported that all the countries were willing to take part and had offered complete infrastructural support. The priority areas to be tackled were discussed with the potential local counterparts.
Pollution problems were dealt with using isotope techniques in a number of field studies carried out within the technical co-operation programme. In Costa Rica, one of the studies carried out during 1994 was centred on the determination of the transfer rate of nitrate and other pollutants to groundwater using tracer techniques. In Cuba, the effectiveness of a 50 km dike in increasing the recharge of water derived from precipitation and in preventing seawater intrusion due to intense pumping in a coastal aquifer was studied. It was found that the dike increased the recharge and stabilized the coastline. This led to the development of a mangrove swamp and a reduction in the adverse effects caused by seawater intrusion. The results of a study on contamination sources and surface water dynamics carried out in the Bay of Montevideo revealed that the contamination originating in the Bay reaches the bathing areas of Montevideo city in the Rio de la Plata.
Studies on bedload sediment transport using radioactive tracers were performed in the Magdalena River near Barranquilla and Las Flores, Colombia. The objective of the study was to evaluate the river transport capacity for dredged sediments to a dumping site. The results show that the location of the proposed new dumping site was properly selected. Field experiments with radioactive tracers were continued in the Hai Phong port area in Viet Nam to study bottom sediment dynamics near the navigation channel. The studies will be completed in 1995. Field work to tackle erosion and siltation problems in the Danube delta, Romania, and the Markala Reservoir, Mali, was initiated.
Co-operation between the Agency and UNESCO in the field of isotope hydrology continued with the convening of a working group in Vienna in December on nuclear techniques in hydrology. The scope and layout of a suitable textbook in this area were discussed.
Analytical and intercalibration services
The Isotope Hydrology Laboratory organized the fifth Agency intercomparison exercise for the low level tritium analysis of water. Intercomparison samples were prepared and sent to 82 laboratories, out of which 65 returned the results of their measurements. The results were evaluated by three external experts from New Zealand, the United Kingdom and the USA.
In order to improve the overall quality and intercomparability of data from the joint IAEA/WMO Isotopes in Precipitation Global Network, the Isotope Hydrology Laboratory organized an intercomparison exercise for 28 laboratories engaged in stable isotope analyses of precipitation. Four water samples (of 50 mL each) covering the range of 2H and 18O values usually observed in precipitation were sent to participating laboratories for analysis. The results will be evaluated and made available to all participating laboratories.
Assistance was provided to five projects oriented towards strengthening analytical capabilities for environmental isotope assay (tritium, radiocarbon, stable isotopes) in Member States. This includes setting up new laboratories and upgrading existing ones.