|IAEA Technical Co-operation - A Partner in Development|
Promoting a Sustainable Environment
PROMOTING A SUSTAINABLE ENVIRONMENTWithin 25 years, an estimated 60 percent of the world's population will live in urban areas. But many cities - especially in developing countries - are expanding beyond the capacity of their infrastructure to sustainably support them. Environmental problems including water and air pollution, inadequate sewage treatment and solid waste disposal and ozone depletion are having serious economic and human health consequences for many of the new "mega-cities." Air pollution in Mexico City, for example, already contributes to 12,000 deaths per year. And in the Thai capital, Bangkok high lead exposure from car emissions has been found to reduce the average IQ of children.
To address some of these problems, IAEA is building new partnerships with governments and international organizations to assess and plan environmental mitigation through the application of nuclear techniques. These involve a variety of applications from using isotopes as tracers for selected pollutants, to the adaptation of electron accelerators for cleaning flue gases from fossil-fueled power plants. IAEA is also an important technical resource for national programmes in geothermal energy production and environmental management including the mitigation of marine pollution.
The IAEA Marine Environment Laboratory (MEL) located in Monaco helps Member States in addressing problems related to polluted oceans and coastal zones. Numerous analytical techniques are used to investigate radio-nuclide contamination, chemical concentrations and dispersion of waters among other issues. MEL's training programmes help to increase Member States capacity to understand, monitor and protect the marine environment. The Laboratory is also an international centre for analytical quality control services for radioactive and non-radioactive marine pollutants. (For further information, see the brochure, "Guarding the World's Seas: IAEA's Marine Environment Laboratory").
Geothermal energy is one of the most environmentally friendly sources of electric power. To develop it effectively, however, reliable information about the temperature and flow of fluids deep within the earth's crust must be obtained. Nuclear technology provides accurate methods both for determining the origins of geothermal fluids and for tracing water movement and heat flows. An Agency Model Project is currently assisting El Salvador in expanding its geothermal capacity.
San Salvador, El Salvador.
Geothermal exploitation was continually disrupted during El Salvador's long and bloody civil war, and oil imports made up almost half of the country's total energy supply by 1995. But the war is finally over and Salvadorians are eager to show that their country is moving ahead. Indeed, electricity demand is growing at roughly 5 percent a year and the country's Hydroelectric Executive Commission for Rio Lempa (CEL) is implementing a five-year plan to double geothermal energy production.
A key figure in the Commission's undertaking is Ms. Aída de Zamora, a geologist who directs CEL's Isotopic Hydrology Laboratory. She cordially escorts visitors down a picturesque road past Mayan archeological ruins to the town of Ahuachapán, where a geothermal field in operation since 1975 today generates 58 megawatts from 32 wells. "Isotopic hydrology, radiotracers and sample analysis have helped us to build a conceptual model of the site and to better locate new wells," says Ms. de Zamora.
At another worksite 130 kilometres east of San Salvador, a team of scientists is collecting vapor samples at the steam vent know locally as "Infiernillos (little hells) of Chinameca" to determine the feasibility for drilling. Exploration around Chinameca started in 1978 across an 800 square kilometres area and was gradually reduced to 70 square kilometres. "Geochemistry, geology, geophysics and radiotracers are used in a combined effort to identify the priority area for development," explains CEL's Superintendent of Investigations, Mr. Renato Jacobo, as he carefully places gas samples into an ice cooler for condensation.
At the sprawling 650 hectare Berlin geothermal plant some 112 kilometres southeast of El Salvador, dozens of scientists and support staff sample water, check manometres and proof the purity of steam vapor before it is fed into the turbine. "Decision-making on drilling targets for production, re-injection of wastewater, and management and utilization of the reservoir all become more accurate using isotope analysis," explains Jane Gerardo-Abaya, Technical Officer for the two year Model Project. "This information can save millions of dollars in drilling costs and facilitate the optimal utilization of the resource."
The project is enhancing national capabilities to interpret critical isotope and geochemical data. Analysis for oxygen-18, deuterium and tritium provide the baseline hydrology and chemistry. The radioactive isotope iodine-131, or iodine-125 is used to trace water movement and determine the rate of flow from one well to another. A hydrological model is then developed to illustrate quantitatively the direction of fluid flows. Finally, samples from production and injection wells are regularly collected and analyzed to provide an understanding of the effects of ongoing exploitation, re-injection of wastewater and to ensure sustainability.
Over the years, several IAEA TC projects have helped El Salvador to exploit geothermal resources by transferring know-how and equipment. The Agency assisted in establishing the local isotope laboratory, providing it with a mass spectrometre, sample preparation lines, training on mass spectrometry and expert services, thus enabling the independent analyses of stable isotopes required for reservoir monitoring.
Given the present rate of geothermal production, El Salvador's oil import bill is expected to drop by at least US$9 million annually. Greater geothermal output, moreover, will enable CEL to connect an additional 225,000 households to the country's electric grid. Financial support for the exploitation of 38 new wells in Anuachapán, Berlín and San Vicente is coming from a US$168 million loan from the Inter-American Development Bank. "Our goal for next year is to produce 30 percent of the country's installed generating capacity using geothermal energy," says CELs General Manager, Mr. J. A. Rodriguez Rivas. Thus, thanks to its natural bounty, its own recent scientific advances and some well-targeted assistance from the IAEA, the Land of Volcanoes, long plagued by war and poverty, is literally steaming towards greater prosperity.
When fossil fuels (especially coal and oil) are burned, "acid rain" is produced as SO2 aerosols become sulphuric acid, and NOx aerosols change into nitric acid by exposure to sunlight. Not only does acid rain destroy vegetation and buildings, the gases are also believed to contribute to "global warming." Most nations around the world are now committed to containing them, and recent global treaties require all countries to pass and implement laws limiting national SO2 emissions.
Switching from coal to hydropower, natural gas or nuclear may be an answer for some. But Poland has no viable hydro source; it cannot afford to import natural gas from Russia; and its nuclear power programme is postponed indefinitely. For the foreseeable future, Poland must rely on its huge reserves of brown coal. Indeed, the livelihoods of hundreds of thousands depend on the industry.
How can Poland ensure that new industries are not as environmentally damaging as in the past and that gas emissions standards set by the EU are met? Legislation enacted in the early 1990s requires utilities to progressively reduce SO2 emissions, beginning in 1997. Technologies are readily available for removing either SO2 or NOx from the flue gases of coal-fired power plants, but until recently there was none that could extract both in one single-stage process.
A coal-fired power plant in Szczecin is now the site of a four-year TC Model Project to demonstrate, on an industrial scale, a novel technology that can do just that. Electron Beam Dry Scrubbing (EBDS) works by recycling the flue gases through a chamber, before they escape from the chimney, and exposing them to low-energy electron radiation from an accelerator. As a result the toxic SO2 and NOx are transformed to other more benign chemical forms. By adding ammonia to the chamber, the resulting by-product, a dry powder, can be used as fertiliser. Other cleaning systems do not have this beneficial effect and produce a lot of waste. And although it is a radiation process, no radioactivity is produced in the operation and there is no residual radiation.
EBDS was developed some 20 years ago and was used in pilot plants in Germany, Japan and the United States. By the time it became available for industrial scale use in the mid-1980s, utilities in these heavily regulated countries had already fitted most older coal-fired power plants with other proven scrubbing techniques, or had committed to installing more efficient boilers that would produce less emissions.
Studies carried out in those countries, as well as in Poland - where an earlier Agency technical co-operation project helped set up a pilot EBDS plant near Warsaw in 1988 - have shown that the technique is 25 to 30 percent less costly to install and to operate than conventional systems. When NOx removal also becomes compulsory, the advantages of EBDS will be greater. The value of the agricultural by-product and the relatively smaller waste disposal problem make it additionally attractive. There is a strong interest in EBDS across the energy sector in Poland, among its neighbours and in developing countries with large coal reserves that are industrializing fast. Ukraine has an ongoing programme, and the IAEA has just launched a new TC project to assess the option in Bulgaria.
Poland has opened the doors to the Szczecin plant, allowing the IAEA to bring visitors who are keen to see it operating. China plans to install cleaning systems in some 60 power plants, and will complete its first 500-megawatt facility this year. In Latin America, Brazil, Chile and Mexico already have pilot projects and are closely watching progress in Szczecin.
The Polish Government is investing 60 percent of the US$20 million needed to set up the EBDS system, and all the personnel and operational costs. The remaining 40 percent is shared between Japan, the Republic of Korea and the IAEA. The plant is scheduled to be fully operational by the end of 1998. Hopefully, it will show Poland a way to attain EU emission standards without having to compromise industrial growth, and demonstrate to the energy sector worldwide a cost efficient and environmentally friendly technology.
Radioactive contamination is a serious problem in some countries of Eastern and Central Europe and the former Soviet Union. Extensive mining and milling of uranium ores have affected large areas that now require restoration and appropriate land-use management to ensure the safety and health of surrounding populations. While most concerned Member States are now fully aware of the extent and severity of this problem, environmental restoration has not, until recently, enjoyed a high priority due to pressing economic concerns.
In 1993, however, the IAEA-TC began supporting a series of workshops to raise government awareness of this long neglected problem, and to characterize radioactively contaminated sites and evaluate doses to the general public. The second phase of this project started in 1995 and concentrated on assessing contamination of uranium mining and milling sites and supporting the development of plans for concrete corrective actions aimed at environmental restoration. In only a few years, there has been a marked shift from basic scientific surveys and discussions to identification of responsibility ties and evaluation of the resources for implementing restoration programmes.
In all, some 15 countries have been participating in the project. IAEA TECDOCS now summarize the national situation in environmental contamination and outline ongoing or foreseen restoration plans. New TC remediation projects began during the 1997-98 Programme in Bulgaria, the Czech Republic, Slovenia and several other affected countries. In Slovenia, a new initiative is helping to assess the effectiveness of the decommissioning performed at Zirovsky Vrh, a mining and milling tailings disposal facility shut down in 1990. In Ukraine, the Agency is assisting in evaluating radioactive contamination in the living environment due to the use of uranium tailings in building materials. Finally in Bulgaria, the Agency is helping to improve safety in the storage, handling and disposal of radioactive waste at the Novi Han Repository, some 40 kilometres from Sophia. The facility's operating license was suspended by national authorities in 1994 because it did not meet acceptable safety standards.
Every source of electrical power produces impacts on human health and the environment. In order to respond to the priorities identified by the 1992 Rio Summit on Environment and Development, the IAEA joined forces with eight other international organizations* to examine the health and environmental effects of different electricity generating systems. This work evolved into an IAEA-led interagency project called "DECADES".
DECADES has subsequently assembled one of the world's most comprehensive databases on technical, economic and environmental aspects of different energy sources for electricity generation, and has developed sophisticated computer software for power sector planning. The reference Technology Database includes an inventory covering all current and prospective energy sources - coal, oil, gas, hydro, nuclear, geothermal, solar, wind, wave and biomass - and encompasses the full energy chain concept, allowing comparisons not just between electricity generating plants but also by considering all steps of the chain from tapping of the resource to final disposal of wastes. Some 35 countries are constructing their own databases on this frame, customizing them for their own conditions and decision making.
Software (known as DECPAC) has also been developed for integrated electricity system analysis. It can help a country-user to screen, compare and assess different electrical system expansion strategies, taking into account various environmental burdens such as emissions of SO2, NOx and "greenhouse gases" from the full energy chains, including mining, transportation, fuel fabrication and waste disposal.
During its second phase, DECADES will be enhancing the basic model to cover even more comprehensive coverage of environmental burdens, and to quantify impacts on crops, human health and economic infrastructure. Other challenges being addressed are enhancing the model for forecasting the future energy and electricity needs in developing countries, demand side management and regulatory analysis. The IAEA is disseminating the DECADES databases and software globally through training programmes and co-ordinated research efforts. Further information may be obtained from the Planning and Economic Studies Section, Division of Nuclear Power and the Fuel Cycle, IAEA Vienna, Austria.
* Organizations participating in the project: European Commission, Economic and Social Commission for Asia and the Pacific (ESCAP), IAEA, International Institute for Applied Systems Analysis (IIASA), OECD Nuclear Energy Agency (OECD/NEA), Organization of Petroleum Exporting Countries (OPEC), UN Industrial Development Organization (UNIDO), World Bank and World Meteorological Organization (WMO).