Factsheets and FAQs
Managing Radioactive Waste
For well over half a century, nuclear technologies have been contributing to a better quality of life in a wide variety of fields:
Energy: Almost one-fifth of the world's electricity is supplied by nuclear power plants. In some countries, nuclear power accounts for over 50% of the supply.
Medicine: Nuclear techniques are extensively used in the diagnosis and treatment of life-threatening diseases like cancer.
Economic Development: Nuclear applications are enhancing the productivity of industry and agriculture worldwide, and contributing to scientific advancement in many areas.
Environmental Protection: Isotopic techniques are improving the management of water resources and the biosphere, and helping to control pollution.
Like many natural and human-induced processes, however, applications of atomic energy produce wastes - residues that must be handled and disposed of effectively in order to protect human health and the environment.
According to the IAEA, radioactive waste is any material that contains a concentration of radionuclides greater than those deemed safe by national authorities, and for which no use is foreseen. Because of the wide variety of nuclear applications, the amounts, types and even physical forms of radioactive wastes vary considerably: some wastes can remain radioactive for hundreds or thousands of years, while others may require storage for only a short decay period prior to conventional disposal.
To facilitate communication and information exchange among its Member States, the IAEA instituted a revised waste classification system in 1994 that takes into account both qualitative and quantitative criteria, including activity levels and heat content. IAEA's three principal classes include exempt waste, low and intermediate level waste, and high level waste.
Exempt Waste: (EW) contains such a low concentration of radionuclides that it can be excluded from nuclear regulatory control because radiological hazards are considered negligible.
Low and Intermediate Level Waste: (LILW) contains enough radioactive material that it requires actions to ensure the protection of workers and the public for short or extended periods of time. This class includes a range of materials from just above exempt levels to those with sufficiently high levels of radioactivity to require use of shielding containers and in some cases periods for cooling off. LILW may be subdivided into catagories according to the half-lives of the radionuclides it contains, with "short lived" being less than 30 years and "long lived" greater than 30 years.
High Level Waste: (HLW) contains sufficiently high levels of radioactive materials that a high degree of isolation from the biosphere, normally in a geologic repository, is required for long periods of time. Such wastes normally require both special shielding and cooling off periods.
Substantial amounts of radioactive waste are generated through civilian applications of radionuclides in medicine, research and industry. But a major source of non-military waste is nuclear power generation, including various steps in the nuclear fuel cycle such as fuel fabrication, power plant operation, reprocessing, and the decommissioning of nuclear facilities.
The generation of electricity from a typical 1000 MW(e) nuclear power station, which would supply the needs of a city the size of Amsterdam, produces approximately 300 m3 of low and intermediate level waste per year and some 30 tonnes of high level solid packed waste per year.
By way of comparison a 1000 MW(e) coal plant produces some 300,000 tonnes of ash alone per year, containing among other things radioactive material and heavy metals which end up in landfill sites and in the atmosphere.
Nuclear power generation facilities produce about 200,000 m3 of LILW and 10,000 m3 of HLW (including spent fuel designated as waste) each year worldwide.
Radioactive Waste Management (RWM) incorporates all administrative, operational and safety-related activities that are involved in the treatment, conditioning, storage and disposal of all categories of radioactive wastes, including transportation. While RWM methods vary from country to country, the primary objective is the same - protect people and the environment from hazards arising from radioactive waste and effluents, both for the present and the future. The IAEA promotes a "systems approach" to RWM, that is, a logical, integrated strategy for determining the requirements, technologies, resources and impacts of each element of a waste management system.
Management and Disposal of LILW (Short Lived)
These types of wastes are often treated (to achieve volume reduction) and/or conditioned (waste immobilization) prior to disposal. A variety of safe and effective treatment options are available including chemical precipitation, incineration and compaction. These may be followed by immobilization in materials such as concrete, bitumen, or polymers.
Disposal methods for treated and conditioned wastes are typically in shallow concrete-lined trenches or engineered surface structures. Safe near surface disposal of LILW has been practiced in many countries for over 30 years. The isolation period is usually up to 300 years, thus facilitating institutional and administrative control of the disposal site.
Disposal methods for low and intermediate level wastes vary in IAEA Member States. The two main options currently employed or planned by countries are:
- near surface disposal facilities; and
- geologic repositories.
Worldwide, about 40 near surface disposal facilites have been safely operating during the past 35 years, and an additional 30 facilities are expected to be in operation over the coming 15 years.
Management and Disposal of LILW (Long Lived)
Some LILW contains long lived radionuclides in quantities that require a high degree of isolation from the biosphere. This is typically provided by disposal in geologic formations at a depth of several hundred meters. Such wastes remain in storage pending ultimate disposal.
Management and disposal of HLW and spent fuel
Most countries operating nuclear power plants also have or are developing facilities for managing HLW. Although national strategies differ, the approach and methodologies are often quite similar, thus creating a sound basis for information exchange and other co-operative activities.
Not all countries with spent fuel, either from nuclear power reactors or from research reactors, have active disposal programmes mainly because they plan to return spent fuel to a foreign supplier. Typically, these countries must provide interim storage for 5-10 years prior to returning the spent fuel.
Once spent fuel has been removed from a nuclear reactor, it is placed in interim storage at the reactor site. Afterwards, it may be handled in two different manners:
- Placed in storage facilities away from the reactor for 5 to 100 years, conditioned after an appropriate decay period, then stored before final disposal in a geologic repository; or
- Reprocessed after away-from-reactor storage. The resulting liquid HLW is then immobilized in a stable matrix (i.e. borosilicate glass), and then stored until final disposal in a geologic repository.
Regardless of which option is selected, there is broad scientific agreement that deep geologic disposal using a system of engineered and natural barriers to isolate the waste is the best method.
The first geological repositories for high level and long lived wastes are expected to begin operation around 2010. About 20 more repositories are projected to be commissioned by the end of 2030. (see figure 3). The principal features of the geological repository concept is to place packaged waste in a stable formation several hundred meters below the surface with engineered barriers around and/or between the waste packages and the surrounding rock.
The IAEA has fostered international co-operation in the waste management field since it was established in 1957. Reflecting the very diverse range of interests among its Member States, the IAEA's waste management programme encompasses activities which benefit Member States regardless of their degree of sophistication in the uses of nuclear energy.
IAEA's waste management programme concentrates on several key activities:
- Collecting, reviewing and publishing up-to-date scientific and technical information.
- Providing direct services, particularly to developing Member States and the newly independent states of the former Soviet Union, through technical assistance, training, and other programmes to strengthen national infrastructures, including the demonstration of waste management techniques.
- Fostering and co-ordinating research and development through co-ordinated research programmes.
- Establishing safety standards for the management and disposal of wastes by building international consensus.
- Implementing international codes of practice and safety conventions.
- Providing advisory and peer review services for both developed and developing countries.
- Providing a forum for the dissemination and exchange of information at international conferences, symposia and seminars including the promotion of education, public information and training.
- Developing and implementing special projects, including assessment of the environmental and radiological impacts of waste disposal.