Radioactive Waste: Toward Sustainable Solutions

Published Date: 4 May 2009

© IAEA Electricity production using nuclear power does not emit greenhouse gases like carbon dioxide into the air. But it generates radioactive wastes in solid, liquid, and gaseous forms that can contaminate the environment and endanger people if not properly controlled and managed. (Photo Credit: Dean Calma/IAEA; Dukuvany Nuclear Power Plant, Czech Republic) Beyond electricity production, wastes containing radioactive substances are generated by applications of nuclear science and technology in fields of medicine, industry, scientific research, and the military. Radioactive wastes also arise when nuclear facilities are decommissioned and permanently shutdown.  Nearly 200 nuclear plants and fuel-cycle facilities worldwide are being dismantled or soon will be. (Photo Credit: Juelich Reserach Centre; Merlin Research Reactor, Germany) Civilian nuclear applications are nationally regulated and guided by IAEA international standards covering safety and security.  The first safety standard on waste that the IAEA published was in 1961, addressing radioactive waste disposal into the seas.  Ocean disposal of radioactive waste was banned in 1993. IAEA safety standards today cover activities throughout the nuclear fuel cycle. (Photo Credit: ANSTO, Australia; Opal Reseach Reactor control room. Radioactive waste is categorized and managed in terms of its radioactive content and thermal characteristics.   Wastes categorized as "high-level" -- including spent nuclear fuel and byproducts of fuel reprocessing activities --  must be immobilized and transported for isolation in engineered vaults or underground repositories. The wastes pose long-term hazards to people and the environment. Scientific approaches for solidifying and immobilizing high-level wastes include vitrification in borosilicate glass. (Photo Credit: World Nuclear Transport Institute) Most of the world's radioactive wastes are categorized as "low-level" wastes (or sometimes as "low-and-intermediate" level).  They can include contaminated work clothing, rags, mops, filters, tools, and medical supplies, such as tubes and syringes.  The earth's environment also has naturally occurring radioactive elements and ores that end up in residues or wastes; these arise from uranium mining, for example, or from oil and gas production. ( Photo Credit: IAEA; Uranium mining site at Uchkouduk, Uzbekistan) More than 100 disposal facilities for low-level wastes are in operation around the world.  They range from concrete vaults to mined facilities to excavated trenches a few meters deep. Waste are prepared and packaged for long-term storage disposal. Some countries have underground geological repositories for low-level radioactive wastes. In the United States, the world's first deep repository for long-lived wastes is deep inside a salt dome. The wastes -- called transuranic -- contain plutonium and other radioactive elements that can take thousands of years to decay. (Photo Credit: Sellafield Ltd., UK Waste Packaging and Encapsulation Plant) All radioactive wastes are prepared, or conditioned, for storage or disposal for cost and safety reasons.  The only way they finally become harmless, however, is through radioactive decay -- for high-level wastes, this can take hundreds or thousands of years.  For such wastes, the international consensus is that geological repositories are required.  Right now, no repository or facilities for long-term disposal of high-level waste exist anywhere in the world. (Photo Credit: POSIVA; Samples of Core Sediments taken for scientific research of geological repository, Finland ) Many countries have research and development projects to build a deep geological repository for high-level waste.  They include Finland, the United States and Sweden, which already operates a repository built below the seabed for disposal of lower level wastes from nuclear activities. Repositories for high-level waste are targeted for operational service in 2020 and beyond, though political decisions are not final in many cases. Some countries are studying shared solutions, specifically regional and multinational approaches to the disposal of radioactive wastes in a geological repository. (Photo Credit: Bengt O. Nordin; Inside the Final Repository for Radioactive Operational Waste, or SFR, Sweden) Natural analogues are helping scientists study how geologic barriers can isolate radioactive waste.  In Oklo, Gabon, French scientists studying a uranium mine discovered that a natural nuclear chain reaction occurred there nearly two billion years ago that generated plutonium and other transuranic elements. The materials stayed immobile, held in place by the surrounding geology. (Photo Credit: NAGRA, Switzerland; View of the Oklo Site) Volumes of radioactive wastes are rising around the world from expanding applications of nuclear science and technology.  Additionally, the legacy of radioactive wastes and contaminated sites, including ex-military sites, is raising challenges of international dimensions.  They include the remediation of uranium mining sites that have contaminated environments, and the control of abandoned, lost, or disused radioactive sources. (Photo Credit: Vadim Mouchkin/IAEA; training in border control of radiation sources) Drawing close attention on safety and security grounds are "orphan" radioactive sources, or those outside of regulatory control. Many end up in scrapyards and metal recycling facilities every year.  Serious accidents have happened requiring international responses.  Countries are working through the IAEA to improve the monitoring, regulation and disposal of radioactive sources. On the security front, countries are working through the IAEA and partner organizations to prevent illicit trafficking of nuclear and radioactive materials that if not controlled could end up in the wrong hands. (Photo Credit: Petr Pavlicek/IAEA; a scene in 1987 at the scrapyard in Goiania, Brazil, site of a serious accident involving an abandoned radiation source.)  Many countries do not generate large amounts of radioactive wastes.  Yet they require technical assistance and guidance to establish sufficient infrastructures and capabilities for managing and disposing of wastes in safe, secure and affordable ways.  IAEA projects provide support for research, training, equipment, and expert services to national authorities. (Photo Credit: K. Skornik/IAEA; scene from training in radiation safety in the Middle East) International "peer reviews" of national programmes for radioactive waste management are a prime feature of the Joint Convention on the Safety of Spent Fuel Management and the Safety of Radioactive Waste Management.  At periodic review meetings, Contracting Parties take stock of each other's experience in implementing the agreement, reviewing compliance with each of the Conventionīs 25 Articles. (Photo Credit: A. Funnell/IAEA; Third Review Meeting of Joint Convention, May 2009) © IAEA