Radioactive waste is the residual "useless" products generated from human activities entailing radioactive materials (sealed radioactive sources, radioactive liquids or materials with natural radioactivity). Radioactive materials are used on a daily basis:
- in medicine, diagnostic examinations and nuclear medicine treatments, using radiopharmaceutical products, in radiotherapies (for example, irradiation of tumors, intra-tissue implants for prostate cancer, etc.)
- in industry, for radiography purposes, irradiation of materials for sterilization purposes, control of qualitative and operational parameters (for example, measurement of level or thickness of materials), and others,
- in research and training, biological experiments, location of ledges, etc.
Nuclear waste is a special class of radioactive waste and refers to the residual nuclear fuel (usually uranion and the products thereof), which no longer may be used for the operation of a reactor. Due to their characteristics, their risk and the need for special treatment, spent fuel, although being radioactive waste, is reported and treated separately.
Just like all radioactive materials, radioactive waste is tapered based on the natural half-time of the isotope included therein. For example, an amount of cobalt (60Co) will remain half after a period of 5.6 years, which is the natural half-time of cobalt (60Co). Each isotope has its own half-time, which may be extremely short (for example just 12 seconds for barium 143) or even extremely long (for example 1577 years for Ra-226, 5730 years for C-14 and 4.5 billion years for uranium 238). Thus, some isotopes, and consequently radioactive waste, never "die" and call for a long-term and careful treatment in special installations, whilst a simple in-situ management is enough for short-lived isotopes.
Due to its riskiness for public health and the environment, radioactive waste has to be managed either under directly/quickly by their producer or in the long-term under organized management within specialized facilities approved by the Greek State. According to international standards, the final management of radioactive waste may be performed in two ways:
• by release to the environment, provided that the established release levels are met, as described in the related Regulations. Such institutional release levels have been set, on the assumption that no person should receive radiation above 10 μSn (microsievert) per year out of total releases of radioactive substances made to the environment. It should be noted that the dose limit for a person for ionizing radiation practices is 1000 μSν per year. Such limits are common both at European and international level.
• by disposal (namely by permanent and final rejecting, with no intention for recovery) within a specific radioactive waste disposal facility. There are several types of installations for the disposal of radioactive waste, such as, land field disposal, near surface disposal, borehole, etc. The selection of the type of the disposal facility depends on multiple factors, such as the kind, the form, the status and the quantity of radioactive waste, the packaging of radioactive waste, the existing and future environmental, geological, seismic and climate conditions, the conducted studies (e.g. environmental, geological, hydrological, seismic, etc.) and the related scientific, research and developmental programs carried out, the developmental programs for area reformations, the existing and future infrastructures and the availability of spaces, financial social factors, etc.
Deep geological disposal does not refer to Greece as it is applied to nuclear waste (spent fuel). The permanent and indefinite storage of radioactive waste in authorized spaces is not considered to be final management (it is not a technically sustainable solution and is not currently legally accepted pursuant to the EU law), whilst there are no means for destruction of radioactive waste (combustion for example).
Pursuant to Directive 2011/70/EURATOM, each member-state is responsible and undertakes the management of radioactive waste generated within its territory.
According to the national policy for the management of radioactive waste, the import to Greece of waste from other countries is strictly and explicitly prohibited. The waste we have to manage is our own waste. EEAE is the competent regulatory authority in the field of safe management of radioactive waste.