1.14. Within any State or region, a number of disposal facilities of different designs may be required in order to accommodate radioactive waste of various types. The classification of radioactive waste is discussed in an IAEA Safety Guide [12] and the different classes of radioactive waste are presented in the Annex. The following disposal options have been adopted in one or more States, corresponding to recognized classes of radioactive waste:
(a) Specific landfill disposal: Disposal in a facility similar to a conventionall and fill facility for industrial refuse but which may incorporate measures to cover the waste. Such a facility may be designated as a disposal facility forvery low level radioactive waste (VLLW) with low concentrations or quantities of radioactive content [12]. Typical waste disposed of in a facility of this type may include soil and rubble arising from decommissioning activities.
(b) Near surface disposal: Disposal in a facility consisting of engineered trenches or vaults constructed on the ground surface or up to a few tens of metres below ground level. Such a facility may be designated as a disposal facility for low level radioactive waste (LLW) [12].
(c) Disposal of intermediate level waste: Depending on its characteristics, intermediate level radioactive waste (ILW) can be disposed of in different types of facility [12]. Disposal could be by emplacement in a facility constructed in caverns, vaults or silos at least a few tens of metres below ground level and up to a few hundred metres below ground level. It could include purpose built facilities and facilities developed in or from existing mines. It could also include facilities developed by drift mining into mountainsides or hillsides, in which case the overlying cover could be more than 100 m deep.
(d) Geological disposal: Disposal in a facility constructed in tunnels, vaults or silos in a particular geological formation (e.g. in terms of its long term stability and its hydrogeological properties) at least a few hundred metres below ground level. Such a facility could be designed to receive high level radioactive waste (HLW) [12], including spent fuel if it is to be treated as waste. However, with appropriate design, a geological disposal facility could receive all types of radioactive waste.
(e) Borehole disposal: Disposal in a facility consisting of an array of boreholes,or a single borehole, which may be between a few tens of metres up to a few hundreds of metres deep. Such a borehole disposal facility is designed for the disposal of only relatively small volumes of waste, in particular disused sealed radioactive sources. A design option for very deep boreholes, severalkilometres deep, has been examined for the disposal of solid high level waste and spent fuel, but this option has not been adopted for a disposal facility by any State.
(f) Disposal of mining and mineral processing waste: Disposal usually on or near the ground surface, but the manner and the large volumes in which the waste arises, its physicochemical form and its content of long livedradionuclides of natural origin distinguish it from other radioactive waste. The waste is generally stabilized in situ and covered with various layers of rock and soil.