WNWR 2019 — 2. ORIGINS AND CLASSIFICATION
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The IAEA identifies six types of waste, focusing on solid waste. There have been limited disputes over the management strategies for the first four categories of waste described below (up to and including low-level waste). While some countries have in place long-term management strategies for waste that falls into these categories (for example, the UK and France), others pursue at best interim storage strategies (such as Germany and Japan). The main issues where political controversies arise, and where there are not yet any agreed and operational long-term management facilities anywhere in the world, concern the categories of intermediate-level and, especially, high-level waste. In relating waste categories to management options, the IAEA assumes that these options will always take the form of various kinds of land-based disposal. This includes surface disposal and a variety of sub-surface options, in the latter case including ‘disposal’ in deep geological repositories.
2.3.1 THE IAEA CLASSIFICATION The IAEA system takes varying account of all three characteristics outlined above and defines the six following categories: EXEMPT This category involves very low concentrations of radionuclides so that there is no need, in the view of the IAEA, for any specific radiation protection measures. The IAEA safety guide suggests that this is waste suitable for exemption (from regulatory control) 10, exclusion, or clearance. In principle, such material can thus be transferred from one country to another without any form of regulatory oversight. VERY SHORT-LIVED WASTE (VSLW) This category contains radionuclides with a very short half-life, which are often stored until their activity levels allow them to be re-categorized as exempt. Some gaseous and liquid waste is categorized as VSLW. In general terms, the recommended management strategy is storage for decay and is supposed to be applied for radionuclides with half-lives of the order of 100 days or less. VERY LOW-LEVEL WASTE (VLLW) Within this category, substantial amounts of waste stem from the operation and decommissioning of nuclear facilities, as well as waste arising from the mining and processing of uranium ores. Managing this waste, unlike those in the two categories above, requires full account of radiation protection and safety. Characteristic activity levels of radionuclides that fall within this category are between ten and a hundred times those of levels for exempt waste. The IAEA suggests that safe management for this waste will involve engineered surface landfill facilities, requiring both active and passive institutional controls over a significant but unspecified period. The classification systems for many countries do not recognize the categories Exempt and VSLW, and some like the US reject the idea that any radioactive material should fall outside continuing regulatory oversight. LOW-LEVEL WASTE (LLW) Low-level waste (LLW) is defined as waste with levels of radioactivity low enough for near-surface or sub-surface disposal, if the disposal sites offer robust containment and isolation for what the IAEA describes as “limited periods of time”. However, these limited periods of time turn out to be up to a few 10 In the US, the term Below Regulatory Control (BRC) is used for this categorization.
