Kinds of Nuclear Waste

Nuclear waste is radioactive material that has no immediate use. In the United States nuclear waste generally is divided into two main categories: high-level nuclear waste (HLW) and low-level radioactive waste (LLW). Two less common categories are tailings from uranium mining and milling, and a special category derived from particular aspects of nuclear weapons production and defense-related activities. This latter, less commonly discussed, category is called defense wastes and, because of its makeup, is sometimes called transuranic wastes; it makes up about half of the HLW in the United States. This article focuses on HLW and LLW from nuclear power reactors.

HLW comprises most of the radioactivity associated with nuclear waste. Because that designation can cover radioactive waste from more than one source, the term spent nuclear fuel (SNF) will be used to discuss HLW originating from commercial nuclear reactors. LLW comprises...