Chapter 9 - Sources and Characteristics of Nuclear Wastes

Abstract

This chapter highlights the classification scheme of nuclear waste. Key parameters in classification scheme are the radionuclide concentrations and half-lives. Radioactive waste is generally classified by activity level into exempt, low-level waste (LLW), intermediate-level waste (ILW) and high-level waste (HLW). Often LILW is used to mean low and intermediate level wastes. The most commonly accepted classification scheme includes radionuclide half-lives by separating waste into two classes: short lived and long lived. Nuclear waste arises from three main sources, the Nuclear Fuel Cycle (NFC) used for power generation and military uses, Non-NFC institutes (including nonnuclear industries, medical and research institutions) and accidents. The NFC is the main source of radioactive waste. NFC produces all types of radioactive wastes, including HLW, which are further defined as Open NFC and Closed NFC. Non-NFC institutions generate lower amounts but a greater range of radioactive waste. These include many industrial users of radionuclides, research institutions, including nuclear research centres (often housing research reactors), medical and other small users. Non-NFC institutions generate mainly LLW. The NFC comprises a number of activities starting from exploration of uranium ore and ending with disposal of wastes. The NFC is divided into three phases: Front end, Operational phase and Back end, which includes decommissioning of active facilities. The NFC Operational phase waste arises from the electricity generation process as well as from maintenance activities.