A general aim in the management of radioactive waste is to reduce the associated risks to as low as practicable by appropriate processing, containment and eventual disposal. Firstly, however, the amount of waste should be minimized, that is, avoided to the extent possible. It may be achieved through the optimization of nuclear facility design, including the appropriate choice of materials, the application of good operational practices and the recycling and reuse of materials.

The amount of material which requires treatment as a waste may also be reduced if the parts which are sufficiently low in activity concentration to satisfy the regulatory requirements for clearance can be identified. These materials may be separated and treated as non-radioactive materials, that is, reused, recycled or disposed of as normal waste. Further reduction in the amount of waste to be treated can be achieved by segregating waste containing only very short-lived radionuclides from other waste types. This waste can be stored to allow decay to below levels that allow clearance from control. Finally, the volumes of radioactive waste that need treatment may be reduced by processing to decrease the space they occupy by mechanical (compacting, shredding) or thermal (incineration, vitrification) methods.

The generally preferred approach for the management of radioactive waste is to concentrate the waste and to contain the radionuclides in it by means of the waste matrix and a waste container followed by disposal in an appropriate disposal facility designed to provide isolation from the biosphere. For radioactive waste in liquid and gaseous forms, however, it may be appropriate to release them to the environment provided that their concentrations are sufficiently low to satisfy the requirements set by the national regulatory body. Otherwise, they must also be concentrated and contained after appropriate processing and managed as solid waste.

Policies and strategies for managing spent fuel and the various types of radioactive waste are discussed in IAEA (2009b). Decisions on the fate of different types of radioactive waste are essentially based on radiation protection considerations; they imply that radioactive waste management solutions should:

provide protection from external radiation by shielding,

contain and isolate radioactive material from the human environment, and

prevent inadvertent human ingress to the radioactive material.

In the following paragraphs the technical options for ensuring that these criteria are met for the different types of radioactive waste are set out with reference to the IAEA waste classification scheme (IAEA, 2009c).