Waste Technology Section
Predisposal Management of Radioactive Waste
Brief Overview of Predisposal Steps
Predisposal includes all the steps carried out prior to disposal, such as
The position of these steps in the life cycle of radioactive waste from generation through disposal is depicted in the illustration below:
Pre-treatment of radioactive waste is the initial step in waste management that occurs after waste generation. It consists of
- Chemical adjustment, and
It may include a period of interim storage.
Treatment of radioactive waste includes those operations intended to improve safety or economy by changing the characteristics of the radioactive waste. The basic objectives of treatment are
- Volume reduction
- Radionuclide removal from waste, and
- Change of physical and chemical composition
|Filtration-ion exchange-ultrafiltration plant for liquid waste (Russian Federation)||Clariflocculator for chemical treatment of low level liquid waste (India)|
|In-drum compactor for solid waste (Philippines)||Incinerator for L&ILW|
Conditioning covers those operations that produce a waste package suitable for handling, transportation, storage and/or disposal. It may include immobilisation, enclosure of the waste in containers, and, if necessary, providing additional packaging. Immobilization refers to the conversion of waste into a waste form by solidification, embedding or encapsulation. Common immobilization matrices include cement, bitumen and glass.
|In-drum cementation of liquid waste||In-drum cement mixer (Thailand)|
Joule-heated ceramic melter for vitrification of high level waste (Russian Federation)
Two step vitrification process schematic: calcination followed by induction melting
Demonstration of Cold Crucible Induction Melting Technology for vitrification of HLW (India)
Storage of radioactive waste involves maintaining the radioactive waste such that
- Isolation, environmental protection and monitoring are provided, and
- Actions involving treatment, conditioning and disposal are facilitated
Storage may be practiced for decay or thermal considerations prior to geological disposal. In other cases, storage may be practiced for reasons of economics or policy.
|Storage building for low and intermediate level waste packages|
|Below ground storage for high dose rate waste|
Stacking of waste drums in storage building (Netherlands)
Characterization of waste is an important aspect at every stage of predisposal management. It involves determination of the physical, chemical and radiological properties of the waste to establish the need for further adjustment, treatment, conditioning, or its suitability for further handling, processing, storage or disposal.
|LLW drum gamma scanner||Core drilling of cemented waste product for characterization (Spain)|