ABSTRACT
As commercial production of nuclear energy power is running into its sixth decade, a growing number of nuclear installations are at or reaching the decommissioning phase. Since the beginning of the commercial nuclear industry, as of July 2016, 157 civilian nuclear power reactors worldwide have been permanently shut down or are undergoing decommissioning. 1 They were either shut down at the end of their life as originally envisaged in the design, or prematurely closed as a result of financial, political or technical reasons. More than 56 per cent of all the operating reactors are more than 30 years old and about 15 per cent are more than 40 years old. 2 In addition, more than 480 research reactors and several hundred other fuel cycle facilities have been decommissioned or are undergoing decommissioning. 3 Decommissioning of the nuclear facilities poses a huge management, technological and environmental challenge for the international community as nearly 75 per cent of the total waste volume predicted to arise from the whole nuclear programme is from decommissioning and clearance of nuclear sites. 4 Decommissioning of nuclear installations may include the decommissioning of power plants, nuclear research reactors and nuclear fuel cycle facilities. Decommissioning is also a complex and multi-dimensional problem that involves both technical and non-technical aspects. In its broadest sense decommissioning covers all of the administrative and technical actions relating to early planning for cessation of operations and release of the site from nuclear regulatory control. 5 These actions may include early strategic and financial planning, removal of spent or unused fuel to a reprocessing or storage site, decontamination of 84structures and equipment, dismantling of plant and equipment, shipping radioactive and other waste to offsite disposal sites, remediation of contaminated land and remaining structures, and other related activities leading to an acceptable end state for the site. 6 Decommissioning requires activities such as planning, physical and radiological characterization, facility and site decontamination, and dismantling of materials.
