The focus will then shift to the concept of repositories and their impact in the long term. The last section will discuss how the UK is likely to resolve the issue of nuclear waste in the long term and whether that will be in line with the current thinking on that issue.
The issue of radioactive waste disposal is a very serious one. Nuclear power for instance contributes to 23% of UK electricity needs.(Department for Environment, Food and Rural Affairs.2001) However its sustainability is suspect until efficient means to manage and dispose radioactive nuclear wastes is found. Stockpiles of nuclear waste are accumulating in several nations. Improper storage can cause exposure to radiation, which results in health and environmental hazards. Also these can be used as weapons of mass destruction if they are found by terrorist organizations. Hence strategies for disposal must involve a multi-dimensional approach with consideration ethical and environmental factors while taking into account the principles of inter and intra-generational equity.
Radio active or nuclear waste is the product of a nuclear process, radioactive waste consists of materials containing radioactive chemical elements. generated in the processing of fuel for nuclear reactors or nuclear weapons and in the process of nuclear fission. (Wikipedia)
Radiation occurs from the decay of radioisotopes. Each of these radioisotopes in the radioactive waste has a half-life which is the time taken for half its atoms to decay. The faster a radioisotope decays, the more radioactive it is. (World Nuclear Association 2001)
Fig1. Comparison in the corresponding rates of decay of uranium ore and other HLW from the reprocessing of spent fuel.
Source:World Nuclear Association 2001, Radioactive Wastes.
The classification of radioactive wastes and their disposal depends on how long it remains highly radioactive, the concentration of the radioactive material in the waste and whether the waste is heat generating. The persistence of the radioactivity determines how long the waste requires management. The concentration and heat generation dictate how the waste should be handled. (World Nuclear Association 2001).
Radioactive wastes are generally classified into
Low-level Wastes (LLW) -generated from hospitals and industry, as well as the nuclear fuel cycle, contain very small amounts of radio active substances that do not need to be shielded in the process of handling or transportation. (World Nuclear Association 2001)
Intermediate-level Wastes (ILW) contain higher amounts of radioactivity and some require shielding. It comprises of resins, chemical sludges and metal fuel cladding, as well as contaminated materials from reactor decommissioning. It may be solidified in concrete or bitumen for disposal. Generally short lived waste from reactors is buried in shallow repositories, while long lived waste from fuel reprocessing will be disposed of deep underground (Wikipedia)
High-level Wastes (HLW) result from of the use of uranium fuel in a nuclear reactor. It contains the fission products and transuranic elements generated in the reactor core. Highly radioactive and hot, HLW's require cooling and shielding. HLW accounts for over 95% of the total radioactivity produced in the process