What are the significant issues and developments in radiation protection?
Radiationprotection is a dynamic field. The wealth of scientific knowledge upon which it is founded increases constantly. There are new advances in technology both with respect to providing protection and the use of radiation sources. Also, regardless of the general status of protection, there are a number of conceptual and practical issues which remain open.
There is a growing feeling that future advances in biology might result in breakthroughs in fundamental scientific knowledge which could change the dose-effect relationship and risk models, and provide genetic analysis techniques capable of identifying some specific radiation-induced tumours above the general background of tumour incidence. Developments such as these could affect how the principles for radiation protection are implemented. For example, experimental data on adaptive responses or stimulation of cellular repair at very low doses, if confirmed, could affect estimates of stochastic risk of low doses and lead to revised approaches to situations such as those involving intervention.
Some practices are in a constant state of evolution with new technologies and procedures replacing the old. The use of radiation in medicine is an example of such a situation. Several models of power reactors based on new safety concepts are being developed. Nuclear fusion is a truly new practice undergoing long term development which may become a reality in the decades to come. These are examples of the types of developments that can involve new radiation protection issues and strategies. Also, another area which is expected to reach an industrial dimension in the next few decades is decommissioning of commercial nuclear power plants. Here, emphasis in radiation protection should focus on optimised strategies for the protection of workers and the public. Of particular interest is the practical application of the protection principles to exempt wastes associated with huge amounts of slightly contaminated scrap materials and valuable metals.
Applying the concepts of protection against potential exposure to sources used in medicine, industry and research as well as applying the concepts to waste disposal, presents a particular challenge with much yet to be done. Mistakes or accidents involving relatively simple sources have resulted in serious injury and deaths. There is a need to improve the ability to assess and manage the risks from potential exposure, particularly with respect to accounting for the complete human-machine systems and interfaces in safety evaluations. This is particularly important for radiation therapy, because the margin of error is small when treating patients with high-radiation doses. Since devices and procedures used in radiation medicine are constantly evolving, keeping current with understanding and managing potential exposure risk is particularly difficult.
Adequate treatment of the long-time aspect (thousands of years) of waste disposal is a difficult problem with respect to potential exposure. Although there seems to be a consensus that the radiation protection objective of waste disposal is not to subject people in the future to a risk that is significantly greater than society is willing to accept now, the challenge consists in demonstrating the case against specific national performance criteria to the satisfaction of the regulatory authorities. It involves a very complex safety analysis of the disposal system. The main difficulties in providing a robust safety analysis for disposal are a lack of information about the frequency of disruptive events, lack of feedback from operating experience and design evaluation, and lack of environmental models for the future. Overcoming these difficulties requires the concerted efforts of radiation protection, waste management and other specialists at both international and national levels.
Finally, there is the social dimension of radiation protection. Radiation causes public anxiety regardless of how well present radiation practices enable persons to live in relative safety with radiation. The cause of this anxiety is only speculative and probably cannot be attributed to a single cause, but rather a combination of things, such as its association with nuclear weapons, the fact that it cannot be detected by the human senses and that it can produce cancer. This has led to a keener sensibility to the costs than to the benefits of some radiation practices.
For this and other good reasons, decision-making in several areas of radiation protection cannot be isolated from its social dimension and must involve the social parties affected. Better involvement of social parties in radiation protection decisions requires improvement in the information provided and education of interested parties about radiation, its benefits and impacts, and the protection against these impacts. Although society is showing an ever increasing interest and willingness in being involved in decisions affecting life and well-being, from the standpoint of radiation protection, a reinforced and better focused effort is needed.