International standards for radiological safety and environmental protection

As indicated previously, the approach to radiation safety that has been accepted universally is to prevent deterministic effects (acute effects such as skin damage, organ damage and ultimately death) and reduce the likeli­hood of stochastic effects (cancer and genetic effects) to levels that are not significant. The underlying concepts to applying this approach are elabo­rated extensively in the recommendations of the ICRP, an international commission established in 1928 by the International Congress on Radiology [9]. This was on account of the increasing recognition of the dangers associated with medical uses of X-rays by the medical profession and the need to establish appropriate protection regimes. The work of the ICRP increased substantially in the second half of the twentieth century with the advent of the nuclear industry and the legacy of nuclear weapons develop­ment and use towards the end of the Second World War. The ICRP has updated its recommendations on a regular basis around every ten years as knowledge about the effects of exposure to radiation has increased and as the philosophy of protection has developed and matured. The ICRP is an independent scientific body and its recommendations have no legal stand­ing. The recommendations are, however, generally used by the international standards setting bodies as a basis for developing international standards. With regard to radiation safety, the IAEA is the body mandated by the United Nations to establish international safety standards for nuclear, radi­ation, RAW and radioactive material transport safety. The safety standards are based on a set of fundamental safety principles [ 37] endorsed both technically and politically by all the member countries of the IAEA. The principles are set down in Box 3.2.

The system of radiation protection recommended by the ICRP and adopted in the international safety standards for radiation protection of the IAEA[6] [38] has three general principles, which concern justification of practices and activities, optimisation of protection and the application of individual radiation dose limits, and are expressed in Safety Principles 4, 5, 6 and 10 in Box 3.2. The system of protection also has a number of dimen­sions; it differentiates three types of exposure situations, namely planned, emergency and existing situations and three types of exposure: occupa­tional, public and medical. The first of these three, ‘occupational’, concerns exposure of persons on account of their work situation, such as workers in a nuclear power plant, a waste management facility, a uranium mine or a nuclear medicine department in a hospital. ‘Medical exposure’ is exposure of patients to radiation for either diagnostic (e. g., X-ray) or therapeutic (e. g., radiotherapy) purposes. Medical exposure is not relevant to RAW management or contaminated areas and will not be dealt with further. The third category is ‘public exposure’ and is all exposures other than occupa­tional or medical. Public exposure can arise from various causes such as discharge into the environment of radioactive effluents, migration of radio­nuclides from radioactive waste disposal facilities into the accessible biosphere, transport of radioactive material in public areas, the use of radio­active consumer products, etc.

Planned situations are those in which a facility or activity where radioac­tive material will be present is knowingly and deliberately developed and operated. This means that safety and protection measures can be planned and put in place, and the radiation exposure of people associated with the activity or operation of the facility can be controlled to whatever level is decided. The protective measures can be design features of the facility such as shielding or containment features or can be operational controls such as limiting access in certain areas or decontaminating working areas. All

Box 3.2 International fundamental safety principles

Principle 1: Responsibility for safety

The prime responsibility for safety must rest with the person or organisation responsible for facilities and activities that give rise to radiation risks.

Principle 2: Role of government

An effective legal and governmental framework for safety, including an inde­pendent regulatory body, must be established and sustained.

Principle 3: Leadership and management for safety

Effective leadership and management for safety must be established and sus­tained in organisations concerned with, and facilities and activities that give rise to, radiation risks.

Principle 4: Justification of facilities and activities

Facilities and activities that give rise to radiation risks must yield an overall benefit.

Principle 5: Optimisation of protection

Protection must be optimised to provide the highest level of safety that can reasonably be achieved.

Principle 6: Limitation of risks to individuals

Measures for controlling radiation risks must ensure that no individual bears an unacceptable risk of harm.

Principle 7: Protection of present and future generations

People and the environment, present and future, must be protected against radia­tion risks.

Principle 8: Prevention of accidents

All practical efforts must be made to prevent and mitigate nuclear or radiation accidents.

Principle 9: Emergency preparedness and response

Arrangements must be made for emergency preparedness and response for nuclear or radiation incidents.

Principle 10: Protective actions to reduce existing or unregulated radiation risks

Protective actions to reduce existing or unregulated radiation risks must be justi­fied and optimised.

 

waste management operations are planned (even if the waste is generated by an accident or arose in a previously uncontrolled activity), as are all activities to clean up contaminated areas or decisions not to clean up areas. As such the radiation safety recommendations pertaining to planned situa­tions will apply. Despite measures to prevent accidents and the fact that such accidents are rare, they can happen during RAW management

 

activities and for such circumstances the recommendations for emergency situations would apply. Unlike planned exposure situations, it is not possible to control exposures from accidents a priori and as such the requirements are in general to plan for accidents and emergencies and to put mitigatory measures in place to limit exposures to the extent reasonably possible in the event of an accident. Contaminated environments do exist on account of accidents such as Chernobyl or past uncontrolled practices such as some uranium mining activities, and these are considered existing exposure situ­ations. In existing exposure situations, exposures are occurring and the system of protection calls for measures to be put in place to reduce expo­sures such as limiting access to certain areas or cleaning up of contaminated facilities and/or land.

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