Today we will talk about the International system of radiation protection. As was realized very early in the twentieth century, ionizing radiation can be detrimental to living organisms. So, it is essential that activities involving radiation exposure, such as the production and the use of radiation sources and radioactive material, the operation of nuclear facilities and radioactive waste management, be covered by measures to protect individuals exposed to radiation. The United Nations Scientific Committee on the Effects of Atomic Radiation compiles assesses and disseminates information on the health effects of radiation. For over 60 years, the International Commission on Radiological Protection (ICRP), a private organization, has developed recommendations in the area of radiation protection. The Basic Safety Standards were published by the IAEA and represent a broad international consensus on the appropriate handling of radioactive sources. Ionizing radiation and radioactive substances are natural and permanent features of the environment, and the risks associated with radiation exposure can therefore only be restricted, not eliminated entirely. In addition, the use of human-made radiation is widespread. Sources of ionizing radiation are essential to modern health care, the use of nuclear techniques is expanding in industry, agriculture, we use irradiation to preserve foodstuffs and reduce wastage, sterilization is used to eradicate disease carrying insects. Industrial radiography is in routine use, for example to examine welds and detect cracks and to help prevent the failure of engineered structures. All in all, the use of nuclear energy, applications of radioactive substances and ionizing radiation continues to expand. Radiation protection is not intended to protect individuals or the environment from all the effects of ionizing radiation, but to ensure that the amount of radiation absorbed by an organism does not have negative consequences. Here, we need to introduce two terms (two definitions). First practices. Practices are human activities that add radiation exposure to that which people normally incur from background radiation or that increase the likelihood of their incurring exposure. Also interventions and those are human activities that seek to reduce the existing radiation exposure or the existing likelihood of incurring exposure that is not part of a controlled practice. For a practice, provisions for radiation protection can be made before its commencement, and the associated radiation exposures and their likelihood can be restricted from the outset. By contrast, in the case of interventions, the circumstances giving rise to exposure or the likelihood of exposure must already exist and an exposure reduction can be achieved only by means of remedial or protective actions. “Practices” include not only the production of radiation sources, the use of radiation and radioactive substances in medicine, research, industry, agriculture and teaching, and the generation of nuclear power (including the entire cycle of related activities, from the mining and processing of radioactive ores to the operation of nuclear reactors and fuel cycle facilities and the management of radioactive waste), but also activities such as the underground mining of coal and phosphatic and other minerals, should they enhance exposure occurring radioactive substances. Situations that may require intervention include, on the one hand, chronic exposure to naturally occurring sources of radiation (such as radon in dwellings) and to radioactive residues from past activities and events, and, on the other hand, emergency exposure situations such as may result from accidents and from deficiencies in existing installations. The objective of nuclear law is to establish a legislative framework for the safe management of all sources and types of ionizing radiation. It should ensure that individuals, society and the environment are adequately protected against radiological hazards, and it should cover not only practices but also interventions. It should, in addition, cover the medical uses of radiation, situations in which a patient may be voluntarily exposed to high doses of radiation for therapeutic purposes. Let us recall what we have learned in our first lecture. When it comes to practices, the law ensures that the practices are ‘justified’: that they produce sufficient benefit for the exposed individuals and for society to offset the radiation detriment that they may cause (we know it as the justification principle). The law should also ensure that doses, the number of people exposed and the likelihood of incurring exposure are at all times kept as low as reasonably achievable (the ALARA principle of optimization). And finally, it should impose restrictions on the dose that an individual may incur (dose limits), so that no person is subject to an unacceptable risk attributable to radiation exposure, and we know it as the principle of minimization. In the case of interventions, the justification is that the proposed intervention will do more good than harm. The law will provide the form, scale and duration of any intervention to be such that the intervention is optimized, so that the net benefit is maximized. The scope of radiation protection applies to all activities and facilities in which ionizing radiation is emitted by radioactive material of any origin or generated by equipment. The purpose of radiation protection is to ensure that the hazards from radiation are kept ALARA, social and economic factors being taken into account. We should also mentions that the law excludes those cases of exposure to ionizing radiation for which the magnitude or likelihood of the exposure is unamenable to control, for instance exposure to the natural radioactivity in a human body and to cosmic rays at the ground level. There are also certain exemptions – exemption means that, although the practice or the material has not been excluded from regulatory control, it is considered to be of no regulatory concern. There are three exemption criteria: the radiation risk for individuals is sufficiently low to be of any regulatory concern; the collective radiological impact is sufficiently low not to warrant regulatory control; and the practice, with any associated facilities, is considered to be inherently safe, with no likelihood of scenarios that could lead to a failure to meet criterion (1) or (2). In addition, there are certain activities that lack justification to be practiced at all. Absence of a justification is a reason for a regulatory body to refuse to issue a licence. Activities are deemed not to be justified if they result in a deliberate increase in the activity of radioactive substances in an associated commodity or a product. Such activities are: first of all, activities involving food, beverages, cosmetics or any other commodity or product intended for ingestion, inhalation or percutaneous intake by, or for application to, a human; secondly, activities involving the frivolous use of radiation or radioactive substances in products such as toys and personal jewelry or adornments. Another concept that needs to be mentioned is clearance. Clearance means the removal of a radioactive material or a radioactive object involved in authorized practices from further control by a regulatory body. Clearance levels are values, established by a regulatory body, below which, the sources of radiation may be released from regulatory control. Clearance is thus the release of materials whose activity level is so low that no form of post-release regulation is required in order to ensure that the public is sufficiently protected. Thus, clearance may apply to practices that have not been exempted. Its purpose is analogous to that of the exemption of practices, with the essential difference that clearance applies only to material that is already under regulatory control. Clearance levels, as a rule, need to be higher than exemption levels, so that exempted materials do not again become subject to regulatory control.
