[en] The continuous use of nuclear power to generate electricity and the continued threat of radioactive materials being used for nefarious reasons reminds us of the importance to stay prepared to respond to nuclear or radiological emergencies. Stringent nuclear safety and nuclear security requirements, the training of personnel, operational checks and legal frameworks cannot always prevent radiation-related emergencies. Though these events can range in severity, each has the potential to cause harm to the public, employees, patients, property and the environment. Until the Chernobyl nuclear accident in 1986, there was no international information exchange system. Immediately following that accident, the international community negotiated the so-called Emergency Conventions to ensure that the country suffering an accident with an international transboundary release of radioactive material would issue timely, authenticated information, while the States that could field technical support, would do so in a coordinated fashion. The Conventions also place specific legal obligations on the International Atomic energy Agency (IAEA) with regard to emergency preparedness and response. (Author)

[en] Radiological emergencies arise when there is a hazard due to radiation exposure from a source. Preparedness for such emergencies is vital to ensure effective response and mitigation of harm to the public and the environment. The International Atomic Energy Agency’s Incident and Emergency Centre (IEC) is the global focal point for emergency preparedness and response for nuclear and radiological safety or security related emergencies. By providing a 24/7 operational system, the IEC shares with Member States and International Organizations clear, factually correct, objective and easily understandable information, performs assessment of this information, and provides international assistance for emergencies, upon request, with involvement of the IAEA Response and Assistance Network (RANET). To ensure effective preparedness, the IEC works with Member States in their national level exercises to practice the conduct and sharing of assessment and prognosis during an event, to learn lessons regarding the difficulties generating such harmonized messages and to improve this process. This preparation is vital for the IAEA to maintain a suitably robust capability and adaptability for the wide range of emergencies that can arise from radioactive sources. (author)

[en] Short communication

[en] Full text: The rational behind the decisions on radiation protection for public in case of nuclear or radiological accident is primarily based on radiation risks. Investigation of long-term medical consequences of the Chernobyl accident provides a unique opportunity to obtain a new data on these risk factors. Risk assessment of radiation induced cancers requires a period of time following the accidental exposure, during which the latent period will be finished and certain amount of excess cancer cases may be revealed. This time period now elapsed for the Chernobyl accident. During last 15 years studies of stochastic consequences of the Chernobyl accident among population of Belarus have allowed estimating risk coefficient only for radiation induced thyroid cancer. On the other hand only prognosis of possible radiation induced excess cases for solid tumours could be made. Such prognosis was indeed performed for Belarusian population using models of RERF, UNSCEAR and BEIR. Radiation risks for fatal cancers during life time and lost of life expectancy were calculated as parameters of radiation detriment. The results strongly support the necessity of aimed medical follow-up for different categories of population based on level of doses, age of exposure and gender. The paper will present results of prognosis for radiation induced cancers of different types: incidence rate of fatal cancers during lifetime (per 10⁵ of population), excess incidence rate for different types of cancer (per 10⁵ of population), and lost of life expectancy in case of death from radiation induced cancer. (author)

[en] Radiological emergencies arise when there is a hazard due to radiation exposure from a source. Preparedness for such emergencies is vital to ensure effective response and mitigation of harm to the public and the environment. The International Atomic Energy Agency’s Incident and Emergency Centre (IEC) is the global focal point for emergency preparedness and response for nuclear and radiological safety or security related emergencies. By providing a 24/7 operational system, the IEC shares with Member States and International Organizations clear, factually correct, objective and easily understandable information, performs assessment of this information, and provides international assistance for emergencies, upon request, with involvement of the IAEA Response and Assistance Network (RANET). To ensure effective preparedness, the IEC works with Member States in their national level exercises to practice the conduct and sharing of assessment and prognosis during an event, to learn lessons regarding the difficulties generating such harmonized messages and to improve this process. This preparation is vital for the IAEA to maintain a suitably robust capability and adaptability for the wide range of emergencies that can arise from radioactive sources. (author)

[en] The thyroid doses received by the juvenile population of Belarus following the Chernobyl accident ranged up to about 10 Gy. The thyroid cancer risk estimate recommended in NCRP Report No. 80 was used to predict the number of thyroid cancer cases among children during 1990-1992 in selected Belarussian regions and cities. The results obtained using this risk estimate show an excess of thyroid cancer cases being registered vs. the predicted cases. Thyroid cancer incidence rate among boys under investigation is higher than among girls in the postaccident period. The excess of the observed over the expected incidence in the general juvenile population is caused by the high thyroid cancer incidence rate among boys. These results, which can be considered part of the first stage of a thorough thyroid cancer risk estimation after the Chernobyl accident, demonstrate the critical need to complete these studies in depth. 6 refs., 5 figs., 3 tabs

[en] The IAEA’s Statute authorizes the IAEA to establish or adopt — in consultation and, where appropriate, in collaboration with the competent organs of the United Nations and the specialized agencies concerned — standards of safety for the protection of health and the minimization of danger to life and property, and to provide for the application of these standards. The IAEA commenced its safety standards programme in 1958. The first Safety Standard in the area of emergency preparedness and response (EPR), Safety Requirement No. GS-R-2 (Preparedness and Response for a Nuclear or Radiological Emergency) was issued in 2002 and co-sponsored by seven international organizations. This Safety Requirements publication established the requirements for an adequate level of preparedness and response for a nuclear or radiological emergency in any State. In 2015, it was superseded by Safety Requirement No. GSR Part 7 (Preparedness and Response for a Nuclear or Radiological Emergency), which was co-sponsored by 13 international organizations (FAO, IAEA, ICAO, ILO, IMO, INTERPOL, OECD/NEA, PAHO, CTBTO, UNEP, OCHA, WHO and WMO). Currently, the set of Safety Standards in the area of EPR includes Safety Requirement No. GSR Part 7 and three Safety Guides, while two additional Safety Guides are at the final stage of preparation or publication. The safety standards in the area of EPR are based on the scientific considerations derived from the findings of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). They take into account the recommendations of international expert bodies, notably the International Commission on Radiological Protection (ICRP), and provide for their practical application.

[en] Belarus is one of the most contaminated Republic due to the Chernobyl accident. 23% of the entire area of Belarus was contaminated with radionuclides. To protect the population after the accident different types of protective actions were performed during all phases, based on various temporary dose limits. An analysis of conducted protective actions and lessons obtained during the emergency response is briefly presented

[en] Various measures, introduced to reduce external and internal radiation doses of inhabitants of territories contaminated by the Chernobyl accident, are described. Average annual doses are given. It is concluded that while factors such as reduction of psychoemotional tension need to be explored, risk coefficients for chronic exposure at low doses should be specified. (author)

[en] Low doses of radiation and the protection of the thyroid gland is one of the most important issues at the early stage of the accident. In addition to the existing experience, the Chernobyl data obtained in Belarus could provide a new information to protect the human thyroid in the case of the reactor accident. The majority of Belarusian territory was contaminated with I-131 with density of contamination ranged from 0.4 to 37 MBq/sq.m. In response to the Chernobyl accident, several types of protective actions to decrease exposure of the thyroid were taken in Belarus. However, Implementation of most of the protective actions was delayed by days. Low efficiency of thyroid gland protection lead to the formation of avoidable thyroid doses and, as a consequence, to the development of radiation-induced thyroid cancer. These cancers are being seen among the population living near the plant and also among people who were living at a considerable distance. The effectiveness of protective actions for thyroid was assessed by the analysis of registered thyroid cancer cases under the framework of risk assessment. The cohort of Belarusian population under 18 years old at the time of the accident was studied. Those who were living within 100 km from the NPP received the highest thyroid doses. The recent IAEA generic intervention level for thyroid blocking was exceeded in this group and also for the people who were living up to 400 km from the reactor. Among the population of the mentioned age group for contaminated Gomel and Brest regions within 100 km from the NPP, the average annual incidence rate of thyroid cancer during 1991-1997 is 31,0 per 10⁵; from 100 to 200 km -10,9; from 200 to 300 km - 13.5; from 300 to 400 km - 3.3; more than 400 km - 1,6 per 10⁵. These incidence rates are higher than background level and show the necessity of thyroid protection from uptake of radioiodine at great distance from the accident. This approach was not used before the Chernobyl. Considering cost-benefit analysis along with basic principles of radiation protection, costs of such measures within these territories will be justified in the case of emergency. (author)