Recommended citation
ICRP, 2020. Radiological protection of people and the environment in the event of a large nuclear accident: update of ICRP Publications 109 and 111. ICRP Publication 146.Ann. ICRP 49(4).
Authors on behalf of ICRP
M. Kai, T. Homma, J. Lochard, T. Schneider, J.F. Lecomte, A. Nisbet, S. Shinkarev, V. Averin, T. Lazo
Abstract - This publication provides a framework for the protection of people and the environment in a large nuclear accident, drawing on experience of the Chernobyl and Fukushima accidents. In managing accidents, the Commission makes a distinction between the early and intermediate phases, considered emergency exposure situa-tions, and the long-term phase, considered an existing exposure situation. In emergency and existing exposure situations, mitigating the radiological consequences on humans and the environment is achieved using the fundamental principles of justification of decisions and optimisation of protection. The Commission recommends a set of reference levels for the optimisation of protection of the general population and responders, both on-site and off-site, for all accident phases. Implementation of protective actions should not only take account of radiological factors, but also consider societal, environmental, and economic aspects to protect health, ensure sustainable living conditions for the affected people, ensure suitable working conditions for the responders, and maintain the quality of the environment. In the early phase of an accident, urgent protective actions have to be taken, often with little information. Decisions rely on actions identified during preparedness planning that best match the actual situation. During the intermediate phase, protective actions reduce radiation exposures progressively. When the radiological situation is sufficiently characterised, the long-term phase begins, during which further protective actions are implemented to improve living and working conditions. Authorities should invite key representative stakeholders to participate in the preparedness process, and in the management of the successive phases of the accident. It is the role of the authorities to implement radiation monitoring and health surveillance, and to provide the conditions and means for sharing information and expertise to enable individuals to develop a radiological protection culture and to make informed decisions about their own protection.
© 2020 ICRP. Published by SAGE.
Keywords: Chernobyl accident; Fukushima accident; Emergency exposure situation; Existing exposure situation; Justification; Optimisation; Reference level; Protective actions; Stakeholder involvement; Co-expertise process; Radiological protection culture.
Key Points
A large nuclear accident causes a breakdown in society affecting all aspects of individual and community life. It has large and long-lasting societal, environmental, and economic consequences.
Characterisation of the radiological situation on-site and off-site is essential to guide protective actions, and should be conducted as quickly as possible.
The Commission recommends using reference levels to guide the implementation of protective actions during the early, intermediate, and long-term phases of an accident.
The objective of radiological protection is to mitigate radiological consequences for people and the environment whilst, at the same time, ensuring sustainable living conditions for the affected people, suitable working conditions for the responders, and maintaining the quality of the environment.
Responders, who are likely to be the most exposed individuals, should be provided with appropriate protection, taking into account the requirements of the response onsite and off-site.
Responsible organisations should promote the involvement of local communities in a co-operative process with experts (co-expertise process) to help achieve a better assessment of the local situation, the development of an adequate practical radiological protection culture, and informed decision-making among those affected.
Preparedness planning is essential for mitigating the consequences during phases of a large nuclear accident, and should involve stakeholders.
Executive Summary
(a) Large nuclear accidents result when there are significant releases of radioactive material into the environment, impacting widespread areas and affecting extensive populations. They are unexpected events that profoundly affect individuals, society, and the environment. They generate complex situations and legitimate concerns, particularly regarding health, for all those affected by the presence of undesirable sources of radioactivity. Management of these situations requires the long-term mobilisation of considerable human and financial resources. Radiological protection, although indispensable, only represents one dimension of the contributions that need to be mobilised to cope with the issues facing all affected individuals and organisations.
(b) For managing these events, the Commission makes a distinction between the early and intermediate phases of the accident, considered as emergency exposure situations, and the long-term phase, considered as an existing exposure situation. The Commission also distinguishes between on-site and off-site to differentiate activities at the damaged installation and in the affected areas. The present recommendations may be applicable to other types of radiological emergencies, with due consideration of the differences that inevitably exist between a nuclear accident and these emergencies.
(c) Characterisation of the radiological situation on-site and off-site is essential to guide protective actions, and should be conducted as quickly as possible to address the uncertainties regarding the intensity, duration, and extent of the radioactive contamination. (d) In emergency and existing exposure situations, the objectives of radiological protection are achieved using the fundamental principles of justification and optimisation. The principle of justification ensures that decisions regarding the implementation of protective actions result in a benefit for the affected people and the environment, as these actions can potentially induce significant disruption. The principle of optimisation of protection applied with reference levels aims to limit inequity in the distribution of individual exposures, and to maintain or reduce all exposures to as low as reasonably achievable, taking into account societal, environmental, and economic factors.
(e) Justification and optimisation are applied in the mitigation of radiological consequences to people and the environment during all phases of the accident, and should take careful account of all non-radiological factors in order to preserve or restore the living and working conditions of all those affected, including decent lifestyles and livelihoods.
(f) People involved in the direct management of the consequences of a nuclear accident are diverse in terms of their background, status, degree of preparation, and training on radiological protection. They include emergency teams (firefighters, police officers, medical personnel, etc.), workers (occupationally exposed or not), and other people such as elected representatives or citizens acting as volunteers. All these categories are considered by the Commission as ‘responders’. They deserve to be adequately protected and provided with suitable working conditions.
(g) For the protection of responders on-site, the reference level during the early phase should not generally exceed 100 mSv, while recognising that higher levels, in the range of a few hundred millisieverts, may be permitted to responders in exceptional circumstances to save lives or to prevent further degradation at the facility leading to catastrophic conditions. Lower reference levels may be selected based on the situation, in accordance with the severity of the accident. During the intermediate phase, the reference level should not exceed 100 mSv. For the long-term phase, the reference level should not exceed 20 mSv per year, with possible special arrangements limited in time. The Commission recommends that responsible organisations should take all practical actions to avoid unnecessary accumulation of exposures for responders involved in both the early and intermediate phases.
(h) For the protection of responders off-site, the Commission recommends selection of a reference level not exceeding 100 mSv for the early phase and 20mSv per year for the intermediate phase. For the long-term phase, the reference level should be selected within the lower half of the recommended band of 1–20 mSv per year.
(i) For the protection of people, the reference level should not generally exceed 100 mSv for the entire duration of both the early and intermediate phases. The Commission recommends that responsible organisations should adopt a lower reference level whenever possible. For the long-term phase, the reference level should be selected in the lower half of the recommended band of 1–20 mSv per year for existing exposure situations, taking into account the actual distribution of doses in the population and the societal, environmental, and economic factors influencing the exposure situation. The objective of optimisation of protection is a progressive reduction in exposure to levels towards the lower end of the band, or below if possible.
(j) In some nuclear accident scenarios, release of radioactive iodine can result in high thyroid exposures due to inhalation or ingestion. Specific efforts should be made to avoid, or at least reduce, intakes of radioactive iodine, particularly in children and pregnant women. During the early phase or just after, exposed people should be monitored to detect potential exposure to radioactive iodine.
(k) Management of the protection of people in affected areas in the intermediate and long-term phases is a complex process involving not only radiological factors, but also societal, environmental, and economic considerations. This process includes actions implemented by national and local authorities, and self-help protective actions taken by residents of the affected areas. In these phases, radiation exposures of people living and working in affected areas are largely dependent upon individual lifestyles. The Commission recommends that authorities, experts, and stakeholders should co-operate in the so-called ‘co-expertise process’ to share experience and information, promote involvement in local communities, and develop a practical radiological protection culture to enable people to make informed decisions. Individual measurements with suitable devices, together with relevant information, are very helpful in the implementation of this process.
(l) For the protection of the environment, the Commission recommends that fauna and flora should be protected using its framework based on Reference Animals and Plants, together with derived consideration reference levels. The impacts of protective actions on pets and livestock, as well as on the environment, in terms of sustainable development, conservation, preservation, and maintenance of biological diversity should also be addressed.
(m) The Commission recommends that plans should be prepared in advance to avoid severe and long-term consequences following a nuclear accident. Such preparedness plans should comprise a set of consistent protective actions, adapted to local conditions at nuclear sites, taking into account the societal, environmental, and economic factors that will affect the impact of the accident and its response.
Given the significant concern about military action around the Zaporizhzhia nuclear power plant, and the possibility of similar activity around other NPPs in Ukraine, the International Commission on Radiological Protection (ICRP), in partnership with SAGE publishing UK, has made ICRP Publication 146 Radiological Protection of People and the Environment in the Event of a Large Nuclear Accident immediately free to access. Although this publication was not specifically intended to cover radioactive releases due to military action, the principles and guidance provided should be helpful should such an unfortunate event occur. We hope this helps those responsible for planning the response to a large nuclear accident to be better prepared, and that it will not be necessary to put these plans into action. (23 August 2022)
ICRP, 2020. Radiological protection of people and the environment in the event of a large nuclear accident: update of ICRP Publications 109 and 111. ICRP Publication 146.Ann. ICRP 49(4).
Authors on behalf of ICRP
M. Kai, T. Homma, J. Lochard, T. Schneider, J.F. Lecomte, A. Nisbet, S. Shinkarev, V. Averin, T. Lazo
Abstract - This publication provides a framework for the protection of people and the environment in a large nuclear accident, drawing on experience of the Chernobyl and Fukushima accidents. In managing accidents, the Commission makes a distinction between the early and intermediate phases, considered emergency exposure situa-tions, and the long-term phase, considered an existing exposure situation. In emergency and existing exposure situations, mitigating the radiological consequences on humans and the environment is achieved using the fundamental principles of justification of decisions and optimisation of protection. The Commission recommends a set of reference levels for the optimisation of protection of the general population and responders, both on-site and off-site, for all accident phases. Implementation of protective actions should not only take account of radiological factors, but also consider societal, environmental, and economic aspects to protect health, ensure sustainable living conditions for the affected people, ensure suitable working conditions for the responders, and maintain the quality of the environment. In the early phase of an accident, urgent protective actions have to be taken, often with little information. Decisions rely on actions identified during preparedness planning that best match the actual situation. During the intermediate phase, protective actions reduce radiation exposures progressively. When the radiological situation is sufficiently characterised, the long-term phase begins, during which further protective actions are implemented to improve living and working conditions. Authorities should invite key representative stakeholders to participate in the preparedness process, and in the management of the successive phases of the accident. It is the role of the authorities to implement radiation monitoring and health surveillance, and to provide the conditions and means for sharing information and expertise to enable individuals to develop a radiological protection culture and to make informed decisions about their own protection.
© 2020 ICRP. Published by SAGE.
Keywords: Chernobyl accident; Fukushima accident; Emergency exposure situation; Existing exposure situation; Justification; Optimisation; Reference level; Protective actions; Stakeholder involvement; Co-expertise process; Radiological protection culture.
Key Points
A large nuclear accident causes a breakdown in society affecting all aspects of individual and community life. It has large and long-lasting societal, environmental, and economic consequences.
Characterisation of the radiological situation on-site and off-site is essential to guide protective actions, and should be conducted as quickly as possible.
The Commission recommends using reference levels to guide the implementation of protective actions during the early, intermediate, and long-term phases of an accident.
The objective of radiological protection is to mitigate radiological consequences for people and the environment whilst, at the same time, ensuring sustainable living conditions for the affected people, suitable working conditions for the responders, and maintaining the quality of the environment.
Responders, who are likely to be the most exposed individuals, should be provided with appropriate protection, taking into account the requirements of the response onsite and off-site.
Responsible organisations should promote the involvement of local communities in a co-operative process with experts (co-expertise process) to help achieve a better assessment of the local situation, the development of an adequate practical radiological protection culture, and informed decision-making among those affected.
Preparedness planning is essential for mitigating the consequences during phases of a large nuclear accident, and should involve stakeholders.
Executive Summary
(a) Large nuclear accidents result when there are significant releases of radioactive material into the environment, impacting widespread areas and affecting extensive populations. They are unexpected events that profoundly affect individuals, society, and the environment. They generate complex situations and legitimate concerns, particularly regarding health, for all those affected by the presence of undesirable sources of radioactivity. Management of these situations requires the long-term mobilisation of considerable human and financial resources. Radiological protection, although indispensable, only represents one dimension of the contributions that need to be mobilised to cope with the issues facing all affected individuals and organisations.
(b) For managing these events, the Commission makes a distinction between the early and intermediate phases of the accident, considered as emergency exposure situations, and the long-term phase, considered as an existing exposure situation. The Commission also distinguishes between on-site and off-site to differentiate activities at the damaged installation and in the affected areas. The present recommendations may be applicable to other types of radiological emergencies, with due consideration of the differences that inevitably exist between a nuclear accident and these emergencies.
(c) Characterisation of the radiological situation on-site and off-site is essential to guide protective actions, and should be conducted as quickly as possible to address the uncertainties regarding the intensity, duration, and extent of the radioactive contamination. (d) In emergency and existing exposure situations, the objectives of radiological protection are achieved using the fundamental principles of justification and optimisation. The principle of justification ensures that decisions regarding the implementation of protective actions result in a benefit for the affected people and the environment, as these actions can potentially induce significant disruption. The principle of optimisation of protection applied with reference levels aims to limit inequity in the distribution of individual exposures, and to maintain or reduce all exposures to as low as reasonably achievable, taking into account societal, environmental, and economic factors.
(e) Justification and optimisation are applied in the mitigation of radiological consequences to people and the environment during all phases of the accident, and should take careful account of all non-radiological factors in order to preserve or restore the living and working conditions of all those affected, including decent lifestyles and livelihoods.
(f) People involved in the direct management of the consequences of a nuclear accident are diverse in terms of their background, status, degree of preparation, and training on radiological protection. They include emergency teams (firefighters, police officers, medical personnel, etc.), workers (occupationally exposed or not), and other people such as elected representatives or citizens acting as volunteers. All these categories are considered by the Commission as ‘responders’. They deserve to be adequately protected and provided with suitable working conditions.
(g) For the protection of responders on-site, the reference level during the early phase should not generally exceed 100 mSv, while recognising that higher levels, in the range of a few hundred millisieverts, may be permitted to responders in exceptional circumstances to save lives or to prevent further degradation at the facility leading to catastrophic conditions. Lower reference levels may be selected based on the situation, in accordance with the severity of the accident. During the intermediate phase, the reference level should not exceed 100 mSv. For the long-term phase, the reference level should not exceed 20 mSv per year, with possible special arrangements limited in time. The Commission recommends that responsible organisations should take all practical actions to avoid unnecessary accumulation of exposures for responders involved in both the early and intermediate phases.
(h) For the protection of responders off-site, the Commission recommends selection of a reference level not exceeding 100 mSv for the early phase and 20mSv per year for the intermediate phase. For the long-term phase, the reference level should be selected within the lower half of the recommended band of 1–20 mSv per year.
(i) For the protection of people, the reference level should not generally exceed 100 mSv for the entire duration of both the early and intermediate phases. The Commission recommends that responsible organisations should adopt a lower reference level whenever possible. For the long-term phase, the reference level should be selected in the lower half of the recommended band of 1–20 mSv per year for existing exposure situations, taking into account the actual distribution of doses in the population and the societal, environmental, and economic factors influencing the exposure situation. The objective of optimisation of protection is a progressive reduction in exposure to levels towards the lower end of the band, or below if possible.
(j) In some nuclear accident scenarios, release of radioactive iodine can result in high thyroid exposures due to inhalation or ingestion. Specific efforts should be made to avoid, or at least reduce, intakes of radioactive iodine, particularly in children and pregnant women. During the early phase or just after, exposed people should be monitored to detect potential exposure to radioactive iodine.
(k) Management of the protection of people in affected areas in the intermediate and long-term phases is a complex process involving not only radiological factors, but also societal, environmental, and economic considerations. This process includes actions implemented by national and local authorities, and self-help protective actions taken by residents of the affected areas. In these phases, radiation exposures of people living and working in affected areas are largely dependent upon individual lifestyles. The Commission recommends that authorities, experts, and stakeholders should co-operate in the so-called ‘co-expertise process’ to share experience and information, promote involvement in local communities, and develop a practical radiological protection culture to enable people to make informed decisions. Individual measurements with suitable devices, together with relevant information, are very helpful in the implementation of this process.
(l) For the protection of the environment, the Commission recommends that fauna and flora should be protected using its framework based on Reference Animals and Plants, together with derived consideration reference levels. The impacts of protective actions on pets and livestock, as well as on the environment, in terms of sustainable development, conservation, preservation, and maintenance of biological diversity should also be addressed.
(m) The Commission recommends that plans should be prepared in advance to avoid severe and long-term consequences following a nuclear accident. Such preparedness plans should comprise a set of consistent protective actions, adapted to local conditions at nuclear sites, taking into account the societal, environmental, and economic factors that will affect the impact of the accident and its response.
Given the significant concern about military action around the Zaporizhzhia nuclear power plant, and the possibility of similar activity around other NPPs in Ukraine, the International Commission on Radiological Protection (ICRP), in partnership with SAGE publishing UK, has made ICRP Publication 146 Radiological Protection of People and the Environment in the Event of a Large Nuclear Accident immediately free to access. Although this publication was not specifically intended to cover radioactive releases due to military action, the principles and guidance provided should be helpful should such an unfortunate event occur. We hope this helps those responsible for planning the response to a large nuclear accident to be better prepared, and that it will not be necessary to put these plans into action. (23 August 2022)
Translations
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Other Resources
Free Excerpt from ICRP Publication 146Preliminary Japanese Translation of excerpts from ICRP Publication 146
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