1 Scope
This document specifies the types of emergency preparedness for nuclear facilities based on hazard assessment and the management requirements for their different emergency preparedness types.
This document applies to the classification of nuclear emergency preparedness for nuclear facilities in China and for nuclear facilities in neighbouring countries affecting China during emergency preparedness.
2 Normative references
The contents of the following documents constitute essential provisions of this document through normative references in the text. Where a reference is dated, only the version corresponding to that date is applicable to this document; where a reference is not dated, the latest version (including all amendment sheets) is applicable to this document.
GB 18871-2002 Basic standards for ionising radiation protection and safety of radiation sources
3 Terminology and definitions
The following terms and definitions apply to this document.
3.1
Helper in emergency
A member of the public who willingly and voluntarily assists in a nuclear and radiological emergency response.
Note: Emergency helpers are protected and informed of the risks of radiation exposure while assisting in a nuclear and radiation emergency response.
3.2 Protective action
Protective action
Action taken to avoid or reduce the dose that may be received in an emergency exposure situation.
Note: An emergency exposure situation is an exposure situation that is the result of a malicious act, accident or other unanticipated event. Such exposure situations require immediate action to avoid or mitigate adverse effects. Reduction of emergency exposures is achieved through protective and other response actions.
3.3
Precautionary urgent protective action
Emergency protective action taken to avoid or minimise the risk of serious deterministic effects, depending on the situation at the time, before or shortly after the release or exposure of radioactive material.
3.4 emergency protective action
emergency protective action
Protective action taken rapidly (usually within a few hours to a day) in a nuclear and radiation emergency situation, where delay would significantly reduce its effectiveness.
Note: Emergency protective action includes iodine thyroid blockade, evacuation, short-term sheltering, actions to reduce inadvertent ingestion, personal decontamination and prevention of ingestion of potentially contaminated food, milk or drinking water.
4 Objectives and tasks of emergency preparedness
4.1 Make every effort to prevent accidents and mitigate their consequences. The most serious consequences of hazards caused by the facility are the loss of control of nuclear reactor cores, nuclear criticality reactions, radioactive substances, etc. Therefore, to ensure that the incidence of accidents is kept at a very low level, the following measures should be taken:
a) Prevention of failures or abnormal operating conditions (including security failures) that could lead to loss of control;
b) prevent the escalation of failures or abnormal conditions that have already occurred;
c) prevent the loss of control of radioactive material.
4.2 The objective of emergency preparedness is to provide the operating unit, local and national with the capability to respond effectively to emergencies by establishing the following infrastructure elements
a) Delegation of authority and responsibility;
b) Management systems;
c) organisation and staffing;
d) Coordination;
e) plans and procedures;
f) tools, equipment and facilities; g) training, drills and exercises.
4.3 The tasks of emergency preparedness are as follows.
a) Establish and maintain a coherent emergency management system designed to protect human life, health and the environment in the event of an emergency. The characteristics of an emergency management system are:
1) The system should be designed to match the results of the hazard assessment and to enable an effective emergency response to reasonably foreseeable accidents, including very low probability accidents; and
2) the system is integrated, as far as practicable, with the emergency management system for all hazards.
b) Emergency plans and procedures are in place that are appropriate to the nature and magnitude of the hazard, and appropriate emergency preparedness is in place.
5 Hazard assessment as a basis for classification of emergency preparedness
5.1 The operator should carry out a hazard assessment of the nuclear facility using a graded approach. The results of the hazard assessment shall be used as the basis for emergency preparedness. 5.2 The subject of the hazard assessment shall include:
a) accidents that may affect the facility, including over-design basis accidents
b) Nuclear emergencies in combination with conventional events that may cause wider radiological effects and may reduce the ability to support emergency response, such as earthquakes, volcanic eruptions, tropical cyclones, severe weather, tsunamis, aircraft crashes or emergencies caused by social security events;
c) co-incidental events, and inter-facility interactions; d) accidents at nuclear facilities outside of the country that may affect domestic areas.
5.3 The hazard assessment should include the identification of facilities and sites where uncontrolled sources of risk may exist.
5.4 The hazard assessment shall be based on the results of historical accident experience and accident analysis of nuclear facilities, probabilistic safety assessments, etc., including over-design basis accidents. The hazard assessment shall incorporate the results of the nuclear security threat assessment and the hazard assessment shall also identify non-radiological hazards that may affect the effectiveness of response actions.
5.5 In the hazard assessment, facilities, sites, onsite areas and offsite areas should be identified, and where limited information is available and uncertainty exists, the following actions may be required:
a) Preventive emergency protective actions to bring the expected dose below the acute exposure in Table E.1 in Appendix E of GB 18871-2002
a) Take precautionary emergency protective action to keep the expected dose below the dose action level for acute exposures in Table E.1 in Appendix E of GB 18871-2002 to avoid or minimise severe deterministic effects;
b) take emergency protective and other response actions to avoid or minimise severe deterministic effects and to reduce the risk of stochastic effects;
c) take early protective and other response actions;
d) take other emergency response actions, such as longer-term medical actions, and response actions aimed at terminating the emergency; e) implement protection for emergency (response) personnel.
5.6 Hazard evaluation reviews should be carried out periodically with the aim of
a) identify all facilities, sites, onsite areas and offsite areas that may require emergency response;
b) consider changes in hazards within and outside the country, changes in nuclear security threat assessments, lessons learned from research, operations and emergency exercises, and technological developments. If necessary, use the results of the review to revise emergency plans and procedures.
6 Types of emergency preparedness
The classification of a nuclear facility's emergency preparedness depends, firstly, on the nature of the facility and, secondly, on the type and quantity of radioactive material contained in the facility and the hazards of a potential accident (probability of occurrence and level of hazard). The types of emergency preparedness for nuclear facilities corresponding to hazards are divided into four categories (see Table 1), which facilitate the development of justification and optimisation analyses of emergency preparedness and response. Emergency preparedness is based on hazard assessment and emergency preparedness should be matched to hazards and potential consequences as a specific application of the classification approach.
7 Management of different emergency preparedness types
7.1 Emergency management actions
The emergency management actions that may be required for different emergency preparedness types are shown in Table 2.
7.2 Emergency states
The possible emergency states involved in the different emergency preparedness types are shown in Table 3.
7.3 Emergency response activation
The arrangements for activating emergency response for different emergency preparedness types are shown in Table 4.
7.4 Mitigating Actions
Preparations for mitigation actions consider all possible operating conditions affecting the emergency response, including facility operating conditions, natural events, human-caused events or conditions arising from other events affecting infrastructure within the site and other facilities in the vicinity. These preparations include the emergency management procedures and guidelines to be used by operators for mitigation actions for all scenario emergency situations. Consideration is given to maintaining a well-functioning nuclear security system. Mitigation actions for the different emergency preparedness types are shown in Table 5.
Bibliography
Foreword
1 Scope
2 Normative references
3 Terminology and definitions
4 Objectives and tasks of emergency preparedness
5 Hazard assessment as a basis for classification of emergency preparedness
6 Types of emergency preparedness
7 Management of different emergency preparedness types
Bibliography
