1 Scope
This document sets out the basic requirements for the control of radiation exposure of emergency response personnel.
This document applies to the control of radiation exposure of emergency response personnel during a nuclear and radiation emergency response.
2 Normative references
The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, the date of the reference documents, only the date of the corresponding version applies to this document; do not note the date of the reference documents, the latest version (including all the revision of the list) applies 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
Emergency exposure situationemergency exposure situation caused by an accident. Exposure due to malicious acts or other accidental events.
NOTE: This exposure situation requires immediate action to avoid or mitigate adverse consequences. Reducing emergency exposure can only be achieved through protective and other response actions.
This can only be achieved through protective and other response actions.
3.2
Projected dose
The dose of radiation to which the person would be expected to be exposed if no protective action is taken.
3.3 emergency response worker
Emergency response worker A worker who has specific responsibility for emergency response.
Note: Emergency response workers are also referred to as emergency personnel. This includes staff employed directly or indirectly by registrants and licensees, as well as staff of external emergency response organisations, such as police, firefighters, etc.
Staff, such as police, firefighters, medical personnel and drivers and crew of evacuation vehicles, are usually primarily emergency workers who are designated in advance of an emergency to facilitate targeted training, but may or may not be designated in advance.
3.4
helper in emergency
A member of the public who willingly and voluntarily assists in nuclear and β-emergency response.
4 Radiation exposure control requirements
4.1 Basic requirements
4.1.1 Legitimacy
4.1.1.1 In an emergency situation, emergency response actions to reduce or avoid radiation exposure shall be justified.
4.1.1.2 The justification for protective and other response actions in a nuclear and radiation emergency is made clear during the emergency preparedness phase when considering the potential exposure of emergency responders to doses.
4.1.2 Optimisation
The form, scale and duration of protective and other response actions should be optimised so that, overall, the greatest net benefit is obtained under normal social and economic circumstances. The requirements are as follows.
a) During the preparedness phase, the optimisation process should be applied to the protection of emergency responders;
b) In the initial phase of nuclear and radiological emergency response, the protection of emergency workers should be managed in such a way as to minimise exposure from all routes, taking into account the changing and difficult conditions of the emergency; and
c) The process of optimising the protection of emergency responders during the later stages of a nuclear and radiological emergency and during the transition from an emergency to an existing exposure situation should be implemented as required by practice.
4.1.3 Exposure control requirements for emergency responders
4.1.3.1 During general emergency operations, the exposure of emergency responders shall not exceed 50 mSv and in exceptional circumstances, such as exceeding 50 mSv, all reasonable efforts shall be made to keep the exposure of emergency responders below the values in Table 1.
5 Protection of emergency responders
5.1 Arrangements for emergency organisation and operating units
5.1.1 Emergency response personnel should be identified in advance as competent to respond. Pre-arrangements include health monitoring of emergency responders to assess their competence for their initial and subsequent emergency tasks.
5.1.2 The emergency organisation and the operating unit should make arrangements for the registration and inclusion in the emergency response of personnel not identified as emergency responders prior to the emergency and of emergency assistance personnel.
5.1.3 The emergency organisation and the operating unit should identify the expected hazards on and off site to enable emergency responders to carry out their response functions in accordance with hazard assessment and protection strategies in an emergency situation.
5.1.4 Ensure that appropriate protective arrangements are in place for the anticipated hazardous conditions encountered by emergency responders in carrying out their response functions. Such arrangements include, as a minimum:
a) Training of pre-identified emergency responders;
b) immediate training for emergency responders and emergency assistance personnel who have not been identified in advance, prior to the implementation of the response; c) management, control and recording of the dose administered;
d) provide appropriate specialist protective equipment and monitoring equipment; and
e) provide iodine thyroid blockade, as appropriate, in cases of potential radioiodine exposure;
f) the right of emergency responders to be informed of the corresponding risks and to do so voluntarily when carrying out their specified special duties
g) Medical examinations, longer-term medical actions and psychological counselling are carried out as appropriate.
5.2 Protective management
5.2.1 Emergency response organisations and operators should use all practical means to minimise the exposure of emergency responders during nuclear and radiological emergency response and to optimise protective measures.
5.2.2 In a nuclear and radiation emergency, a graded approach applies to the management of the protection of emergency responders. If the expected dose to emergency responders exceeds 50 mSv, the protection, preparedness, dose monitoring etc. should be managed in a graded manner.
Note; A graded approach is a process or a method implemented for a control system (e.g. a regulatory or safety system) where the stringency of the controls and conditions match, as far as practicable, the likelihood of loss of control, the possible consequences and the level of risk.
5.2.3 The emergency response organisation and the operating unit shall ensure that:
a) emergency response personnel who may be exposed to doses exceeding an effective dose of 50 mSv when taking emergency response action should participate voluntarily;
b) they are clearly and fully informed in advance of the health hazards involved and of the protective measures available; c) they are trained, as far as possible, in emergency operations.
5.2.4 Emergency responders who have not been designated in advance should not be the initial emergency responders for the life-saving operations in Table 1.
5.2.5 Arrangements should be made in advance to evaluate the individual doses received by emergency responders during emergency response as soon as possible and to limit their exposure to further emergency exposures where possible.
6 Emergency exposure evaluation
6.1 Emergency exposure evaluation requirements
6.1.1 The emergency organisation and the operating unit shall take all reasonable steps to evaluate and record the exposure of emergency responders in an emergency situation. Where possible, doses to emergency responders and accidental exposures to staff during emergency response should be recorded separately from those received in the course of daily work, but should be noted in the staff member's occupational exposure record.
6.1.2 The precision required for any exposure evaluation should increase with the level of exposure the staff member may have received. Guidance documents may be developed in advance so that emergency responders are expressed in terms of directly measurable quantities such as dose received, dose rate or air concentration. Exposure of emergency response personnel should be monitored individually by the use of an applicable method, such as a direct reading dosimeter or a personal dose alarm.
6.1.3 Occupational exposure records should be established and maintained in a simplified standard format by all emergency response organisations and operating units to avoid confusion. Information on doses received and associated health risks should be communicated to the appropriate emergency response personnel.
6.1.4 In the event of a nuclear power plant accident, criticality accident, industrial irradiation facility accident, emergency response to loss or theft of a radioactive source, staff may be accidentally exposed to high levels of exposure. Such exposures may be evaluated using data from personal and workplace monitors, or other more sophisticated and specialised retrospective dosimetry techniques such as chromosomal aberration analysis, electron spin resonance (ESR), accident simulation and computer modelling.
6.1.5 Particular attention should be paid to the applicability of dosimetric functions if the personal dose to emergency responders may significantly exceed that expected under normal working conditions and may approach the dose action level for acute exposures in Table E1.1 of GB 18871-2002.
6.2 Evaluation of external exposure
6.2.1 The choice of personal dosimeter depends on the type of radiation and the tissue or organ. Depending on the practicalities of personal monitoring, H,(10), H,(3) and H,(o.07) personal dosimeters are selected for personal monitoring respectively. The following types of dosimeters can be used.
7 Management of overexposed personnel
7.1 Emergency response organisations and operating units should have plans in place to manage and address situations where personnel may be overexposed during an emergency, including the medical management and possible health effects of overexposed personnel.
7.2 In the event of a significant overexposure, the emergency response organisation and the nuclear facility operator shall immediately conduct an investigation and analysis to evaluate the dose received by personnel.
7.3 In cases where the assessed dose is significantly higher than the dose limit (100 mSv or higher), specialised dose investigations, including biological dose monitoring (e.g. analysis of chromosomal aberrations in somatic cells, mainly lymphocytes), and further diagnostic or medical treatment should be carried out. The medical management of persons exposed to high doses of external radiation should take into account all adverse health effects, especially deterministic effects.
7.4 In cases where persons have ingested large amounts of radioactive material, effective measures should be taken to reduce the dose. The medical intervention to be taken depends on the type of radionuclide ingested, the size of the organ-content equivalent dose, the efficiency of protective measures and the potential hazards. Medical interventions should be implemented if they are justified, i.e. if the effect of the dose reduction outweighs the side effects. Examples of such treatment include the use of tri-sodium calcium salts (Ca-DTPA) to promote the excretion of steel-based elements, forced diuresis after fluoride ingestion, and surgical excision of contaminated wounds.
7.5 A detailed investigation of the accident will involve experts in different fields, in particular occupational physicians and radiation protection specialists. There should be close liaison between these specialists to ensure that all actions taken to provide a medical surface are effectively coordinated. When it is suspected that the received dose is close to or above the broad values for deterministic effects, the absorbed dose and whole-body distribution are evaluated as accurately as possible and the affected person is given an appropriate medical examination.
Bibliography
Foreword
1 Scope
2 Normative references
3 Terminology and definitions
4 Radiation exposure control requirements
5 Protection of emergency responders
6 Emergency exposure evaluation
7 Management of overexposed personnel
Bibliography
