1FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS, INTERNATIONAL ATOMIC ENERGY AGENCY, INTERNATIONAL LABOUR ORGANIZATION, OECD NUCLEAR ENERGY AGENCY, PAN AMERICAN HEALTH ORGANIZATION, UNITED NATIONS OFFICE FOR THE COORDINATION OF HUMANITARIAN AFFAIRS, WORLD HEALTH ORGANIZATION, Preparedness and Response for a Nuclear or Radiological Emergency, IAEA Safety Standards Series No. GS-R-2, IAEA, Vienna (2002).

2The ‘new normality’ is the situation compared with the situation before the emergency. In the context of this Safety Guide, the new normality represents either an existing exposure situation or a planned exposure situation.

3Notwithstanding the definitions of these terms, for reasons of brevity, in this Safety Guide the term ‘emergency’ is intended to mean a nuclear or radiological emergency, unless otherwise specified.

4From the definitions, it is obvious that each emergency exposure situation takes place within a nuclear or radiological emergency; however, in a nuclear or radiological emergency, an emergency exposure situation might not apply to every individual. There might be situations in which conditions indicative of a nuclear or radiological emergency have been identified at a site and the appropriate emergency class has been declared (i.e. an adequate level of emergency response has been activated) before any exposures occur as a result of these conditions.

5Examples of such emergencies include a general emergency at a nuclear power plant, an emergency involving a lost dangerous source, an emergency arising from an accidental overexposure of patients, an emergency involving a release (irrespective of whether intentional or not) of radioactive material to the environment and an emergency arising from a transport accident involving nuclear or radioactive material.

6“(1) For a system of control, such as a regulatory system or a safety system, a process or method in which the stringency of the control measures and conditions to be applied is commensurate, to the extent practicable, with the likelihood and possible consequences of, and the level of risk associated with, a loss of control.(2) An application of safety requirements that is commensurate with the characteristics of the facilities and activities or the source and with the magnitude and likelihood of the exposures” (GSR Part 7 [2]).

7An interested party is a “person, company, etc. with a concern or interest in the activities and performance of an organization, business, system, etc.” (GSR Part 7 [2]).

8A Safety Guide on arrangements for public communication in preparedness and response for a nuclear or radiological emergency is in preparation. Further practical guidance on public communication in emergency preparedness and response can also be found in Refs [20, 21].

9A situation is considered stable when the source has been brought under control, no further significant accidental releases or exposures resulting from the event are expected and the future development of the situation is well understood.

10These emergency arrangements include arrangements for the implementation of urgent protective actions, early protective actions and other response actions.

11For example, the urgent response phase may last just hours in the case of a small scale emergency, such as a radiological emergency during transport or a radiological emergency involving a sealed dangerous source.

12For example, the early response phase may last hours to a day in the case of a small scale emergency, such as a radiological emergency during transport or a radiological emergency involving a sealed dangerous source.

13The exposure situation in the transition phase is still an emergency exposure situation even though the emergency response phase is over, as presented in Figs 1 and 2.

14See also paras 3.20, 3.22 and 4.98, particularly with regard to the delineation of areas.

15States usually have arrangements in place for returning to normal social and economic activity after any type of emergency. Such arrangements would also be expected to support the preparations for the transition to either an existing exposure situation or a planned exposure situation after a nuclear or radiological emergency. To this end, all the arrangements necessary to be put in place in accordance with this Safety Guide need to be integrated with one another in accordance with an all-hazards approach.

16Such prerequisites may include, as appropriate, those stated in paras 3.6, 3.7, 3.9–3.12, 3.19 and para. 3.20 (e)–(g).

17When deciding on the termination of a nuclear or radiological emergency, some of the urgent protective actions and early protective actions (e.g. evacuation) might be already under consideration to be adapted or lifted. Other actions (e.g. restrictions on food, milk and drinking water) might remain in place in the longer term after the termination of the emergency, and some actions, such as iodine thyroid blocking, might already have been implemented and require no further consideration in the transition phase. For details see paras 4.70–4.101.

18Effective dose, equivalent dose to a tissue or organ, or relative biological effectiveness weighted absorbed dose to a tissue or organ, as appropriate. See GSG-2 [5] for details.

19Including the public, workers (including emergency workers), helpers and patients, as appropriate.

20For example, the hazards associated with a nuclear power plant in normal operation and its associated emergency arrangements will differ from the hazards associated with an accident damaged nuclear power plant and its associated emergency arrangements.

21The purpose of such an interim response capability is to provide an improved response to any future emergency, postulated on the basis of the hazard assessment, before the full emergency arrangements are put in place. This interim capability might not be optimal and would need to make use of all available means and resources with only minimal additional arrangements (e.g. training, a few revised procedures).

22Paragraph 5.26 of GSR Part 3 [3] requires that employers “ensure that the exposure of workers undertaking remedial actions is controlled in accordance with the relevant requirements on occupational exposure in planned exposure situations.”

23Community resilience is the capacity of a community to be able to recover quickly and easily from the consequences of a nuclear or radiological emergency.

24Including the public, workers (including emergency workers), helpers and patients, as appropriate.

25Examples of self-help actions include, but are not limited to, avoiding prolonged visits to certain areas, changing farming practices and land use, and reducing the consumption of certain foods.

26A source is “Anything that may cause radiation exposure — such as by emitting ionizing radiation or by releasing radioactive substances or radioactive material — and can be treated as a single entity for purposes of protection and safety” (GSR Part 3 [3]).

27Depending on the type of emergency, the planned exposure situation can be associated with the normal operation of the facility or activity, with cleanup and decommissioning, or with the ending of the operational life of the source involved in the emergency.

28The residual dose is the “dose expected to be incurred after protective actions have been terminated (or after a decision has been taken not to take protective actions)” (GSR Part 7 [2]).

29Individual monitoring is “Monitoring using measurements by equipment worn by individuals, or measurements of quantities of radioactive substances in or on, or taken into, the bodies of individuals, or measurements of quantities of radioactive substances excreted from the body by individuals” (GSR Part 3 [3]).

30For example, more detailed planning can be made for a general emergency at a facility in emergency preparedness category I (e.g. a nuclear power plant), particularly for the urgent response phase and the early response phase. In this case, aspects such as the potentially affected areas, the habits and customs of the potentially affected population and land use can be identified at the preparedness stage as part of the hazard assessment. A radiological emergency involving a dangerous source can occur at any location, and therefore a more generic approach towards preparedness would need to be adopted.

31For example, if two options within the protection strategy provide the same level of protection of the public during the emergency response phase, the one that is less disruptive to society would be the preferred option, as this option will better support later efforts associated with the termination of the emergency and the overall recovery.

32Examples of unjustified actions at this level of dose would include the unsafe evacuation of patients (e.g. the evacuation of seriously ill patients without ensuring the provision of continuous medical care) from hospitals in areas where evacuation has been ordered.

33For emergency exposure situations that may result in doses over a period of less than one year, the residual dose will be the total dose from all exposure pathways for the entire duration of the emergency. For a large scale emergency resulting in longer term exposures due to residual radioactive material in the environment, the residual dose will encompass the total dose from all exposure pathways over one year from the onset of the emergency. For residual doses to be used during the response, the total residual dose includes the doses received from all exposure pathways (received dose) and the doses expected to be received in future (projected residual dose), with account taken of the implementation of the protection strategy, if any.

34For further details see GSG-2 [5].

35If the responsible authorities cannot fulfil some of the relevant prerequisites in Section 3 or the preconditions in para. 4.101 for evacuated areas, such areas should be delineated, and relocation can be considered instead of evacuation for these areas to enable the timely termination of the emergency.

36Further information can be found in Ref. [33].

37Helpers in an emergency are members of the public and thus do not have the status of workers (for an employer) as defined in GSR Part 3 [3]. However, once registered and integrated into the emergency response operations, helpers are required to be protected in accordance with Requirement 11 of GSR Part 7 [2].

38Such organizations may come from either the public sector or the private sector and may provide different services.

39Depending on the national legal and regulatory framework, technical service providers as specified in GSG-7 [35], for example, may be identified as relevant institutions.

40Such tools and models include the tools and models for reanalysis of historical data and for meteorological modelling.

41Generic procedures for medical response in a nuclear or radiological emergency, including for longer term medical follow-up and psychological counselling, are provided in Ref. [37]. Guidelines on mental health and psychosocial support in emergencies are provided in Refs [38–40].

42Protocol to Amend the Paris Convention on Nuclear Third Party Liability (2004 Protocol to the Paris Convention) [54] and Protocol to Amend the Brussels Supplementary Convention on Third Party Liability in the Field of Nuclear Energy (2004 Protocol to the Brussels Supplementary Convention) [55] are not yet in force.

43Referred to in Refs [50, 53] as ‘absolute liability’.

44Details on the methodology for deriving OILs can be found in Ref. [56].

45Carrying out normal activities, such as children playing on the ground and people working outside.

46The simultaneous use of OIL_T and OIL6 will ensure that all relevant exposure pathways are considered, covering the ingestion of affected food, milk or drinking water (with OIL6), external exposure from radioactive material deposited on the ground (i.e. ground shine), external exposure from resuspended radioactive material (i.e. air shine), the inhalation of resuspended radioactive material and the inadvertent ingestion of soil (e.g. from dirt on the hands) (with OIL_T).

47For a nuclear or radiological emergency involving a large scale release of radioactive material to the environment. The default value was calculated in accordance with the assumptions outlined in Ref. [56]. The contributions from the progenies that are in equilibrium with the respective radionuclides were also considered.

48OIL_T,LWR is OIL_T for a release of radioactive material resulting from a severe emergency at a light water reactor or its spent fuel, in accordance with the assumptions outlined in Ref. [56].

1Applicable for the duration of the emergency work.

1This first approximation was roughly based on the occupational dose limit of 5 rem (50 mSv) per year (about 240 workdays at 8 h/day) recommended at the time and considering that the dose limit for the public was ten times lower. This value was confirmed later because the underestimation of residential occupancy compared with occupational occupancy was counteracted by the fact that the cleanup lasted about three months.

1All times are given in local time (UTC +02).

1Readiness action levels represent the initiating levels for a new operational mode introduced for the Hungarian Nuclear Emergency Response System (referred to as ‘Readiness Operational Mode’) for implementation when no public protective actions are warranted but when coordination may be needed in the operation of the national radiation monitoring and warning system, in consequence assessment and in the provision of information to the public.

1This summary was drafted by the National Commission for Nuclear Safety and Safeguards of Mexico on the basis of internal records related to the incident and does not include nuclear security considerations in relation to the incident.

2All times in the case study are local time (UTC –06).

3On the basis of this activity, the ⁶⁰Co source falls into Category 1 of radioactive sources in line with the IAEA Safety Standards Series No. RS-G-1.9, Categorization of Radioactive Sources [I–31].

1Since, in the Mexican regulation, there are no exposure limits to the public in case of a radiological emergency, it was agreed to use the limit of non-stochastic effects for the occupationally exposed personnel.

1DANISH EMERGENCY MANAGEMENT AGENCY, ICELANDIC RADIATION SAFETY AUTHORITY, NATIONAL INSTITUTE OF RADIATION PROTECTION (DENMARK), NORWEGIAN RADIATION PROTECTION AUTHORITY, RADIATION AND NUCLEAR SAFETY AUTHORITY (FINLAND), SWEDISH RADIATION SAFETY AUTHORITY, Protective Measures in Early and Intermediate Phases of a Nuclear or Radiological Emergency: Nordic Guidelines and Recommendations (2014), http://www.nrpa.no/filer/56bc06c397.pdf

2The concept of an ‘intermediate phase’ as used in the Nordic Guidelines and Recommendations (see previous footnote) roughly equates to the transition phase, as the term is used in this Safety Guide.