1A nuclear or radiological emergency is an emergency in which there is, or is perceived to be, a hazard due to (i) the energy resulting from a nuclear chain reaction or from the decay of the products of a chain reaction or (ii) radiation exposure [2].

2INTERNATIONAL ATOMIC ENERGY AGENCY, Planning and Preparing for Emergency Response to Transport Accidents Involving Radioactive Material, IAEA Safety Standards Series No. TS‑G‑1.2 (ST‑3), IAEA, Vienna (2002).

3GSR Part 7 [2] uses the term ‘State’, while the Transport Regulations [3] use the term ‘country’. In this Safety Guide, the terms ‘State’ and ‘country’ are used synonymously.

4In this Safety Guide, the term ‘radioactive material’ means “Material designated in national law or by a regulatory body as being subject to regulatory control because of its radioactivity” [4]. This matches the definition in GSR Part 7 [2] and includes all material that falls within the definition of radioactive material in the Transport Regulations [3]. The term ‘radioactive material’ also includes nuclear material, as defined in the IAEA Nuclear Security Series.

5Emergency preparedness category IV is defined as follows (footnotes omitted):“Activities and acts that could give rise to a nuclear or radiological emergency that could warrant protective actions and other response actions to achieve the goals of emergency response in accordance with international standards in an unforeseen location. These activities and acts include: (a) transport of nuclear or radioactive material and other authorized activities involving mobile dangerous sources such as industrial radiography sources, nuclear powered satellites or radioisotope thermoelectric generators; and (b) theft of a dangerous source and use of a radiological dispersal device or radiological exposure device. This category also includes: (i) detection of elevated radiation levels of unknown origin or of commodities with contamination; (ii) identification of clinical symptoms due to exposure to radiation; and (iii) a transnational emergency that is not in category V arising from a nuclear or radiological emergency in another State. Category IV represents a level of hazard that applies for all States and jurisdictions” [2].

6This authority and responsibility would typically be assigned to an individual in the organization that has the primary role during each phase of the response. The authority and responsibility may be transferred between organizations as the emergency response progresses.

7For a transport emergency, the term ‘site area’ refers to the inner cordoned off area established by first responders around a suspected hazard [2].

8Depending on the situation and the national arrangements, the radiological assessor may come from government, technical support organizations, or consignors and carriers.

9The Transport Regulations [3] define the A1 and A2 values as follows: “A₁ shall mean the activity value of special form radioactive material that is listed in Table 2 or derived in Section IV [of the Transport Regulations] and is used to determine the activity limits for the requirements of these Regulations. A₂ shall mean the activity value of radioactive material, other than special form radioactive material, that is listed in Table 2 or derived in Section IV [of the Transport Regulations] and is used to determine the activity limits for the requirements of these Regulations.”

10Operational intervention levels are “A set level of a measurable quantity that corresponds to a generic criterion” [2].

11An emergency class is “A set of conditions that warrant a similar immediate emergency response” [2]. In accordance with para. 5.14(e) of GSR Part 7 [2], a transport emergency is classified as “other nuclear or radiological emergency”, while recognizing that in some States the emergency classes may differ from those specified in GSR Part 7 [2].

12An inner cordoned off area is “An area established by first responders in an emergency around a potential radiation hazard, within which protective actions and other emergency response actions are taken to protect first responders and members of the public from possible exposure and contamination” [2].

13An emergency worker is “A person having specified duties as a worker in response to an emergency” [2].

14Emergency preparedness and response arrangements apply only for amounts of radioactive material exceeding the exemption levels specified by the regulatory body [11] and are commensurate with the level of hazard [2]. Therefore, the transport of amounts of radioactive material that only slightly exceed the exemption levels will need only limited emergency arrangements.

15A notification point is “A designated organization with which arrangements have been made to receive notification…and to initiate promptly the predetermined actions to activate a part of the emergency response” [2].

16A container with a safe geometry is one whose dimensions and shape are such that a criticality event cannot occur even with all other parameters at their worst credible conditions.

17For the purposes of the World‑Wide Navigational Warning Service, a coordinated global service for the promulgation of navigational warnings, the world’s oceans are divided into 21 geographical sea areas termed NAVAREAs (navigational areas). In each area, one designated country is responsible for disseminating navigational information.

18For transport by air, the content of a Type B(U) or Type B(M) package is limited to 3000A₁ or 10⁵ A₂, whichever is the lower, for special form radioactive material; or 3000A₂ for all other radioactive material (see para. 43 of the Transport Regulations [3]).

1These dose rate limits do not apply to consignments transported under exclusive use or special arrangement.