Transport accidents to fuel flasks are divided into two categories, namely Nuclear Flask Incidents and Nuclear Flask Emergencies.

A nuclear flask emergency will be declared when a railway or road transporter carrying a flask has suf­fered or might suffer a mishap, and any of the fol­lowing conditions exists or is suspected to exist:

• The flask is involved in, or endangered by, fire.

• There are dangerous loads (e. g., petrol, liquified gas) in the vicinity.

• There is visible damage to the flask or its cover, which is suspected to be due to the mishap.

• The flask is tilted out of the upright position, or is displaced from its normal position, on the transport vehicle.

• The flask is endangered in some other way, e. g., by sabotage or a security threat.

A nuclear flask incident will be declared when the transport vehicle has suffered a mishap other than a mechanical failure and none of the above conditions exist.