2. What types of Radiological Emergency are there?

A Nuclear Accident is one involving a device using a controlled nuclear chain reaction for some purpose. For example, a Nuclear Reactor has nuclear fuel which, through a self-sustaining and controlled nuclear chain reaction, produces heat, turning turbines and producing electricity. Because of the energy involved in this process, there is potential for considerable radioactive material to be released and dispersed into the environment. Such a release would be due to a “nuclear accident” and results in a Radiological Emergency. Normally, nuclear accidents with releases into the environment are very rare but they have the potential to lead to widespread dispersion of radioactive material. 

A Radiological accident is initiated by lost radiation sources, accidents during transportation of radioactive sources or materials, equipment or human errors in the operation of radiation sources. It could result in a Radiological Emergency if there is a risk of human exposure. 
Sources, often called “sealed sources”, are usually small metal containers in which a small amount of radioactive material is sealed.