What is International Nuclear and Radiological Event Scale (INES) ?
INES is a tool for promptly and consistently communicating to the public the safety significance of events associated with sources of ionizing radiation.
What is the purpose of INES?
The primary purpose of INES is to facilitate communication and understanding between the technical community, the media and the public on the safety significance of events. The aim is to keep the public as well as nuclear authorities accurately informed on the occurrence and consequences of reported events.
What is the Scope of INES ?
The INES scale applies to any event associated with the use, storage and transport of radioactive material and radiation sources, whether or not the event occurs at a facility; this includes events involving the loss or theft of radioactive sources or packages and the discovery of orphan sources, such as sources being discovered in scrap metal.
INES is also used for the rating of events resulting in actual exposure of workers and the public in medical, research and educational institutions. The scale does not cover the actual or potential consequences for patients exposed as part of a medical procedure. INES is intended for use in civil, i.e. non-military applications and only relates to the safety aspects of an event. It is not appropriate to use INES to assess or to compare safety performance between facilities, organizations or countries.
Description of INES:
INES uses a numerical rating to explain the significance of events associated with sources of ionizing radiation. Events are rated at seven levels: Levels 1–3 are “incidents” and Levels 4–7 “accidents”. The scale is designed such that the severity of an event is approximately ten times greater for each increase in level of the scale. These levels consider 3 areas of impact:
1. People and the environment
2. Radiological barriers and control
3. Defense in depth
Events without safety significance are rated as Below Scale/Level 0. Events that have no safety relevance with respect to radiation or nuclear safety are not rated on the scale.