The International Nuclear Event Scale (INES) Rating System
The International Nuclear Event Scale is a means for promptly communicating to the public in consistent terms the safety significance of events reported. By putting events into proper perspective, it can facilitate common understanding among the nuclear community, the media and the public.
The INES National Officers are committed to communicate as quickly as possible official information on the consequences of an event to all the participating countries through the IAEA INES Information Service. The criteria for identifying which events should be communicated are:
- Events rated at Level 2 (anomaly) and above (operational safety),
- Events attracting international public interest (Level 1 and below).
For rapid information exchange on these nuclear events, IAEA, OECD/NEA and WANO jointly manage a Nuclear Event Web Based System (NEWS), where event descriptions are provided and rated according to the INES scale.
Events are classified on the Scale at 7 levels; the upper levels (4-7) are termed “accidents” and the lower levels (1-3) “incidents”. Events which have no safety significance are classified below scale at level 0 and are termed “deviations”. Events which have no safety relevance are termed “out of scale”. Each level is defined in detail within the INES User’s Manual. Events are considered in terms of three safety attributes or criteria represented by each of the columns: off-site impact, on-site impact, and defence in depth degradation.
- More about the INES Rating
- INES User's Manual, Corrigendum to the User's Manual
- Clarification for the Rating of Fuel Damage Events
- INES Additional Guidance for the Rating of Transport of Radioactive Material and Radiation Source Events
- General guidelines
- Examples of Events rated according to the INES Scale
- Zack T. Pate at the WANO Biennial General Meeting,
Click for the First Part of the Speech and Second part of the Speech
18 March 2002, Seoul, South Korea