IAEA revising INES event reporting scale
21 September 2007
The International Atomic Energy Agency (IAEA) is revising its International Nuclear Event Scale (INES), a scale used to report the severity of a nuclear or radiological incident or accident.
Originally developed in the 1990s, the INES was established to communicate to the media and the public the safety significance of reported nuclear and radiological incidents and accidents. INES classifies events on a scale at seven levels: levels four to seven are termed "accidents", with level seven being classed a "major accident", and levels one to three "incidents". Events without safety significance are termed "deviations" and are classified below scale at level zero. Events without relevance to radiological or nuclear safety are termed "out of scale".
The IAEA said the revision of INES would make it "a more versatile and informative tool." The revision aims to consolidate the use of the scale to all events associated with radiation and radioactive material, including transport related events.
Rejane Spiegelberg-Planer, the IAEA's Incident Reporting Coordinator and INES officer, said, "We've brought INES into the world of nuclear and radiological events surfacing in the 21st century." She added, "Our aim is to consolidate the old INES manual and the additional guidance documents and clarifications that had been issued over the past 15 or more years."
The revised scale is designed to better address areas and activities such as the transportation of radioactive material, or human exposure to sources of radiation. The underlying methodology has not changed. However, the previous procedures were not detailed enough to consistently rate events related to radiation sources and transport, and they have been considerably improved, the IAEA said.
The criteria used for rating radioactive sources and transport events have been reviewed and consolidated according to additional guidance which was in pilot use for almost two years and then approved by IAEA Member States in 2006.
The revised scale considers that the impact on people and the environment may be localized, i.e. radiation doses to one or a few people close to the location of the event, or widespread, as with the release of radioactive material from an installation.
The IAEA said that the revision of INES is "the culmination of a lengthy and complex process," which has involved IAEA experts, as well as the INES Advisory Committee and consultants in nuclear safety and radiological protection. Once reviewed by INES members, the target date for officially issuing the new and improved scale is the end of 2008.
Further information
International Atomic Energy Agency (IAEA)
IAEA's International Nuclear Event Scale
WNA's Safety of Nuclear Power Reactors information paper
WNN Nuclear Event Reports