Key Issues
International Nuclear Event Scale Enhances Public Communications
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Background
Each nation establishes its own regulations for the commercial use of nuclear materials. Each country also has its own methodology for classifying the safety significance of events involving such materials. However, INES provides an internationally consistent tool for communicating the safety significance of all events to the public both locally, and when necessary, internationally. The INES complements, but does not replace, individual nations’ classification methods.
The NRC some 30 years ago established a four-level approach to classify nuclear power plant events. Although plants use the NRC scale in public and media communications, it is primarily a tool for protecting public safety.
The INES scale, developed in 1989, is oriented to public and media communications following an event. More than 60 nations, including the United States (via the NRC), now participate in the INES.
The NRC began limited participation in the INES in 1993, initially communicating internationally only reactor events that rated “alert” or higher on its scale. In 2002, the NRC announced that it would evaluate all reported nuclear events (reactor, fuel cycle, materials and transportation) for possible rating on the INES. The NRC has committed to provide a provisional report to the IAEA within 48 hours giving the INES classification of any U.S. events that it deems to warrant a rating of level two (“incident”) or higher on the seven-level INES. (The NRC may report more quickly in an emergency.)
Some national regulatory agencies also report events at level one (“anomaly”). The IAEA shares the data with participating nations through their INES “national officers.” In the United States, the NRC serves as national officer for the INES.
NRC Classification Approach Is Proven and Effectiv e
The NRC’s four emergency action level classifications range from “notification of unusual event”—which requires no emergency-plan activation—to “alert,” “site area emergency” and “general emergency.” The NRC provides guidance for classifying events at nuclear plants based on the potential severity of the incident.
The U.S. nuclear energy industry has found the NRC classification system to be a highly effective emergency response tool for use during an event at a nuclear power plant, whether it involves equipment malfunction or a security concern. The NRC approach is well-established and well-understood by local and state emergency response organizations in the 31 states that have nuclear power plants.
Background
Each nation establishes its own regulations for the commercial use of nuclear materials. Each country also has its own methodology for classifying the safety significance of events involving such materials. However, INES provides an internationally consistent tool for communicating the safety significance of all events to the public both locally, and when necessary, internationally. The INES complements, but does not replace, individual nations’ classification methods.
The NRC some 30 years ago established a four-level approach to classify nuclear power plant events. Although plants use the NRC scale in public and media communications, it is primarily a tool for protecting public safety.
The INES scale, developed in 1989, is oriented to public and media communications following an event. More than 60 nations, including the United States (via the NRC), now participate in the INES.
The NRC began limited participation in the INES in 1993, initially communicating internationally only reactor events that rated “alert” or higher on its scale. In 2002, the NRC announced that it would evaluate all reported nuclear events (reactor, fuel cycle, materials and transportation) for possible rating on the INES. The NRC has committed to provide a provisional report to the IAEA within 48 hours giving the INES classification of any U.S. events that it deems to warrant a rating of level two (“incident”) or higher on the seven-level INES. (The NRC may report more quickly in an emergency.)
Some national regulatory agencies also report events at level one (“anomaly”). The IAEA shares the data with participating nations through their INES “national officers.” In the United States, the NRC serves as national officer for the INES.
NRC Classification Approach Is Proven and Effectiv e
The NRC’s four emergency action level classifications range from “notification of unusual event”—which requires no emergency-plan activation—to “alert,” “site area emergency” and “general emergency.” The NRC provides guidance for classifying events at nuclear plants based on the potential severity of the incident.
- A notification of unusual event, the lowest classification, means that a minor plant event—either an operational event or security threat—has occurred, but no radiation release is expected.
- An alert means that there is an actual or potential reduction in the plant’s safety level or a security event that could threaten site personnel or damage plant equipment.
- A site area emergency suggests a more serious event. Major safety equipment either has failed or is deemed likely to fail.
- A general emergency is the most serious event. In this instance, radiation may leak outside the plant and beyond the plant boundary.
The U.S. nuclear energy industry has found the NRC classification system to be a highly effective emergency response tool for use during an event at a nuclear power plant, whether it involves equipment malfunction or a security concern. The NRC approach is well-established and well-understood by local and state emergency response organizations in the 31 states that have nuclear power plants.
