2009 Status of Safety at AREVA group facilities
Alternatives #5: The renaissance of solar homes
Alternatives #4: Hydrocarbons, cocktails of the future
Alternatives #3: Geothermal modesty
Alternatives #2: Tomorrow's reactors
Alternatives #1: Energies, what scenario for 2050?
Quiz: Test what you know about sustainable development
Quiz: Checking on the state of the Earth
Game: Nuclear energy key words
Game: Energy Memory Game
Event reporting
Nuclear events occurring in AREVA group facilities are ranked on the International Nuclear and Radiological Event Scale (INES) and are made public in France when they are level 1 or above.
The ines: facilitating communications by ranking events
The INES was conceived by the International Atomic Energy Agency (IAEA) to facilitate communications with the media and the public about nuclear events by giving them a means for understanding and comparing their level of severity. The scale has been adopted worldwide since 1991.
In 2004, it was extended to include radiological events related to irradiation sources and to the transportation of radioactive materials. While the method seems simple at first, the operator can nonetheless find it difficult to recommend a classification for an event, especially when it is on the lower end of the scale, which is most often the case.
A guide by the French nuclear safety authority ASN tries to facilitate the task. Before an event can be classified, a series of questions must be asked about the causes and consequences of the event.
Three types of criteria are considered:
- criteria related to the off-site consequences of the event, such as the dose absorbed by workers or members of the public, or radioactive releases to the environment;
- criteria related to the on-site consequences, such as contamination or above normal dose rates;
- criteria related to defense in depth, which involves various protective barriers designed to prevent and limit the consequences of the event.
It should be noted that maintaining several levels of defense in depth (physical barriers, safety culture, worker skills, appropriate procedures, etc.) is a decisive factor.
Once the event has been analyzed, the operator must document items included into the classification proposal and send them to ASN. ASN can reclassify the level of the event. The INES classification is not limited to the potential severity of an event; it also considers the root causes of the event and the number of defense in depth barriers remaining.
At AREVA, all events are subject to an analysis of the causes, and lessons learned are shared to improve prevention. Similarly, “weak signals” are a major concern and are reported by the sites.
Reporting and dealing with weak signals
Lessons learned are crucial to ensuring the safety of nuclear operations. They involve analyzing all events occurring in the facilities so as to learn from them and ensure they are not repeated by taking appropriate measures.
Sharing these lessons learned among the group's entities is fundamental in safety, especially in fields such as criticality control and fire prevention. Continuous improvement in safety management is important.
Paying attention to weak signals during risk assessment is useful in identifying the most effective preventive actions so that the highest level of safety can be maintained. This means raising awareness among all involved so that even the smallest deviation can be detected, identified, analyzed and dealt with.
