Every three years, each nuclear installation is required to take part in a national emergency exercise, involving the entire national emergency response organisation. The various prefectures involved in these exercises have been seen to be constantly progressing. To ensure that this constant improvement continues, the exercise scenarios are made increasingly complex and include increasing numbers of parameters and players. The exercises are also a means of improving existing procedures:
– the Channel and North Sea region maritime prefecture took part in the exercises at Penly and La Hague in 2005. These exercises tested and improved joint interaction with the land-based prefectures;
– the scenarios increasingly frequently include a health component, involving treatment of the injured (sometimes contaminated), who have to be given care and be evacuated in a potentially or actually hazardous environment;
– the various emergency command post procedures now include joint audio-conferences which can, when necessary, improve the understanding of sometimes complex situations.

Experience feedback from these emergency exercises also brings to light those actions or procedures which need to be improved. All the stakeholders take these points on board and actively look for solutions. In this respect, the ASN calls all participants together twice a year to review good procedures, but also to define where improvements could be made.

Finally, on 30 September and 27 October 2005, two incidents which occurred in the nuclear power plants at Nogent-sur-Seine and Le Blayais triggered a national emergency response. The ASN's emergency response centre was activated in less than 30 minutes and the oft-practiced procedures were put into motion calmly and unhurriedly. The incidents did not entail any measures to protect the populations and no radioactivity was released into the environment.

As in any other nuclear safety field, emergency response structures have to develop on the basis of experience. The main sources of experience in France are the exercises and exchanges with other countries, as well as any significant events in France (see point 2.2.3) or abroad (Tokai-Mura accident on 30 September 1999).

On 14 December 2005, the ASN held the seventeenth national conference of local information committees (CLIs), jointly with the national CLI association (ANCLI). This conference was devoted to local emergency management and involved discussion of the potential role of the CLIs, particularly in the post-accident phase.

In the event of substantial accidental release from a nuclear reactor, provision has been made for the absorption of stable iodine tablets by populations in the vicinity of the site concerned, with a view to providing thyroid protection against the harmful effects of radioactive iodine. Up until 1997, emergency plans provided for distribution of tablets, in the event of an accident, from concentrated stocks, generally stored on or near the nuclear sites. The first accident exercise sessions (1995 and 1996), which included the actual distribution of dummy tablets, in an emergency context, soon showed the difficulties involved. Apart from time considerations, this method was intrinsically contradictory: the population was asked to take shelter immediately, while at the same time emergency teams were carrying out urgent door-to-door distribution of tablets. In 1997, preventive distribution of stable iodine tablets to the populations living in the vicinity of the nuclear power plants was carried out.

The tablets distributed had a shelf-life of 3 years. A further preventive distribution of stable iodine tables therefore took place in 2000. Since then, the shelf-life of the tablets has been raised to 5 and then 7 years. In 2005, the third preventive distribution of iodine tablets took place (see box). It involved two phases. The first phase was at the beginning of the year on four sites, in order to assess the most efficient distribution method in terms of population coverage (circular of 8 February 2005 concerning preventive distribution of stable iodine tablets). On the basis of the lessons learned from this phase, a second distribution phase was applied to all remaining sites, starting in the summer (circular of 11 August 2005 concerning preventive distribution of stable iodine tablets). During the course of this campaign, the ASN sent out a folder to about 500,000 homes, presenting nuclear safety and radiation protection supervision (see chapter 6 point 1.2.5).