In the event of an incident, the operators of nuclear installations have the following tasks:

• They analyse the incident in respect of its danger to the population.
• They implement suitable actions to control the incident and to limit its impact on personnel and the population.
• They quickly update:
  1. ENSI and the National Emergency Operations Centre (NEOC) and,
  2. in the event of quickly occurring accidents and when the warning and alert criteria are reached, they additionally update the cantonal authorities.
• They determine the source term and communicate it to ENSI in a timely manner. The source term is the quantity and type of released radionuclides combined with the variation over time of the release.

ENSI’s tasks in the event of an incident

ENSI performs the following tasks:

• It informs the NEOC immediately about events in Swiss nuclear installations.
• It accesses the appropriateness of the actions taken by the nuclear installation operator and checks their implementation.
• It creates forecasts about the course of the accident in the installation, the spread of radioactivity in the surroundings and the consequences this could have.
• It advises the Federal Office for Civil Protection (FOCP) and the Federal Civil Protection Crisis Management Board (CCMB) about the arrangement of protective actions for the population.
• It rates the incident according to the International Nuclear Events Scale (INES) of the IAEA.