ENSI operates the MADUK system, a measurement network for automatic dose rate monitoring in the vicinity of the nuclear power plants (MADUK is a German acronym). It implements the transmission of plant parameters and stack emission values from the nuclear power plants. The measuring network has been in operation since 1994. The system measures the dose rate in the vicinity of nuclear power stations around the clock, all year round. It also makes it possible to detect malfunctions and accidents because dose increases relative to natural dose values are automatically displayed in the ENSI system. In the event of an accident, MADUK supports the emergency response organisation in identifying the affected area and assessing possible actions.

The MADUK network for measuring dose rates consists of a total of 57 exposure measurement stations. They are divided into four sub-networks with 12 to 17 stations each within a radius of around six kilometres around the Swiss nuclear power stations and the Paul Scherrer Institute. The measuring probes of the MADUK system complete and supplement the Switzerland-wide radioactivity monitoring network NADAM: Network for Automatic Dose rate Alerting and Measuring). This has a further 58 measuring stations spread throughout Switzerland.

ENSI’s MADUK control centre processes and archives the data and, if necessary, provides an immediate alert to the ENSI emergency response organisation, as well as backing up the exposure data over the long term. In addition, the values are also available on the ENSI website. Furthermore, various sub-systems provide data exchange with the external partners National Emergency Operations Centre (NEOC) and Baden-Württemberg remote nuclear reactor monitoring station.