Tomorrow, Wednesday, the nationwide siren test will take place. The general alarm would also sound in the event of a serious incident in a nuclear power plant if there was a danger to the population. The Swiss Federal Nuclear Safety Inspectorate ENSI works closely with the National Emergency Operations Center (NEOC) in such a case.
Swiss nuclear power plants are safe. This has currently also been confirmed by the EU stress test. Should an incident nevertheless occur in which leaking radioactivity is to be expected, emergency measures have been defined that are regularly reviewed and practiced. To alert the population at risk, among other things, the general alarm would sound.
Every year, on the first Wednesday afternoon of February, the siren test takes place in all regions of Switzerland. Checking the alarm systems and all processes also serves to ensure the safety of the Swiss population in the event of radioactive substances escaping from one of the nuclear facilities.
ENSI advises and consults
All Swiss nuclear facilities are obliged to report any accident to ENSI immediately. In the event of a serious incident, or if such an incident is imminent, alarm measures are prepared. "ENSI is able to simulate the dispersion of radioactive substances following a leak from a nuclear power plant in Switzerland," says Georges Piller, head of ENSI’s Radiation Protection Division. Among other things, the measuring network for automatic dose rate monitoring MADUK and dispersion calculations derived from it are used for this purpose.
In the event of a leak, it is possible to calculate which areas will be reached by a radioactive cloud at what time. In this way, the measuring bodies and emergency forces can be deployed in a targeted manner and the population can be alerted in good time so that they can protect themselves as a precautionary measure.
In cooperation with ENSI, which provides advice in such a situation, the NEOC alerts the population. This is called to listen to the radio. The siren is used to announce instructions (prepare or implement protective measures) or official notices, which are broadcast by the NEOC immediately after the siren alarm.
Radius determines measure
Depending on the distance to a nuclear power plant, the population is located in different zones. These play a role in protective measures and emergency organization.
Zone 1 covers an area with a radius of about five kilometers around the NPP. In this area, protective measures may even be required immediately in the event of a fast-moving accident. These are coordinated with the cantonal police.
Zone 2 is adjacent to Zone 1 and covers an area with a radius of about 20 kilometers. In the event of a serious accident, a danger to the population may also arise in this area, which makes protective measures necessary. In zones 1 and 2, iodine tablets were distributed directly to the population. The intake protects against the storage of radioactive iodine in the thyroid gland.
The area of the rest of Switzerland is designated as zone 3. In this area, any necessary protective measures are ordered by the responsible emergency organization agencies. The iodine tablets for zone 3 are stored decentrally and are only distributed to the population in the event of an incident.
A lot of noise for safety
Switzerland has a dense network of more than 8,000 sirens, which ensure that the population is alerted at all times. The Federal Office for Civil Protection FOCP, in cooperation with the cantons, communes and dam operators, ensures that the alarm systems are kept up to date and operational at all times.
Also next Wednesday: From 13.30 o’clock to 14.00 hours, the general alarm is sounded and from 14.15 o’clock to 15.00 o’clock the water alarm is tested. The two alarms differ in sound and cause: a regular ascending and descending wail of one minute duration means "general alarm", which sounds in case of possible hazards. The water alarm, which is used in the endangered areas below dams when there is a danger of flooding, consists of twelve low continuous tones of twenty seconds each at ten-second intervals.
If the general alarm sounds outside the prescribed siren tests, the population is requested to listen to the radio, follow the instructions of the authorities and inform their neighbors.
In case of a water alarm, one should leave the endangered area immediately. The population in the affected areas is informed in advance about the local escape possibilities by means of information leaflets.
FOCP hotline from 1. to 10. February 2012
For questions from the public, the Federal Office for Civil Protection FOCP has set up a special telephone hotline that provides answers on all aspects of emergency response. The external information center can be reached at 061 202 05 69. She’s been there from Monday to Saturday between 08.00 o’clock and 19.00 hrs in operation and until 10. February 2012 posted.