Triggering the alarm

In the event of nuclear incident abroad, the alert would first be raised through the  EU and IAEA international notification systems.  The Irish radiation monitoring network would then provide the first measurements of any radioactive cloud that reached Ireland. In addition, Ireland has a bilateral agreement with the UK so that Ireland will be informed directly in the event of a nuclear accident in the UK.

As soon as any radiation monitoring station detects an unusually high level of radiation, an alarm is automatically activated.

The location of the monitoring stations

Ireland has 15 permanent radiation monitoring stations distributed across the country. Most are located near the east and south coasts, where any radioactive plume drifting over the sea from the UK or Europe would most likely make its first contact with Ireland.

How the data is collected

The monitoring stations continuously measure the gamma dose rate. Data from the gamma dose rate monitors is continuously fed back to a central computer at RPII. If elevated radiation levels are detected, an alarm system is automatically triggered.

In addition, the RPII operates a network of air sampling systems to supplement the gamma dose rate measurements. These systems continuously sample particles suspended in the air. In the case of a nuclear emergency these air filters will be analysed to ascertain the quantity and type of radionuclides present in the plume.

Radon washout

Occasionally, gamma radiation levels can increase temporarily due to a phenomenon called radon washout. This occurs when rain collects radon from the air and deposits it on the ground.

It results in a small - but detectable - increase in the gamma dose rate measurement, which usually lasts no more than few hours. This increase poses no health risk, but may trigger the RPII alarm system – if this happens, the RPII duty officer examines the data to confirm whether or not the gamma dose rate has been caused by radon washout.

Additional monitoring

In the event of a nuclear emergency, foodstuffs, livestock, soil, vegetation, water and other environmental samples will be monitored and analysed in the days and weeks after the accident.

For more information on post-emergency monitoring, see The Plan.

Working together to protect Ireland

Various other agencies help operate the continuous monitoring network

• Met Éireann
• The Defence Forces
• The local authorities in the areas where the monitoring stations are based.