The National Radiation Monitoring Network was established in the 1980s and it is an important element of Ireland’s preparedness and response arrangements under the National Plan for Nuclear and Radiological Emergency Exposures. In the event of a nuclear or radiological emergency, data from the network will support the National Emergency Coordination Group in making decisions on public protective actions.
The radiation monitoring stations consist of air samplers, precipitation collectors and instruments to measure gamma dose rate.
Met Éireann, the Defence Forces, Local Authorities and the third level institutions UCD and SETU all help to support the work of the national radiation monitoring network.
The EPA operates a network of 25 permanent radiation monitoring stations around Ireland which constantly monitor radiation levels in the environment. Here you will find information on this network and how we would use it in the event of a nuclear accident overseas.
Ambient Gamma Radiation
Ambient gamma radiation is measured continuously at 23 stations and data is transmitted to the EPA every hour. Three of these stations (Johnstown Castle, Clonskeagh and Caherciveen) also have spectroscopic detection systems. These units allow on-site radionuclide identification so that in the event of elevated ambient gamma radiation levels, the specific atoms contributing to these increased levels can be determined.
Aerosol Measurements
Online aerosol sampling units allow continuous monitoring of radioactive aerosols in air while the offline units contain air filters which must be changed weekly and sent to the Radiation Monitoring Laboratory in Dublin for analysis. One of these air filters is measured from each station every month for Cs-137 and other gamma emitters.
The network includes two high-volume air samplers (at UCD and SETU) and high-volume aerosol samples are obtained from these each week. Samples from the high-volume aerosol sampler in UCD are analysed weekly by the EPA for Cs-137 and other gamma emitters. One high-volume aerosol sample per month from the high-volume aerosol sampler in SETU is analysed by SETU and the data is sent to the EPA.
Both the high- and low-volume air samplers contain charcoal cartridges which are effective at collecting iodine and can be used in a nuclear emergency to measure concentrations of iodine radionuclides in the air.
Precipitation Collectors
Rainwater samples collected at the Clonskeagh and Glasnevin stations are analysed every month for Cs-137 and other gamma emitters. Rainwater samples from all the other stations are collected every month and retained for one month. These rainwater samples are not routinely analysed.
In case of an accident
Data from the gamma dose rate monitors is continuously fed back to the EPA. This 24-hour monitoring ensures that we are always aware of the levels of naturally occurring radiation in the environment but also that we will get the first measurements in the event of a radioactive 'cloud' reaching Ireland. If elevated radiation levels are detected, an alarm system is automatically triggered. The EPA responds to alarm activations and assesses what action is required.
In the event of nuclear incident abroad, the alert would first be raised through the European Commission and the 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 treaty with the UK so that Ireland will be informed directly in the event of a nuclear accident in the UK.
In the event of a nuclear emergency, foodstuffs, livestock, soil, vegetation, water and other environmental samples will be monitored and analyzed in the days and weeks after the accident.
For more information on post-emergency monitoring, see our FAQS section about the National Plan.
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 EPA alarm system – if this happens, the EPA duty officer examines the data to confirm whether or not the gamma dose rate has been caused by radon washout.
