People in Ireland would not have to shelter indoors, relocate or evacuate the country, a study of a worst case scenario accident at the Sellafield nuclear fuel reprocessing plant has found.
However, the report from the Environmental Protection Agency also found that such a scenario would lead to people here receiving twice the average annual dose of radiation they normally receive from a variety of sources.
The report also says significant food controls would have to put in place in order to avoid long term health consequences.
The Government commissioned study outlines the findings of the EPA's assessment of the potential radiation doses to the Irish public from a variety of different severe accident scenarios at Sellafield.
These include two unspecified severe events where there would be an aerial release of hot radioactive material into a plume, a meteorite impact and the impact of a large aircraft.
The study modelled how a radioactive cloud might disperse in the atmosphere following a release from the plant in Cumbria in England, and focused on worst case weather conditions for Ireland.
Such a scenario would involve the plume being blown east from the plant, and depositing radioactive material in rain along its path.
The report says the probability of such a scenario is low, because for almost 90 per cent of the time, the prevailing weather conditions over Ireland would push the plume away from the country, not towards it.
However, assuming the worst case scenario, the authors then examined how this might impact on people here.
In particular they looked at how ingestion into the food chain would impact on human health during the passage of the cloud over the country, a week later and a year later.
They found that the doses that people here would be exposed to from inhaling the radioactivity, the radioactivity in the air and on the ground would not be so high as to require people to shelter, relocate or even evacuate.
But the report does state that staying indoors, particularly during the passage of the plume overhead, could reduce the amount of radioactivity that people would be exposed to by up to 80 per cent.
The most severe radiological impact on Ireland would come from a meteorite striking the site during the month of May, the study claims.
In normal conditions, the average annual dose of radiation that people here are exposed to from all sources is 4,000 μSv.
The report finds that a worst case scenario accident at Sellafield would see the public exposed to twice that amount from inhalation, radioactivity in the air and on the ground over a year.
However, if no protective action were taken, the research found the annual radiation dose from eating contaminated foods could be over 370,000 μSv, with a noticeable increase in cancers for decades to come.
This highlights the importance of the introduction of effective food controls, the report says.
The EPA says Ireland has a National Emergency Plan for Nuclear Accidents, which in such a scenario would "provide a coordinated emergency response to a situation where there is widespread radioactive contamination in Ireland."
The plans includes guidance on protective actions such as sheltering and food controls to reduce the radiation dose received by the population, which while effective in controlling radioactivity levels, would have high socio-economic costs and implications for many years, it says.
Among the impacts would be a loss of tourism and damage to markets for Irish seafood and farm products, which the report says could continue long after radioactivity levels return to normal.
The report follows an earlier risk assessment of various potential scenarios, by looking at the most severe potential scenarios and their effects into the longer term.
Another recently published study, carried out for the government by the ESRI, estimated the potential economic impact of a nuclear accident on the economy here at between €4bn and €161bn, depending on the severity.