International experts have told the Irish Government that a radioactive leak at the Sellafield nuclear site would cause no observable health effects in the country.
The independent team of nuclear physicists, chemists and engineers used previously secret data from the facility in Cumbria to declare the low risk.
But they found that some severe incidents at Sellafield or the low-level waste repository have the potential to do significant damage to Ireland's tourism, seafood and farming industries because of concerns over radioactivity.
Phil Hogan, Ireland's Environment Minister, said vigilance was key. He said: "My department and others will now study the information in the report in detail and use it to feed it into Government policies relating to Sellafield and nuclear policy in the UK.
"Ireland must continue to be vigilant in relation to Sellafield as work to decommission the site over the lifetime of the Sellafield Plan continues. It is critical from an Irish perspective that the UK decommissioning of the site is undertaken safely and in accordance with best international practice."
Possible scenarios examined by the independent risk assessment panel included earthquakes, meteorite strikes, plane crashes, terrorist attacks, explosions, fires, and human error.
They also looked at the very long term and what the impact would be hundreds of years from now from rising seas and severe coastal storms on the waste repository. It found that currents and sea water would dilute the remains of radioactive materials.
Based on calculations that overestimate the consequences of such a release, the report found the increase in radioactivity levels in seawater would be barely detectable anywhere near the coast of Ireland.
Sellafield is expected to cost at least £67.5 billion (83.7 billion euro) to decommission and clean up. The site is regarded as the UK's largest and most hazardous nuclear site, storing enough high and intermediate level radioactive waste to fill 27 Olympic-sized swimming pools.
The operators are being prosecuted over allegations that it sent four bags of low-level radioactive waste to a nearby landfill site in Cumbria.