Where is Sellafield? The UK’s Sellafield nuclear site, located on the Cumbrian coast, is at its closest point about 180 km from Ireland’s coastline. It is further from Ireland than the nearest nuclear power station – Wylfa in Wales is about 110 km from the closest point in Ireland.

A brief history: Sellafield served several purposes since work began there in the 1940s. Nuclear reactors at the Sellafield Site previously produced plutonium for nuclear weapons or generated electricity. These reactors have all been shut down and are being decommissioned and dismantled. Tonnes of radioactive material such as used fuel from nuclear reactors in the UK and abroad are currently being processed or stored at Sellafield. Some of the Sellafield facilities date from the early days of the site; some were constructed as recently as 2011; and others continue to be built to support decommissioning.

The Windscale accident: Windscale – renamed Sellafield in 1981 – was the site of a fire in 1957 in what remains Britain’s most serious nuclear accident. The prevailing wind sent a radioactive plume in a South Easterly direction over Britain. Part of the plume swirled back over the Irish Sea and may have just touched the east coast of Northern Ireland, but made no impact on Ireland.

That Ireland was not impacted by radiation from the Windscale fire was confirmed by a 2005 study by a team of UCD physicists of the isotope concentration levels in lake sediments. These studies correlate well with international data and show a steady increase from very low levels during the 1950s and early 1960s, which the team attributes to atmospheric weapons testing.

From the 1980s onwards, a more dramatic increase in fallout is detected, coinciding with greater discharges from nuclear reprocessing activities at Sellafield and at the French facility at Cap La Hague in Normandy. The signature of the 1986 Chernobyl fire is also evident, but there is no trace of the Windscale event.

This study is not a standalone analysis but is part of an ongoing, 25-year effort by the physicists to build up a comprehensive picture of fallout patterns across Ireland. They have analysed radioisotope accumulation in peat bogs near Louisburgh, Co Mayo, and on the Carlingford Peninsula in Co Louth and have also studied the buildup of Carbon-14 in tree rings on the east and the west coasts.

These findings confirm a study published in December 2000 which concluded that there was no link between the fire at Windscale and speculation over a “cluster” of Down Syndrome babies to six mothers who had been pupils at St. Louis Secondary School, Dundalk in 1956-57.

The study was carried out by an international group of scientists led by an Irish epidemiologist, Dr. Geoffrey Dean. The group established that three of the six girls in question had left the school, and the Dundalk area, some months before the fire occurred.

The Radiological Protection Institute of Ireland (RPII) responded: “Therefore if there was a common cause for the six cases at the school – and the study does not identify any – this common cause could not have been the fire at Windscale.”. They also accepted “in light of this finding” that the suggestion of a link between the Down’s Syndrome’s births and the Windscale fire was “unfounded.”

Although Sellafield continues to provoke controversy on both sides of the Irish Sea, these studies appear to lay to rest whatever fears had persisted that the 1957 fire had any significant impact on Ireland’s east coast.

Current activities: The Sellafield nuclear site is currently a collection of facilities to process and store used fuel from nuclear reactors in addition to other radioactive materials.

One of the facilities that will remain operating for many years is the Low-Level Waste Repository, which began operating in 1959 and is still needed to support disposal of low-level radioactive waste from all over the UK. This waste is made up of lightly contaminated materials such as clothing, soil, and building rubble.

Current risks to Ireland: Changes in operating practices and initiatives in line with international safety standards indicate that safety at the site has improved. However, because of the site’s location, its history, and the amount and type of radioactive materials there, some Irish people have concerns about how an incident at the site might impact Ireland and the Irish Sea.

Therefore, the Irish Government commissioned an assessment by a team of independent experts (on risk assessment, nuclear facility operations, chemistry, the effects of radiation on people, and how organizations perform) to determine the potential risks to Ireland associated with the Sellafield Site and the Low-Level Waste Repository.

They addressed incidents (for example, equipment failures, natural disasters, and accidents caused by human error or terrorist attack) that could affect current activities at Sellafield or the Low-Level Waste Repository, excluding transportation of radioactive materials on the Irish Sea and discharges from Sellafield that result from normal operations and are within limits set by UK regulators.

They concluded that, even for very rare severe incidents such as impacts by meteorites that disperse highly concentrated radioactive materials or release large quantities of intermediate-activity materials:

  • there would be no observable health effects in Ireland;
  • possibly major socio-economic impact for Ireland in terms of tourism and perception of contamination of food supplies and fisheries;
  • possibly prolonged major increased radiation level monitoring by Irish authorities.





Other monitoring: Levels of radioactive materials in the Irish environment continue to be monitored by the Radiological Protection Institute of Ireland.

Liquid radioactive waste is discharged from the plant into the Irish Sea via a pipeline, about 3 km from land. Gases are released from the plant via a number of chimneys (referred to as ‘stacks’). Discharges into the Irish Sea peaked in the mid-1970s and have dropped significantly in recent years. This is as a result of improved waste treatment facilities at Sellafield, which convert much of this radioactive waste into a solid for long-term storage.

Artificial Radioactivity in the Irish Sea: Discharges from Sellafield cause low levels of artificial radioactivity to be detected in sediments, seawater, seaweeds, fish and shellfish taken from the Irish Sea. Radioactivity levels in the Irish marine environment are monitored extensively by the EPA so as to monitor the radiation dose received by the Irish population. A wide range of marine samples is collected and analysed on a regular basis.  More information on radiation monitoring.

The results of this monitoring are published by the EPA in environmental monitoring publications and on their monitoring map. These results show that the increased radiation exposure resulting from artificial radioactivity in the Irish marine environment is very small and, even for those who consume large amounts of fish and shellfish from the Irish Sea, this amounts to much less than 1 per cent of the total radiation dose received by a member of the Irish public from all sources of radiation.

Transporting radioactive materials by sea: Radioactive materials are routinely transported through the Irish Sea to and from Sellafield. Shipments pass through the Irish Sea to the ports of Barrow-in-Furness and Workington.

The transportation of radioactive material is carried out on vessels which adhere to safety standards set by the International Maritime Organisation. The containers used to carry the radioactive material must comply with standards set by the International Atomic Energy Agency.  More information on the External linksafe transport for radioactive material.

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