Sellafield, located in the northwest of England, is one of largest and most complex nuclear facilities in the world. Its operations in the past included generation of nuclear power (which ended in 2003) and the reprocessing of nuclear fuel (which ended in 2022). Currently the primary focus of operations at Sellafield is the processing of nuclear waste from UK nuclear reactors for packaging and storage as well as the clean-up of legacy waste storage facilities on the site. The Nuclear Decommissioning Authority is responsible for decommissioning and cleaning up Sellafield and operates under the UK's Government Department for Energy Security and Net Zero (DESNZ).
Sellafield is a large and complex nuclear facility, and the EPA is aware of the hazards associated with the radioactive waste processing and storage facilities on the site and the legacy of Sellafield’s past operations. Given its scale and the materials stored on the site the EPA takes the risks posed by the site seriously and continues to engage with UK regulators to maintain its knowledge of the site and to ensure we are kept up to date with relevant issues.
Release of radioactivity from Sellafield into the environment
EPA monitoring of discharges to sea from Sellafield and radioactivity in the Irish Sea
Swimming in the Irish Sea and eating fish from the Irish Sea
Transporting radioactive materials by sea
Leaks reported from Sellafield
Potential impact on Ireland from a radiological incident at Sellafield
Activities at Sellafield give rise to the discharge of low-level radioactive materials in the form of liquids and gases into the environment. These discharges are regulated by the UK authorities and limits for releases are set by the Environment Agency of England and Wales (EA). The EA is required by law to report the actual discharges annually. In addition, the UK Environment Agency updates the EPA in Ireland on discharges from Sellafield every 6 months so that the EPA are aware of the emissions from the site. More information on discharges from the Sellafield site can also be found in the UK Radioactivity in Food and the Environment (RIFE) reports: Radioactivity in food and the environment (RIFE) report - GOV.UK (www.gov.uk)
The EPA and its predecessors have been monitoring the levels of artificial radioactivity in the marine environment since 1982. The discharge of low-level liquid wastes from Sellafield is the most significant source of artificial radioactivity in the Irish marine environment and the focus of the marine monitoring is to assess radioactivity discharged from the Sellafield site. A wide range of marine samples are collected and analysed regularly. Low levels of artificial radioactivity can be detected in sediments, seawater, seaweeds, fish, and shellfish taken from the Irish Sea. The levels of radioactivity discharged into the Irish Sea from Sellafield have decreased significantly since its peak in the 1970s and 1980s. This is because of improved waste treatment facilities at Sellafield, which convert much of this radioactive waste into a solid form for long-term storage.
The EPA’s marine radioactivity monitoring continues to assess changes in artificial radioactivity because of current and past discharges into the Irish Sea.
Find out more information on the EPA’s marine monitoring programme.
The EPA also maintains a National Radiation Monitoring Network that combines 24-hour measurements from a gamma dose rate monitoring network and a programme of sampling and analysis of air filters and rainwater in the EPA’s radiation monitoring laboratory. This provides a baseline of atmospheric radiation levels and enables a quick comparison of measurements to identify elevated radiation levels should they occur.
Information on the latest gamma dose rate measurements are located at map of monitoring locations
The levels of artificial radioactivity that we have measured in the Irish Sea have no significant health effect on the Irish public, whether sailing, swimming or diving in the Irish Sea, or eating fish from the Irish Sea.
Results from the EPA’s marine radioactivity monitoring programme show that the radiation exposure a person receives from artificial radioactivity from eating seafood in the Irish Sea is very small when compared to the levels of natural radioactivity in the environment. Radiation exposure from all artificial radioactivity (including that from Sellafield) makes up less than 1% of the overall radiation exposure, or dose, a member of the Irish public receives. The most significant exposure pathway is exposure to radon gas in your own home, which makes up nearly 60% of your radiation exposure (chart below).
Radioactive materials are occasionally transported through the Irish Sea from Sellafield. Shipments pass through the Irish Sea to the ports of Barrow-in-Furness and Workington.
Safety standards set by the International Maritime Organisation apply to vessels used to transport these radioactive materials and the containers used must comply with standards set by the International Atomic Energy Agency. More information on the safe transport of radioactive material can be found on the International Atomic Energy Agency website.
In 2019, a significant leak was reported from the Magnox Swarf Storage Silo (MSSS) in Sellafield. The EPA was informed of the leak. The MSSS is a radioactive waste storage facility constructed between 1964 and 1983. The facility consists of 22 concrete silos, housing 10,000 tonnes of solid waste and radioactive cover water. The leaks, first detected in the 1970s, are hard to locate due to complex infrastructure and radiation risk. While the location of the leak is not certain, evidence indicates that it relates to the Original Building (OB) of the MSSS (the MSSS has had 3 extensions over the years of its operation).
In 2020, the leak rate was stabilised to approximately 2 to 3 cubic meters per day. Since April 2021, the reported leak rate is between 2.3 - 2.5 cubic meters per day. The UK Regulators have stated that based on the current understanding of the leak, any risk to the off-site environment and public is expected to be very low and has remained within the boundaries of the Sellafield site and contained in the soil, not posing a risk to the public. This situation could change, and the UK regulators are monitoring it closely. The MSSS is expected to continue to leak radioactive water into the ground until the late 2050s and will be largely emptied between 2054 and 2059. The EPA frequently receives updates on the MSSS leak from the UK regulators to ensure we are kept informed of any relevant or related issues.
Based on the current information available the EPA have determined that the leak from MSSS poses negligible risk to Ireland.
The EPA takes into consideration non-routine or emergency situations that could arise on the Sellafield site when planning, preparing and exercising response to nuclear emergencies abroad. In 2016 the EPA published a report on the potential radiological impact of a severe accident at the Sellafield site. Previous studies have shown that the likelihood of a severe accident at Sellafield is low, the accident scenarios studied were those identified as having the greatest potential to have an impact on Ireland. These scenarios included operator error, earthquakes, fires, floods, meteorite strikes and terrorist attacks. This assessment concluded that significant radiological effects in Ireland are unlikely as a result of an accident at Sellafield. For each of the worst-case scenarios, the predicted doses were below the levels which would require measures such as sheltering, relocation or evacuation of people. Depending on the weather conditions, however, the resulting increase in radioactivity levels in Ireland could require the introduction of food and agricultural protective actions in Ireland. More information can be found here: Potential radiological impact on Ireland of postulated severe accidents at Sellafield(epa.ie)
In addition, in 2016 the ESRI prepared a report on behalf of the Irish Government on the potential economic costs that would be associated with a nuclear accident close to Ireland in north-western Europe. The report found that a nuclear accident in north-western Europe could have a significant impact on the economy and that where a nuclear accident does occur, even with no radiological deposition on Ireland there would still be a substantial economic impact. The outcomes from this study are reported here: The Potential Economic Impact of a Nuclear Accident - An Irish Case Study (esri.ie)
Decommissioning and clean-up of the Sellafield site will continue until 2125. Much of the clean-up of the legacy waste storage facilities that are of most concern to the UK regulators is due to be completed before 2060, with MSSS to be the last storage facility estimated to be completed by 2059.
The EPA does not engage directly with Sellafield Ltd but does engage actively with the UK authorities with responsibility for regulation of the Sellafield facility: the Office for Nuclear Regulation and the UK Environment Agency. The EPA meet with these regulators on an ongoing basis.
The EPA also participates in the UK-Ireland Contact Group meeting on Radiological Matters twice a year in support of the Department of Climate, Energy and the Environment (DCEE). These meetings are convened jointly by DCEE and the UK Department of Energy Security and Net Zero (DESNZ).
EPA technical experts and representatives from the Department of Climate, Energy and the Environment also visited the Sellafield site in 2022 and 2023, where they visited several waste storage facilities. EPA continues to engage actively with the UK authorities on radiation matters of interest to Ireland, including in relation to the hazard reduction and decommissioning programmes for the Sellafield site. A further visit to the site is planned for late-2025.