RPII Marine Monitoring Report highlights Sellafield as main source of artificial radioactivity in Ir

Date released: May 22 2003

Discharged radioactive waste from the British Nuclear Fuels plc (BNFL) reprocessing plant at Sellafield continues to be the dominant source of artificial radioactivity in the Irish Sea, according to a report published today by the Radiological Protection Institute of Ireland.

The report details the results of the Institute’s monitoring of radioactivity in the Irish marine environment during 2000 and 2001.

The consumption of fish and shellfish is the main way the Irish public are exposed to radiation as a result of discharges from Sellafield. The doses due to eating fish and shellfish, at 1.18 microsieverts (µSv) in 2000 and 1.20 µSv in 2001, appear to have reached a plateau in recent years. Commenting on the report, the Institute’s Principal Scientific Officer, Dr. Tony Colgan stated that “these doses are very small and represent less than 1% of the annual average radiation dose of approximately 3620 µSv received by members of the Irish public from all sources of radiation. Consequently, they do not constitute a significant health risk”. He emphasised that “it continues to be safe to eat seafood from the Irish Sea and to use the marine environment for both leisure-based and commercial purposes”.

The Institute has been monitoring the radioactivity of the Irish Sea since 1982 and has built up an invaluable database of information, which demonstrates the trends over that period. Caesium-137 is the radionuclide of greatest radiological significance, accounting for approximately 60-70% of the total radiation dose. The other principal contributors to dose are technetium-99, americium-241 and plutonium. Increased discharges of technetium-99 from Sellafield since 1994 have resulted in corresponding increases in the contribution of this radionuclide to the doses to seafood consumers during the period 1994 to 2001. Technetium-99 currently contributes up to 30% of the radiation dose to typical consumers of fish and shellfish.

Dr. Colgan commented that “further reductions in these doses are being pursued through the implementation of the OSPAR Strategy with regard to Radioactive Substances. All Contracting Parties to the OSPAR Convention for the Protection of the Marine Environment of the North-east Atlantic have committed themselves to progressive and substantial reductions in radioactive discharges from their facilities (Sintra Declaration). Ireland is actively engaged through the OSPAR Commission in ensuring that the discharge strategies adopted by all parties to OSPAR (particularly France and the United Kingdom who engage in the reprocessing of spent fuel) will effectively meet the commitments set out in the Sintra Declaration and reduce radioactive discharges to the marine environment.”

The Institute continues to monitor the radiation levels in the Irish Sea and to evaluate their impact on the Irish population and the Irish marine environment. In the Institute’s view the highest possible standards of safety and waste management should apply to nuclear facilities, including the implementation of best available techniques for the further reduction of discharges, with the goal of minimising the environmental impact of discharges.


Notes To Editors

  1. Approximately 300 samples of fish, shellfish, seaweed, seawater and sediment were collected in 2000 and again in 2001. Fish and shellfish were routinely collected from commercial landings at major Irish fishing ports. Particular attention was given to collecting samples from the ports of Carlingford, Clogherhead and Howth where the highest levels of contamination are usually found due mainly to the water circulation patterns in the Irish Sea. Seawater and sediment samples were also taken at offshore sites in the western Irish Sea.
  2. Both the Marine Institute and the Department of Communications, Marine and Natural Resources assisted the Institute with this sampling. All samples were analysed for gamma-emitting radionuclides, specifically caesium-137, at the Institute’s radio-analytical laboratory. Selected samples were analysed for carbon-14, technetium-99, americium-241 and plutonium.
  3. The results show that the activity concentration of caesium-137, the artificial radionuclide giving rise to the highest radiation dose, has remained relatively stable since the mid 1990s but at a lower level than that observed during the previous two decades. The highest activity concentrations observed are on the north-east coastline.
  4. The Institute also operates a research programme aimed at understanding the long-term behaviour of both caesium-137 and plutonium in the Irish Sea. This work will allow predictions to be made of the effects of any proposed change in discharge patterns at Sellafield on the radiation doses to consumers of seafood.