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RADIOACTIVITY IN THE SEA AND FOOD IN IRELAND

Objective


A reduction of radioactivity in the Irish Sea was found subsequent to changes at the Sellafield reprocessing plant. Radioactivity in foodstuffs produced in the Republic of Ireland has also been studied.

The values of 134-caesium now existing in seaweed and water at the Irish coast preclude its accurate measurement unless large volume samples and very long counting times are used. It is therefore doubtful that much further scientific information could be obtained by continued monitoring. Any sudden input pulse due to an accidental discharge at Sellafield could, however, be reliably and accurately detected at the Irish coast after the appropriate transit time. It may be concluded that the results of this project have been broadly achieved and that the unanticipated effect of the Chernobyl accident provided confirmatory data for conclusions drawn from the data resulting from the Sellafield discharges.

Studies have been made of the reduction of radioactivity in the Irish Sea subsequent to changes to the Sellafield reprocessing plant and, also, of radioactivity in foodstuffs produced in the Republic of Ireland.

The values of 134-caesium now existing in seaweed and water at the Irish coast preclude its accurate measurement unless large volume samples and very long counting times are used. It is therefore doubtful that much further scientific information could be obtained by continued monitoring. Any sudden input pulse due to an accidental discharge at Sellafield could, however, be reliably and accurately detected at the Irish coast after the appropriate transit time. It may be concluded that the results of this project have been broadly achieved and that the unanticipated effect of the Chernobyl accident provided confirmatory data for conclusions drawn from the data resulting from the Sellafield discharges.
RADIATION DOSAGE TO THE POPULATION OF IRELAND DUE TO MAN-MADE ISOTOPES ARISES FROM THE MARINE ENVIRONMENT AS A RESULT OF FALLOUT AND OF DISCHARGES FROM THE SELLAFIELD NUCLEAR REPROCESSING PLANT IN THE UNITED KINGDOM AND ALSO FROM THE TERRESTRIAL ENVIRONMENT DUE TO FALLOUT. THE CONTRIBUTION TO POPULATION DOSE AS A RESULT OF SELLAFIELD DISCHARGES HAS BEEN ASSESSED AT BETWEEN 2 AND 3 MAN SIEVERT PER ANNUM OVER THE PAST FIVE YEARS DUE TO 137-CAESIUM. WORK IN THIS LABORATORY HAS ALSO ESTABLISHED THAT SEAWEED OF THE FUCUS VARIETTY IS AN EXCELLENT INDICATOR OF CHANGES IN THE 137-CAESIUM CONTENT OF THE SURROUNDING WATER. THE DISCHARGES TO THE IRISH SEA FROM SELLAFIELD WILL BE REDUCED SIGNIFICANTLY AS A RESULT OF NEW PLANT FROM 1985 ONWARDS, AND AS A RESULT THE LEVELS OF 137-CAESIUM SHOULD BEGIN TO FALL SOME TIME LATER AT THE IRISH COAST.
IT IS PROPOSED TO FOLLOW THIS DECREASE BY MEASUREMENTS OF 137-CAESIUM LEVELS IN FUCUS SEAWEED AND SEA WATER COLLECTED AT POINTS ALONG THE IRISH COAST OF THE NORTH IRISH SEA. MEASUREMENTS WILL BE MADE USING A HIGH EFFICIENCY HYPERPURE GERMANIUM SOLID STATE DETECTOR WHICH WILL ALSO ENABLE MEASUREMENTS OF THE 137-CS AND 134-CS RATIOS TO FACILITATE TRANSPORT TIME MEASUREMENTS.MEASUREMENTS HAVE ALREADY BEEN MADE OF 137-CS LEVELS ON SEDIMENTS AT THE IRISH COAST; FURTHER MEASUREMENTS MADE WHEN THE LEVELS IN SEA-WATER DECREASE WILL ENABLE ESTIMATES TO BE MADE OF THE AMOUNT OF RESUSPENSION THAT TAKES PLACE. THIS IS OF RELEVANCE ALSO TO ESTUARINE DEPOSITION OF 137-CS.
IT HAS BEEN ESTABLISHED BY PRELIMINARY MEASUREMENTS THAT SIGNIFICANT (50 BQ KG TO THE POWER OF MINUS 1 APPROX) LEVELS OF 137-CS EXIST IN VEGETATION IN SOME BOG REGIONS OF IRELAND. THIS ALSO RESULTS IN DETECTABLE LEVELS IN SOME ANIMALS AND OTHER FOOD PRODUCTS. AS A FRACTION OF IRELAND'S FOOD PRODUCTS ORIGINATE FROM THESE AREAS, IT IS PROPOSED TO DETERMINE THE POPULATION DOSE FROM THESE PRODUCTS, TO ASSESS THE CHARACTERISTICS OF BOGLAND WHICH LEAD TO THE RETENTION OF THE 137-CS AND TO DETERMINE IF THE CAESIUM ORIGINATES FROM FALLOUT OR FROM THE MARINE ENVIRONMENT VIA AN AEROSOL PATHWAY.
THE CONTRIBUTION TO POPULATION DOSAGE FROM EXPORTED FOODSTUFFS WOULD ALSO BE ASSESSED. CERTAIN AREAS IN IRELAND HAVE BEEN SHOWN TO CONTAIN HIGH LEVELS OF NATURAL RADIOACTIVITY. THE RADIOACTIVITY CONTENT OF FOODS FROM THESE AREAS WILL ALSO BE MEASURED AND POPULATION DOSES ESTABLISHED WHERE APPROPRIATE.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

University of Dublin
Address
Trinity College
Dublin 2
Ireland