Predicting the 137Cs ingestion dose from marine fish consumption in Hong Kong after an accidental release

Caesium-137 is one of the more important radionuclides released during a nuclear power plant accident. Based on a mathematical model developed earlier by the present authors for estimating 137Cs ingestion dose from consumption of marine fish in Hong Kong, doses due to an accidental release into Daya Bay from the Guangdong Nuclear Power Station are predicted. Assuming a release of 30000 TBq of 137Cs, results show that the cumulative dose rises rapidly during the first five years and then gradually levels off. In the first and 50th years after discharge, doses to an average Hong Kong citizen would cumulate to 17 and 38 microSv respectively, which are dominated by the contribution from fish cultured in Hong Kong waters. The first year dose to members of the critical group of local fish farmers is estimated to be 1600 microSv, accumulating to 3600 microSv in the 50th year. Apart from this small number of critical group members whose doses may need some monitoring, the doses to the population at large are considered small compared with an annual dose of 175 microSv from ingestion of natural radionuclides in food and drinks in Hong Kong.