Regulating Discharges from Nonnuclear Industry in Relation to Environmental Radiological Protection

The discharge of produced water containing naturally occurring radionuclides as well as the production of solid wastes containing TENORM (technologically enhanced naturally occurring radioactive material) from oil- and gas exploitation in the North Sea has challenged the regulatory regime of radiation protection and environmental protection in Norway. In Norway, solid waste containing more than 10 Bq/g of the nuclides 226Ra or 228Ra or 210Pb is classified as low radioactive waste (LSA-scale). The definition of LSA-scale differs between different countries, ranging from 0.5 Bq/g to 10Bq/g, depending on the interpretation of exclusion, exemption and clearance limits. There is a need for work towards international consensus on regulations of this area, as transboundary movement of this type of waste is quite common. The amount of discharges of produced water into the North Sea from Norwegian sector ranged from 75-10 6 m3 to 120-106 m3 annually in the period 1997-2002. The concentrations of 226Ra in the produced water ranged from 0.05 to 15 Bq/l, compared to the average activity concentration of 226Ra in open surface waters around 1.5 mBq/l. Based on Norwegian data, NRPA estimated that the discharge of radium isotopes, originating from the production of oil in the North Sea in 2002 was 0.27 TBq for 226Ra. Traditionally, only doses to exposed workers have been regulated through the radiation protection authorities, and little attention has been paid to the possible effects on the environment from this practice. Until more information on dose response is available in the marine environment, discharges and handling of LRA waste should be dealt with from a precautionary principle point of view. (Author) 14 refs