ICRP Publication 142: Radiological Protection from Naturally Occurring Radioactive Material (NORM) in Industrial Processes.

The purpose of this publication is to provide guidance on radiological protection in industries involving naturally occurring radioactive material (NORM). These industries may give rise to multiple hazards and the radiological hazard is not necessarily dominant. The industries are diverse and may involve exposure of people and the environment where protective actions need to be considered. In some cases, there is a potential for significant routine exposure of workers and members of the public if suitable control measures are not considered. Releases of large volumes of NORM may also result in detrimental effects on the environment from radiological and non-radiological constituents. However, NORM industries present no real prospect of a radiological emergency leading to tissue reactions or immediate danger for life. Radiological protection in industries involving NORM can be appropriately addressed on the basis of the principles of justification of the actions taken and optimisation of protection using reference levels. An integrated and graded approach is recommended for the protection of workers, the public, and the environment, where consideration of non-radiological hazards is integrated with radiological hazards, and the approach to protection is optimised (graded) so that the use of various radiological protection programme elements is consistent with the hazards while not imposing unnecessary burdens. For workers, the approach starts with characterisation of the exposure situation, and integration, as necessary, of specific radiological protective actions to complement the protection strategy already in place or planned to manage other workplace hazards. According to the characteristics of the exposure situation and the magnitude of the hazards, a relevant reference level should be selected and appropriate collective or individual protective actions taken. Exposure to radon is also treated using a graded approach, based first on application of typical radon prevention and mitigation techniques, as described in Publication 126. A similar approach should be implemented for public exposure through the control of discharges, wastes, and residues after characterisation of the situation. If the protection of non-human species is warranted, it should be dealt with after an assessment of radiological exposure appropriate for the circumstances, taking into account all hazards and impacts. This should include identification of exposed organisms in the environment, and use relevant derived consideration reference levels to inform decisions on options for control of exposure.

Measurements of radioactivity in environmental samples from the southern Urals.

A region between Chelyabinsk and Ekaterinburg in the Southern Urals has been heavily contaminated due to operational and accidental releases from the first Soviet plutonium production facility Mayak. In 1992 and 1993, the German Federal Office for Radiation Protection organized a measuring campaign involving two Russian institutes to assist with the validation of former Soviet measurement data. The results of this measuring campaign are reported here. Environmental samples were collected from areas affected by significant radioactive releases into the Techa river, which started in 1948, and by fallout from the explosion of a fission product storage tank in 1957. Soil, sediment, water, milk and food samples were independently analysed for 90Sr, 137Cs and plutonium by the three institutes involved. This paper presents data on the present levels of environmental radioactivity. The highest contamination of areas accessible to the local population was found in the vicinity of the Techa river around Muslumovo. Activity concentration of floodplain samples reached up to 37,000 Bq.kg-1 137Cs, 5,600 Bq.kg-1 90Sr and 9.9 Bq.kg-1 Pu. Milk and potatoes from private farms in Muslumovo showed low activity in the range from 0.7 Bq.kg-1 to 25 Bq.kg-1 90Sr. The results of the three independent measurement teams showed sufficient agreement. One Russian laboratory obtained plutonium activities that exceeded the results of the other laboratories by about 20%. Contrary to the International Chernobyl Project, there was no overestimation of 90Sr activities in the Russian analyses. Therefore, the validity of earlier data sets acquired with same methodology and quality control can be considered a valuable basis for further assessments and for dose reconstruction in epidemiological projects.

First attempts at validation of radiation exposure of the population along the Techa River, southern Urals.

A research programme sponsored by the German Federal Ministry for the Environment, Nature Protection and Nuclear Safety (BMU) was conducted during 1992 and 1993 in the Southern Urals, to provide an initial validation and comparison of results of population exposure arising from the release of radioactive waste from the MAYAK nuclear facility between the years 1948 and 1967. This programme included investigations of the contamination of the soil, of food (milk, drinking-water, potatoes) and whole-body-counter measurements of inhabitants of settlements at the Techa River. The nuclides of interest were plutonium isotopes and the long-lived fission products 137Cs and 90Sr. Results of these investigations, particularly in and around the village of Muslyumovo (78 km downstream from the point of release of the radioactive waste into the Techa River), are shown. These investigations are a first step towards an independent validation of the enormous data base collected by the Russian institutes and of derived values of the doses to the population of the Techa River.