NRPB-W60: Non-technical summary

Non-technical summary

The OMINEX project provides advice and recommendations on designing and implementing internal dose monitoring programmes in the workplace, in such a way that best use is made of available resources, while minimising costs. The results of the project should be of use to dosimetry service managers, regulators and senior medical staff in the nuclear industry. The project was carried out by a consortium of European research/advisory organisations working together with nuclear industry organisations. This report presents the main results and findings of the project. More detailed information is given in the reports and papers that were published during the course of the project, for which references are given.

Work was organised into five distinct but inter-related 'Work Packages'. In the first two Work Packages, surveys were carried of current internal dose monitoring practice in European Union (EU) countries, and of their associated costs. The most important finding was that, in many instances, there is little consensus across the EU on the optimum design of an internal dose monitoring programme for particular radionuclides/compounds.

In OMINEX, the underlying approach to optimisation was to consider costs versus 'benefits', the latter being quantified primarily by assessing either the sensitivity or accuracy with which intakes and doses are determined from the results of monitoring. In the third Work Package, surveys were carried out of bioassay and in vivo monitoring procedures in EU laboratories, and of measurement parameters affecting uncertainties in these measurements. This information was then used as an input to investigations into ways of exploiting available methods and techniques to reduce uncertainties in measurements, leading to the development of recommendations on the optimisation of bioassay and in vivo measurement parameters. A novel aspect of the project was the development of a methodology to assess total uncertainty in intakes and doses assessed from monitoring measurements, taking into account uncertainties in intake patterns, measurements, and respiratory tract and systemic model parameters. This work was carried out in the fourth Work Package.

Development of advice on individual monitoring programmes was carried out in the fifth Work Package. Advice has been developed on routine and special monitoring following exposure to a range of radionuclides that represent some of the most difficult problems in internal dose assessment and are of the most radiological interest, ie tritium, cobalt-60, radioiodine, caesium-137, uranium, plutonium and thorium. Emphasis has been placed on compounds of these radionuclides that are encountered in the nuclear industries. Where achieving adequate accuracy was judged to be the more important requirement (tritium, cobalt, radioiodine), recommendations on optimised monitoring were developed from considerations of uncertainties in assessed doses. Where achieving adequate sensitivity was judged to be the more important requirement (primarily, this applies to the actinides), considerations of minimum detectable dose were employed. Advice is provided on choice of monitoring method(s), (for example, excretion monitoring versus in vivo monitoring), choice of measurement technique (for example, alpha spectrometry versus mass spectrometry), monitoring intervals, measurement frequency, required measurement sensitivity and accuracy, measurement parameters needed to achieve this performance, the resulting uncertainty in assessed intakes and doses, and minimum detectable doses.

Last reviewed: 17 September 2009