The Mayak Worker Dosimetry System (MWDS-2013) is a system for interpreting measurement data from Mayak workers from both internal and external sources. This paper is concerned with the calculation of annual organ doses for Mayak workers exposed to plutonium aerosols, where the measurement data consists mainly of activity of plutonium in urine samples. The system utilises the latest biokinetic and dosimetric models, and unlike its predecessors, takes explicit account of uncertainties in both the measurement data and model parameters. The aim of this paper is to describe the complete MWDS-2013 system (including model parameter values and their uncertainties) and the methodology used (including all the relevant equations) and the assumptions made. Where necessary, Supplementary papers which justify specific assumptions are cited.
Bibliographical noteFunding Information:
As part of an ongoing study (Joint Coordinating Council on Radiation Effects Research (JCCRER) Project 2.4), funded by the United States Department of Energy (USDOE), various protocols for assessing the internal doses of Mayak Production Association (PA) workers have been generated: DOSES-1995, DOSES-2000, DOSES-2005 and MWDS-2008. These doses are used as inputs to epidemiological studies (JCCRER Project 2.1) to determine the risk of exposure to plutonium aerosols. The purpose of this paper is to present the latest Mayak Worker Dosimetry System MWDS-2013 in sufficient detail for an independent source to duplicate the doses or scrutinise the methodology. The paper is concerned with internal doses from inhaled plutonium only; external doses are considered in a separate paper. The paper only deals with a subset (~8 000) of the full Mayak Worker Cohort, namely, those workers who have actual measurements (mainly urine). For many workers, the number of urine measurements is small: 40% of the cohort having three or less measurements, 70% less than 9 and only 5% having more than 20 measurements. The paper thus acts both as a template for internal dose reconstruction and a statement for the record as to how the doses are derived. Reference to other papers in this special edition will be made to give more detail and to justify the choice of parameter values made with a scientific basis.
This work was conducted as part of the Joint Coordinating Committee for Radiation Effects Research (JCCRER) Project 2.4, Mayak Worker Dosimetry. It was jointly funded by the U.S. Department of Energy (U.S. DOE) and the Federal Medical Biological Agency (FMBA) of the Russian Federation.