The Mayak Worker Dosimetry System (MWDS-2013): How to Reduce Hyper-Realisations to Realisations.

Area of Science:

• Medical Physics
• Radiation Dosimetry
• Epidemiology

Background:

• Previous dosimetry databases (MWDS-2008, DOSES-2005) used single realizations for organ dose calculations.
• These databases did not explicitly address uncertainties in model parameters or differentiate between shared and unshared parameters.

Purpose of the Study:

• To introduce and evaluate methods for converting multiple hyper-realizations of organ doses into tractable realisations for epidemiological analysis.
• To account for uncertainties in model parameters, including shared and unshared types, in absorbed dose calculations.

Main Methods:

• A multiple-realisation approach generating 1000 realisations to capture parameter uncertainty.
• Bayesian calculation of organ doses resulting in hyper-doses (distributions) rather than single values.
• Development and discussion of methods to convert hyper-realisations to realisations and derive single point estimates for epidemiological analysis.

Main Results:

• The MWDS-2013 explicitly handles uncertainties in model parameters.
• It differentiates between shared and unshared parameters, preserving information on their effects on internal and external doses.
• Multiple hyper-realisations were generated, requiring conversion for epidemiological tractability.

Conclusions:

• The chosen method for converting hyper-realisations to realisations facilitates preliminary epidemiological analyses.
• The MWDS-2013 provides a more robust estimation of absorbed doses by incorporating parameter uncertainties.
• Single point dose estimates were also derived to support epidemiological investigations.