Model testing using data on I released from Hanford

Thiessen, K. M.*; Napier, B. A.*; Filistovic, V.*; Homma, Toshimitsu; Kanyr, B*; Krajewski, P.*; Kryshev, A. I.*; Nedveckaite, T.*; Nnyei, A.*; Sazykina, T. G.*; Tveten, U.*; Sjblom, K.-L.*; Robinson, C.*

The Hanford test scenario described an accidental release of I to the environment from the Hanford Purex Chemical Separations Plant in September 1963. Based on monitoring data collected after the release, this scenario was used by the Dose Reconstruction Working Group of BIOMASS. Predicted doses to actual children with high milk consumption ranged from 0.006 to 2 mSv. The predicted deposition at any given location varied among participants by a factor of 5 to 80. Predicted ingestion doses for children, normalized for predicted deposition, varied by about a factor of 10. The exercise provided an opportunity for comparison of assessment methods and conceptual approaches, testing model predictions against measurements, and identifying the most important contributors to uncertainty in the assessment result. Key factors affecting predictions included the approach to handling incomplete data, interpretation of input information, selection of parameter values, adjustment of models for sitespecific conditions, and treatment of uncertainties.