Spreadsheet modelling of radiological impacts from radioisotope disposal in municipal waste systems

Beak Consultants Limited was retained by the Atomic Energy Control Board of Canada to investigate the potential risks to municipal workers and the public resulting from disposal of low levels of radioisotope wastes into municipal treatment systems. A generic model was prepared utilizing a commercial spreadsheet program on a PC computer. The model involved a source term for 13 radioisotopes (H-3, C-14, Co-57, Tc-99m, I-125, I-131, Th-201, P-32, P-33, Ni-63, Zn-65, Po-210 and Am-241), aquatic and atmospheric dispersion, and dose calculation. The model was applied to the Hamilton-Burlington area for this study. The model predicted maximum dose levels less than 2.0 E-6 Sv/a per person. This predicted dose is 0.04% of the regulatory limit for members of the general public (5 E-3 Sv/a per person)