Abstract
A method was developed to estimate 90Sr contamination density on a concrete surface or on the surface of soil or water within 1 g/cm2 using 70-μm dose equivalent rates. The 70-μm dose equivalent rates from contaminated areas of various sizes were calculated at heights of 3.0, 5.0, 10.0, and 50.0 cm using egs5 Monte Carlo code. The ratio between the measured 70-μm dose equivalent rate ratio at 50 cm and that at 3.0, 5.0, or 10 cm can be used to estimate the effective radius of the contaminated area by using the calculation results. The contaminated density is obtained from the measured 70-μm dose equivalent rate with the calculated radially dependent conversion factor.
