Becquerel/sievert survey meter and operational measurands

A Becquerel/Sievert (BS) survey meter was conceptually developed. The BS survey meter can be used easily, like conventional radiation survey meters, to measure radioactivity and radiation dose simultaneously. Simulation of radioactivity measurement by using the BS survey meter was conducted using a model of Cs-137 circular surface contamination. As a result, the radioactivity of Cs-137 measured using the BS survey meter was underestimated. The cause of the underestimation was determined, and an inequality in the upper and lower limits of radioactivity was derived. These results indicate that the upper and lower limits of radioactivity could be used as operational measurands with the BS survey meter. (author)