Detecting Hidden Radiation: A New Approach to Safety

Radiation workers face unique challenges, especially when it comes to detecting internal contamination. External contamination can often mask internal issues, making it difficult to get accurate readings. A recent study introduced a new method to tackle this problem using a Quick Scan Whole Body Monitor (QSWBM). This tool can help identify external hotspots of Cesium-137, a common radioactive isotope. The study used computational phantoms and the FLUKA code to evaluate different ratios of net count rates in the QSWBM detectors. Two key ratios, R_D and R_AP, proved effective in screening various external hotspot scenarios. R_D compares the net count rates in the upper and lower detectors during anterior counting, while R_AP looks at the ratio of net count rates in anterior and posterior counting. In cases of accidental contamination, where external contamination is widespread, the study suggests using an in-vitro method. This involves analyzing urine samples with gamma spectrometry to estimate internal contamination accurately. The High-Purity Germanium (HPGe) detection system was calibrated for different bottle sizes to ensure precise measurements. The study also found that the Minimum Detectable Activity (MDA) values for this method are sensitive enough to quantify excretion rates that could lead to a Committed Effective Dose (CED) of less than 1 mSv, even up to 10 days after intake. This means that even low levels of radiation can be detected and measured accurately. This new approach provides a reliable way to monitor radiation workers and ensure their safety. By combining whole body monitoring with in-vitro analysis, it offers a comprehensive solution for detecting both external and internal contamination.