Measurement of Radiation Background and Estimation of the Annual Effective Dose for Workers in the Radiochemistry Laboratories at the Al-Tuwaitha Site

Abstract

      This study was achieved to calculate the annual effective dose equivalent (AEDE) in units of (mSv.y^-1), and the average radiation dose rate (ADR) in units of (μSv.h^-1) which were measured by portable devices.   The study was carried out on the workers of the destroyed radiochemistry laboratory located at Al-Twuitha nuclear site (south of Baghdad). Radiation background was determined for comparison with the radioactive dose of soil samples measured with HPGe detector and portable devices type LUDLUM.  The radioactivity levels of the area around the radiochemistry laboratory building were within the limits of radiation background.  The result showed a significant increase of the annual effective dose of C1 laboratory workers, as the annual effective dose of the lysate cell 1 (AHC1)in the lab was about 18.995 mSv/y, with an occupancy factor of 0.042, for an average working hours of  one hour per day.  An annual effective dose of 24.073 mSv/y was also recorded in hot cell 2 (HCL2), an increase of more than 4 mSv/y, for an occupancy factor of 0.083, equivalent to 2 hours of work per day.  The glove boxes 11 (GB11) of Laboratory C2 recorded an annual effective dose of 19,720 mSv/y for an occupancy factor of 0.125, equivalent to 3 working hours per day.  The C3 Laboratory and the rest of the laboratories and the health physics rooms recorded an annual effective dose within the workers’ allowable limits of 20 mSv/y.