RADIATION PROTECTION MEASURES TAKEN DURING REPATRIATION OF SEALED HIGH ACTIVITY RADIOACTIVE SOURCES IN CAMEROON.

Operational measures taken for the repatriation of Alcyon II 60Co Teletherapy head and El Dorado 6 60Co Teletherapy devices located in Yaounde and Douala respectively are reported. Operations carried out have permit to store Alcyon head in the CC 33 container and to transfer 60Co source from El Dorado 6 device to YKT1B container. These containers are approved as Type B package for securely transport. Optically stimulated luminescence dosimeters had been distributed to all involved persons to estimate the received effective dose during operations. It appears by the present study that, the most received individual effective dose is 130 µSv during the whole process.

²³8U, ²³5U, ¹³7Cs and ¹³³Xe in soils from two campuses in University of Douala-Cameroon.

An evaluation of (238)U, (235)U, (137)Cs and (133)Xe in soils from two campuses in University of Douala-Cameroon using gamma spectroscopy based Broad Energy Germanium Detector (BEGe6530) has been performed. The mean activities in soils from Campuse 1 were 40.16 ± 8.98 Bq/kg for (238)U, 3.39 ± 0.33 Bq/kg for (235)U, 0.46 ± 0.33 Bq/kg for (137)Cs and 0.14 ± 0.16 Bq/kg for (133)Xe. In Campus 2, the mean activities in soils were 31.45 ± 12.24Bq/kg, 3.02 ± 1.00 Bq/kg, 0.30 ± 0.26 Bq/kg and 0.35 ± 0.24 Bq/kg for (238)U, (235)U, (137)Cs and (133)Xe, respectively. Using the in situ survey meter, the mean values of the absorbed dose rate measured was 71.43 nGy/h for Campus 1 and 62.72 nGy/h for Campus 2. The evaluated average outdoor effective dose for Campus 1 and 2 were 87.60 µSv/yr and 76.93 µSv/yr, respectively. The overall results obtained in this work were generally low compared to that of UNSCEAR.