Two cases of recovery of kilocurie sources fallen from telegamma units

Recently, two incidents involving the fall of kilocurie sources from telegamma units during repairs occurred in India. In one case it was a 60Co source of activity 222 TBq (6,000 Ci) and in the other case, it was a 137Cs source of activity 75.85 TBq (2,050 Ci). The line of action planned for the recovery of the sources was to cover the sources with large quantities of lead shots sent through a sloping pipe, thereby reducing the exposure rate. Once this was arranged, the workers could go inside for further retrieval action. An aluminium container was designed and positioned over the source drawer and lead shots were poured into this container. The retrieval operation was executed as planned but with slight modifications as necessitated at the sites. The collective effective dose for the recovery of the first source was approximately 0.07 person-sievert (7 person-rem) and for the second one was < 0.01 person-sievert (1 person-rem).