Radiation safety in gas industry of Bangladesh

Abstract

Uncontrolled radiation is dangerous for both public and environment. In petroleum industries, the major sources of ionizing radiation are generation of NORM (Naturally Occurring Radioactive Materials), usc of Nuclear Well Logging techniques and Radiography of different machine parts. To control such life threatening hazards, NSRC Act was promulgated in 1993 and NSRC Rule8 were notified in Ranglade,h Ga7-eUein 1997. These Act and Rules arc the basis oflhi" research work. Eight NORM samples were collected randomly from diIT~r~nl gas pru~es~ plants of Bangladesh and the data shows that the radioactivity level [or Separator Sludge Sample W<lS 5.47 to 2811.50 pei/gm [safe limit: 5 rei/gm] and for Produced Water Sample was 1163,82 to 1424,94 peiiL [saFe limi!: 5 pCi/L]. Finally, data are analyzed by geostmistical approach to gct model equation~ and ~ome recommendations are made for ensuring radiation safety, An extensive Nuelear Well Loggmg ~urvey was conducted at Titas Well No, 5 and data show~ that the safe distance to avoid radiation dose must be 11.5 meter for Illes gamma source and 24 meter for wArn_Be neutron source. For proper shielJing of these two sources, an extra 2.81 cm lead for I17CSsource and 67.00 em diameter waler shielding for 241Am-Be source must he u~ed to reduce lhe radiation dose for well loggers. Fur Industrial Radiography part, a detail survey wa., carried oul at radH)aclive source storage pit uF Titas Gas Transmission and Distribution Company Ltd and data ~how~ that the diameter of "Controlled Area" for both the two present Inlr gamma sources are 140 meter. Care must be taken to avoid any sort of souree lost silllation from the device as the safe distance for these two sources are 500 meter. For propcr shielding of these two sources, an extra 4,21 cm lead for 1~21rsouree [Model No 5476; Serial No. 03840 B] and 4.12 cm lead for Inlr source [Model No. 5399; Serial No. 03841 BJ lTIllstlJe ll,ed to en~ure mdiation safet)' lor mdlOgraphers. Besides, the author tried to point oul many deliciencies, which should be removed to reduce the radiation dose to the personnel of gas indus!ry uf Bangladesh.