Montana oil rig workers exposed to unshielded well-logging source; Texas firm firmed $90,000

NRC announced a proposed civil penalty of $90,000 against Schlumberger Technology Corporation of Sugar Land, Texas. The fine is related to a May 21, 2002 incident involving the loss of control of a well-logging source containing approximately 1.3 curies of Cesium-137 on an oil rig near Havre, Montana. Thirty-one oilfield workers were identified as being exposed to the source, including thirteen who received doses estimated to be in excess of NRC's 0.1 rem annual limit for individual members of the public. The highest estimated exposure was 0.4 rem, which is less than 10 percent of the annual allowable dose for radiation workers. In a letter to company announcing the proposed fine, NRC regional administrator Bruce Mallett said "While none of the oilfield workers received a radiation exposure that is considered harmful, ... the NRC takes seriously any incident that results in members of the public being unnecessarily exposed to radioactive material."

The company's well-logging crew apparently left the rig without performing required radiation survey intended to verify that the source had been fully retracted into its shield. Two of the workers signed paperwork indicating that required surveys had been performed. NRC considered prohibiting these two from further licensed activities, but decided to issue individual notices of violation to them, too. One was an engineer-in-training. He told NRC that he was told by another worker that he didn't have to perform a survey, and then he felt pressured to sign off on the form. The other was the lowest-paid member of the crew, and told NRC he signed under the assumption that the engineers had performed survey.
[Ref: Notices of Violation related to NRC Inspection Report No. 030-06388/02-001