Radiography is an industrial procedure in which radiation is used to inspect the welds on piping and other metal components in much the way an X-ray is taken in medical applications. A radioactive source was mistakenly left partially outside the shielded area of a radiography camera after use. Two workers operating the camera received substantial radiation exposures when they failed to follow basic radiation safety practices. The radiographer's assistant received 11.8 rem, giving him a total annual radiation dose of 12.8 rem, and the radiographer received 3.9 rem, giving him a 5.7 rem annual radiation dose.
Federal limits restrict the annual dose to a radiation worker to a maximum of five rem.
In this case, the workers did not experience any immediate adverse health effects. In its investigation of this incident, the NRC found that the radiographer failed to adequately supervise his assistant during radiography operations, neither worker adequately performed a required survey to be sure the radioactive source was fully shielded, and one worker failed to wear an operating personal dosimetry instrument during radiographic operations. Anvil reported the incident to the NRC, conducted a thorough investigation and improved the safety of its operations. The incident was judged to be a Severity Level II problem on the NRC's four-level scale, with Level I being the most serious.