A Pennsylvania scrapyard discovered cesium in an outbound truck last month, exposing workers to small doses of radiation.

Coatesville Scrap checks inbound and outbound trailers for radiation using detectors mounted to its scales. On Oct. 31, a radiation source later identified as cesium-137 triggered an alarm and was removed, according to a report made public by the Nuclear Regulatory Commission Friday. Scrapyard personnel moved a small piece of metal to a remote part of the yard, placed it in a lead pipe, crimped the ends and left it behind a large piece of equipment. The NRC dispatched an inspector who detected radiation measured at 320 milli-roentgens per hour at the pipe's surface.

Investigators determined that three people were involved in locating the metal, which had to be found by shoveling through the load. According to the NRC, one worker was in contact with the material for about 2.5 hours on and off. The uncalibrated dosimeter worn by the person who moved the material and placed it in the pipe recorded a whole-body dose of 364 micro-roentgens. The NRC estimated a possible extremity dose in the worker's hand of 10 rad. No contamination was found on the hands and feet of the workers involved.