Measurements of radioactivity in swipes taken from one employee's nostrils showed readings of 5,000 to 7,000 disintegrations per minute, indicating that he may have inhaled some of the plutonium.
The employee, a postdoctoral researcher in Los Alamos' Weapon Component Technology Group, received a chelation treatment late Wednesday at Los Alamos' Occupational Medicine Group. The treatment involves chemicals that latch onto heavy metals such as plutonium so the body's natural processes can remove them.
A conservative estimate of what sort of dose the employee's exposure created awaits further analysis, which could take about a week. Additional knowledge of the chemical form of the plutonium and the size of the airborne particles, as well as a comprehensive set of bioassay analysis also will lead to a more accurate dose calculation.
Laboratory health physicists, based on what they know so far, say the intake could deliver a dose over the next 50 years roughly equal to or slightly less than twice the dose created by natural background radiation. Background radiation in Northern New Mexico represents about 325 millirems annually. By comparison, Department of Energy standards limit workers to an exposure of 5,000 millirems annually.
Nose swipes from the second employee showed counts of 60 to 90 disintegrations per minute, a low level of activity that did not call for any treatment. A urine sample from that employee has also been sent for analysis.
The postdoctoral researcher was working in a laboratory in Los Alamos' Plutonium Facility. He was in the process of replacing a valve on a connection between two glove boxes. The continuous air monitors in the room alarmed, indicating the presence of airborne radioactivity.
When the CAM alarms sounded, both employees left the room and monitored themselves. Radiation control technicians arrived immediately and surveyed the exposed employees for contamination. The postdoc had significant contamination on his face, head and chest. Health physicists arrived to take nose swipes on both employees.
An analysis is underway to determine how this incident occurred. Laboratory personnel also are learning more about the characteristics of the plutonium involved so they can develop a more accurate estimate of the dose to the two employees and provide information that Laboratory physicians can use in deciding whether to recommend additional chelation or other medical treatments.
Los Alamos National Laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national security, is operated by Los Alamos National Security, LLC, a team composed of Bechtel National, the University of California, The Babcock & Wilcox Company, and Washington Group International for the Department of Energy's National Nuclear Security Administration.
Los Alamos enhances national security by ensuring the safety and reliability of the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health, and global security concerns.