Workers resumed normal activities at the Lujan Center this week, after investigators spent two weeks determining whether minute traces of mercury in two experimental areas posed a health risk to workers. Workers voiced their concerns about potential mercury contamination in the experimental areas and potentially in other areas of the Lujan Center on April 10; Laboratory managers issued a "stop work" order at the facility on April 11. Under Laboratory policy, workers can stop work if they have a concern about the safety of their activities.
"The 'stop work' was the right call," said Geoff Greene, deputy division director of the Los Alamos Neutron Science Center. "Our workers had concerns about their working environment and the spread of mercury contamination. We had a duty to investigate. I am pleased to announce that the investigation has shown that mercury contamination has not spread.
"The investigation has helped us identify some areas where we could improve training and processes to make working at the facility even safer," Greene said. "We will continue to monitor experimental areas to ensure that our work controls are appropriate for work conditions."
At the Lujan Center, mercury is used in shutters that stop neutron beams. This mercury is totally contained within the shutters. On a few occasions, small quantities of mercury have fallen on the floor. When this has occurred, the material was cleaned up with special vacuum machines by workers wearing appropriate protective clothing and gear. Despite the cleanup, traces of mercury could have remained on surfaces in experimental areas.
Continuous air monitors at the Lujan Center have shown that mercury vapor levels in areas where employees work are well below exposure limits established by the Occupational Health and Safety Administration. However, monitoring indicates that minute traces of mercury remain in some areas in the Lujan Center.
After the April 11 "stop work," Greene asked employees to serve on four teams to look at safety and health issues associated with the Lujan Center. The four teams analyzed potential hazards at the facility; devised and implemented a method to check for mercury contamination outside of the Lujan Center; determined whether existing work controls were adequate to prevent the spread of contamination, and, if the controls were not adequate, developed procedures to help ensure that workers are safe and that contamination does not spread; and provided up-to-date information to all employees about the issue.
The investigation teams' findings are as follows:
o No one at the Lujan Center was exposed to hazardous levels of mercury. Mercury vapor detectors at the facility have shown that vapor levels in the employees' breathing zones in most cases were not detectable; in those instances when vapor was detected, it was well below OSHA safe-worker limits.
o Since the "stop work" on April 11, employees were given the option of being tested for mercury contamination by health-care providers at the Laboratory's Occupational Medicine facility. To date, no worker has shown mercury in blood or urine tests.
o Mercury was not found on workers' personal property or outside the Lujan Center. Employees who were concerned about the possibility of mercury being tracked from experimental areas to their personal vehicles were given the option of having their shoes and vehicles checked. To date, safety specialists at the facility tested 19 pairs of shoes, 23 personal vehicles and five government vehicles for traces of mercury; surveyors found no contamination on any of the items tested.
o Workers expressed the need for more thorough training on how to use mercury vapor detectors. On April 25, an expert from Arizona Instruments, maker of the detectors, provided on-site instruction on the proper use and calibration of the instruments. The representative also assisted safety specialists when they sampled employee shoes and vehicles.
o Members of the hazards analysis team confirmed that work controls at the Lujan Center protect the health and safety of workers.
o Workers at LANSCE and the Lujan Center can continue to receive information about the facility, the "stop work" and subsequent actions on a special Website developed by the Lujan Center communications team.
The Lujan Center is part of LANSCE, a facility that uses a high-energy proton linear accelerator to generate neutrons for a number of scientific and defense applications. The facility is open to scientists who come to Los Alamos to use neutrons to gain insight into material properties and nuclear physics; the facility has played a role in helping scientists better understand the nature of the universe as well as helping industry design better consumer products.
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.