A class action has been filed against Bechtel Corporation and related companies on behalf of workers and visitors who worked on tunnels at the U.S. Department of Energy's Yucca Mountain site, who allege that contractors and subcontractors knowingly exposed them to toxic dusts and gases from 1992 to 2003 and intentionally concealed the dangers. The action seeks unspecified compensatory and punitive damages.

The Energy Department's Yucca Mountain Project is intended to be the world's first and largest high-level waste repository. Although the construction of the repository has not yet begun, tunneling, drilling, boring, and testing have been undertaken to scientifically characterize the geological formations at the site. The initial drilling of tunnels in Yucca Mountain began in October and November 1994. The action alleges that although the DOE and its contractors knew or should have known that there were numerous minerals that would be turned into fine highly toxic dust by the dry drilling process that was used, the defendants did next to nothing to protect the health and safety of the workers and visitors.

The lawsuit further alleges that the defendants:

(1) knew that dusts could cause diseases such as silicosis, lung cancer, mesothelioma, chronic obstructive pulmonary disease, renal disease, and tuberculosis, but still exposed workers and visitors at the site; (2)
knew that dust levels exceeded applicable regulatory limits and called for, at the very least, high-quality respiratory protection and protective clothing; (3) concealed information from workers and visitors, deliberately doctoring field readings of particulate matter in the Yucca tunnels; (4) opted not to use water or take alternate precautions to minimize dust; (5) ignored a report that there was up to 70 percent silica in the rock matrix at the site and failed to implement several listed protective measures; (6) provided little or no respiratory protection for almost two years after tunneling began when "clouds of toxic dust visibly choked the tunnels at the project"; and (7) had no formal safety and health requirements management process in place, and nothing that systematically correlated safety and health requirements with existing procedures and DOE orders.

According to a Public Citizen news release dated March 11, 2004, more than 1,200 employees are estimated to have been exposed to potentially dangerous amounts of silica dust while working at the site. The group also reported that three individuals associated with the site have been diagnosed with silicosis and one has died from it. "Unfortunately, this is indicative of a larger pattern by DOE of pushing projects forward regardless of the human costs," said Public Citizen's Wenonah Hauter. Hauter is director of the group's Critical Mass Energy and Environment Program. Hauter claimed that although DOE announced a free silicosis testing program for former site workers, obtaining information about the test program is all but impossible. Hauter went on the record stating that that there is no Web site for workers seeking information on the program, and a hotline number is not widely distributed.

Senator Harry Reid (D-Nev.) on February 19, 2004, asked Labor Secretary Elaine Chao to immediately investigate cases of silicosis among workers at DOE's Yucca Mountain site.