Workers say seven pipefitters objected in 1997 when told to install a valve rated to withstand less pressure than required for a test of radioactive waste pipes. The crew was later laid off, but a settlement required the contractor, Fluor Federal Services, to rehire them.
The plaintiffs' attorneys contended that foremen on the job were told they would have to lay off seven other pipefitters to bring the first seven back. Attorneys for Fluor Federal Services argued there was not enough work at the Hanford site for all of the pipefitters.
An attorney told AP the company would consider an appeal.
Jury awards ranged from $89,700 for one plaintiff to more than $553,000 for another. The plaintiffs sought lost wages, and all but one sought damages for emotional distress. The lawsuit involved five of the original seven pipefitters and six included in the second layoffs.
"It's the workers who are putting themselves in danger when things don't go right, and they are the ones, for the most part, who know what they are working around," one plaintiff told AP. "If they have concerns, they need to be addressed, and they need to be addressed properly."
An attorney for Fluor Federal Services told AP the company's view is that it did not retaliate against workers.
The Hanford site was created as part of the top-secret Manhattan Project to build an atomic bomb. Today, it is the nation's most contaminated nuclear site. Cleanup costs are expected to total $50 billion to $60 billion, with the work to be finished by 2035.