A nuclear whistleblower in the US will be paid millions of dollars in exchange for dropping his legal charges against the company that fired him for uncovering unsafe disposal of nuclear waste.

AECOM, a distinguished name in infrastructure industry, has reached a $4.1 million settlement with Walter Tamosaitis, a former employee that blew the whistle on an unsafe nuclear waste processing plant in Hanford, Columbia, home to the largest nuclear landfill in the US.

“The company has not tolerated, and will not tolerate, retaliation or harassment in any form against anyone who raises a safety issue in good faith,” AECOM said in a statement on Wednesday. “The company is pleased to put this matter behind us and continue with the important cleanup work at the Hanford site.”

Before being sacked, Dr. Tamosaitis was leading a team of 100 scientists and engineers who were assigned with designing a method to neuter millions of gallons of highly toxic nuclear sludge which was stored in leaking underground tanks near Columbia River.

He was working for URS at the time, a company that was acquired by AECOM later on.

His team came up with the plans to make a high-tech “vitrification” facility that would turn the sludge into glass that can be safely buried for thousands of years. Initially, the plant was estimated to cost $12 billion to build.