The Hanford Nuclear Reservation confirmed radioactive material was found on a worker's clothing from a leaking tank at the site in the state of Washington Photo by Tobin Fricke/Wikimedia Commons

May 20 (UPI) -- Authorities are investigating radioactive material found on a worker's clothing one week after a tunnel collapse at the waste nuclear waste site in the state of Washington.

Around 7 p.m. Thursday, Washington River Protection Solutions, a government contractor contractor in charge of all 177 underground storage tanks at the nuclear site. detected high radiation readings on a robotic device that seven workers were pulling out of a tank. Then, contamination was also discovered on the clothing of one worker -- on one shoe, on his shirt and on his pants in the knee area.


"Radiological monitoring showed contamination on the unit that was three times the planned limit. Workers immediately stopped working and exited the area according to procedure," said Rob Roxburgh, deputy manager of WRPS Communications & Public Relationssaid to KING-TV.

Using leak-detection instruments, WRPS said it did not find liquid escaping the tank.

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"Everybody was freaked, shocked, surprised," said a veteran worker, who was in direct contact with crew members. "[The contamination] was not expected. They're not supposed to find contamination in the annulus [safety perimeter] of the double shell tanks."

On Saturday, the Hanford Site confirmed the incident had occurred and employees had returned to "normal work location at their regularly scheduled times," according to an advisory.

The tank, known as AZ 101, was put into service in 1976 and its life expectancy was 20 years.

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On May 9, workers noticed that a section of a tunnel at the nuclear waste site had collapsed, creating a 20-foot hole. Workers filled the hole with soil.

The tunnel was constructed during the Cold War to hold rail cars loaded with equipment contaminated during plutonium production. It has been sealed since the mid-1990s, according to the Department of Energy.

"Today's news of another potential leak in a tank at Hanford only strengths my resolve to hold the Department of Energy accountable for its responsibility to clean up this contaminated site," Washington state Attorney General Bob Ferguson said in a statement to Seattle pi. "This isn't the first potential leak and it won't be the last."

Earlier Thursday, the governors of Washington and Oregon urged President Donald Trump, U.S. Secretary of Energy Rick Perry and White House Budget Director Mick Mulvaney for enough budget money "to accelerate the safe and efficient cleanup of nuclear waste at Hanford.

"Today, cleanup efforts are needed for the over 50 million gallons of radioactive and chemical waste stored in 177 tanks, more than 60 square miles remaining of groundwater contamination and thousands of still contaminated buildings and waste sites," Washington Gov. Jay Inselee and Oregon Gov. Kate Brown wrote in the letter.

The state of Washington has legally binding agreements with the the Energy Department to treat, remove or permanently store Hanford's waste.

The cleanup of Hanford began in the 1980s and the Hanford N-reactor ceased producing plutonium in 1987.