Six underground nuclear tanks in Washington State are leaking radioactive waste, the state’s government announced on Friday, describing the development as “disturbing.” The leak at the Hanford Nuclear Reservation has so far not posed an immediate health risk to the public, Governor Jay Inslee’s office said. But it had not been stopped. Established in 1943 as part of the Manhattan Project, the facility holds millions of liters of a highly radioactive stew left from decades of plutonium production for nuclear weapons. The tanks are long past their intended 20-year lifespan. The US Department of Energy had earlier said that liquid levels were decreasing in one of the 177 tanks at south-central Washington's Hanford Nuclear Reservation. Monitoring wells near the tank have not detected higher radiation levels, AP says. The site, in the town of Hanford in south-central Washington, was home to the B Reactor, the world's first full-scale plutonium production reactor. Plutonium produced at the facility was used in the first nuclear bomb, tested at the Trinity site, as well as in the Fat Man, the 21-kt bomb detonated over Nagasaki, Japan.

Nine workers at the Hanford Plutonium Finishing Plant are being checked as a precaution to determine whether they may have breathed in radioactive material. Last week, radiation release alarms sounded as workers were completing the removal of contaminated material from within a glovebox. No contamination was found on the skin or personal clothing of those workers, who were using respirators. However, nasal smears indicated radioactive material might have been breathed in by some of the workers who helped the glovebox workers remove the protective clothing worn over their personal clothing after the alarm sounded, according to CH2M Hill Plateau Remediation Co. The four workers who were at the glovebox and the five workers who helped them remove their protective clothing will have further tests. Results should be available within two weeks.