US residents near the Hanford Nuclear Reservation may be in grave danger: a nuclear safety board found that the underground tanks holding toxic, radioactive waste could explode at any minute, due to a dangerous buildup of hydrogen gas.

After Sen. Ron Wyden (D-Ore.) asked the Defense Nuclear Facilities Safety Board (DFNSB) about the risks posed by the nuclear site, board members relayed their concerns about the potential for hydrogen gas buildup within the walls of a tank – particularly those with double walls.

‘All the double-shell tanks contain waste that continuously generates some flammable gas,’ the board said in a letter received by Wyden on Monday. ‘This gas will eventually reach flammable conditions if adequate ventilation is not provided.’

The safety board had previously issued a warning about their concerns, which have not yet been addressed. In September, the board sent a letter to the Department of Energy, claiming that there were no adequate safeguards to protect against the buildup of flammable gasses inside Hanford’s waste storage tanks. The letter, which outlines the concerns shared with Sen. Wyden on Monday, was declassified on Tuesday.

If the tanks were to explode, there would be flammable releases that would ‘have considerable radiological consequences, endanger personnel, contaminate […]