A collapsed tunnel at the Hanford Site in Washington State, overseen by the Richland's Operations Office under the Department of Energy, lead to the declaration of a “site area emergency” on Tuesday, after a worker checking one of two storage tunnels noticed a 20-feet section had caved in.
There was no reported leakage of radiation and residents in the nearby towns of Benton and Franklin were not put on alert or ordered to take action, although workers at the Hanford Site were sequestered for their protection while the incident was being investigated.
Officials on site immediately declared an “alert,” which indicates that employees in the vicinity of the tunnel could be in jeopardy. That alert was lifted, but the incident was later declared to be be a “site area emergency,” which indicates that workers at the entire Hanford campus could be at risk.
The tunnel that collapsed is one of two built in the 1950s and 1960s. They were designed to store rail cars loaded with contaminated equipment associated with the nearby Plutonium Uranium Extraction Plant, called PUREX. The tunnel with the collapsed section was the shorter of the two, which holds eight rail cars under about eight to 10 feet of soil. The longer tunnel holds up to 28 rail cars, according to the World Nuclear Association.
About 3,000 workers were involved in the site area emergency warning, workers in the area known as the 200 East Area, which includes the PURX facility, which is listed as highly contaminated. The collapse was discovered at 8:20 a.m. on Tuesday. By days end, workers were already filling in the collapsed section with clean soil to stabilize the tunnel and to prevent further collapse.