While the latest rockfall at the Waste Isolation Pilot Plant occurred in the storage area where a container of nuclear waste burst open in 2014, there is no sign the incident released any radioactive material, the Energy Department said Friday.
The underground transuranic waste storage facility was evacuated Thursday following the rockfall. On Friday, geotechnical, radiological control, and mine rescue personnel went back into the underground salt mine, joined by an official with the Mine Safety and Health Administration. They determined that the rockfall had occurred in Room 4 of Panel 7, noting that rock debris on the floor indicated that much of the ceiling in the room had come down. Nothing came down outside Room 4 in this instance, according to the DOE statement posted on the WIPP website.
Officials had anticipated the roof fall, given “accelerated convergence rates (salt movement)” in recent months, the update says. Personnel had already been barred from entering the room.
“Although portions of Panel 7 remain contaminated as a result of the February 2014 radiological release, there were no indications of a release of radioactive contamination associated with the rock fall,” according to the release.
There have been four underground rockfalls at WIPP since late September, all in areas to which access had been prohibited following the underground fire and subsequent, unrelated radiation release that have kept the facility closed since February 2014. DOE and WIPP prime contractor Nuclear Waste Partnership plan to reopen WIPP in December.
“The Department of Energy and Nuclear Waste Partnership will be working with the MSHA to develop a plan and path forward to address ground control issues in Panel 7,” DOE said. “After nearly three years of reduced ground control, areas in the WIPP underground are showing signs of increased salt creep that naturally occurs over time. This salt creep is what will eventually seal the transuranic waste and was an important characteristic in the selection of the location for the WIPP repository.”
