Dan Leone
WC Monitor
2/5/2016
It is now safe for workers to enter certain areas of the underground Waste Isolation Pilot Plant (WIPP) near Carlsbad, N.M., without wearing air-filtering respirators, the Energy Department said Jan. 29.
Personnel more than 2,520 feet south of WIPP’s northernmost tip — an access corridor where no waste is stored, but which is adjacent to four waste-filled storage areas called panels — no longer need to wear powered air-purifying respirators, DOE said in a statement posted to its WIPP website.
“Although low levels of surface contamination exist in these areas, surveys, sampling and air monitoring data have confirmed that remaining contamination is fixed and not available for resuspension to the air, thus eliminating the need for respiratory protection,” DOE said.
According to ambient air-quality sensors at WIPP — measurements DOE said were independently verified by certified health physicists from the Idaho National Laboratory and the Savannah River Site — surface and airborne alpha particles in roughly 7,000 feet worth of corridors have fallen below the federally mandated threshold for respirator use. There were no detectable beta particles in the corridor, a spokesman at DOE headquarters in Washington said by email Thursday. Light alpha particles are generally not hazardous unless ingested; heavier beta particles can be stopped with light protective shielding.
Respirators south of WIPP’s so-called S-2520 line had been mandatory since 2014, when radiation leaked from a barrel of transuranic waste stored in Panel 7, just north of S-2520. The barrel came from the Los Alamos National Laboratory in Los Alamos, N.M., some 300 miles north of WIPP.
Workers south of S-2520 must still wear protective clothing, booties, and gloves, and respirators are still required to enter Panel 7, DOE said. Respirators filter air and are not attached to a tank of clean air.
After the 2014 leak, DOE moved to contain radioactive airborne particles by spraying fresh water on WIPP’s interior walls and floors. Because WIPP is carved from an ancient salt cavern, its interior, once moistened, naturally aids the cleanup by absorbing airborne contaminants into a saltwater solution and trapping them in a thin crust left over when the water evaporates, according to the department.
DOE plans to reopen WIPP in December and last month approved a new cost and schedule estimate for doing so as part of a revised integrated performance measurement baseline the agency has not released publicly.
