The Defense Nuclear Facilities Safety Board (DNFSB) said the Energy Department might rely too much on its waste acceptance criteria program to keep potentially combustible material out of the Waste Isolation Pilot Plant near Carlsbad, N.M.
The DOE’s National Transuranic Program employs the criteria at department facilities around the country to flag hazards in defense-related transuranic material being shipped to WIPP, according to a DNFSB staff report attached to a May 29 letter from board Chairman Bruce Hamilton to Energy Secretary Dan Brouillette.
The report includes the findings from the nuclear health and safety watchdog’s review of WIPP’s documented safety analysis (DSA) –the written policy approach to keeping the underground facility safe.
The National Transuranic Program relies on analysis and specialized chemical reviews of drums as part of the waste acceptance criteria, with the intent of avoiding any repeat of a February 2014 accident in which a waste drum from the Los Alamos National Laboratory in northern New Mexico overheated and caused a radiation leak at WIPP. That effectively suspended WIPP waste operations for nearly three years.
The agency’s waste acceptance vetting has come a long way since then, the DNFSB said. The waste analyses and specialized chemical reviews “have improved,” but the system is not infallible, it cautioned. Developing adequate knowledge of waste container contents and evaluating all hazardous reactions “is difficult and susceptible to human error,” the report says.
The documented safety analysis for WIPP, however, “assumes the WAC will not fail,” DNFSB staff wrote. The Defense Nuclear Facilities Safety Board nonetheless recommended the Energy Department implement greater defense-in-depth, or supplemental precautions. Specifically, continuous air monitoring of radiological conditions in the WIPP underground would improve its ability to detect and respond to potential problems should a potentially combustible drum not detected by screening end up at the site.
In addition, the DNFSB noted the Energy Department’s Carlsbad office has vacancies in its safety programs division and has had to rely on headquarters to supplement certain safety reviews. This situation could hinder federal oversight of safety efforts by WIPP prime contractor Nuclear Waste Partnership, the board said.
The DNFSB staff report also said the Energy Department analysis should be improved to address potential accidents such as a fire in the WIPP waste shaft, mishaps with the waste hoist, or the collapse of underground roof for an entire room.
“We are evaluating the Board’s concerns and will take the appropriate actions to address them,” a DOE spokesman said in a Tuesday email.
