The Energy Department and its contractor at the Waste Isolation Pilot Plant (WIPP) in New Mexico could do more to ensure their new safety procedures prevent a repeat of a 2014 radiation release blamed on an improperly packaged drum of contaminated waste, according to the Defense Nuclear Facilities Safety Board (DNFSB).
“The Department of Energy (DOE) strategy for preventing recurrence of the 2014 radiological release event at the Waste Isolation Pilot Plant (WIPP) needs to be improved prior to resuming transuranic waste receipt and disposal activities,” DNFSB Chairman Joyce Connery said in a March 28 letter to Energy Secretary Ernest Moniz. “We understand that to preclude a repeat event, WIPP’s upgraded Documented Safety Analysis will rely on improvements to DOE’s process for verifying that transuranic waste complies with WIPP’s Waste Acceptance Criteria (WAC). While work is underway to strengthen the WAC compliance process, DOE management has not formally documented its plan for defining and implementing these crucial process improvements.”
Connery’s letter included a Jan. 13 DNFSB report, which was based on a December meeting with officials from DOE’s Carlsbad Field Office and executives with site operator Nuclear Waste Partnership, which has helmed the two-year accident recovery effort expected to conclude in December, when the underground salt mine is slated to reopen to shipments of transuranic waste from across the DOE weapons complex.
While generally laudatory of DOE and NWP’s progress, the DNFSB report concluded a formal WIPP safety document the parties are revising, known officially as a Documented Safety Analysis, does not thoroughly consider the possibility that drums of waste that arrive after WIPP reopens could burst open, as the improperly package drum from the Los Alamos National Laboratory did in February 2014.
According to the DNFSB report, DOE and its contractor argued WIPP’s updated packaging and storage standards — or Waste Acceptance Criteria, in official parlance — should be enough to prevent future shipments from bursting open. However, the board pointed out these standards did not prevent the 2014 accident.
DOE’s National Transuranic Program, based at the Carlsbad Field Office, is working on tweaks to the agency’s official Waste Acceptance Criteria, “but these plans are not yet fully developed and documented,” DNFSB said in its report.
The drum that caused the 2014 accident contained organic kitty litter, which should not have been used to pack up the waste inside the container, which eventually reacted with nitrate salts in the drum, pressurizing the vessel and bursting its lid open.
Similarly packaged drums remain in WIPP. According to the DNFSB report, DOE thinks the risk of worker contamination is minimal in the mine, even if another drum bursts. However, the agency and its contractor acknowledge “additional credited safety controls are needed” to be sure.
