Defense board concerned with worker safety at Savannah River

September 1, 2023
By Exchange Monitor

The three members of the Defense Nuclear Facilities Safety Board recently visited the Savannah River National Security Site to examine personnel safety controls for a planned facility expected to churn out at least 50 nuclear warhead cores annually next decade.

The Defense Nuclear Facilities Safety Board (DNFSB) “has been reviewing the design of the Savannah River Plutonium Processing Facility” (SRPPF) … and “interacted with project personnel and corresponded with DOE multiple times regarding concerns about the proposed safety control set for protecting facility workers,” the board said in a letter to Energy Secretary Jennifer Granholm dated Aug. 3 and published online this week.

“The whole Board traveled to the site to better understand the position of the project on this matter,” DNFSB chair Joyce Connery wrote. “After hearing directly from the project, the board remains concerned that the proposed safety control set may not adequately protect facility workers. Gloveboxes in SRPPF will stage and process kilogram quantities of highly hazardous weapons-grade plutonium.”

The DNFSB has requested a report and briefing within 45 days “providing DOE’s position on the adequacy of the safety strategy for facility worker protection, focusing on impacts to long-lead procurements, such as glovebox systems.”

Inhalation of small quantities of plutonium is recognized to result in large radiological doses to lab personnel, the DNFSB said. Some forms of the material will be “pyrophoric,” meaning it can ignite upon exposure to air, releasing aerosolized plutonium. 

This pyrophoric behavior of plutonium was previously implicated in major fires at DOE’s Rocky Flats Plant, the long-demolished facility outside of Denver where much of the plutonium cores for U.S. nuclear weapons were assembled during the Cold War, the DNFSB said.  

Other forms of weapons-grade plutonium that will be staged and processed in gloveboxes in SRPPF include plutonium oxide, which is dispersible and readily aerosolizes when spilled, the board said. 

“Multiple scenarios can result in significant radiological exposure to the facility worker,” the DNSFB said in its letter. “DOE safety standards require that safety significant controls be selected for cases where significant radiological exposure to a facility worker may occur.” 

On May 11, Savannah River officials briefed the board members “on their position that additional safety controls are not required. Project personnel assert facility workers can use their senses to detect accidents such as a glovebox spill or fire and exit the area before receiving significant radiological exposure.” 

As workers are sufficiently protected from exposure to plutonium, project personnel avoided designating significant safety controls, such as gloveboxes, glovebox ventilation, continuous air monitors, and glovebox fire controls, that other DOE plutonium processing facilities have traditionally designated, the board found. 

The controls are part of the existing design of SRPPF, “but they are not currently classified as safety significant,” the board found. “As a result, they lack the increased reliability of designated safety controls needed to protect the worker.” [emphasis added]