Department of Energy contractor Mid-America Conversion Services has restarted the depleted uranium hexafluoride conversion plant at the Portsmouth Site in Ohio for the first time since 2020, but operations at the Paducah Site in Kentucky are expected to be down until next month after a June 10 accident there, the agency said.
Both depleted uranium hexafluoride (DUF6) plants, which turn the DUF6 left over from decades of uranium enrichment at DOE gaseous diffusion plants into uranium oxide, entered extended outages in March 2020. DOE said this was because of the COVID-19 pandemic. The plants stayed offline to make various upgrades. Paducah was the first to return to service, in November 2021, but suspended work following an incident last month.
“The DUF6 maintenance team is implementing a rigorous process to restart DUF6 operations [at Paducah] in August,” an agency spokesperson said by email Tuesday.
“At DUF6 in Paducah, the plant’s designed warning system recently detected an off-process issue that was immediately assessed and contained,” the spokesperson said, adding there were no worker exposures nor environmental releases.
Conversion Unit (CU)303 “experienced an unexpected increase in pressure and indicated the potential for unreacted DUF6 being introduced into the CU-303 through a leaking valve which was intended to serve as an unreacted DUF6 pressure boundary,” according to the site’s description of the incident.
“Samples were taken in several areas revealing that uranium has been introduced into the process equipment downstream of the CU,” at a level that exceeds 350 microCuries, according to the site.
There are four operating lines at Paducah and each line contains two conversion units for a total of eight total conversion units at the facility, according to the DOE spokesperson.
Meanwhile, the spokesperson also confirmed plant upgrades are now complete at Portsmouth and DUF6 conversion resumed this week.Refurbishments at the site included new computers and piping, DOE officials said this past March at the Waste Management Symposia conference in Phoenix.
