Depleted uranium hexafluoride conversion operations are going slower and costing more than the Department of Energy expected only a few years ago, according to an audit by the agency’s Office of Inspector General.
When DOE brought its first depleted uranium hexafluoride (DUF6) conversion plant online in 2010, it still thought converting 800,000 metric tons of this enrichment byproduct into a more stable form for disposal or transport would take 25 years and cost $4.6 billion.
But by 2019, the year before most people heard the term COVID-19, the DOE recalculated and said the project would take 18 years longer, until 2054, and the price would rise to about $11.7 billion, the Office of Inspector said in a report this month.
“We estimated that it may take until 2074 to convert the inventory,” which would further drive-up costs and delay final remediation costs at former gaseous diffusion plants in Kentucky and Ohio, according to the Inspector General’s office.
The DOE started converting DUF6 into a more stable depleted uranium oxide form at Portsmouth in 2010 and Paducah in 2011, according to the report.
In the 12 years since DUF6 operations started, and at a cost of over $1 billion, DOE has converted only 11% of the 800,000 metric ton initial inventory, the DOE Inspector General said in the audit report dated Nov. 1.
“In addition to COVID-19 impacts, delays in converting the DUF6 occurred, in part, due to inherent technical or mechanical flaws that resulted in numerous shutdowns of the plants,” the Inspector General office said in the document. While the agency has spent a lot on modifications to the plants at the Paducah Site in Kentucky and the Portsmouth Site in Ohio, “it has not completed comprehensive studies of the plants’ flaws and their realistic capabilities.”
The DOE Inspector General’s office wants DOE’s Portsmouth/Paducah Project Office to do a “comprehensive review of the facilities” that addresses technical problems and determines an optimal conversion rate at the plants.
The DOE Office of Environmental Management is working on it, a spokesperson told Exchange Monitor via email Thursday. The DOE office is also looking at the DUF6 facilities’ “design capabilities and inherent design flaws,” the spokesperson said.
DOE and its contractor, Atkins-led Mid-America Conversion Services, suspended operation of the plants in March 2020 as the government grappled with the arrival of the potentially-deadly COVID-19 virus in the United States.
By December 2021, about 21 months after the plants’ pandemic shutdown, DOE did a restart readiness assessment at Paducah and restarted DUF6 work there, according to the report. DUF6 conversion started back at Portsmouth in July 2022.
During the extended outages, extensive work and retrofits were performed to improve plant performance and reliability, the Inspector General said. But challenges remain.
“The DUF6 plants are multifaceted, unique chemical processing operations that include five distinct processes and numerous systems” that should work in harmony, the DOE Office of Inspector General said. It requires “integration of multiple mechanical, chemical, temperature, scrubbing, recycling and storage systems.”
Despite the COVID shutdown refurbishment, “officials told us problems continued to hinder the Paducah plant’s conversion operations after its recent restart,” according to the Inspector General. DOE originally figured it would take about four months to bring the Paducah DUF6 plant back up to full operations. But at the four-month mark in April 2022, one of the four conversion lines at Paducah plant was still down.
The DOE Office of Inspector General audit ran from November 2020 through August 2022.
