SPOKANE, Wash. -- Design changes at a new radioactive waste disposal plant at the country's most contaminated nuclear site in south-central Washington were not properly verified to ensure safety, the U.S. Department of Energy's Inspector General concluded in a report issued Thursday.
The audit was highly critical of the design change process at the Hanford Nuclear Reservation's $12.2 billion vitrification plant, considered the cornerstone of cleanup at the site. The one-of-a-kind plant is designed to convert about 56 million gallons of dangerous radioactive waste into a glasslike substance for eventual burial.
The audit said contractor Bechtel National Inc. was required to ensure the vitrification process is safe for workers, the public and the environment, but failed to do that in the design change process.
Hanford was created by the Manhattan Project during World War II in the race to build an atomic bomb. The sprawling complex near Washington's Tri-Cities of Richland, Kennewick and Pasco is involved in a multi-decade cleanup program that already has cost more than $40 billion.
The inspector general's office said it launched an investigation after receiving a complaint that Bechtel was missing design control documentation on the plant and could not demonstrate that some equipment was properly manufactured.
"We substantiated the allegation," the inspector general said. "Our review revealed significant shortcomings" in the Energy Department's managing of design and construction changes for waste processing equipment.
The audit found that in September 2012, the inspector general found several instances in which design changes requested by suppliers did not receive required safety reviews.
In a review of 235 documents covering a three-year period, "Bechtel discovered that more than a third of the changes made to supplier design documents had not received the required Nuclear Safety review and approval," the report said.
The problems were systemic, according to the report.
An example was Bechtel approving action to repair the giant lid of a machine that is used to melt nuclear waste that did not meet design specifications, the report said.
Bechtel was unable to provide evidence that the supplier had actually made required repairs to the lid, or that it had re-examined the repair to make sure it met safety requirements, the report said.
"Neither Bechtel nor the Department could confirm that the design changes were actually completed," the report said.
The report said its findings mirror quality-assurance problems found in two previous audits of the vitrification plant.
In its response to the latest audit, the Energy Department's Office of Environmental Management agreed with the findings and said it will "take prompt actions to address the issues identified."
Peggy McCullough, project director for Bechtel, told employees in a message Thursday that the contractor had already been taking steps to address the concerns raised in the audit.
"We are refining our procedures and have conducted staff training to achieve the compliance we desire and require," McCullough wrote.