The Energy Department and a contractor building a waste treatment plant at the nation's most contaminated nuclear site procured and installed tanks that did not always meet requirements of a quality assurance program or the contract, a federal audit concluded Monday.
The audit also found that the agency had paid the contractor a $15 million incentive fee for production of tank that was later determined to be defection and, while it demanded the fee be returned, never followed up to ensure that it was.
In recent months, the $12.3 billion plant under construction at south-central Washington's Hanford nuclear reservation has been the subject of whistleblower complaints about its design and safety. The plant is being built to convert highly radioactive glass into a stable glass form for permanent disposal underground.
The tanks' design is significant because they will be located in so-called "black cells," which are areas of the plant that will be too radioactively hot for workers to enter once the plant is operating.
The audit focused on tanks that were received and installed prior to mid-2005. No tanks of similar design have been received since then.
The Energy Department said in a statement Monday that it has taken steps to improve quality assurance and oversight, conducting technical surveillance on tanks and holding installations until any design issues can be independently verified.
"This report continues to highlight the importance of ensuring nuclear quality standards and identifying any potential issues. The Energy Department is committed to continuing to implement opportunities for improvement as we move forward on this important project at Hanford," said Lori Gamache, spokeswoman for the agency's Office of River Protection in Richland, Wash.
The audit raised questions about missing documents for 10 out of 2,000 welds on the tanks, said Todd Nelson, spokesman for contractor Bechtel National Inc., but it also acknowledged significant improvements to the program in recent years.
"That level of documentation is sufficient for any other industry, but we will ensure that all of that documentation is in place before the black cells are closed and, certainly, before the plant begins operation," he said.
The $15 million fee was included as part of a later contract modification, he said.
The Energy Department also noted the contract modification in its response to the audit. The response said the agency will investigate whether questions about the tanks were resolved at a later date to justify the fee and if the agency can ask for the fee to be returned, under the modified contract.
The federal government created Hanford in the 1940s as part of the top-secret Manhattan Project to build the atomic bomb. Today, it is the nation's most contaminated nuclear site, with cleanup expected to last decades.
The cornerstone of that cleanup is the vitrification plant to treat millions of gallons of highly radioactive waste. The waste is currently stored in aging, underground tanks, many of which have leaked into the groundwater, threatening the neighboring Columbia River.