The winner of a decade-long, $45-billion liquid-waste cleanup contract at the Hanford Site on Tuesday appealed a court order that blocked work on the deal at the behest of a losing bidder.

Hanford Tank Waste Operations and Closure asked the Court of Appeals for the Federal Circuit to overturn a June decision by the Court of Federal Claims that enjoined DOE from turning the Hanford Site’s liquid waste program in Washington state over to the new team, led by BWX Technologies with partners Amentum and Fluor.

The appeals court had not docketed the winner’s case on Wednesday evening.

Most of the proceedings in the Atkins team’s lawsuit have been sealed, but an order this week in the trial court by Judge Marian Horn directed all parties to turn in a status report by Sept. 1.

In a quarterly earnings call with investors last week, Perma-Fix Environmental Services, Atlanta, identified itself as a member of Hanford Tank Disposition Alliance and said that DOE could make a decision about the disputed contract by September. The agency awarded the Hanford Integrated Tank Disposition contract to the BWX Technologies team in April.

The winning bidder’s appeal is yet another twist in what has quickly become one of the most hotly contested competitions in the 34-year history of DOE’s Office Environmental Management.

In June, the Court of Federal Claims, as part of a lawsuit brought by the Atkins-led Hanford Tank Disposition Alliance, ruled that DOE had improperly awarded the new Hanford contract to Hanford Tank Waste Operations and Closure because the BWX Technologies-led team did not keep its corporate registration with the government active during the competition for the contract.

The trial court sent the contract back to DOE, where it remained as of Wednesday evening. The agency could decide to award the deal to the Atkins-led team, which also includes Jacobs and Westinghouse Government Services, or elect to scrap all the bids and begin a new competition for the work.

If DOE goes back to the drawing board, it will mark the second time the agency has tried and failed to transition its biggest, most challenging environmental cleanup project over to new management.

The new contract calls for safely managing Hanford’s underground radioactive-waste tank farms and beginning the difficult task of emptying them by taking over the site’s Bechtel-built Waste Treatment and Immobilization Plant and using it to solidify a portion of the waste, which is left over from decades of plutonium production that began with the Manhattan Project.