Industry News
Load moving in the nuclear industry comes with unique challenges, particularly when the cargo is high-level radioactive waste (HLW) stored in specially sealed canisters. The common method for moving these types of casks is with wheeled casters and rails. However, the technique is inefficient and costly due to lack of mobility and inherent risks associated with the process. When a load becomes imbalanced, the floor beneath the track can be damaged to the point of halting the entire project until the flooring can be replaced. There is literally no margin for error and certainly no quick turnaround should an incident like this occur.
As an alternative, several facilities have turned to air bearing-based vehicles, instead of inflexible wheeled rollers or forklifts, with considerable success. One 200-acre site in New York successfully relocated nearly 24,000 tons of radioactive waste using air bearing-based vehicles.
Launched more than 50 years ago, West Valley Nuclear Waste Facility, located 35 miles south of Buffalo, New York, was at one time the only commercial nuclear fuel reprocessing center in the U.S. From 1966 to 1972, the site accepted and reprocessed spent nuclear fuel from the production of plutonium and uranium for weapons. Suppliers of the spent fuel were other commercial and U.S. Department of Energy (DOE) facilities with reactors. According to the New York State Department of Environmental Conservation, the site also housed a variety of other radioactive wastes and “left behind a legacy of radioactive contamination” when it ceased operations in 1975. Recognizing the mammoth and costly task involved in a cleanup and relocation of HLW, the state appealed and received help from the federal government through a congressional act in 1980.
How mammoth? A vitrification facility, which supports a storage process in which nuclear waste is mixed with chemicals to form molten glass, was constructed on the site in the 1980s. Between 1996 and 2002, 600,000 gallons of liquid and sludge in two underground storage containers were vitrified.
“This had to be the most highly radioactive waste in the DOE in the United States,” said Dan Meess, a chief engineer working at the West Valley Demonstration Project where a $464 million contract was awarded for Phase I decommissioning activities. Meess has been working on-site for the last six years.
“We made 275 high-level waste stainless steel canisters around 10 feet high, two feet in diameter, filled them with molten glass and let them solidify,” Meess said, adding that caps on the open end of the canister had to be sealed remotely. From 2002 to 2015, the canisters—each weighing 5,000 pounds—sat in racks inside the facility’s Main Plant Process Building, a structure built in the 1960s and slated for demolition.
According to Babcock and Wilcox, the prime contractors at West Valley, each canister has “a minimum 50-year life expectancy.” The canisters had to be relocated, but with no federal waste repository available to accept them, they had to be moved to a specially constructed 16,000-square-foot storage pad with a three-foot-thick foundation a quarter-mile from the building. West Valley, in effect, became the first site in the U.S. to place HLW into long-term outdoor storage.
The company determined the most efficient way to move the inventory would be to load one cask at a time into a liner capable of housing five canisters. Each cask had a bolted steel and concrete cover to shield the high radiation levels, along with a welded stainless-steel lid for the liner. All of the operations had to be performed by a remote operator. The weight of each cask with the five canisters was 87 tons.
