Uranium purchases by U.S. commercial nuclear power plants totaled 43 million pounds of triuranium octoxide last year, 15 percent lower than 2016 and the lowest since 1998, according to an Oct. 3 report from the U.S. Energy Information Administration. Triuranium octoxide, called yellow cake, represents the first step in nuclear fuel production. The agency attributed the change to increasing nuclear plant retirements and rising inventories held by operators, although purchases tend to vary from year to year. Canada, Australia, Russia, Kazakhstan, and Uzbekistan accounted for 84 percent of uranium purchases last year, while the U.S. supplied seven percent. During the first half of this year, uranium concentrate production totaled 592,000 pounds, almost half the production over the same period in 2017. This year’s production is expected to see the lowest levels since the upward trend in the early 1950s. The closure of New Jersey’s Oyster Creek in September marks the sixth reactor to retire in five years, and 12 more have announced planned retirements in the next seven years. Plant operators in competitive markets have cut back purchase plans in anticipation of retirements, the agency said.