The Hanford vitrification plant contractor, Bechtel National, has been slow to spot problems with items it purchases for the huge plant and has not been aggressive enough about recovering the costs, according to a new audit by the Department of Energy Office of Inspector General. In one example, Bechtel did not identify piping for high-level radioactive waste that had a bend 90 degrees off from specifications until September 2013, more than nine years after it was delivered to Hanford, the audit said.