The US Navy spent about US$71 million on cleanup, planning and initial repairs on the fire-damaged USS Miami before scuttling plans to restore the nuclear-powered submarine.
The Navy intended to repair the attack submarine, damaged last year, at Portsmouth Naval Shipyard and return it to duty before the discovery of additional cracks in pipes drove the estimated repair costs up from US$450 million to US$700 million.
The Navy announced last month it was scrapping plans to repair the Miami because of the higher estimates coupled with mandated budget cuts.
Loren Thompson, defense analyst at the Lexington Institute, said the waste of taxpayer dollars underscores the challenges facing the Navy as it shifts priorities to meet reduced funding.
The Miami was severely damaged by a fire set by a shipyard worker in May 2012 while it was in dry dock during a 20-month overhaul at the Kittery, Maine shipyard.
The submarine remains will be towed to Puget Sound Naval Shipyard in Washington State, where it will eventually be cut up for scrap. Inactivation costs are estimated to be US$54 million, the Navy said.