A fire-damaged submarine is expected to return to Navy service by the middle of 2015 following the replacement of cables, pipes and other scorched interior components, the Navy's top officer said Wednesday.

Navy Adm. Jonathan Greenert, the chief of Naval operations, said the military concluded the USS Miami can carry enough of a workload in the future to make it worth doing the repairs, which are estimated to cost about $450 million.

"She has 10 years left in her to meet her roughly 30-year service life. That's at least five deployments," Greenert said on a visit to Groton, where the submarine is based.

The fire broke out on May 23 while the nuclear-powered submarine was in dry dock at the Portsmouth Naval Shipyard in Kittery, Maine, for a 20-month overhaul. A former shipyard worker from Portsmouth, N.H., is accused of setting the fire.

The intensity of the blaze raised concerns about the integrity of the hull, which must withstand extreme pressure when the sub changes depths and travels deep underwater. But Greenert said a review of metallurgical aspects of the hull found no major defects.

"We don't see any major replacements to the hull plating," said Greenert, who spoke to reporters following a briefing with two Connecticut lawmakers, U.S. Sen. Richard Blumenthal and U.S. Rep. Joe Courtney.

A Navy official told the office of U.S. Sen. Susan Collins of Maine that engineers tested more than 1,000 different points on the hull. Although the Navy concluded there is no need to replace large sections of the hull, it's possible that some smaller portions could be replaced, an aide to Collins said.

The Navy told Collins' office that it considered scrapping the Miami or returning it to the fleet with operational limits before deciding on the full-scale repair. In a news release Wednesday, the Navy said the submarine will be ready to respond to any assignment from combatant commanders.

Greenert said the Navy is confident the Miami overhaul can be completed for $450 million, plus-or-minus $50 million. An earlier estimate put the damage to the 22-year-old submarine at $400 million. It costs about $2.6 billion to build a new, Virginia-class attack submarine.

The Navy intends to fund the repairs by reallocating, or "reprogramming," its own money and by asking Congress for additional money. The Navy is requesting $100 million to be reprogrammed for the current fiscal year and is seeking $150 million more for the next fiscal year.

Last month, the Navy announced its intent to enter into an agreement with Groton-based Electric Boat for advanced planning for potential repairs to be performed at Portsmouth Naval Shipyard. Electric Boat will be among several private contractors involved in the job, Greenert said.

It took more than 100 firefighters about 12 hours to put out the fire, which damaged forward compartments including living quarters, a command and control center and the torpedo room. It did not reach the back of the submarine, where the nuclear propulsion components are located.

Casey James Fury, 24, has been charged with two counts of arson for setting the May 23 fire and a second blaze outside the sub on June 16. He is in jail pending trial in Maine.


Associated Press writer David Sharp in Portland, Maine, contributed to this report.