PORTSMOUTH — The USS Miami nuclear submarine, which was heavily damaged by an arsonist last year while in dry dock at the Portsmouth Naval Shipyard, will not be repaired, according to a prepared statement from the U.S. senators who represent New Hampshire and Maine.

KITTERY, Maine — The nuclear submarine USS Miami, damaged last year in an arson fire while in dry dock at the Portsmouth Naval Shipyard, will not be repaired, according to the U.S. Navy.



Citing federal budget cuts and cost overruns on the Miami repair job, the Navy told Congress on Tuesday that it would cost an additional $390 million in fiscal year 2014 to repair the submarine. In April, the Navy found previously undetected cracks in the Miami. The discovery of the unanticipated damage raised repair costs from an estimated $450 million to $700 million, according to the Navy.



Electric Boat, based in New London, Conn., was awarded a $94 million contract in September to plan the repairs, and the repair contract was also expected to be awarded to the Connecticut shipyard.



But, given the fiscally constrained environment and the automatic spending cuts known as sequestration that were triggered in March, Navy officials knew additional funding would not be available.



“The decision to inactivate Miami is a difficult one, taken after hard analysis and not made lightly,” said Rear Adm. Rick Breckenridge, director of Undersea Warfare, in a prepared statement. “We will lose the five deployments that Miami would have provided over the remaining 10 years of her planned service life, but in exchange for avoiding the cost of repairs, we will open up funds to support other vital maintenance efforts, improving the wholeness and readiness of the fleet.”



Inspections revealed that due to cracking in the steel piping and fasteners used in the air, hydraulic and water cooling systems, a significant number of components in the torpedo room and auxiliary machinery room would require replacement. This previously undetected damage increased the cost of the repair job.



Additionally, a review of other recent submarine repair efforts resulting from major damage revealed that the funding for the Miami repair was insufficient.



“The increased cost estimate and scope means that without $390 million in additional funding in FY’14, funding the repairs would require cancellation of dozens of remaining availabilities on surface ships and submarines,” said Breckenridge, noting that the Miami repair cost would compound the pressure from sequestration in 2014. “The Navy and the nation simply cannot afford to weaken other fleet readiness in the way that would be required to afford repairs to Miami.”



U.S. Sens. Kelly Ayotte, R-N.H., Susan Collins, R-Maine, Angus King, I-Maine, and Jeanne Shaheen, D-N.H., released the following joint statement Tuesday after the U.S. Navy reversed course on the submarine repairs:



“We are disappointed by the Navy’s decision to discontinue repairs to the USS Miami. Inactivating the Miami will mean a loss to our nuclear submarine fleet — yet another unfortunate consequence of the across-the-board cuts known as sequestration. We will continue to work together to find a responsible budget solution that replaces sequestration.



“We do recognize that the Navy has determined that the damage to the Miami is more severe than originally thought and would require a significant increase in anticipated repair costs. We are also encouraged that the chief of Naval Operations has assured us that the inactivation process and other planned maintenance work at PNS will continue to provide a consistent workload in the long term for the shipyard’s skilled and dedicated work force.”



In March, former shipyard worker Casey Fury was sentenced to 17 years in federal prison for setting fire to the Miami. He admitted to setting the blaze, citing a desire to go home early and an anxiety disorder as reasons why.



During Fury’s sentencing hearing, U.S. District Court Judge George Singal said it was necessary to weigh the “significant” loss to the Navy and the risk placed on firefighters, while also taking into consideration Fury’s mental illness.



Fury was sentenced on two counts of arson for setting the May 23, 2012, fire that severely damaged the Miami, and a smaller fire outside the submarine several weeks later. Singal also ordered Fury to pay the Navy $400 million in restitution.



- Portsmouth Herald staff writer Christopher Cheney contributed to this report.