GAO reviewed the Navy's program to inactivate and dispose of nuclear-powered submarines, focusing on: (1) the program's current status; and (2) whether the Navy is effectively managing costs. GAO found that: (1) at the end of fiscal year 1990, the Navy had initiated the inactivation of 42 of the 100 nuclear-powered submarines it planned to inactivate by 2000; (2) the Navy encountered three environmental compliance issues with defueled reactor compartment disposal; (3) the Navy began recycling submarines in 1990 to help resolve storage problems; (4) inactivations are less costly when they are completed at the Puget Sound Naval Shipyard; (5) the Navy is scheduling inactivations for facilities that effectively reduce costs; and (6) the Navy is assessing work-load policies and practices for nuclear shipyards. GAO also found that: (1) shipyards have increased their efficiency and reduced the number of workdays required to complete inactivations; (2) additional improvements are possible, since the costs between shipyards vary widely; (3) the Navy controls costs by overseeing shipyard inactivation work; and (4) the Navy is estimating standards and developing uniform work categories for inactivations.