Replacement of the aging Ohio-class nuclear ballistic missile submarine – without compromising future shipbuilding budgets – is a top priority to Chief of Naval Operations Adm. Jonathan Greenert. Speaking before an Aug. 5 all-hands meeting of the N2/N6 (information dominance) directorate at the Pentagon, according to the U.S. Naval Institute Press. “We have [a] strategic nuclear modernization challenge of the next 20 years and it starts with the Ohio replacement,” Greenert said, according to UNSI. Tackling the projected cost — $100 billion – is a key issue that must be resolved, he said.