GROTON, Conn. — The Navy says its attack submarine Pittsburgh had to return to its Connecticut base recently because of what was described as a “minor” moisture leak within its nuclear propulsion plant.

The Day reports that the leakage was discovered during a routine inspection while the ship was at sea. The source was near a valve in the propulsion plant. The issue did not affect the ability of the propulsion plant to function properly.

Cmdr. Sarah Self-Kyler, spokeswoman for the Navy’s Atlantic submarine fleet, said the moisture was contained within the reactor compartment, and did not affect the safety of the reactor or pose a risk to the crew.

Sub base personnel and the crew are working on the problem, best addressed in port.

The Groton-based submarine was commissioned in 1985.