KITTERY — The Navy shipyard that overhauls and repairs nuclear-powered submarines has won a pair of environmental awards.

Portsmouth Naval Shipyard is the winner of two Chief of Naval Operations environmental awards for conservation and environmental restoration.

Capt. William Greene, shipyard commander, says that being a good environmental steward helps the shipyard meet its mission without harming “the numerous natural resources of the beautiful seacoast community we call home.”

The awards, announced last month, mark the fifth consecutive year the shipyard received awards for its environmental programs.