The Portsmouth Naval Shipyard is conducting a routine training event Tuesday.
During the training exercise, gates to the Shipyard will be closed for a short duration, which could impact traffic. The gate closures will be around mid-morning - not during peak commuting times.
The regularly scheduled training is meant to better prepare Shipyard staff in case of emergency.
Coordination has taken place with local law enforcement and first responders, the Navy says.
The shipyard conducted a similar security drill in January.