Diablo Canyon Nuclear Power Plant; Morro Bay, California

Morro Bay, California | 1987-Apr-21

Initial Notification: At approximately 0940 on April 21, 1987, the U.S. Coast Guard Marine Safety Office, Alameda, was notified by the Coast Guard National Response Center in Washington, D.C. that a check valve had malfunctioned at the Diablo Canyon Nuclear Power Plant in Morro Bay, California. Sixty-eight pounds of ferric sulfate had been mixed with 5,500 gallons of water in the plant's reverse osmosis facility and inadvertently discharged into a small bay with direct access to the Pacific Ocean. An orange-yellow, scum-like material was noticed floating on the surface of the embayment in the vicinity of the discharge pipe. All of the requisite Federal State agencies and local environmental concerns were notified immediately. Samples were immediately taken in the vicinity of the discharge to determine the toxicity level. The check valve was repaired the same day and the nuclear power plant returned to normal operations that same day. USCG district 12.