DIARY-U.S. refinery operations-Exxon Beaumont refinery shuts HCU due to leak -sources

July 10 (Reuters) - The following is a list of refinery incidents reported in the United States on July 10: * Shell Convent refinery restarts gasoline, alkylation units -sources * Total Port Arthur refinery shuts reformer for repairs -sources * Marathon Texas City gasoline unit shut for repair -sources * Exxon Beaumont, Texas plant reports control valve malfunction on July 9