(Adds Motiva comment, paragraphs 3-4)
HOUSTON, Feb 16 (Reuters) - A 60,000-barrel-per-dayhydrocracking unit was shut on Monday at Motiva Enterprises' 600,250-bpd Port Arthur, Texas, refinery because of aleaking seal on the unit's compressor, said sources familiarwith plant operations.
The hydrocracker, called HCU 2, uses hydrogen under highheat and pressure to make motor fuels from gas oil. It is theonly HCU primarily making fuel, mostly diesel, at the PortArthur refinery. U.S. refiners have seen higher profits becauseof exports of diesel.
A Motiva spokesman said one of the Port Arthur refinery'sunits had an operational upset on Saturday afternoon.
"There were no injuries associated with this situation,"Motiva spokesman Ray Fisher said. "All appropriate agencies werenotified. For reasons of commercial confidentiality, we do notprovide details about the operational status of individual unitsor information on supply."
The Port Arthur refinery is in the midst of a plannedseven-week overhaul of its 92,000-bpd gasoline-producing fluidiccatalytic cracking unit. Units associated with the FCCU,including an 18,000-bpd alkylation unit and a 49,000-bpdcatalytic reformer are also shut as part of the work, whichbegan on Jan. 13.
Motiva's Port Arthur refinery is the largest in the UnitedStates. Motiva is a 50-50 refining venture between Royal DutchShell PLC and Saudi Aramco. (Reporting by Erwin Seba; Editing by Marguerita Choy, AndreaRicci and Peter Cooney)