* Refinery plans 80,000 bpd CDU restart early next week
* Motiva probing how citywide April 14 power outage affectedplant (Adds details, background)
HOUSTON, April 25 (Reuters) - Motiva Enterprises plans to begin returning a 205,000 barrel per day (bpd) crudedistillation unit to production on Friday at its 600,000 bpdPort Arthur, Texas, refinery, sources familiar with refineryoperations said on Thursday.
A Motiva representative was not immediately available todiscuss operations at the Port Arthur refinery, which is thenation's largest. Motiva has declined to discuss details of the restart of the refinery since an April 14 power outage knockedall units out of production.
If the restart of the 205,000 bpd CDU, called VPS-4, goes asexpected, then Motiva plans to return an 80,000 bpd crude unit,called VPS-2, to production early next week, the sources said.
The refinery's largest CDU, 325,000 bpd VPS-5, restarted onApril 21 and has remained in operation despite the outage of aplant operated by a third-party provider producing steam andhydrogen for the refinery. The loss of steam forced VPS-2 andVPS-4 out of production.
At the time of the April 14 power outage, some of Motiva'sown boilers were down for maintenance leaving the refinerywithout sufficient steam to restart all of the crude units, thesources said. The refinery has since brought its boilers on-lineenabling the restart of the two crude units.
The boilers produce steam to generate power and for use inthe crude distillation process among others at a refinery.
Motiva is investigating why switches meant to isolate therefinery's internal electrical power system from that of outsideprovider Entergy Texas failed to operate on April 14when Port Arthur was hit by a citywide power outage due to asubstation failure.
The three CDUs at the Port Arthur refinery do the initialrefining of crude oil coming into the refinery and providefeedstock for all other units.
Motiva is a 50-50 joint venture between Royal Dutch ShellPlc and Saudi Aramco. (Reporting by Erwin Seba; Editing by Kenneth Barry)
