(Updates with Morganza Spillway, nuclear facilities)
May 11 (Reuters) - Heavy flooding in the U.S. Midwest shut Ohio River terminals, limited barge movements and threatened to disrupt refinery operations along the Mississippi River to the Gulf of Mexico on Wednesday.
There are 10 refineries, including the second-largest U.S. refinery, located along the Mississippi River, that can process 2.4 million barrels per day of oil, or 13.7 percent of the country's refining capacity.
Valero Energy Corp's (VLO.N) and Motiva Enterprises (RDSa.L) refineries in St. Charles Parish, Louisiana, west of New Orleans, will be flooded if the Morganza Spillway, which would send floodwaters from the Mississippi down the Atchafalaya River, is not opened, the St. Charles Parish emergency preparedness director said on Wednesday. [ID:nN11256696]
Scores of U.S. heartland rivers from the Dakotas to Ohio have flooded following a snowy winter and heavy spring rains, feeding near-record crests on the lower Mississippi River.
Valero Energy Corp's 180,000-bpd refinery in Memphis, Tennessee, continued operating on Wednesday in the center of the worst flooding where high waters forced evacuations in residential areas. The river crested near 48 feet (14.6 meters) on Tuesday at Memphis.
The U.S. Army Corp of Engineers was planning to open the Morganza spillway by early next week, which will send flood waters from the Mississippi to the Atchafalaya River, likely disrupting operations at Alon USA Energy's (ALJ.N) 80,000 bpd Krotz Springs, Louisiana, refinery.
REFINERIES AT RISK FROM FLOODS (in bpd)
*Alon USA Energy (ALJ.N) Krotz Springs, Louisiana : 80,000
*Chalmette Refining (XOM.N) Chalmette, Louisiana: 192,500
*ConocoPhillips (COP.N) Belle Chasse, Louisiana: 247,000
*Exxon Mobil Corp (XOM.N) Baton Rouge, Louisiana: 504,500
*Marathon Oil Corp (MRO.N) Garyville, Louisiana: 436,000
*Motiva Enterprises (RDSa.L) Convent, Louisiana: 235,000
*Motiva Enterprises (RDSa.L) Norco, Louisiana: 234,700
*Murphy Oil Corp (MUR.N) Meraux, Louisiana: 120,000
*Valero Energy Corp (VLO.N) Memphis, Tennessee: 180,000
*Valero Energy Corp (VLO.N) St. Charles Louisiana: 185,000
NUCLEAR FACILITIES AT RISK FROM FLOODS
* Entergy's (ETR.N) 1,176-megawatt Waterford nuclear plant in St. Charles Parish, Louisiana.
* Entergy's 978-megawatt River Bend nuclear plant in West Feliciana Parish, Louisiana.
* Entergy's 1,268-megawatt Grand Gulf nuclear station in Clairborne County, Mississippi.
Nearly 20 percent of barge terminals the U.S. Coast Guard monitors on the Ohio River remained closed on Wednesday. The Smithland Lock and Dam at mile marker 918.5 on the river remains closed, obstructing barge traffic both up and downstream. [ID:nN09291512]
The tanker Zaliv Baikal turned back from going to a dock in Baton Rouge because its captain didn't think the vessel had enough clearance beneath the I-10 Bridge over the Mississippi at Baton Rouge.
Berths at Exxon's docks in Baton Rouge were flooding on Wednesday, which may make docking tankers difficult in the coming days, according to sources familiar with refinery operations. Exxon said the refinery continues to operate normally.
Barge traffic is moving along the Mississippi River with some restrictions and no closures. Barges were running near Baton Rouge, but facing difficult river conditions.
Mississippi River restrictions include length of barge (no greater than 600 feet), energy requirement (greater than 250 horsepower), speed (3 miles/hour) and prior notification requests before navigation starts. To that end, barge traffic is open in places like St Louis and Memphis with restrictions. (Reporting by Erwin Seba, Kristen Hays, Selam Gebrekidan, Janet McGurty, Bruce Nichols; Editing by Marguerita Choy and Lisa Shumaker)