U.S. West Coast energy operations brace for tsunami

A computer generated image provided by the National Oceanic and Atmospheric Administration (NOAA) shows the projected travel times of the tsunami caused by the magnitude 8.9 earthquake which struck Japan on March 11, 2011.

NEW YORK (Reuters) - U.S. energy companies with operations in Hawaii, Alaska and along the coasts of California, Oregon and Washington were on alert on Friday for the possibility of a tsunami set off by a massive earthquake off Japan reaching U.S. shores.

Tesoro Corp (TSO.N) which has the largest concentration of refinery capacity in the region, said it had closed a few retail stations in some low lying areas of Hawaii as a precaution and was monitoring operations at its refineries in Hawaii, Alaska, California and Washington.

The first signs of the tsunami began to wash up on Hawaiian shores early Friday, as waves seen on local television footage rose steadily over the southern beaches on the island of Oahu.

The island state of Hawaii ordered evacuations of its coastal areas and braced for a tidal wave hours after the massive 8.9 earthquake in Japan, 3,800 miles (6,200 km) away, triggered the tsunami warning across most of the Pacific basin, including northern California and Oregon.

The U.S. government said shorelines appear to be out of major danger from the tsunami, caused by the large quake which killed hundreds in Japan, but that there is still some risk to the U.S. West Coast.

Nuclear power plant operator PG&E Corp (PCG.N) said it declared an unusual event at its Diablo Canyon power plant in California due to the tsunami warning, which is normal operating procedure at the California but both reactors there were operating normally.

Southern California Edison, a unit of Edison International, said workers would be monitoring "unusual small waves" that were likely to hit the coast.

"The San Onofre plant was designed with a 30-foot (9-metre) tsunami protective wall," company spokesman Gil Alexander said in response to a question on what safety measures the plant would be undertaking.

Both reactors at San Onofre plant were operating normally, he added. (Reporting by New York Energy Desk and Bangalore Energy Desk, writing by Janet McGurty; Editing by Marguerita Choy)