Nuclear steam generators hit the road

SAN ONOFRE — Portions of four massive nuclear steam generators that were part of the San Onofre nuclear power plant for nearly 30 years will each soon make their way through North County on a truck longer than a football field.

Southern California Edison said the move is safe, despite low-level radioactivity.

The utility company, a majority owner of the San Onofre Nuclear Generating Station, is beginning to individually transport the four steam-generator lower assemblies from its power plant to Clive, Utah, where they will be discarded.

The power plant has already replaced the four generators with new ones built by Mitsubishi Heavy Industries, a $674 million project.

At a nuclear power plant, a steam generator transfers heat from high-pressure water that has been superheated by nuclear reactions to distilled water that turns into steam to drive turbines.

The upper portion of the steam generator was discarded on site.

The truck, with the steam generator loaded, was on display at the San Onofre power plant Tuesday. It could also be easily seen from cars driving by on Interstate 5. The 600-horse-power truck is 399 feet long and has 192 tires.

It will haul a lower assembly, which weighs 760,000 pounds, from the power plant, down Interstate 5 to Oceanside. It will then take back roads to reach Interstate 15 and head to Temecula. The truck will take more back roads to Highway 395 north. It will cross into Nevada on Highway 6, then move onto Interstate 80 to Clive, where Energy Solutions will discard the steam generator. The truck will have a highway patrol escort.

The truck will travel about 15 mph, getting about 1.5 miles per gallon. The 832-mile trip will take about three weeks. It will then return to San Onofre and transport the next one of the four generators. Edison hopes to discard all four this year.

Edison would not disclose when it would depart due to security reasons. The utility company called a news conference Tuesday to communicate that moving the generator poses no threat to the public.

“No one along the transport route will receive any exposure,” said Craig Harberts, the senior project manager for Edison. “If you were to stand approximately 6 feet away from the lower assembly itself ... if you stayed there for an hour, you would pick up approximately what you’d receive in a dental X-ray.”

Pete Dietrich, Edison’s senior vice president and chief nuclear officer, said the replacement of the steam generators has created more than 1,300 jobs in the region and $300 million in local spending.

Edison owns 79 percent of the San Onofre power plant. San Diego Gas & Electric owns 18 percent, and the city of Riverside owns 3 percent.

The plant generates 2,200 megawatts of electricity 24-hours per day. It powered about 19 percent of Edison customers in Southern California last year.