Energy officials scramble for backup power supply in wake of San Onofre nuclear plant shutdown

Ed Joyce/KPCC

Huntington Beach gas-fired power plant

California energy officials are looking for replacement power if the San Onofre nuclear plant is still offline when summer electricity demand increases. San Onofre has been shut down since January due to faulty tubes in its steam generators.

Officials have begun to eye two natural gas-powered plants in Huntington Beach. The twin units were retired the same month the San Onofre nuclear plant was shut down, but now the organization that operates the state's power grid (California Independent System Operator, or Cal-ISO) wants those units restarted.

“We just have to do some work," said Eric Pendergraft, president of AES Southland, the plant's operator. "[We need] to repair some of the things we had done to render the units inoperable."

He said that should take about three weeks, but the work won’t start until AES makes sure all regulatory approvals are in place. A gas line feeding the plants was severed when the plants shut down and three-foot holes were cut in the boilers. But, according to Pendergraft, undoing that work is straightforward.

AES Southland is developing plans to move to state-of-the-art natural gas-fired units at the Huntington Beach facility.

The Huntington Beach gas-fired plant units now use “once-through cooling,” where ocean water is pumped to cool the plant and then discharged back into the ocean. However, the process has been criticized for releasing the water back to the ocean at too high a temperature, affecting the ecosystem and water quality.

The pumping systems also capture larger marine life and smaller organisms. As a result, the California State Water Board has required that all coastal power plants, including the units at Huntington Beach, cease using the “once-through cooling" process by the end of 2020.

The state’s two nuclear power plants, at San Onofre and Diablo Canyon, have until the end of 2024 to comply with the regulation. Pendergraft said the two units can provide enough electricity for about 400,000 homes.

AES leases the units from an affiliate of Southern California Edison, operators of the San Onofre nuclear plant.

The federal Nuclear Regulatory Commission sent a special inspection team to the San Onofre Nuclear Generating Station after the problems with the tubes in the steam generator. Last week, NRC Chairman Gregory Jaczko visited the nuclear plant and met with anti-nuclear activists in Dana Point.

Jaczko said there is no timeline for restarting the plant. He also said there will be a public meeting to discuss the report from the special inspection team.

In the meantime, Edison and the inspectors have yet to determine the exact cause or causes for the tube problems at both generator units at the San Onofre plant.

Correction: An earlier version of this story identified AES as a subsidiary of Southern California Edison; while affiliated, they are a subsidiary of Edison International, not Southern California Edison.

More in Environment / Science

Comments

blog comments powered by Disqus