Unit 2 at PG&E's Diablo Canyon Power Plant safely returns to full power

July 16, 2013

AVILA BEACH, Calif. – Unit 2 at Pacific Gas and Electric Company's (PG&E) Diablo Canyon Power Plant returned to full power on Tuesday, July 16, 2013. The unit safely went off line on July 10 after an electrical disturbance occurred in equipment that supports moving power to the state's electric grid.

"The Diablo Canyon team worked in a safe, efficient and methodical manner to bring Unit 2 back into service," said Ed Halpin, PG&E's Senior Vice President and Chief Nuclear Officer. "The return to full power is a reflection of the dedication, commitment and focus of our talented crew of operators, engineers and maintenance personnel."

An investigation into the shut down determined the electrical disturbance was a result of a flashover event on a lightning arrestor located on the non-nuclear side of the plant. The flashover occurred during routine maintenance that involved pressure washing, known as "hot washing," of electrical insulators near the lightning arrestor. Upon sensing the disturbance, the unit performed as designed and automatically went off line to protect equipment. Unit 1 was unaffected and continued to generate power.

Following the successful repair of the lightning arrestor, Unit 2 began providing electricity to the state's power grid on July 14, and safely transitioned to 100 percent power the morning of July 16.

Diablo Canyon Power Plant is a nuclear power facility owned and operated by PG&E. Its two units together produce approximately 2,300 net megawatts of carbon-free electricity, about 10 percent of all electricity generated in California, and enough energy to meet the needs of more than three million Northern and Central Californians.

Pacific Gas and Electric Company, a subsidiary of PG&E Corporation (NYSE:PCG), is one of the largest combined natural gas and electric utilities in the United States. Based in San Francisco, with 20,000 employees, the company delivers some of the nation's cleanest energy to 15 million people in Northern and Central California. For more information, visit http://www.pge.com/about/newsroom/ and www.pgecurrents.com .