Scores of conservation groups and other parties sent letters to the coastal commission opposing the project and turned out in force at Wednesday's meeting in Santa Monica. Some wore "Stop Ocean Blasting" T-shirts, and others held signs.
Michael Jasny with the Natural Resources Defense Council testified that the air guns would inflict "severe and profound insult" on sea life.
Representatives from the Northern Chumash Tribal Council said their ancestors have inhabited the coastline for thousands of years. They urged the panel to protect the ecosystem.
"We cannot let this happen," tribal administrator Fred Collins said. "Please do not let this project go forward."
Mandy Davis, spokeswoman for a newly formed group called the Citizens Opposing Acoustic Seismic Testing, said the Pacific would become an "acoustic prison" if the project went forward.
Many claimed the utility had done too little to explore other, less damaging options and said it should analyze data it collected from previous studies before embarking on a new one. Krausse of PG&E countered that different studies provide different information.
To minimize impact to sea life, PG&E proposed starting off with one air cannon at a low decibel before ramping up to full power. It also planned to have spotters on the vessel and in an aircraft to alert operators of marine mammals in the region. Air guns would be silenced and work would cease if an animal strays too close.
The twin-reactor Diablo Canyon generates enough electricity to power more than 3 million homes in Central and Northern California. After the Japanese nuclear crisis, the utility asked federal nuclear regulators to delay issuing extended operating permits until thorough seismic studies are completed. The permits expire in 2024 and 2025.
The Nuclear Regulatory Commission does not require 3-D fault mapping for license renewal.
Alicia Chang can be reached at: http://twitter.com/SciWriAlicia