Diablo Canyon Power Plant

The Diablo Canyon Power Plant in San Luis Obispo County, California, is a two-unit nuclear power electric generating facility owned and operated by Pacific Gas & Electric. The facility has been the center of controversy since its approval for construction in 1968, particularly with regards to the overall design and its ability to withstand powerful earthquakes.

Both of the reactor units at the Diablo Canyon Power Plant were completed in 1973, but the opening of the facility was delayed for years because of a series of investigation concerning the plant’s safety. New seismographic research had discovered fault lines in the region, and mistakes in the interpretation of major blueprints for the facility were revealed. Over a two week period in 1981 more than 1,900 protesters were arrested at or near the power plant. However in 1982 the Nuclear Regulatory Commission deemed the project within tolerance limits. Unit 1 became operational in 1985 and Unit 2 was commissioned the following year.

The two units at the Diablo Canyon Power Plant are pressurized water reactors supplied by Westinghouse; together Units 1 and 2 produce about 18,000 gigawatt-hours of electricity per year, supplying the needs of about 2.2 million individuals. The nearby Pacific Ocean is the source for the secondary cooling water required at the facility.

During construction of the Diablo Canyon Power Plant, asbestos was likely used in the design of many parts of the facility’s structures. Asbestos is commonly used as a flame retardant and general insulating material, and is inexpensive to gather in large quantities. Workers at the Diablo Canyon Power plant and other similar projects may have been exposed to asbestos during and after construction, and long-term exposure to asbestos fibers has been proven to cause several illnesses, the most dangerous of which is mesothelioma. By the late 1980s asbestos was being removed from most power stations across the country, but employees who worked on the construction and early operation at the Diablo Canyon facility may have been exposed to asbestos fibers on a daily basis.

Seismologists have also raised new concerns over the structural integrity at Diablo Canyon Power Plant. The facility was designed to withstand a 7.5 magnitude earthquake, but new suspicions continue to circulate about the probability of exposed fuel rods and loss of coolant during and after a moderate sized tremor with a shallow focus point.