Diablo Canyon Power Plant
Encyclopedia
Diablo Canyon Power Plant is an electricity-generating nuclear power plant
at Avila Beach in San Luis Obispo County, California
. The plant has two Westinghouse-designed 4-loop pressurized-water
nuclear reactor
s operated by Pacific Gas & Electric. The facility is located on about 750 acre (303.5 ha) in Avila Beach, California
. Together, the twin 1,100 MWe reactors produce about 18,000 GW·h of electricity annually, supplying the electrical needs of more than 2.2 million people, sent along the Path 15
500-kV lines that connect to this plant. It was built directly over a geological fault line
, and is located near a second fault.
The plant is located in Nuclear Regulatory Commission Region IV
.
In November 2009, PG&E applied to the Nuclear Regulatory Commission
(NRC) for 20-year license renewals for both reactors.
supplied by Westinghouse
. It went online on May 7, 1985 and is licensed to operate through November 2, 2024. In 2006, Unit One generated 9,944,983 MW·h of electricity, at a nominal capacity factor
of 101.2 percent.
supplied by Westinghouse. It went online on March 3, 1986 and is licensed to operate through August 20, 2025. In 2006, Unit Two generated 8,520,000 MW·h of electricity, at a capacity factor of 88.2 percent.
The plant draws cooling water from the Pacific Ocean
, and during heavy storms both units are throttled back by 80 percent to prevent kelp
from entering the cooling water intake. The cooling water is used once and is not recirculated but rather returned to the Pacific Ocean at higher temperature.
from four faults, including the nearby San Andreas
and Hosgri fault
s, but was later upgraded to withstand a 7.5 magnitude quake. It has redundant seismic monitoring and a safety system designed to shut it down promptly in the event of significant ground motion.
However, by the time of the plant's completion in 1973, a seismic fault, the Hosgri fault
, had been discovered several miles offshore. This fault had a 7.1 magnitude quake 10 miles offshore on November 4, 1927, and thus was capable of generating forces equivalent to approximately 1/16 of those felt in the 1906 San Francisco earthquake
.
The company updated its plans and added structural supports designed to reinforce stability in case of earthquake. In September 1981, PG&E discovered that a single set of blueprints was used for these structural supports; workers were supposed to have reversed the plans when switching to the second reactor, but did not. According to Charles Perrow
, the result of the error was that "many parts were needlessly reinforced, while others, which should have been strengthened, were left untouched." Nonetheless, on March 19, 1982 the Nuclear Regulatory Commission decided not to review its 1978 decision approving the plant's safety, despite these and other design errors.
In response to concern that ground acceleration
, or shaking, could cause spillage of submerged fuel rod assemblies which, upon exposure to air, could ignite, PG&E and NRC regulators insist that the foregoing scenario is anticipated and controlled for, and that there is no basis to anticipate spillage. Additional seismic studies are in process, however completion of those studies is not a condition precedent to re-issuance of the operating licenses for the two onsite units.
Starting October 22, 2008, Unit 2 was taken offline for approximately two days due to a rapid influx of jellyfish
at the intake.
The Nuclear Regulatory Commission's estimate of the risk each year of an earthquake intense enough to cause core damage to the reactor at Diablo Canyon was 1 in 23,810, according to an NRC study published in August 2010.
In April 2011, in the wake of the Fukushima nuclear incident in Japan, PG&E asked the NRC not to issue license renewals until PG&E can complete new seismic studies, which are expected to take at least three years.
According to a SLO Tribune interview with PG&E's Chris Johns, "tragedy in Japan has prompted more concerns from Diablo Canyon’s 1,800 employees than any other issue, Becker said. Plant managers are holding brown-bag lunch meetings with employees to address those concerns".
The DCISC consists of three members, one each appointed by the Governor, the Attorney General and the Chairperson of the California Energy Commission. They serve staggered three-year terms. The committee has no authority to direct PG&E personnel.
defines two emergency planning zones around nuclear power plants: a plume exposure pathway zone with a radius of 10 miles (16.1 km), concerned primarily with exposure to, and inhalation of, airborne radioactive contamination, and an ingestion pathway zone of about 50 miles (80.5 km), concerned primarily with ingestion of food and liquid contaminated by radioactivity.
The 2010 U.S. population within 10 miles (16.1 km) of Diablo Canyon was 26,123, an increase of 50.2 percent in a decade, according to an analysis of U.S. Census data for msnbc.com. The 2010 U.S. population within 50 miles (80.5 km) was 465,521, an increase of 22.4 percent since 2000. Cities within 50 miles include San Luis Obispo (12 miles to city center) and Paso Robles (31 miles to city center).
Emergency sirens were installed when the plant went operational. Federal law requires an early warning system that radiates out 10 miles from any nuclear facility. However, the county siren coverage goes farther, extending from Cayucos in the north down to upper Nipomo to the south. Due to the real threat of a nuclear power-plant all businesses are required to have a siren information sticker in their business generally located with in the restrooms. Schools, government offices, and any other public building will have a PAZ card(Protective Action Zone). These cards show the 12 zones of evacuation with zone one being the plant it self. The cards also show the direction of evacuation on the highways.
from the anti-nuclear
protesters of the Abalone Alliance
. Over a two-week period in 1981, 1,900 activists were arrested at Diablo Canyon Power Plant. It was the largest arrest total in the history of the U.S. anti-nuclear movement
.
In spring of 2011, State Senator Sam Blakeslee
and US Representative Lois Capps both expressed concern for a renewed safety review. Speaking before the Senate Committee on Environment and Public Works, the congresswoman stated that she believed the "Nuclear Regulatory Commission should stay the license renewal process until the completion of independent, peer reviewed, advanced seismic studies of all faults in the area." The Alliance for Nuclear Responsibility began circulating a petition to similar effect, going further and calling for an outright halt to relicensing. An array of San Luis Obispo-based anti-nuclear groups including Mothers for Peace also called for the closure of Diablo Canyon nuclear power plant.
The Alliance for Nuclear Responsibility also works at the level of the California Public Utilities Commission
and initiated a letter writing campaign to Governor Jerry Brown
, which requests he "instruct the CPUC to rescind the Certificate of Public Convenience and Necessity for ... Diablo Canyon ... and allow them to operate conditionally only under the agreement by the utilities to immediately begin to fully comply with completion of the state-directed AB 1632 [seismic]studies."
On June 2, 2011, the NRC announced that it would delay the environmental part of the relicensing application but that it had completed the safety portion. A few days later, the Atomic Safety Licensing Board indicated that it would defer adjustment of the adjudicatory schedule of the four contentions brought by SLOMFP, a community based organization, accordingly. The ASLB made no findings regarding the merits of the contentions. Both parties to the dispute claim these developments as victories: Pacific Gas and Electric as well as San Luis Obispo Mothers for Peace.
Nuclear power plant
A nuclear power plant is a thermal power station in which the heat source is one or more nuclear reactors. As in a conventional thermal power station the heat is used to generate steam which drives a steam turbine connected to a generator which produces electricity.Nuclear power plants are usually...
at Avila Beach in San Luis Obispo County, California
San Luis Obispo County, California
San Luis Obispo County is a county located along the Pacific Ocean in the Central Coast of the U.S. state of California, between Los Angeles and the San Francisco Bay Area. As of the 2010 census its population was 269,637, up from 246,681 at the 2000 census...
. The plant has two Westinghouse-designed 4-loop pressurized-water
Pressurized water reactor
Pressurized water reactors constitute a large majority of all western nuclear power plants and are one of three types of light water reactor , the other types being boiling water reactors and supercritical water reactors...
nuclear reactor
Nuclear reactor
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid , which runs through turbines that power either ship's...
s operated by Pacific Gas & Electric. The facility is located on about 750 acre (303.5 ha) in Avila Beach, California
Avila Beach, California
Avila Beach , pronounced AH-vuh-luh, is a census-designated place in San Luis Obispo County, California, USA and located about 160 miles northwest of Los Angeles, and about 200 miles south of San Francisco. The ZIP Code is 93424. The community is inside area code 805...
. Together, the twin 1,100 MWe reactors produce about 18,000 GW·h of electricity annually, supplying the electrical needs of more than 2.2 million people, sent along the Path 15
Path 15
Path 15 is an portion of the north-south power transmission corridor in California, U.S. It forms a part of the Pacific AC Intertie and the California-Oregon Transmission Project....
500-kV lines that connect to this plant. It was built directly over a geological fault line
Fault line
In geology, fault line refers to the surface trace of a fault.Fault line, Fault Line, or faultline may also refer to:* "Faultline", a song from the 2008 studio album Versus by The Haunted...
, and is located near a second fault.
The plant is located in Nuclear Regulatory Commission Region IV
Nuclear Regulatory Commission Region IV
The Nuclear Regulatory Commission Region IV is one of the regions of the Nuclear Regulatory Commission. Headquartered in Arlington, Texas, oversees the southern midwestern and the western United States.Region IV consists of 14 nuclear power plants....
.
In November 2009, PG&E applied to the Nuclear Regulatory Commission
Nuclear Regulatory Commission
The Nuclear Regulatory Commission is an independent agency of the United States government that was established by the Energy Reorganization Act of 1974 from the United States Atomic Energy Commission, and was first opened January 19, 1975...
(NRC) for 20-year license renewals for both reactors.
Unit One
Unit One is a 1,122 MWe pressurized water reactorPressurized water reactor
Pressurized water reactors constitute a large majority of all western nuclear power plants and are one of three types of light water reactor , the other types being boiling water reactors and supercritical water reactors...
supplied by Westinghouse
Westinghouse Electric Company
Westinghouse Electric Company LLC is a nuclear power company, offering a wide range of nuclear products and services to utilities throughout the world, including nuclear fuel, service and maintenance, instrumentation and control and advanced nuclear plant designs...
. It went online on May 7, 1985 and is licensed to operate through November 2, 2024. In 2006, Unit One generated 9,944,983 MW·h of electricity, at a nominal capacity factor
Capacity factor
The net capacity factor or load factor of a power plant is the ratio of the actual output of a power plant over a period of time and its potential output if it had operated at full nameplate capacity the entire time...
of 101.2 percent.
Unit Two
Unit Two is a 1,118 MWe pressurized water reactorPressurized water reactor
Pressurized water reactors constitute a large majority of all western nuclear power plants and are one of three types of light water reactor , the other types being boiling water reactors and supercritical water reactors...
supplied by Westinghouse. It went online on March 3, 1986 and is licensed to operate through August 20, 2025. In 2006, Unit Two generated 8,520,000 MW·h of electricity, at a capacity factor of 88.2 percent.
The plant draws cooling water from the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
, and during heavy storms both units are throttled back by 80 percent to prevent kelp
Kelp
Kelps are large seaweeds belonging to the brown algae in the order Laminariales. There are about 30 different genera....
from entering the cooling water intake. The cooling water is used once and is not recirculated but rather returned to the Pacific Ocean at higher temperature.
Earthquake hazard
Diablo Canyon was originally designed to withstand a 6.75 magnitude earthquakeEarthquake
An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...
from four faults, including the nearby San Andreas
San Andreas Fault
The San Andreas Fault is a continental strike-slip fault that runs a length of roughly through California in the United States. The fault's motion is right-lateral strike-slip...
and Hosgri fault
Hosgri fault
The Hosgri Fault is an offshore fault zone located near the Central Coast of California in San Luis Obispo County. The main fault stretches for about , and the coastal communities closest to it are Cambria, San Simeon and Morro Bay, Baywood Park-Los Osos, and Avila Beach...
s, but was later upgraded to withstand a 7.5 magnitude quake. It has redundant seismic monitoring and a safety system designed to shut it down promptly in the event of significant ground motion.
History
Pacific Gas & Electric Company went through six years of hearings, referenda and litigation to have the Diablo Canyon plant approved. A principal concern about the plant is whether it can be sufficiently earthquake-proof. The site was deemed safe when construction started in 1968.However, by the time of the plant's completion in 1973, a seismic fault, the Hosgri fault
Hosgri fault
The Hosgri Fault is an offshore fault zone located near the Central Coast of California in San Luis Obispo County. The main fault stretches for about , and the coastal communities closest to it are Cambria, San Simeon and Morro Bay, Baywood Park-Los Osos, and Avila Beach...
, had been discovered several miles offshore. This fault had a 7.1 magnitude quake 10 miles offshore on November 4, 1927, and thus was capable of generating forces equivalent to approximately 1/16 of those felt in the 1906 San Francisco earthquake
1906 San Francisco earthquake
The San Francisco earthquake of 1906 was a major earthquake that struck San Francisco, California, and the coast of Northern California at 5:12 a.m. on Wednesday, April 18, 1906. The most widely accepted estimate for the magnitude of the earthquake is a moment magnitude of 7.9; however, other...
.
The company updated its plans and added structural supports designed to reinforce stability in case of earthquake. In September 1981, PG&E discovered that a single set of blueprints was used for these structural supports; workers were supposed to have reversed the plans when switching to the second reactor, but did not. According to Charles Perrow
Charles Perrow
Charles B. Perrow is an emeritus professor of sociology at Yale University and visiting professor at Stanford University. He is the author of several books and many articles on organizations, and is primarily concerned with the impact of large organizations on society.-Academic appointments:After...
, the result of the error was that "many parts were needlessly reinforced, while others, which should have been strengthened, were left untouched." Nonetheless, on March 19, 1982 the Nuclear Regulatory Commission decided not to review its 1978 decision approving the plant's safety, despite these and other design errors.
In response to concern that ground acceleration
Peak ground acceleration
Peak ground acceleration is a measure of earthquake acceleration on the ground and an important input parameter for earthquake engineering, also known as the design basis earthquake ground motion...
, or shaking, could cause spillage of submerged fuel rod assemblies which, upon exposure to air, could ignite, PG&E and NRC regulators insist that the foregoing scenario is anticipated and controlled for, and that there is no basis to anticipate spillage. Additional seismic studies are in process, however completion of those studies is not a condition precedent to re-issuance of the operating licenses for the two onsite units.
Starting October 22, 2008, Unit 2 was taken offline for approximately two days due to a rapid influx of jellyfish
Jellyfish
Jellyfish are free-swimming members of the phylum Cnidaria. Medusa is another word for jellyfish, and refers to any free-swimming jellyfish stages in the phylum Cnidaria...
at the intake.
The Nuclear Regulatory Commission's estimate of the risk each year of an earthquake intense enough to cause core damage to the reactor at Diablo Canyon was 1 in 23,810, according to an NRC study published in August 2010.
In April 2011, in the wake of the Fukushima nuclear incident in Japan, PG&E asked the NRC not to issue license renewals until PG&E can complete new seismic studies, which are expected to take at least three years.
Labor
Overall, there are approximately 1200 employees of Pacific Gas and Electric and 200 employees of subcontractors. Several unions represent the workforce at Diablo, among them the International Brotherhood of Electrical Workers and the International Association of Machinists. Control Technicians and electricians who work for Crane Nuclear, one of many subcontractors, are represented by the IBEW Local 1245. 1245 also represents PG&E meter readers, clerical workers, etc. Local 639,which is involved with Diablo but is under "spring outage", also supports solar energy development as part of the overall energy industry portfolio. This outage has been retracted as of June 10, 2011 The outages are routine for maintenance and the complex process of refueling, and created 1,000 temporary jobs, according to PG&E. Other workers are represented by the Plumbers and Pipefitters.According to a SLO Tribune interview with PG&E's Chris Johns, "tragedy in Japan has prompted more concerns from Diablo Canyon’s 1,800 employees than any other issue, Becker said. Plant managers are holding brown-bag lunch meetings with employees to address those concerns".
DCISC
The Diablo Canyon Independent Safety Committee (DCISC) was established as a part of a settlement agreement entered into in June 1988 between the Division of Ratepayer Advocates of the California Public Utilities Commission (PUC), the Attorney General for the State of California, and Pacific Gas and Electric Company(“PG&E”).The DCISC consists of three members, one each appointed by the Governor, the Attorney General and the Chairperson of the California Energy Commission. They serve staggered three-year terms. The committee has no authority to direct PG&E personnel.
Emergency planning
The Nuclear Regulatory CommissionNuclear Regulatory Commission
The Nuclear Regulatory Commission is an independent agency of the United States government that was established by the Energy Reorganization Act of 1974 from the United States Atomic Energy Commission, and was first opened January 19, 1975...
defines two emergency planning zones around nuclear power plants: a plume exposure pathway zone with a radius of 10 miles (16.1 km), concerned primarily with exposure to, and inhalation of, airborne radioactive contamination, and an ingestion pathway zone of about 50 miles (80.5 km), concerned primarily with ingestion of food and liquid contaminated by radioactivity.
The 2010 U.S. population within 10 miles (16.1 km) of Diablo Canyon was 26,123, an increase of 50.2 percent in a decade, according to an analysis of U.S. Census data for msnbc.com. The 2010 U.S. population within 50 miles (80.5 km) was 465,521, an increase of 22.4 percent since 2000. Cities within 50 miles include San Luis Obispo (12 miles to city center) and Paso Robles (31 miles to city center).
Emergency sirens were installed when the plant went operational. Federal law requires an early warning system that radiates out 10 miles from any nuclear facility. However, the county siren coverage goes farther, extending from Cayucos in the north down to upper Nipomo to the south. Due to the real threat of a nuclear power-plant all businesses are required to have a siren information sticker in their business generally located with in the restrooms. Schools, government offices, and any other public building will have a PAZ card(Protective Action Zone). These cards show the 12 zones of evacuation with zone one being the plant it self. The cards also show the direction of evacuation on the highways.
Public participation and protest
Diablo Canyon was built and entered service despite legal challenges and civil disobedienceCivil disobedience
Civil disobedience is the active, professed refusal to obey certain laws, demands, and commands of a government, or of an occupying international power. Civil disobedience is commonly, though not always, defined as being nonviolent resistance. It is one form of civil resistance...
from the anti-nuclear
Anti-nuclear
The anti-nuclear movement is a social movement that opposes the use of nuclear technologies. Many direct action groups, environmental groups, and professional organisations have identified themselves with the movement at the local, national, and international level...
protesters of the Abalone Alliance
Abalone alliance
The Abalone Alliance was a nonviolent civil disobedience group formed to shut down the Pacific Gas and Electric Company's Diablo Canyon Power Plant near San Luis Obispo on the central California coast in the United States...
. Over a two-week period in 1981, 1,900 activists were arrested at Diablo Canyon Power Plant. It was the largest arrest total in the history of the U.S. anti-nuclear movement
Anti-nuclear movement in the United States
The anti-nuclear movement in the United States consists of more than 80 anti-nuclear groups which have acted to oppose nuclear power or nuclear weapons, or both, in the United States. These groups include the Abalone Alliance, Clamshell Alliance, Institute for Energy and Environmental Research,...
.
In spring of 2011, State Senator Sam Blakeslee
Sam Blakeslee
Samuel Norman Blakeslee is a Republican California State Senator representing California's 15th State Senate district, a former California State Assemblyman from California's 33rd State Assembly district, and a former State Assembly Republican Leader...
and US Representative Lois Capps both expressed concern for a renewed safety review. Speaking before the Senate Committee on Environment and Public Works, the congresswoman stated that she believed the "Nuclear Regulatory Commission should stay the license renewal process until the completion of independent, peer reviewed, advanced seismic studies of all faults in the area." The Alliance for Nuclear Responsibility began circulating a petition to similar effect, going further and calling for an outright halt to relicensing. An array of San Luis Obispo-based anti-nuclear groups including Mothers for Peace also called for the closure of Diablo Canyon nuclear power plant.
The Alliance for Nuclear Responsibility also works at the level of the California Public Utilities Commission
California Public Utilities Commission
The California Public Utilities Commission is a regulatory agency which regulates privately owned public utilities in the state of California, including electric power, telecommunications, natural gas and water companies...
and initiated a letter writing campaign to Governor Jerry Brown
Jerry Brown
Edmund Gerald "Jerry" Brown, Jr. is an American politician. Brown served as the 34th Governor of California , and is currently serving as the 39th California Governor...
, which requests he "instruct the CPUC to rescind the Certificate of Public Convenience and Necessity for ... Diablo Canyon ... and allow them to operate conditionally only under the agreement by the utilities to immediately begin to fully comply with completion of the state-directed AB 1632 [seismic]studies."
Post-Fukushima developments
According to Victor Dricks, senior public affairs officer for NRC Region IV, the Commission conducted a nationwide review of nuclear power plants for their capacity to respond to earthquakes, power outages and other catastrophic events, and Diablo was found to have "a high level of preparedness and strong capability in terms of equipment and procedures to respond to severe events."On June 2, 2011, the NRC announced that it would delay the environmental part of the relicensing application but that it had completed the safety portion. A few days later, the Atomic Safety Licensing Board indicated that it would defer adjustment of the adjudicatory schedule of the four contentions brought by SLOMFP, a community based organization, accordingly. The ASLB made no findings regarding the merits of the contentions. Both parties to the dispute claim these developments as victories: Pacific Gas and Electric as well as San Luis Obispo Mothers for Peace.
See also
- John Goffman
- Anti-nuclear movement in CaliforniaAnti-nuclear movement in CaliforniaThe 1970s proved to be a pivotal period for the anti-nuclear movement in California. Opposition to nuclear power in California coincided with the growth of the country's environmental movement...
- Conservation Fallout: Nuclear Protest at Diablo CanyonConservation Fallout: Nuclear Protest at Diablo CanyonConservation Fallout: Nuclear Protest at Diablo Canyon is a 2006 book by John Wills.Widespread public opposition accompanied the rise of the U.S. nuclear industry during the 1960s and 1970s...
- International reaction to the Fukushima Daiichi nuclear disaster
- San Onofre Nuclear Generating StationSan Onofre Nuclear Generating StationThe San Onofre Nuclear Generating Station is a nuclear power plant located on the Pacific coast of California. The site is in the northwestern corner of San Diego County, south of San Clemente, and surrounded by the San Onofre State Park and next to the I-5 Highway.Unit 1 is no longer in service...
- Critical Masses: Opposition to Nuclear Power in California, 1958-1978Critical Masses: Opposition to Nuclear Power in California, 1958-1978Critical Masses: Opposition to Nuclear Power in California, 1958-1978 is the first detailed history of the anti-nuclear movement in the United States, written by Thomas Wellock. It is also the first state-level research on the subject with a focus on California...
- Nuclear policy in the United States
- Dark Circle (film)