Diablo Canyon Power Plant

Diablo Canyon Power Plant is on approximately {{convert|750|acre|abbr=on}} of land located just west of Avila Beach, California.{{ r | EIA_1 }} The power-producing portion of the plant occupies around {{convert|12|acre|abbr=on}}. PG&E owns a total of {{convert|12,820| acres}} of land at the site.{{ cite news | url=https://www.sfchronicle.com/business/article/Diablo-Canyon-s-dismantling-Inside-the-12826795.php | title=Diablo Canyon's dismantling - An in-depth look at the painstaking process of decommissioning California's last nuclear power plant | last=Baker | first=David | newspaper=San Francisco Chronicle | date=2018-04-13 | quote=PG&E customers have been paying into a decommissioning fund, bit by bit, since the plant opened in 1985. The fund now has $2.7 billion, according to the utility, and is continuing to grow. ... A typical PG&E residential customer currently pays about 11 cents per month for decommissioning both Diablo Canyon and Humboldt Bay. ... The company also is assembling a community advisory panel that will provide input both on decommissioning Diablo Canyon and what to do with the 12,820 acres of undeveloped coastal hills that PG&E owns around the plant.}}

Unit One is a 1138 MWe pressurized water reactor supplied by Westinghouse. It went online on May 7, 1985, and is licensed to operate through November 2, 2024.{{cite web | url= http://www.eia.gov/cneaf/nuclear/state_profiles/california/ca.html#_ftn1 | title= California Nuclear Profile – Diablo Canyon Nuclear Power Plant | date= September 2010 | publisher= Energy Information Administration, U.S. Department of Energy (DOE) | access-date= January 21, 2011 }} In 2006, Unit One generated 9,944,983 MW·h of electricity, at a nominal capacity factor of 99.8 percent.

Unit Two is a 1118 MWe pressurized water reactor 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 87.0 percent.

The plant's once-through cooling system (OTC) draws water from the Pacific Ocean to condense steam driving its turbines. Unlike evaporative cooling systems used at other plants, Diablo Canyon's OTC is designed so all water can be recycled, and to assure minimal impact on ocean ecosystems. Reactors can be throttled back during heavy storm surges to prevent an excess of kelp from entering the cooling water intake, and power is limited during operation so that water returned to the ocean is no more than {{convert|20|F-change|C-change}} warmer than ambient temperature.

All thermal power stations in California using OTC systems for cooling employ various filtering capabilities to prevent larvae and other aquatic objects from being drawn into impacts with the grids on the intake tubes, known as entrainment.[http://environmentalprogress.org/big-news/2016/9/19/protest-pge-proposal PG&E Submitted False Cost Data in Diablo Canyon Case, New EP Investigation Finds] The Diablo Canyon facility was ranked 13th in estimated power station bio-fouling and egg larvae damage in the state of California in 2013; the less productive fossil gas power units 6 & 7 at Moss Landing Power Plant were ranked as having a far higher impact on fish larvae.[https://web.archive.org/web/20170209050151/http://www.waterboards.ca.gov/water_issues/programs/ocean/cwa316/rcnfpp/docs/fine_mesh_screen_eval.pdf Evaluation of Fine - mesh Intake Screen System for the Diablo Canyon Power Plant. pdf table A1-2 pg 13] In 2014, the California Water Board released a white paper detailing the costs to convert Diablo Canyon to utilize cooling towers instead of the once-through cooling cycle.[https://web.archive.org/web/20170829162105/http://www.waterboards.ca.gov/water_issues/programs/ocean/cwa316/rcnfpp/docs/subbechcom_091214.pdf Proposed Subcommittee Comments on Bechtel’s Assessment of Alternatives to Once-Through-Cooling for Diablo Canyon Power Plant pdf] These upgrade cost estimates have been the subject of controversy and debate, with some arguing instead for construction of an artificial reef to better offset the environmental impact of diminished larvae spawning.

The plant produces electricity for about 6 cents per kWh, less than the average cost of 10.1 cents per kWh that PG&E paid for electricity from other suppliers in 2014.{{ cite news | url=https://www.sfchronicle.com/business/article/Nuclear-power-s-last-stand-in-California-Will-6630933.php?t=d4053ba6dc | title=Nuclear power's last stand in California: Will Diablo Canyon die? | last=Baker | first=David | newspaper=San Francisco Chronicle | date=2015-11-14 | quote=And yet, the plant produces so much electricity that it remains cost-effective, according to PG&E. The utility doesn’t reveal exact prices but says Diablo can generate electricity for roughly 5 to 6 cents per kilowatt-hour. In contrast, PG&E last year paid an average of 10.1 cents per kilowatt-hour to buy electricity from other suppliers, according to the company’s annual report to shareholders. }}

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There are approximately 1,200 employees of Pacific Gas & Electric and 200 employees of subcontractors at the Diablo Canyon site.Public hearing minutes, Santa Barbara Board of Supervisors, Special NRC session of June 16, 2011 Several unions represent the workforce at Diablo, among them the International Brotherhood of Electrical Workers (IBEW) and the International Association of Machinists. The routine outages for maintenance, and the complex process of refueling, create more than 1,000 temporary jobs, according to PG&E.More than 1,000 temporary workers – a boost to the local economy – were brought in to work with PG&E employees to replace a portion of the reactor fuel and to perform maintenance and testing on plant system components that are inaccessible during regular plant operations. The staff uses generative artificial intelligence to find and organize data from the large documentation.{{cite web |last1=Martucci |first1=Brian |title=Generative AI deployment at Diablo Canyon is a first for US nuclear power sector: PG&E |url=https://www.utilitydive.com/news/generative-ai-deployment-at-diablo-canyon-is-a-first-for-us-nuclear-power-s/732953/ |website=Utility Dive |date=14 November 2024}}

Pacific Gas & Electric Company went through six years of hearings, referendums 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 began in 1968, but a seismic fault (the Hosgri fault) had been discovered several miles offshore by the time the plant was completed in 1973.{{cite web|last=Koenen |first=Leon |url=http://www.kcet.org/updaily/socal_focus/environment/31573-diablo-canyon-nuclear-power-plant.html |title=The Diablo Canyon Nuclear Power Plant, a 48-Year Odyssey | Environment | SoCal Focus |publisher=KCET |date=2011-03-25 |access-date=2011-06-10}}{{cite web |url=http://www.ksby.com/news/is-diablo-canyon-prepared-for-possible-earthquake-/ |title=Is Diablo Canyon prepared for possible earthquake? | KSBY.com | San Luis Obispo, Santa Maria, Santa Barbara, Paso Robles |publisher=KSBY.com |date=2011-03-14 |access-date=2011-06-10 |archive-url=https://web.archive.org/web/20110927155016/http://www.ksby.com/news/is-diablo-canyon-prepared-for-possible-earthquake-/ |archive-date=2011-09-27 |url-status=dead }}{{cite web |url=http://www.fox40.com/news/headlines/ktxl-californias-two-nuclear-plants-near-fault-lines-20110314,0,3265997.story |title=California's Two Nuclear Plants Near Fault Lines, But Chris Wills with the California Geological Survey says the types of faults are different than the ones in Japan. – KTXL |publisher=Fox40.com |date=2011-03-14 |access-date=2011-06-10 |archive-url=https://web.archive.org/web/20111123074606/http://www.fox40.com/news/headlines/ktxl-californias-two-nuclear-plants-near-fault-lines-20110314,0,3265997.story |archive-date=2011-11-23 |url-status=dead }}{{cite web |url=http://www.capradio.org/articles/2011/03/25/is-california-underestimating-quake-threat-to-nuclear-plants |title=Is California Underestimating Quake Threat To Nuclear Plants? | Capital Public Radio |publisher=CapRadio |date=2011-03-25 |access-date=2011-06-10 |archive-url=https://web.archive.org/web/20120314054012/http://www.capradio.org/articles/2011/03/25/is-california-underestimating-quake-threat-to-nuclear-plants |archive-date=2012-03-14 |url-status=dead }}{{cite web |url=http://capps.house.gov/press-release/capps-testifies-senate-about-diablo-canyon-safety |title=Capps Testifies Before Senate About Diablo Canyon Safety | U.S. House of Representatives |publisher=U.S. House |date=2011-04-12 |access-date=2014-08-22 |archive-url=https://web.archive.org/web/20121017153156/http://capps.house.gov/press-release/capps-testifies-senate-about-diablo-canyon-safety |archive-date=2012-10-17 |url-status=dead }} This fault experienced a 7.1 magnitude quake 10 miles offshore on November 4, 1927, and thus is capable of generating forces equivalent to approximately {{frac|1|16}} of those felt in the 1906 San Francisco earthquake.{{cite web | title=Lompoc Earthquake (1927) | url=http://www.data.scec.org/chrono_index/lompoc.html | publisher=Southern California Earthquake Data Center | year=2010 | access-date=November 2, 2010 | url-status=dead | archive-url=https://web.archive.org/web/20110606011227/http://www.data.scec.org/chrono_index/lompoc.html | archive-date=June 6, 2011 }}

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.{{cite news |url=https://www.nytimes.com/1981/10/02/us/coast-a-plant-construction-error-tied-to-missing-guide-to-blueprint.html |title=Coast A-Plant Construction Error Tied to Missing Guide to Blueprint |first=Judith |last=Cummings |newspaper=The New York Times | date=October 2, 1981 | page = 14 |access-date=August 31, 2016}} 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.{{cite news | title = U.S. Won't Review Diablo Plant Decision: Nuclear Board Upholds '78 Approval of Quake Design Standards | work = Los Angeles Times | date=March 20, 1982 | page=A35}}

In response to concern that ground acceleration, or shaking, could cause spillage of submerged fuel rod assemblies which could ignite upon exposure to air, PG&E and NRC regulators insist that the foregoing scenario is anticipated and controlled for, and that there is no basis to anticipate spillage.{{cite web | title=Diablo Canyon Independent Safety Committee's Evaluation of Pressurized Thermal Shock and Seismic Interactions for a 20-Year License Extension at the Diablo Canyon Nuclear Power Plant | url=http://www.dcisc.org/pts-public-release.php | publisher=Diablo Canyon Independent Safety Committee | year=2011 | access-date=March 18, 2011}} The launch of additional seismic studies did not delay re-issuance of the operating licenses for the two onsite units.{{cite news | title=In The World of Nuclear Power Crisis | url=http://www.mindfully.org/Nucs/TMI-LifeMay79.htm | work=Life Magazine | date=May 1979 | pages=23–30 | access-date=July 14, 2010 | archive-url=https://web.archive.org/web/20110512165416/http://www.mindfully.org/Nucs/TMI-LifeMay79.htm | archive-date=May 12, 2011 | url-status=dead }}

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.{{cite news |first= Bill |last= Dedman | author-link= Bill Dedman |title= What are the odds? US nuke plants ranked by quake risk |work= NBC News |date= March 17, 2011 |url= https://www.nbcnews.com/id/wbna42103936 |access-date= April 19, 2011 }}{{Cite web |url=http://msnbcmedia.msn.com/i/msnbc/Sections/NEWS/quake%20nrc%20risk%20estimates.pdf |title=Archived copy |access-date=2011-04-19 |archive-url=https://web.archive.org/web/20170525170632/http://msnbcmedia.msn.com/i/msnbc/Sections/NEWS/quake%20nrc%20risk%20estimates.pdf |archive-date=2017-05-25 |url-status=dead }}

In 2009, PG&E applied to the Nuclear Regulatory Commission (NRC) for 20-year license renewals for both reactors.{{cite web|url=https://www.nrc.gov/reactors/operating/licensing/renewal/applications/diablo-canyon.html|title=Diablo Canyon – License Renewal Application|date=March 12, 2011 | work= Operating Reactor Licensing|publisher=Nuclear Regulatory Commission (NRC)|access-date=2011-04-19}}

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 could complete new seismic studies, which were expected to take at least three years.{{cite web | url= http://www.baycitizen.org/pge/story/diablo-canyon/ | title= Seismic Uncertainty at Diablo Canyon | first= John | last= Upton | date= March 17, 2011 | work= The Bay Citizen | access-date= 2011-04-19 | archive-url= https://web.archive.org/web/20121105203456/http://www.baycitizen.org/pge/story/diablo-canyon/ | archive-date= November 5, 2012 | url-status= dead }}

{{cite web

| url = https://www.wsj.com/articles/SB10001424052748704529204576257302591577840

| title = Diablo Plant Delays License Bid for Quake Study

| first = Ben | last = Casselman |author2 = Stephen Power

| date = April 12, 2011 | work = The Wall Street Journal

| access-date = 2011-04-19 }}

On June 24, 2013, at 9:20 PM PDT, Diablo Canyon experienced a loss of offsite power to the startup transformers of both units due to a failure on the 230 kV transmission system. At the time, none of the startup transformers were loaded as both units were online and their electrical systems were at the time being powered by the plant's turbine generators. However, the emergency diesel generators were started with no load during the outage as a precaution in case either unit tripped offline while offsite power was unavailable. The electrical output of the plant via the 500 kV transmission system was not interrupted, allowing both units to remain online during the outage.

{{See also|List of anti-nuclear protests in the United States|Anti-nuclear movement in California}}

Diablo Canyon was built and entered service in the midst of legal challenges and civil disobedience from the anti-nuclear protesters of the Abalone Alliance.{{cite book | last=Wills | first=John | title=Conservation Fallout: Nuclear Protest at Diablo Canyon | location=Reno | publisher= University of Nevada Press | year=2006 | isbn=0-87417-680-8 }} Over a two-week period in 1981, 1,900 activists were arrested and sent to jail for protesting at Diablo Canyon Power Plant, including musician/activist Jackson Browne. 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.{{cite news|url=http://calcoastnews.com/2011/03/blakeslee-and-racheal-maddow-discuss-diablo/ |title=Blakeslee and Rachel Maddow discuss Diablo |work=Cal Coast News |date=2011-03-25 |access-date=2011-06-10}}{{cite web |url=http://capps.house.gov/2011/04/capps-testifies-before-senate-about-diablo-canyon-safety.shtml |title=Capps Testifies Before Senate About Diablo Canyon Safety | Congresswoman Lois Capps, Representing the 23rd District of California |publisher=Capps.house.gov |date=2011-04-12 |access-date=2011-06-10 |archive-url=https://web.archive.org/web/20110602040624/http://capps.house.gov/2011/04/capps-testifies-before-senate-about-diablo-canyon-safety.shtml |archive-date=2011-06-02 |url-status=dead }} Speaking before the Senate Committee on Environment and Public Works, Representative Capps 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,http://a4nr.org/wp-content/uploads/2011/04/042211-A4NR-petition.pdf {{Bare URL PDF|date=March 2022}} 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 closure of the plant.{{cite news

| url=http://www.sanluisobispo.com/news/local/article39149715.html

| title=Anti-nuclear rally at Avila Beach

| first=Julia

| last=Hickey

| date=2011-04-16

| work=The Tribune

| access-date=2016-12-12}}

Due to international reactions to the Fukushima Daiichi nuclear disaster, concerns have continued over the ongoing operations of Diablo Canyon which, like the reactors at Fukushima, is in an area prone to earthquakes and tsunami. The elevation of the Fukushima site is approximately {{convert|20|feet|m}} above sea level, while Diablo Canyon sits on a bluff {{convert|85|feet|m}} above sea level. 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."{{cite web |last=Dricks |first=Victor |url=http://www.independent.com/news/2011/may/31/eyes-diablo/?foo#comments |title=The Santa Barbara Independent The Eyes on Diablo |publisher=Independent.com |access-date=2011-06-10 |archive-url=https://web.archive.org/web/20120908062004/http://www.independent.com/news/2011/may/31/eyes-diablo/?foo#comments |archive-date=2012-09-08 |url-status=dead }}

On June 2, 2011, the NRC announced that it would delay the environmental part of the re-licensing application but that it had completed the safety portion.http://pbadupws.nrc.gov/docs/ML1115/ML111530522.pdf {{Bare URL PDF|date=March 2022}} A few days later, the Atomic Safety Licensing Board (ASLB) indicated that it would defer adjustment of the adjudicatory schedule of the four contentions brought by San Luis Obispo Mothers for Peace (SLOMFP), a community-based anti-nuclear organization, accordingly. The ASLB made no findings regarding the merits of the contentions; both PG&E and SLOMFP claimed these developments as victories.{{cite web |last=Johns |first=Chris |url=http://www.sanluisobispo.com/2011/06/04/1629475/viewpoint-pge-chief-says-it-is.html |title=Viewpoint: PG&E chief says it is committed to safety of Diablo | The Tribune & |publisher=Sanluisobispo.com |date=2011-06-05 |access-date=2011-06-10 |archive-url=https://web.archive.org/web/20110919140240/http://www.sanluisobispo.com/2011/06/04/1629475/viewpoint-pge-chief-says-it-is.html |archive-date=2011-09-19 |url-status=dead }}{{cite web|url=http://mothersforpeace.org/ |title= Mothers For Peace |publisher=Mothersforpeace.org |access-date=2011-06-10}}

S. David Freeman, a former general manager of the Sacramento Municipal Utility District for four years, criticized the continued operation of Diablo Canyon, calling nuclear power the "most expensive and dangerous source of energy on Earth." According to Freeman, Diablo Canyon and the since-closed San Onofre nuclear plant are both "disasters waiting to happen: aging, unreliable reactors sitting near fault zones on the fragile Pacific Coast, with millions or hundreds of thousands of Californians living nearby."{{cite web |url=http://www.sacbee.com/2012/06/02/4532500/time-has-come-for-california-to.html#storylink=cpy |title=Viewpoints: Time has come for California to embrace a nuclear-free future |author=S. David Freeman |date=Jun 2, 2012 |work=Sacramento Bee |access-date=September 2, 2012 |archive-url=https://web.archive.org/web/20120615194034/http://www.sacbee.com/2012/06/02/4532500/time-has-come-for-california-to.html#storylink=cpy |archive-date=June 15, 2012 |url-status=dead }}

In January 2016, several authors of An Ecomodernist Manifesto (including Robert Stone, David Keith, Stewart Brand, Michael Shellenberger, Mark Lynas) signed an open letter to California Governor Jerry Brown, Tony Earley, CEO of Pacific Gas & Electric, and California state officials, urging that the plant not be closed.{{cite news|last1=McDonnell|first1=Tim|title=Closing This Nuclear Plant Could Cause an Environmental Disaster|url=https://www.motherjones.com/environment/2016/02/diablo-canyon-nuclear-plant-climate-change|access-date=11 February 2016|work=Mother Jones|publisher=Foundation For National Progress|date=3 February 2016}}{{cite web|title=Open letter: Do the right thing – stand-up for California's largest source of clean energy|url=http://www.savediablocanyon.org/open-letter/|website=Save Diablo Canyon|access-date=11 February 2016 | archive-url=https://web.archive.org/web/20160207001258/http://www.savediablocanyon.org/open-letter/ | archive-date=2016-02-07 | url-status=dead }} They argued that Diablo is an asset for California in achieving global warming goals since it does not emit greenhouse gases like a natural gas power plant, which are a major contributor to global warming.{{cite news |last=Baker |first=David R. |date=January 29, 2016 |title=Yes nukes! Conservationists rally to save state's nuclear plant |url=http://www.sfchronicle.com/business/article/Yes-nukes-Conservationists-rally-to-save-6794124.php |newspaper=San Francisco Chronicle |location=San Francisco, Calif. |access-date=27 June 2016 }}

S. David Freeman and Damon Moglen from the environmental advocacy group Friends of the Earth, (which was founded in 1969 to oppose Diablo Canyon's construction), commissioned a study to estimate whether it could be cost-effective to replace Diablo with zero-carbon resources.{{ r | UD_2 }} Their study estimated that California will need less grid electricity in the next two decades, and that expected costs to extend Diablo's licenses would be around $17 billion vs. $12–15 billion for replacing it with renewables and energy efficiency.{{ cite report |publisher=V. John White and Associates | url=https://webiva-downton.s3.amazonaws.com/877/6d/5/8551/PlanBfinal.pdf | last=Caldwell | first=James |first2=William |last2=Perea Marcus |first3=V. John |last3= White |first4=Liz |last4=Anthony |title=A Cost Effective and Reliable Zero Carbon Replacement Strategy for Diablo Canyon Power Plant | date= | access-date= | archive-url=https://web.archive.org/web/20161123130308/https://webiva-downton.s3.amazonaws.com/877/6d/5/8551/PlanBfinal.pdf | archive-date=2016-11-23 | url-status=dead }}{{ r | UD_2 }} Freeman and Moglen then arranged for a meeting with PG&E's vice president of policy and federal affairs to present her with their report.{{ r | UD_2 }} The group invited Ralph Cavanagh from the Natural Resources Defense Council, as well as other environmental groups.{{ r | UD_2 }} They included the plant's unions in their discussion, who agreed to closing the plant after being offered $350 million for retraining programs and retention bonuses.{{ cite news | url=https://www.utilitydive.com/news/anatomy-of-a-nuke-closure-how-pge-decided-to-shutter-diablo-canyon/421979/ | title=Anatomy of a nuke closure: How PG&E decided to shutter Diablo Canyon | last=Trabish | first=Herman | newspaper=UtilityDive | date=2016-07-07 }} Lieutenant Governor Gavin Newsom, as a member of the State Lands Commission, was interested in moving the discussion along in part to allow for a slower, greener transition.{{Cite news |last=Cardwell |first=Diane |date=2016-06-21 |title=California's Last Nuclear Power Plant Could Close |language=en-US |work=The New York Times |url=https://www.nytimes.com/2016/06/22/business/californias-diablo-canyon-nuclear-power-plant.html |access-date=2023-02-14 |issn=0362-4331}}

On June 21, 2016, PG&E announced a Joint Proposal with Friends of the Earth, the Natural Resources Defense Council, Environment California, the International Brotherhood of Electrical Workers Local 1245, Coalition of California Utility Employees, and Alliance for Nuclear Responsibility to increase investment in energy efficiency, renewables and storage, while phasing out nuclear power.{{cite news |title=Joint Proposal |url=https://www.pge.com/includes/docs/pdfs/safety/dcpp/JointProposal.pdf |access-date=8 June 2019 |work=Public Document |publisher=PGE |date=20 June 2016 |archive-date=August 9, 2019 |archive-url=https://web.archive.org/web/20190809112906/https://www.pge.com/includes/docs/pdfs/safety/dcpp/JointProposal.pdf |url-status=dead }}

One reason given by PG&E for the closure is that under California's electricity regulations, renewables are given priority over nuclear and fossil-fuel generation, which would likely have resulted in Diablo only running half-time, and because nuclear plants have large fixed costs, this would essentially double its per-kWh generation costs.{{ cite news | url=https://www.sfgate.com/business/article/End-of-an-atomic-era-PG-E-to-close-Diablo-Canyon-8314258.php | title=End of an atomic era: PG&E to close Diablo Canyon nuclear plant | last=Baker | first=David | newspaper=San Francisco Chronicle | date=2016-06-21 | quote=A rising flood of renewable power is pouring onto the state’s electricity grid, and, under California regulations, that power has priority over electricity generated from nuclear reactors or fossil fuel plants. ... “Our analysis continues to show that instead of continuing to run all the time, there will be parts of the year where Diablo will not be needed,” said Earley, who flew to San Luis Obispo to break the news to Diablo’s 1,500 employees in a series of staff meetings Tuesday. “At a plant like Diablo, with large fixed costs, if you effectively only run the plant half the time, you’ve doubled the cost.” }}

PG&E's CEO stated: “I am sorry to see it go, because from a national energy policy standpoint, we need greenhouse gas-free electricity,” Earley said. “But we are regulated by the state of California, and California’s policies are driving this."{{ r | SFC_2016-06-21 }}

Specifically, the operating licenses for Diablo Canyon Units 1 and 2 would not be renewed when they expire on November 2, 2024 and August 26, 2025, respectively. PG&E's application to close Diablo Canyon, including the Joint Proposal, was approved by the California Public Utilities Commission in January 2018. In February, PG&E withdrew its application to the Nuclear Regulatory Commission for a licensing extension.{{cite news |url=http://www.world-nuclear-news.org/C-PGE-accepts-Diablo-Canyon-decision-1302187.html |title=PG&E accepts Diablo Canyon decision |publisher=World Nuclear News |date=13 February 2018 |access-date=13 February 2018}}

In October 2020, experts at the California Independent System Operator (CAISO) warned that when the plant retires the state will reach a "critical inflection point", which will create a significant challenge to ensure reliability of the grid without resorting to more fossil fuel usage, and could jeopardize California's greenhouse gas reduction targets.{{ cite web | url=http://www.caiso.com/Documents/Oct23-2020_Comments-on-Integrated-Resource-Planning-R20-05-003.pdf | title=COMMENTS OF THE CALIFORNIA INDEPENDENT SYSTEM OPERATOR CORPORATION | last= | first= | work=California Independent System Operator | date=2020-10-23 | archive-url=https://web.archive.org/web/20201101143353/http://www.caiso.com/Documents/Oct23-2020_Comments-on-Integrated-Resource-Planning-R20-05-003.pdf | archive-date=2020-11-01 | url-status=live }}{{ cite news | url=https://www.utilitydive.com/news/californias-last-nuclear-plant-is-poised-to-shut-down-what-happens-next/596970/ | title=California's last nuclear plant is poised to shut down. What happens next? – A large amount of carbon-free energy will come offline once the Diablo Canyon power plant retires, raising questions around how the state will replace it. | last=Balaraman | first=Kavya | newspaper=UtilityDive | date=2021-03-23 | quote=Last October, the California Independent System Operator (CAISO) warned in a filing that the system will hit a "critical inflection point" after the nuclear plant retires, with resource needs that are much higher than initially anticipated to ensure reliability. ... Diablo Canyon's retirement could also jeopardize California's GHG emission goals. California enacted legislation in 2018 that requires state regulators to prevent the plant's closure from leading to an increase in emissions. But without enough planning, natural gas power plants could step in to fill the gap, leading to a potential 15.5 million metric tons of additional GHG emissions between now and the end of the decade, according to a report from UCS – roughly equivalent to the impact of 306,000 gasoline passenger vehicles during the same period. }}{{ cite news | url=https://www.latimes.com/business/story/2021-05-18/california-climate-change-nuclear-power-plant | title=California's next climate challenge: Replacing its last nuclear power plant | last=Roth | first=Sammy | newspaper=Los Angeles Times | date=2021-05-18 | quote=But with just three years until the plant begins to power down, California has no plan to directly replace it. That’s despite a state law, overwhelmingly approved by the Legislature and signed by Brown, ordering regulators to “avoid any increase in emissions of greenhouse gases” as a result of Diablo’s closure. It’s common for nuclear shutdowns to be followed by a jump in pollution as fossil fueled power plants fire up more often. ... That’s the problem in California, where officials acknowledge the state is likely to burn more gas after Diablo goes offline. In a recent report studying the possible closure of the Aliso Canyon gas storage facility outside Los Angeles, the Public Utilities Commission cited Diablo’s retirement as one of several reasons gas demand is expected to increase in the coming years. }}

According to David G. Victor, professor of innovation and public policy at UC San Diego: "The politics against nuclear power in California are more powerful and organized than the politics in favor of a climate policy."{{ cite news | url=https://www.cnbc.com/2021/10/02/why-is-california-closing-diablo-canyon-nuclear-plant.html | title=Why California is shutting down its last nuclear plant | last=Clifford | first=Catherine | newspaper=CNBC | date=2021-10-02 | access-date= | pages= | quote=The picture is confusing: California is closing its last operating nuclear power plant, which is a source of clean power, as it faces an energy emergency and a mandate to eliminate carbon emissions. Why? The explanations vary depending on which of the stakeholders you ask. But underlying the statewide diplomatic chess is a deeply held anti-nuclear agenda in the state. "The politics against nuclear power in California are more powerful and organized than the politics in favor of a climate policy," David Victor, professor of innovation and public policy at the School of Global Policy and Strategy at UC San Diego, told CNBC. }}

A 2021 report from researchers at MIT and Stanford states that keeping Diablo Canyon running until 2035 would reduce the state's carbon emissions from electricity generation by 11% every year, save the state a cumulative $2.6 billion, and improve the reliability of the grid.{{ r | Economist_2021-11-10 | LAT_2021-11-14 }} They state that three factors have changed since the 2018 decision to close the plant: the state passed a new law (sb100) which requires 100% emissions-free electricity generation by 2045, the whole western US region is in a continuing mega-drought (limiting hydroelectric generation), and demand for electricity has outpaced supply, especially during heatwaves.{{ cite news | url=https://www.economist.com/united-states/will-the-climate-crisis-force-america-to-reconsider-nuclear-power/21806194 | title=Will the climate crisis force America to reconsider nuclear power? - Reaching net-zero targets will be much harder without it | last= | first= | newspaper=The Economist | date=2021-11-10 | quote=Yet despite California’s aggressive climate goals and a national push to reach net-zero emissions by 2050, Diablo Canyon is set to close down by 2025. A new report from researchers at Stanford University and the Massachusetts Institute of Technology (MIT) reveals just how detrimental that would be. ... These three trends led researchers to ponder how keeping the plant running might change California’s energy outlook. They found that to keep it going to 2035, ten years past its current operating licence issued by the NRC, would cut emissions, bolster the grid’s reliability and save the state $2.6bn. The analysis shows that Diablo’s continued operation would reduce the carbon emissions from power generation by 11% each year from 2017 levels. }} They also stated that keeping Diablo operating until 2045 would save the state a cumulative $21 billion.{{ cite news | url=https://www.bloomberg.com/news/articles/2021-11-08/keep-california-s-last-nuke-to-save-cash-fight-warming-study | title=Keeping California's Last Nuclear Plant Can Save Money, Climate: MIT-Stanford Study | last=Baker | first=David | newspaper=Bloomberg News | date=2021-11-09 | quote=Researchers from Stanford University and the Massachusetts Institute of Technology said in the study released Monday that keeping Diablo Canyon open through 2035 would cut greenhouse-gas emissions from California’s power sector 10% each year, by reducing the amount of electricity needed from natural-gas plants. It would also save $2.6 billion for utility ratepayers. Keep Diablo Canyon open until 2045, and the savings would grow to $21 billion, they said. }}

Steven Chu, energy secretary in the Obama administration, endorsed the study and said: “We are not in a position in the near-term future to go to 100% renewable energy, and there will be times when the wind doesn’t blow, the sun doesn’t shine and we will need some power that we can turn on and dispatch at will, and that leaves two choices: fossil fuel or nuclear" and he noted that countries that have shut down their nuclear plants have ended up using more fossil fuels.{{ r | LAT_2021-11-14 | BB_2021-11-09 | EENews_2021-11-10 }} He also called the decision to shutdown the plant "distressing" and said “Nuclear power is something we should reconsider, and we should ask PG&E to reconsider.”{{ r | BB_2021-11-09 | EENews_2021-11-10 }}

Some of the continued generation from the plant could be used for relieving the drought-caused water shortages by powering a desalination plant (costing half as much as the Carlsbad desalination plant for the same capacity), or to generate hydrogen as a carbon-free fuel for manufacturing and transportation uses, at half the cost of producing it with wind or solar power, with a smaller land footprint.{{ r | Economist_2021-11-10 }}{{ cite news | url=https://www.latimes.com/california/story/2021-11-14/should-californias-last-nuclear-power-plant-stay-open | title=Keeping California's last nuclear power plant open could help state meet its climate goals, study says | last=Nikolewski | first=Rob | newspaper=Los Angeles Times | date=2021-11-14 | quote=The report analyzed various scenarios and concluded that keeping Diablo Canyon running would “significantly reduce California’s use of natural gas for electricity” and save $2.6 billion in costs to the state’s power system from 2025 to 2035. The 2,240 megawatts of electricity generated by the plant can also help grid operators avoid blackouts, such as the statewide outages experienced in August 2020. }}{{cite news | url=https://www.eenews.net/articles/calif-s-last-nuclear-plant-needed-for-100-clean-grid-experts/ | title=Calif.'s last nuclear plant needed for 100% clean grid — experts | last=Mulkern | first=Anne | newspaper=E&E News | date=2021-11-10 | quote=It would also reduce reliance on natural gas, save $2.6 billion in power system costs and bolster system reliability, it said. Keeping the plant open through 2045 and beyond would save up to $21 billion in power system costs, and spare 90,000 acres of land from use for energy production, it said. ... As well, a hydrogen plant connected to Diablo Canyon could help the state meet growing demand for zero-carbon fuels, the report said, noting that it could cost half as much as hydrogen produced using solar and wind power, and with a smaller land footprint.}}

In October 2021 the California Energy Commission and CAISO stated that the state may have summer blackouts in future years as a result of Diablo's closure coinciding with the shutdown of four natural gas plants of 3.7GW total capacity, and inability to rely on imported electricity during West-wide heat waves.{{ r | WSJ_2021-10-16 }} (The reduction of importable electricity is due to both the decades-long drought reducing hydroelectric capacity, and the closing of coal plants.){{Cite Q|Q114357328|access-date=2022-10-02 | quote=While the companies are moving quickly to contract for power, the California Energy Commission and the state’s grid operator have recently expressed concern that the purchases may not be enough to prevent electricity shortages in coming summers. ... The drought has constrained the output of some of the region’s most significant generating facilities, including the Hoover Dam. On top of that, other states have moved to close coal-fired power plants in recent years, reducing the amount of electricity California can import when high temperatures boost electricity demand. “What changed dramatically…is we have had significantly bigger and more West-wide heat waves than ever before,” Mr. Randolph said. “Those aren’t built into our planning standards.” ... The state is also preparing for the closure of four gas-fired power plants on the Southern California coast that together supply more than 3,700 megawatts. The plants had been slated to close last year, but regulators moved to keep one online through 2021 and the other three through 2023 out of concern that California could face electricity shortages on hot days in the evening, when solar power production declines.}}

In a November 2021 opinion article, the editorial board of The Washington Post said: "If the state is serious about achieving carbon neutrality over the next few decades — and it should be — it cannot start by shutting down a source of emissions-free energy that accounts for nearly 10 percent of its in-state electricity production. A new report from experts at the Massachusetts Institute of Technology and Stanford University has made that point clearly: Closing down Diablo Canyon would be the definition of climate incoherence." and "The report finds that without Diablo Canyon, the state’s electricity shortage would have been three times as severe during [2020]’s massive blackouts." and "Closing Diablo Canyon would make the state’s energy transition costlier, longer and more chaotic."{{ cite news | url=https://www.washingtonpost.com/opinions/2021/11/16/closing-californias-last-nuclear-power-plant-would-be-mistake/ | title=Opinion: Closing California's last nuclear power plant would be a mistake |author=Editorial Board | newspaper=The Washington Post | date=2021-11-16 }}

In February 2022 a group of 79 scientists published an open letter highlighting that the plant provides 18 TWh of low-carbon electricity annually and its closure is at odds with decarbonization goals.{{Cite web|title=Keep Diablo Canyon open, 79 scientists, academics and entrepreneurs tell Newsom|url=https://www.sanluisobispo.com/news/local/article258017318.html }}

In response to these concerns, in August 2022 California Governor Gavin Newsom proposed providing PG&E with a $1.4 billion loan to support the continued operation of Diablo Canyon for another 5 to 10 years.

{{cite news

| url = https://apnews.com/article/california-legislature-gavin-newsom-climate-and-environment-4968ee9da7fd1d10ad67bfdf03950873

| title = California governor proposes extending nuclear plant's life

| first = Michael | last = Blood

| date = August 12, 2022 | work = The Associated Press

| access-date = 2022-08-16 }}

The California Legislature approved the loan on September 1 with the passage of Senate Bill 846. The bill also charged the California Public Utilities Commission with monitoring cost increases that might make the plant uneconomical to operate and to close the plant if its operations “prove to be economically disadvantageous, or even financially catastrophic, for California electricity consumers”.{{Cite web |last=Hodgson |first=Mike |date=November 1, 2022 |title=PG&E files first documents with NRC seeking process for relicensing Diablo Canyon |url=https://santamariatimes.com/news/local/govt-and-politics/pg-e-files-first-documents-with-nrc-seeking-process-for-relicensing-diablo-canyon/article_cf141180-1240-5532-8223-5136edcdc65e.html |access-date=2022-11-03 |website=Santa Maria Times |language=en}} PG&E is also expected to seek funding from a $6 billion federal program intended to support the continued operation of nuclear plants facing closure.

{{cite news

| url = https://www.latimes.com/environment/story/2022-04-29/california-promised-to-close-its-last-nuclear-plant-now-newsom-is-reconsidering

| title = California promised to close its last nuclear plant. Now Newsom is reconsidering

| first = Sammy | last = Roth

| date = April 29, 2022 | work = The Los Angeles Times

| access-date = 2022-08-16 }}

{{cite news |title=California unveils proposal to keep Diablo Canyon nuclear plant open with $1.4B loan to PG&E |url=https://www.utilitydive.com/news/california-diablo-canyon-nuclear-plant-open-newsom-bill/629727/ |work=Utility Dive |date=16 August 2022}}

{{cite news |last=Plumer |first=Brad |date=September 1, 2022 |title=California Approves a Wave of Aggressive New Climate Measures |work=The New York Times |url=https://www.nytimes.com/2022/09/01/climate/california-lawmakers-climate-legislation.html |access-date=2022-09-01}}

{{cite news |last=Purper |first=Benjamin |date=1 September 2022 |title=California lawmakers move to keep the state's last nuclear plant open |work=NPR News |url=https://www.npr.org/2022/09/01/1119778975/california-lawmakers-extend-the-life-of-the-states-last-nuclear-power-plant}} PG&E asked the NRC in October 2022 to resume consideration of a license renewal application initially submitted in 2009.{{Cite web |date=February 13, 2023 |title=Bid to keep Diablo Canyon reactors running faces time squeeze |url=https://www.ksby.com/news/local-news/bid-to-keep-california-reactors-running-faces-time-squeeze |access-date=2023-02-14 |website=KSBY |agency=Associated Press}} Regulatory approvals will also be needed from the U.S. Department of Energy, California State Lands Commission, California Energy Commission, California Coastal Commission, and California Public Utilities Commission.{{Cite web |last=Worsham |first=Katherine |date=October 31, 2022 |title=PG&E files for renewal of Diablo Canyon Power Plant licenses |url=https://www.ksby.com/news/local-news/pg-e-files-for-renewal-of-diablo-canyon-power-plant-licenses |access-date=2022-11-01 |website=KSBY}}{{Cite web |last=Roth |first=Sammy |date=2023-03-02 |title=PG&E can keep operating Diablo Canyon — at least for now, feds say |url=https://www.latimes.com/business/story/2023-03-02/pg-e-can-keep-operating-diablo-canyon-feds-say-at-least-for-now |access-date=2023-03-03 |website=Los Angeles Times |language=en-US}}

The Department of Energy approved $1.1 billion in funding in November from the Civil Nuclear Credit program which was included in the Infrastructure Investment and Jobs Act.{{Cite web |last=Calma |first=Justine |date=2022-11-22 |title=California's last operating nuclear plant just got a $1.1 billion lifeline |url=https://www.theverge.com/2022/11/22/23473116/diablo-canyon-nuclear-power-plant-california-energy-department-biden-funding |access-date=2022-11-23 |website=The Verge |language=en-US}}

{{Further|Energiewende}}

File:Energiemix Deutschland.svg

In 2011, Angela Merkel announced that Germany would shut down all its nuclear plants (which at the time generated 25% of the country's electricity) by 2022 and replace that lost generation with renewables. The nuclear reductions that have taken place have resulted in 27% of the country's electricity coming from coal, and increased usage of natural gas, with 40% of that coming from Russia.{{ r | Atlantic_2021-12-08 }} David Frum states that Americans, particularly Californians, should take a lesson from this as it relates to Diablo Canyon's scheduled closure.{{ cite news | url=https://www.theatlantic.com/ideas/archive/2021/12/germany-california-nuclear-power-climate/620888/ | title=The West's Nuclear Mistake - No government that really regarded climate change as its top energy priority would close nuclear plants before the end of their useful lives. | last=Frum | first=David | author-link=David Frum | newspaper=The Atlantic | date=2021-12-08 | quote=Germany has reduced its greenhouse-gas emissions. [From] 2011 [to] 2019, it emitted about 810 million metric tons, an 11.7 percent reduction. That’s a better record than that of the United States, but it pales before nuclear-using Britain, which cut its emissions over the same period by more than 21 percent, a number that suggests what Germany might have accomplished had Merkel chosen a different course. This is a lesson Americans should consider too. The state of California, once a nuclear leader, has decommissioned three of its four nuclear plants, and is planning to close its last in the middle of this decade. Those plants have fallen victim to the same post-Fukushima anxiety that ended Germany’s nuclear era. Their closures portend equally grave consequences for California’s postcarbon future. The still-operating Diablo Canyon plant alone produces about 9 percent of California’s electricity. If Diablo Canyon goes offline in 2024 or 2025, filling that gap will almost certainly require burning more gas. Gas already provides 37 percent of California’s electricity; solar and wind together provide only about 24 percent. In the near term, less nuclear means more gas. }}

{{Main|Diablo Canyon earthquake vulnerability}}

Diablo Canyon was originally designed to withstand a 6.75 magnitude earthquake from four faults, including the nearby San Andreas Fault and Hosgri Fault,{{cite news| url=http://www.time.com/time/magazine/article/0,9171,917988,00.html | archive-url=https://web.archive.org/web/20090326060511/http://www.time.com/time/magazine/article/0,9171,917988,00.html | url-status=dead | archive-date=March 26, 2009 | magazine=Time | title=Energy: A Nuclear Horror | date=February 9, 1976 | access-date=July 14, 2010}} but was later upgraded to withstand a 7.5 magnitude quake.{{cite news | author=David Sneed | title=Diablo Canyon workshop to focus on earthquakes | work=The San Luis Obispo Tribune | date=August 9, 2011 | url=http://www.sanluisobispo.com/2010/08/08/1244213/diablo-canyon-workshop-september.html | access-date=March 19, 2011 | archive-url=https://web.archive.org/web/20110317193217/http://www.sanluisobispo.com/2010/08/08/1244213/diablo-canyon-workshop-september.html | archive-date=March 17, 2011 | url-status=dead }} It has redundant seismic monitoring and a safety system designed to shut it down promptly in the event of significant ground motion.

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 (CPUC), the Attorney General for the State of California, and Pacific Gas and Electric Company (PG&E). It 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.

The Nuclear Regulatory Commission defines two emergency planning zones around nuclear power plants: a plume exposure pathway zone with a radius of {{convert|10|mi}}, concerned primarily with exposure to, and inhalation of, airborne radioactive contamination, and an ingestion pathway zone of about {{convert|50|mi}}, concerned primarily with ingestion of food and liquid contaminated by radioactivity.{{cite web

| url=https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/emerg-plan-prep-nuc-power.html

| title=Backgrounder on Emergency Preparedness at Nuclear Power Plants

| date=2015-08-05

| publisher=Nuclear Regulatory Commission

| access-date=2016-12-12}}

The 2010 U.S. population within {{convert|10|mi}} of Diablo Canyon was 26,123, an increase of 50.2% in a decade, according to an analysis of U.S. Census data for msnbc.com. The 2010 U.S. population within {{convert|50|mi}} was 465,521, an increase of 22.4% since 2000. Cities within 50 miles include San Luis Obispo (12 miles to city center) and Paso Robles (31 miles to city center).{{Cite web |date=2011-04-14 |title=Nuclear neighbors: Population rises near US reactors |url=https://www.nbcnews.com/id/wbna42555888 |access-date=2024-08-16 |website=NBC News |language=en}}

Emergency sirens were installed when the plant initially went operational. Federal law requires an early warning system that radiates out 10 miles from any nuclear facility. The county siren coverage goes farther, extending from Cayucos in the north to upper Nipomo to the south. All businesses are required to have a siren information sticker in their business generally located within 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 itself. The cards also show the direction of evacuation on the highways.

{{Portal|California|Energy|Nuclear technology}}

{{Commons category|Diablo Canyon Power Plant}}

• Critical Masses: Opposition to Nuclear Power in California, 1958–1978 {{ISBN|0299158543}}
• Dark Circle (film)
• Economics of nuclear power plants
• John Gofman
• List of articles associated with nuclear issues in California
• Nuclear policy in the United States
• Largest nuclear power plants in the United States

{{Reflist}}

• {{cite web | url= http://www.eia.gov/cneaf/nuclear/state_profiles/california/ca.html#_ftn1 | title= California Nuclear Profile – Diablo Canyon Nuclear Power Plant | date= September 2010 | publisher= Energy Information Administration, U.S. Department of Energy (DOE) | access-date= January 21, 2011 }}
• {{cite web | url= https://www.nrc.gov/info-finder/reactor/diab1.html | title= Diablo Canyon 1 Pressurized Water Reactor | date= February 14, 2008 | work= Operating Nuclear Power Reactors | publisher= U.S. Nuclear Regulatory Commission (NRC) | access-date= November 25, 2008 }}
• {{cite web | url= https://www.nrc.gov/info-finder/reactor/diab2.html | title= Diablo Canyon 2 Pressurized Water Reactor | date= February 14, 2008 | work= Operating Nuclear Power Reactors | publisher= NRC | access-date= November 25, 2008 }}

{{Wikibooks}}

• [https://www.pge.com/en_US/safety/how-the-system-works/diablo-canyon-power-plant/diablo-canyon-power-plant.page PG&E Diablo Canyon]
• [http://www.directaction.org/handbook/ Activist handbooks from 1979 and 1981 Diablo Canyon protests]

{{Generating stations in California|state=autocollapse}}

{{U.S. nuclear plants}}

{{U.S. anti-nuclear}}

{{Authority control}}

Category:Energy infrastructure completed in 1985

Category:Energy infrastructure completed in 1986

Category:Buildings and structures in San Luis Obispo County, California

Category:Nuclear power plants in California

Category:Nuclear power stations using pressurized water reactors

Category:Pacific Gas and Electric Company

Category:Anti-nuclear protests in the United States

Category:1985 establishments in California