View source for Rancho Seco Nuclear Generating Station

{{Short description|Decommissioned power plant in California, US}}
{{Infobox power station
| name = Rancho Seco Nuclear Generating Station
| image = Rancho Seco Nuclear Generating Station.jpg
| image_caption = 
| country = United States
| location = [[Herald, California]]
| coordinates = {{coord|38|20|43|N|121|7|18|W|region:US-CA_type:landmark|display=inline,title}}
| owner = 
| operator = [[SMUD]] 1974-present
| employees = 
| construction_began = 
| commissioned = April 17, 1975
| decommissioned = June 23, 1989
| np_reactor_supplier = [[Babcock & Wilcox]]<ref name=nrcappendix />
| np_reactor_type = [[Pressurized water reactor]]<ref name=nrcappendix>{{Cite web|url=https://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1437/v2/#_1_55|title=NRC: Generic Environmental Impact Statement for License Renewal of Nuclear Plants: Appendices (NUREG-1437, Volume 2)|website=www.nrc.gov|access-date=2020-01-03}}</ref>
| ps_units_decommissioned = 
| ps_units_uc = 
| ps_units_manu_model = 
| ps_units_planned = 
| ps_thermal_capacity = 1 x 2772 MW<sub>th</sub><ref name=nrcappendix />
| ps_electrical_capacity = 918<ref name=nrcappendix />
| ps_electrical_cap_fac = <40%<ref name=NYT_plant_shutdown />
| status = D
| ps_units_operational = 
| cost = $375 million in 1974 dollars<ref name=NYT_plant_shutdown />
(${{format price|{{Inflation|US-GDP|375000000|1974}}}} in {{Inflation-year|US-GDP}} dollars{{Inflation-fn|US-GDP}})
| ps_annual_generation = 
| website = 
}}

The '''Rancho Seco Nuclear Generating Station''' is a [[nuclear decommissioning|decommissioned]] [[nuclear power plant]] built by the [[Sacramento Municipal Utility District]] (SMUD) in [[Herald, California]].

==History==
In 1966, SMUD purchased {{convert|2100|acre}} in southeast [[Sacramento County, California|Sacramento County]] for a [[nuclear power]] plant, which was built in Herald, {{convert|25|mi|km|0}} south-east of downtown Sacramento.<ref name=CapRadio > {{ cite news | url=https://www.capradio.org/articles/2019/11/05/thirty-years-after-sacramento-voted-to-shut-it-down-rancho-seco-reinventing-itself-while-dealing-with-nuclear-past/ | title=Thirty Years After Sacramento Voted To Shut It Down, Rancho Seco Reinventing Itself While Dealing With Nuclear Past | last=White | first=Randol | date=2019-11-05 | access-date=2020-09-24 | quote=In the 1960s, the Sacramento Municipal Utilities District (SMUD) purchased 2,100 acres about an hour southeast of Sacramento to build Rancho Seco. ... Even if you’ve never been near the plant, you may have seen its twin cooling towers. At 425 feet, they’re the tallest buildings in the Central Valley, just edging out Sacramento’s Wells Fargo Tower. ... Rancho Seco is now home to a natural gas plant, a solar field, and construction is getting underway to create a second array, the largest solar project in the county. }} </ref>

In the early 1970s, a small pond was expanded to a {{convert|160|acre|adj=on}} lake to serve as an emergency backup water supply for the station. The lake has always received its water from the Folsom South Canal and has no relationship with the power plant's daily water supply. Surrounding the lake is {{convert|400|acre}} of recreational area originally operated by the County of Sacramento for day-use activities.

The 2,772&nbsp;MWt [[Babcock & Wilcox]] pressurized water reactor (913 MWe) achieved initial criticality on September 16, 1974, and entered commercial operation on April 17, 1975.<ref name=nrcappendix />

On March 20, 1978, a power supply failure for the plant's non-nuclear instrumentation system led to steam generator dryout (ref NRC LER 312/78-001). This triggered an automatic reactor shutdown. In a 2005 document, the [[United States Nuclear Regulatory Commission]] indicated that it was the third most serious safety-related occurrence in the United States as of 2005 (behind the [[Three Mile Island accident]] and the [[Browns Ferry Nuclear Power Plant|Browns Ferry]] cable tray fire).<ref>{{Cite web|title=Policy Issue Information|url=https://www.nrc.gov/reading-rm/doc-collections/commission/secys/2005/secy2005-0192/2005-0192scy.pdf|publisher=United States NRC}}</ref><ref>{{Cite web|url=https://www.nrc.gov/reading-rm/doc-collections/commission/secys/2005/secy2005-0192/attachment2.pdf|title=Attachment 2 Policy Issue Information|publisher=U.S. Nuclear Regulatory Commission|url-status=live|archive-url=https://web.archive.org/web/20081020224150/http://www.nrc.gov/reading-rm/doc-collections/commission/secys/2005/secy2005-0192/attachment2.pdf|archive-date=20 October 2008|access-date=30 August 2010|quote=When the reactor was at power, a failure of the NNI power supply resulted in a loss of main feedwater, which caused a reactor trip. Because instrumentation drift falsely indicated that the steam generator  contained enough water, control room operators did not take prompt action to open the EFW flow control valves to establish secondary heat removal. This resulted in steam generator dryout. LER 312/78-001}}</ref> The U.S. Nuclear Regulatory Commission (NRC) staff concluded that fundamental design flaws which were known by plant operators and the NRC itself were at the heart of the problem and should have been fixed years before. “In summary, the information was available and known which could have prevented this overcooling transient; but in the absence of adequate plant modifications, the incident should have been expected,” the staff wrote.  <ref>{{Cite web|url=http://www.ca.allgov.com/news/controversies/less-cancer-found-after-rancho-seco-nuclear-plant-closes-130402?news=849611|title = Less Cancer Found after Rancho Seco Nuclear Plant Closes}}</ref>  

The plant operated from April 1975 to June 1989, with a lifetime [[capacity factor]] of less than 40%; it was closed by public vote in June 1989 (53% to 47%) after half of its intended lifetime primarily for economic reasons: ratepayers had seen their rates doubled in the last four years to pay for improvements to the plant, and electricity from natural gas was priced at half that of the electricity generated by Rancho Seco. (2.3 cents / kWh, vs. 5.4 cents / kWh){{ r | NYT_plant_shutdown }}

All power-generating equipment has been removed from the plant, and the {{convert|425 |foot ||adj=mid| high}} cooling towers remain a prominent part of the local landscape as the tallest buildings in the [[Central Valley (California)|Central Valley]].{{ r | CapRadio }} Also scattered throughout the area around the plant are abandoned [[civil defense siren]]s that at one time would have warned people of a radioactivity release from the station. Additions to SMUD's Rancho Seco property have included an 11 MW solar installation and, in 2006, the 600 MW natural gas-fired Cosumnes Power Plant.<ref name=BJ_1 > {{ cite news | url=https://www.bizjournals.com/sacramento/news/2019/05/30/smud-set-to-develop-its-largest-solar-array-with.html | title=SMUD set to develop its largest solar array with Lendlease | last=Anderson | first=Mark | newspaper=Sacramento Business Journal  | date=2019-05-30 | access-date=2020-09-23 | quote=SMUD currently operates a 10.9-megawatt solar array at Rancho Seco. }} </ref><ref>{{Cite web|url=https://www.smud.org/en/Corporate/Environmental-Leadership/Power-Sources|title=Power Sources|website=www.smud.org|access-date=February 15, 2020 | quote=Our biggest single source is the Cosumnes Power Plant and we are always adding to our green energy sources. ... To offer the best price and reliability we completed the 530-megawatt Cosumnes Power Plant in 2006 which is one of the most clean and efficient plants in the western states.  After recent plant upgrades, the Cosumnes plant can now generate up to 600 MW with even better efficiency }}</ref><ref>{{Cite web|url=https://www.eia.gov/electricity/data/browser/#/plant/55970|title=Electricity Data Browser - Cosumnes|website=www.eia.gov|access-date=February 17, 2020}}</ref>

On October 23, 2009, the Nuclear Regulatory Commission released the majority of the site for unrestricted public use, while approximately {{convert|11|acre}} of land including a storage building for low-level radioactive waste and a dry-cask spent fuel storage facility remain under NRC licenses.<ref name="power261009">{{Cite news|url=http://pepei.pennnet.com/display_article/370365/6/ARTCL/INDUS/1/Rancho-Seco-nuclear-power-plant-ends-decommissioning/|title=Rancho Seco nuclear power plant ends decommissioning|date=2009-10-26|work=Power Engineering|publisher=PennWell|access-date=2009-10-30}}
</ref>

According to a study published in the journal ''Biomedicine International'', the statistically significant drop in cancer rates observed in Sacramento County between 1988 and 2009 (plant closed in 1989) might be partially attributable to the closure of the Rancho Seco plant, and the resultant decline in nuclear emissions.<ref>{{cite journal |last1=Mangano |first1=Joseph J. |last2=Sherman |first2=Janette D. |title=Open Journal Systems |journal=Biomedicine International |date=3 May 2013 |volume=4 |issue=1 |url=http://www.bmijournal.org/index.php/bmi/article/view/115/ |access-date=13 August 2018 | quote=Many factors can result in lower cancer incidence over two decades, but elimination of radioactive isotopes should be addressed as one of these potential factors in future reports.}}</ref><ref>{{cite web |last1=Nelson |first1=Roxanne  |title=Cancer Rates Drop After Nuclear Reactor Closes |url=https://www.medscape.com/viewarticle/781880 |access-date=19 August 2020 | quote=The closure of a nuclear reactor could be linked to a long-term decrease in the incidence of cancer. ... "We believe that further research is now warranted to see if there is a cause and effect relation between the elimination of nuclear emissions from power plants and a significant long-term decline of cancers," Mangano said during a press briefing. The Rancho Seco reactor was chosen for the study because of the long post-shutdown period, the availability of county-specific incidence data since before the plant closed, and the fact that there are no other major reactors within 200 miles, he explained.}}</ref> The result has been questioned by radiation expert and health physicist Robert Emery, who suggested it being the result of the [[sharpshooter fallacy]] and highlighted the author Joseph Mangano's history of exaggerated claims about radiological risks.<ref>{{Cite web|last=Fecht|first=Sarah|date=2014-04-08|title=What Can We Do About Junk Science?|url=https://www.popularmechanics.com/science/health/what-can-we-do-about-junk-science-16674140|access-date=2022-02-08|website=Popular Mechanics|language=en-US}}</ref>

The plant cost $375 million<ref name=NYT_plant_shutdown>{{Cite news|url=https://www.nytimes.com/1989/06/08/us/voters-in-a-first-shut-down-nuclear-reactor.html|title=Voters, in a First, Shut Down Nuclear Reactor|last=Wald|first=Matthew L.|date=1989-06-08|newspaper=The New York Times|issn=0362-4331|access-date=2016-07-09 | archive-url=https://web.archive.org/web/20150525112512/https://www.nytimes.com/1989/06/08/us/voters-in-a-first-shut-down-nuclear-reactor.html | archive-date=2015-05-25 | url-status=live | quote=The Sacramento Municipal Utility District, the public agency that owns the Rancho Seco plant, promptly began shutting it down yesterday after the nuclear industry's $580,000 campaign to keep it open had failed to overcome arguments based less on the environment and safety than on economics: the troubled plant could not provide electricity at competitive cost. The vote, by which the utility district's board had agreed to abide, was 53.4 percent to shut the plant and 46.6 percent to keep it open. ... Opponents of the plant, including two members of the district's five-member board, argued that despite $400 million in new investment in the last three years, it would be far cheaper to retire it now, halfway through its expected life span, and buy power from neighboring utilities in the California market, which is glutted with electricity. }}</ref> when it was built in 1974 (${{format price|{{Inflation|US-GDP|375000000|1974}}}} in {{Inflation-year|US-GDP}} dollars{{Inflation-fn|US-GDP}}) and it cost about $120 million in 1974 dollars to decommission (${{format price|{{Inflation|US-GDP|120000000|1974}}}} in {{Inflation-year|US-GDP}} dollars{{Inflation-fn|US-GDP}}), according to the SMUD Rancho Seco Nuclear Education Center.

==Gallery==
<gallery widths="230px" heights="220px">
File:Rancho-Seco-power-plant-California new.jpg|Rancho Seco nuclear power plant (2007)
File:Rancho Seco Park.jpg|Rancho Seco towers
File:Ranchoseco.jpg|The containment building with a part of the cooling tower
File:Rancho Seco cooling tower, 2014.jpg|One of the two cooling towers, showing the base
File:RanchoSecosiren.jpg|One of the many sirens Rancho Seco had
File:Rancho Seco Nuclear Power Plant 20150201.jpg|Rancho Seco from the air in 2015
</gallery>

==See also==
{{stack|{{Portal|California|Energy|Nuclear technology}}}}
*[[Rancho Seco Recreational Park]]
*[[S. David Freeman]], former SMUD leader, notable for his involvement in the decommissioning of the plant.

{{commons category}}

==References==
{{Reflist}}

==External links==
*[https://web.archive.org/web/20050819234012/http://www.nukeworker.com/nuke_facilities/North_America/usa/NRC_Facilities/Region_4/rancho_seco/index.shtml Report on Rancho Seco from nukeworker.com]
*[https://web.archive.org/web/20060222090047/http://www.jbsinstruments.com/Energy/Papers/Rancho_Seco/rancho_seco.html Rancho Seco &ndash; 10 years after pulling the plug: A recharged SMUD seeing better times]
*[https://www.nrc.gov/info-finder/decommissioning/power-reactor/rancho-seco-nuclear-generating-station.html  NRC Rancho Seco]

{{U.S. anti-nuclear}}
{{U.S. Nuclear Plants}}

{{authority control}}

[[Category:Nuclear power plants in California]]
[[Category:Buildings and structures in Sacramento County, California]]
[[Category:Sacramento Municipal Utility District]]
[[Category:Former nuclear power stations in the United States]]
[[Category:Nuclear power stations using pressurized water reactors]]
[[Category:Energy infrastructure completed in 1975]]
[[Category:1975 establishments in California]]
[[Category:Energy infrastructure closed in the 1980s]]
[[Category:1989 disestablishments in California]]