Fort Calhoun Nuclear Generating Station

Fort Calhoun Nuclear Power Plant

Fort Calhoun plant, seen from U.S. Highway 75
Location of Fort Calhoun Nuclear Power Plant in Nebraska
Country United States
Location Washington County, near Blair, Nebraska
Coordinates 41°31′13″N 96°4′38″W / 41.52028°N 96.07722°W / 41.52028; -96.07722Coordinates: 41°31′13″N 96°4′38″W / 41.52028°N 96.07722°W / 41.52028; -96.07722
Status Inactive
Construction began 1966
Commission date August 9, 1973
Decommission date October 24, 2016
Owner(s) Omaha Public Power District
Operator(s) Exelon Nuclear Partners
Nuclear power station
Reactor type Pressurized Water Reactor (PWR)
Reactor supplier Combustion Engineering
Power generation
Units decommissioned 1 x 476 MW
Website
www.oppd.com/AboutUs/22_002696

The Fort Calhoun Nuclear Generating Station is a shut down nuclear power plant located on 660 acres (2.7 km2) between Fort Calhoun, and Blair, Nebraska adjacent to the Missouri River between mile markers 645.6 and 646.0. The utility has an easement for another 580 acres (2.3 km2) which is maintained in a natural state. The power plant is owned by the Omaha Public Power District of Omaha, Nebraska and operated by Exelon Nuclear Partners. When operational, the plant accounts for 25 percent of OPPD's net generation capabilities,[1] but was shut down from April 2011 to December 2013 because regulators had found several problems.[2] The plant was cleared to restart in December 2013.[3]

This plant has one Combustion Engineering pressurized water reactor generating 484 megawatts of electricity.[4] This is currently the smallest rated capacity among all operating commercial power reactors in North America, and as a single-unit plant, this also qualifies it as the smallest rated capacity nuclear power plant. OPPD's two Nebraska City coal-fired plants at 682 (opened 2009) and 649 (opened 1979) MW are both significantly larger.[1][5]

Fort Calhoun houses spent fuel rods in a 40-foot (12 m) deep spent fuel pool next to the reactor, and when the pool had nearly reached capacity in 2006, OPPD began to store spent fuel rods above ground in dry cask storage as well. In total, the Ft. Calhoun reactor has 600,000 to 800,000 pounds (270,000 to 360,000 kg) of high level nuclear waste.[6] The storage was not designed to house spent fuel permanently, but when plans for Yucca Mountain nuclear waste repository were terminated, OPPD stated that they are "prepared to safely store material on-site as long as necessary".[7]

The plant underwent refurbishment in 2006 by having its steam generators, pressurizer, reactor vessel head, low pressure turbines and main transformer replaced. In 2003, the plant had its operating license renewed for an additional twenty years. With the renewal, the license for Fort Calhoun was extended from August 9, 2013, to August 9, 2033.[8]

The 2011 Missouri River floods surrounded the plant with flood water. The nuclear reactor had been shut down and defueled in April 2011 for scheduled refueling. A fire caused electricity to shut off in the spent fuel pools resulting in 90 minutes without cooling[9] qualifying as a "red event", signifying a high-level threat to Fort Calhoun operations.[10] The flood and resulting fire was called "one of the most serious safety incidents in recent years" and resulted in a three-year cold shut-down of the plant.[11]

In August 2012 OPPD signed a deal for Exelon Nuclear Partners to manage the plant although OPPD would maintain ownership.[12]

Surrounding population

The Nuclear Regulatory Commission defines two emergency planning zones around nuclear power plants: a plume exposure pathway zone with a radius of about 10 miles (16 km), concerned primarily with exposure to, and inhalation of, airborne radioactive contamination, and an ingestion pathway zone of about 50 miles (80 km), concerned primarily with ingestion of food and liquid contaminated by radioactivity.[13] In 2010, the population within 10 miles of Fort Calhoun was 20,639; the population within 50 miles was 953,410. The closest major city is Omaha, with a population of 408,958, whose center is 18 miles (29 km) from the plant.[14][15]

Seismic risk

The Nuclear Regulatory Commission's estimate of the risk each year of an earthquake intense enough to cause core damage to the reactor at Fort Calhoun was 1 in 76,923, according to a NRC study published in August 2010.[16][17]

Flooding risk

A flood assessment performed by the Nuclear Regulatory Commission in 2010 indicated that the Fort Calhoun Nuclear Generating Station, "did not have adequate procedures to protect the intake structure and auxiliary building against external flooding events."[18] The assessment also indicated that the facility was not adequately prepared for a "worst-case" flooding scenario. A number of potential flood water penetration points were discovered that could have impacted the raw feed water supply to the cooling system, the auxiliary water supply and main switchgear (electrical) room. By early 2011, corrective measures had been implemented.[18] In 2009 the NRC did a flood risk assessment which found that the protection measures were only designed to handle floods to 1,009 feet (308 m) above sea level which was below the NRC mandated elevation of 1,014 feet (309 m) for the plant. The risk assessment stated that at 1,010 feet (310 m), flooding would have "led to a 100 percent chance of a fuel damage if the emergency gasoline pumps didn't work."[19]

2011 flood and cold shutdown

Fort Calhoun plant on June 16, 2011 during the 2011 Missouri River Floods; vital buildings were protected using water-filled perimeter "flood berms"

On June 6, 2011 the Omaha Public Power District, as required by Nuclear Regulatory Commission guidelines, declared a Notification of Unusual Event[20][21] (minimal level on a 4 level taxonomy) due to flooding of the Missouri River.[22] The Missouri River was above flood stage and expected to rise further, and to remain above flood stage for several weeks to a month. Contractors installed sandbags and earthen berms to protect the facility from flooding.[22] According to officials, the plant was built to withstand a 500 year flooding event and, though by June 14 much of the facility was surrounded by the swollen Missouri River, Omaha Public Power District officials said they were confident that enough redundancies were in place to ensure adequate safety.[23] It was reported on June 17, 2011 that the plant was in "safe cold shutdown" mode for refueling and the anticipation of flooding,[24] and that four weeks' worth of additional fuel had been brought in to power backup generators, should they be needed. The Army Corps of Engineers indicated that with average precipitation, the Missouri River would not go above 1,008 feet (307 m) above sea level and OPPD officials stated that the current flood protection efforts would protect the plant to 1,010–1,012 feet (308–308 m) feet above sea level. Officials indicated the spent fuel pool is at 1,038.5 feet (316.5 m) above sea level.[25]

On June 7, 2011, an electrical component in a switch gear room caused a small fire with Halon extinguisher activation which forced a partial evacuation.[26] The fire was no longer burning when the on site fire brigade arrived and according to officials, the public was never in any danger. The fire impacted pumping of coolant water through the spent fuel pool. Cooling was interrupted for 90 minutes while the estimated time for the pool to reach boiling temperature was over 88 hours.[27] In response, the Omaha Public Power District declared an alert[21][28] (second level on a 4 level taxonomy). The evacuation was the first at the facility since 1992, when 20,000 US gallons (76,000 l; 17,000 imp gal) (ca. 76 t) of coolant leaked into a containment building from the reactor.[29][30]

On June 23 a helicopter contracted by OPPD to survey transmission lines made an unplanned landing 1.5 miles south of the plant. Reports described it as an unplanned landing although photographs showed it on its side in a field. Nobody was injured.[31] The Federal Aviation Administration had declared a "temporary flight restriction," in a two nautical mile radius, centered on the Fort Calhoun nuclear facility. This restriction went into effect on June 6, 2011, at 4:31 PM, and remains in effect "until further notice."[32] Officials noted that the June 6 FAA directive was actually a reminder to a standing order creating no flight zones over all U.S. nuclear power plants which had been in effect after the 2001 9/11 attacks.[33]

On June 26, at 1:30 a.m., a 8-foot (2.4 m) high, 2,000-foot (610 m) long water filled rubber "flood berm" that surrounded portions of the plant was punctured by a small earth mover ("Bobcat") and collapsed.[34] The collapse of the flood berm allowed flood waters to surround the auxiliary and containment buildings at the plant, and also forced the temporary transfer of power from the external electricity grid to backup electrical generators.[19][35] It was reported more than 2 feet (0.61 m) of water rushed in around buildings and electrical transformers.[36] Backup generators were then used to ensure the facility maintained electrical power for cooling.[37] The rupturing of the flood berm also resulted in approximately 100 US gallons (380 l; 83 imp gal) of petroleum being released into the river as many fuel containers were washed out. The fuel/oil containers were staged around the facility to supply fuel for pumps which remove water within the flood containment barriers.[38] The rubber berm was a secondary measure not mandated by the NRC and was put in place by OPPD to provide additional room for work immediately outside the reactor buildings.[19] According to the NRC, the water-filled berm "protects several pieces of equipment that have been brought onsite, including an additional emergency diesel generator for supplying AC electrical power, water pumps, firefighting equipment and sandbagging supplies".[39] On July 11 OPPD installed a new 8-foot (2.4 m) inflatable berm as a replacement.[40]

According to OPPD, the plant is designed to withstand waters up to 1,014 feet above mean sea level. The river was not expected to exceed 1,008 feet. NRC officials were at the plant at the time and NRC statements said the plant remains safe. NRC Chairman Gregory Jaczko confirmed the plant's safety when he visited the plant on June 27.[41][42]

On June 30 one of the pumps used to remove seepage caught fire when a worker was refilling it with gasoline. The worker put the fire out with a fire extinguisher but was burned on his arms and face and he was airlifted via helicopter to Lincoln, Nebraska. OPPD said the fire was in an auxiliary security building area and not in the reactor area and that the plant was never in danger.[43][44]

Restart

Before restarting OPPD spent $180 million recommissioning the plant, and cleared a list of 450 corrective items issued by the NRC.[45] The utility company raised rates twice whilst the plant was down, 5.9 percent in 2012 and 6.9 percent in 2013, citing these costs among other things.[46] The newer problems discovered in 2012 inspection were not included in the calculations.[47] After three years in cold shutdown, the plant regained full power again on December 26, 2013.[48][49]

Two weeks later on January 9, 2014, the plant had to stop producing power again after workers discovered a damaged sluice gate.[50] In mid-March 2014, during maintenance work on the plant's generator, the turbine cooling system began losing water, prompting the automatic failsafe system to shut down the turbines, then the reactor, according to a report filed with the Nuclear Regulatory Commission. The shutdown was expected to be temporary.[50]

Post-flood inspections

Inspections of the plant in 2012 meant to determine damage from the 2011 flooding led to the discovery that there were "problems inside the nuclear containment" that were not related to the flood, but had been ongoing for decades, according to a presentation by the NRC and detailed in a public meeting[51][52] held by the Omaha Public Power District.[53] OPPD discovered that under extreme circumstances, some of the structural supports inside the building that houses the reactor weren't strong enough to support the building.[54] Nuclear industry whistleblower Arnie Gundersen said that the plant was "designed with hand calculations and slide rules in the 1960′s" and that the Fort Calhoun plant managers had known about the "systemic" problems for "years if not decades", but had not told the NRC. He discussed the report:[51]

They discovered that those calculations from the 60′s had errors ... also some of them are missing, and then some of them are just plain incomplete. But Omaha Public Power District admits ... that there were "incorrect and incomplete or missing calculations. There were inconsistencies between the calculations and the drawings. There were incomplete considerations of all load combinations and there were simple numerical errors."

David Lochbaum, director of the Nuclear Safety Project for Union of Concerned Scientists, said the structural problems should have been caught much earlier, and that if the NRC conducted 'more than just spot checks', it might have uncovered them in 2003.[53]

Wallace Taylor, attorney on behalf of the Sierra Club, told the NRC that structural problems at the plant should have kept it from being licensed for operation:[55][56]

At the public meeting in Blair, Nebraska, on September 11, 2012, it was revealed for the first time that there are design and construction problems in the original construction of the plant. It was not made clear how these design and construction defects can be corrected. This is a structural problem that would seemingly require significant reconstruction of the facility.
It also seems obvious that if these defects had been known at the time the reactor was originally licensed, this was a condition that would have warranted refusal to grant a license. Exactly one of the criteria for revoking a license.

Besides problems with the math used in its design, the plant came under scrutiny for failing to replace the Teflon used originally, as directed by the NRC in 1985. In that year, experts revealed that Teflon tends to disintegrate in the presence of high radiation. The plant replaced the Teflon in some places, but left it in others, making Fort Calhoun the only nuclear power plant in the US to use Teflon.[53]

Closure

On June 16, 2016 the Omaha Public Power District voted unanimously to shut down the Fort Calhoun Plant. This decision was based on financial interest to both OPPD and its customers.

"Once closed, a nuclear plant must undergo a decommissioning process to remove or decontaminate materials and equipment that have been exposed to radioactivity. The Nuclear Regulatory Commission requires decommissioning to be completed within 60 years of a plant's closure."[57]

Nuclear decommissioning options considered include the Safstor method, or Decon method. The Safstor method involves placing the facility into safe storage for 40 to 60 year, and proceeding with the decontamination after that time. "The Safstor decommissioning process — estimated at $1.2 billion through 2055 — would begin this year and be completed within 60 years."[58] The Decon Method involves immediate dismantling of the site which would release the site for use in as few as 5 years.

On October 24, 2016 the plant was shut down.[59]

References

  1. 1 2 "OPPD flood bill so far: $26M". Omaha.com. Retrieved 2011-07-13.
  2. ↑ Gerken, James (April 5, 2012). "Nebraska Nuclear Plant To Remain Idle For Months". Huffington Post.
  3. ↑ "Fort Calhoun nuclear power plant OK to restart". Power Engineering. 2013-12-17. Retrieved 2014-01-28.
  4. ↑ "Fort Calhoun Station". Omaha Public Power District. Retrieved 28 June 2011.
  5. ↑ "Nebraska City Station - Omaha Public Power District". Oppd.com. Retrieved 2011-07-13.
  6. ↑ Michio Kaku on July 1, 2011, 1:00 AM. "United States Hit With a Triple Nuclear Threat - How Dangerous is it? (Part 1/2) | Dr. Kaku's Universe". Big Think. Retrieved 2011-07-02.
  7. ↑ Saturday, July 2, 2011 (2011-06-25). "Fort Calhoun plant may store spent fuel rods permanently - Washington County Enterprise and Pilot Tribune:". Enterprisepub.com. Retrieved 2011-07-02.
  8. ↑ "NRC renews license for fort Calhoun nuclear power plant for an additional 20 years" (PDF) (Press release). U.S. Nuclear Regulatory Commission. November 4, 2003.
  9. ↑ http://www.omaha.com/apps/pbcs.dll/article?AID=/20120511/NEWS01/705119889
  10. ↑ Tracy, Ryan; Johnson, Keith (May 9, 2012). "NRC Manager Blocked Safety Concerns, Letter Says". The Wall Street Journal.
  11. ↑ Tracy, Ryan; Johnson, Keith (May 9, 2012). "NRC Manager Blocked Safety Concerns, Letter Says". The Wall Street Journal.
  12. ↑ http://www.wowt.com/news/headlines/OPPD-Handing-Over-Management-Of-Ft-Calhoun-Plant-To--166495246.html
  13. ↑ Backgrounder on emergency preparedness at nuclear power plants (fact sheet), U.S. Nuclear Regulatory Commission
  14. ↑ Dedman, Bill (April 14, 2011). "Nuclear neighbors: Population rises near US reactors". msnbc.com. Retrieved May 1, 2011.
  15. ↑ U.S. Census Bureau, Drozd, David, ed., Nebraska incorporated place census populations with changes and percent changes: 1980 to 2010 (PDF), Omaha: Center for Public Affairs Research, University of Nebraska, retrieved May 4, 2011
  16. ↑ Dedman, Bill (March 17, 2011). "What are the odds? US nuke plants ranked by quake risk". msnbc.com. Retrieved April 19, 2011.
  17. ↑ Hiland, Patrick (September 2, 2010), Safety/risk assessment results for generic issue 199, "Implications of updated probabilistic seismic hazard estimates in central and eastern United States on existing plants" (PDF) (Memorandum to: Brian W. Sheron, Director, Office of Nuclear Regulatory Research), Safety/risk assessment panel for generic issue 199, retrieved June 17, 2011
  18. 1 2 "Licensee event report" (PDF). U.S. Nuclear Regulatory Commission. May 16, 2011. Retrieved June 3, 2011.
  19. 1 2 3 Gaarder, Nancy (June 27, 2011). "Flood test not over for nuke plant". Omaha World Herald. Retrieved 28 June 2011.
  20. ↑ "NRC: Event notification report for June 6th, 2011". Nuclear Regulatory Commission. Retrieved 19 June 2011.
  21. 1 2 "NRC: Emergency classification". Nuclear Regulatory Commission. Retrieved 19 June 2011.
  22. 1 2 "Low-level emergency declared at nuclear power plant". JournalStar.com. Lincoln, Nebraska. June 6, 2011. Retrieved 2011-06-07.
  23. ↑ Smollen, Gary (June 14, 2011). "Fort Calhoun flood defenses". WOWT.com. Retrieved 15 June 2011.
  24. ↑ "A First Hand Look at the Flooding « U.S. NRC Blog". Public-blog.nrc-gateway.gov. 2011-06-28. Retrieved 2011-07-02.
  25. ↑ Gaarder, Nancy (June 17, 2011). "NRC: No flood danger at reactor". Omaha World Herald. Omaha, Nebraska. Retrieved 2011-06-17.
  26. ↑ Tracy, Ryan (June 8, 2011). "Nebraska nuclear plant lost cooling system after fire". Wall Street Journal. Omaha, Nebraska. Retrieved 2011-06-16.
  27. ↑ Cole, Kevin (June 8, 2011). "Nuke plant lost spent fuel pump in suspected fire". KETV news. Omaha, Nebraska. Retrieved 2011-06-08.
  28. ↑ "NRC: Event notification report for June 8, 2011". Nuclear regulatory Commission. June 7, 2011. Retrieved 2011-06-09.
  29. ↑ "Smoke causes scare at nuclear plant". KETV news. Omaha, Nebraska: Hearst. June 7, 2011. Retrieved 2011-06-07.
  30. ↑ Cole, Kevin (June 7, 2011). "Smoke triggers nuclear plant alarm". Omaha World-Herald. Omaha, Nebraska. Retrieved 2011-06-07.
  31. ↑ "No one hurt in emergency helicopter landing". Wowt.com. 2011-06-23. Retrieved 2011-06-27.
  32. ↑ Federal Aviation Administration, "FDC 1/6523 NOTAM Details," (June 6th, 2011 - retrieved on June 19th, 2011).
  33. ↑ "Nebraska nuclear plant threatened by flooding is safe, scientists group finds". KansasCity.com. Retrieved 2011-07-02.
  34. ↑ Wald, Matthew L. (June 27, 2011). "Nebraska Nuclear Plant's Vital Equipment Remains Dry, Officials Say". The New York Times.
  35. ↑ NRC: Event Notification Report for June 27, 2011
  36. ↑ Updated 104 minutes ago 6/27/2011 12:09:19 PM +00:00. "Flood berm collapses at Nebraska nuclear plant – US news – Environment – msnbc.com". MSNBC. Retrieved 2011-06-27.
  37. ↑ Kerley, David. "Nebraska residents in no danger after floods hit nuke plant: Waters breach berm at Fort Calhoun nuclear station – ABC News". Abcnews.go.com. Retrieved 2011-06-27.
  38. ↑ "NRC: Offsite notification due to petroleum release to the Missouri River". Nuclear Regulatory Commission. Retrieved 2011-06-27.
  39. ↑ "The Rising River Puts Flood Preparations to the Test « U.S. NRC Blog". Public-blog.nrc-gateway.gov. 2011-06-22. Retrieved 2011-07-02.
  40. ↑ "The latest on flooding: July 11". Omaha.com. Retrieved 2011-07-13.
  41. ↑ Josh Funk, Associated Press – 20 hours ago. "The Associated Press: Flood berm collapses at Nebraska nuclear plant". Google.com. Retrieved 2011-06-27.
  42. ↑ the CNN Wire Staff (June 27, 2011). "Flood berm bursts at Nebraska nuclear plant". CNN.com. Retrieved 2011-06-27.
  43. ↑ June 30, 2011 (2011-02-07). "Worker Burned At Nuclear Plant - Omaha News Story - KETV Omaha". Ketv.com. Retrieved 2011-07-02.
  44. ↑ NRC: Event Notification Report for July 1, 2011
  45. ↑ Laukatis, Algis. "NRC gives OPPD the go ahead to restart Fort Calhoun Nuclear Station". Journal Star. Retrieved 22 March 2014.
  46. ↑ "After 3 Years, Ft. Calhoun Nuke Back". ISSSource. Retrieved 22 March 2014.
  47. ↑ "Neb. utility touts progress at troubled nuke plant". Denver Post. Retrieved 22 March 2014.
  48. ↑ http://www.omaha.com/article/20131226/NEWS/131229264/1016
  49. ↑ http://pbadupws.nrc.gov/docs/ML1335/ML13351A395.pdf
  50. 1 2 Winchester, Cody. "Generator problems cause 2nd Fort Calhoun shutdown in 3 months". Omaha World Herald. Retrieved 20 March 2014.
  51. 1 2 Gundersen, Arnie. "NRC Fails to Enforce its own Regulation". Fairwainds. Retrieved 21 March 2014.
  52. ↑ "Comments for ODDP Board Meeting; 17 January 2013" (PDF). PDF. Retrieved 21 March 2014.
  53. 1 2 3 Funk, Josh."Bad Math at Idle Nuke Plant Prompts More Questions". Associated Press; printed in Laboratory Equipment. 2013-01-22. Retrieved 2014-03-21.
  54. ↑ Funk, Josh. "Neb. utility touts progress at troubled nuke plant". AP. Associated Press. Retrieved 22 March 2014.
  55. ↑ Schulin, Steve. "http://news.nuclear.com/blog7.php/fort-calhoun-s-license-should". Nuclear News. Retrieved 24 March 2014. External link in |title= (help)
  56. ↑ "Official transcript of proceedings" (PDF). PP 18-19. NRC. Retrieved 24 March 2014.
  57. ↑ Goodrich, Nicole. "OPPD board votes to shut down Fort Calhoun nuclear power plant". KETV. Retrieved 2016-06-17.
  58. ↑ Rohman, Katie. "UPDATED: OPPD management chooses FCS decommissioning option". Washington County Enterprise and Pilot Tribune. Retrieved 2016-06-17.
  59. ↑ "Final shutdown for Fort Calhoun". World Nuclear News. 25 October 2016. Retrieved 27 October 2016.
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