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Monticello Nuclear Generating Plant

Coordinates: 45°20′1″N 93°50′57″W / 45.33361°N 93.84917°W / 45.33361; -93.84917
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Monticello Nuclear Generating Plant
This is a view of Xcel Energy's Monticello Nuclear Generating Plant from the West.
Map
CountryUnited States
LocationMonticello, Wright County, Minnesota
Coordinates45°20′1″N 93°50′57″W / 45.33361°N 93.84917°W / 45.33361; -93.84917
StatusOperational
Construction beganJune 19, 1967
Commission dateJune 30, 1971
Construction cost$455.8 million (2007 USD)[1]
OwnerXcel Energy
OperatorNorthern States Power Company
Nuclear power station
Reactor typeBWR
Reactor supplierGeneral Electric
Cooling towers2 × Mechanical Draft
Cooling sourceMississippi River
Thermal capacity1 × 2004 MWth
Power generation
Units operational1 × 647 MW
Make and modelBWR-3 (Mark 1)
Nameplate capacity647 MW
Capacity factor91.04% (2017)
80.80% (lifetime)
Annual net output5022 GWh (2021)
External links
WebsiteMonticello Nuclear Generating Station
CommonsRelated media on Commons

The Monticello Nuclear Generating Plant is a nuclear power plant located in Monticello, Minnesota, along the Mississippi River. The site, which began operating in 1971, has a single nuclear reactor (boiling water reactor) of the General Electric BWR-3 design generating 671 MWe. The plant is owned by Xcel Energy and operated by Northern States Power, its regional subsidiary.[2]

The reactor was originally licensed until 2010; a renewal license issued in 2006 has allowed it to continue operating until September 8, 2030. In January 2023, Northern States Power Company applied for a license renewal of 20 years beyond 2030.

Regulatory history

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Monticello Nuclear Generating Plant began operating in 1971, has a single boiling water reactor of the General Electric BWR-3 design generating 671 MWe. The nuclear reactor was originally licensed until 2010; a renewal license issued in 2006 allows it to continue operating until September 8, 2030.[3]

In January 2023, Northern States Power Company applied for a license renewal of 20 years beyond 2030.[4][5]

Geography, seismic risk and surrounding population

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The Nuclear Regulatory Commission (NRC) defines two emergency planning zones around nuclear power plants: a plume exposure pathway zone with a radius of 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.[6] The NRC's estimate of the risk each year of an earthquake intense enough to cause core damage to the reactor at Monticello was 1 in 52,632, according to an NRC study published in August 2010.[7][8]

According to the 2010 U.S. Census, the population was 62,976 within 10 miles (16 km) of Monticello, an increase of 36.5 percent in a decade; and 2,977,934 within 50 miles (80 km), an increase of 8.6 percent. Cities within 50 miles include the Twin Cities of Minneapolis (38 miles to city center) and St. Paul (45 miles to city center).[9]

The Monticello section of the Mississippi River remains unfrozen during winter and attracts hundreds of trumpeter swans, largely due to warm water discharged by the nuclear plant.[10]

Incidents and updates

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In November 1971, 50,000 gallons of "low-level" radioactive water was released into the Mississippi River by the facility in order to conduct repairs.[11]

8,500 gallons of cesium-137 contaminated water were released into the Mississippi River by the facility on December 20, 1971 in order to conduct maintenance, and a second amount totaling 5,000 gallons from the same batch was released on December 29, 1971.[12][13]

Roughly 1,300 gallons (4.9 cubic meters) of radioactive water which accidentally leaked from the plant into the Mississippi River in an incident on 5 May 1982, was determined to be "no threat" to the public.[14]

The Monticello Nuclear Power Plant Control Room Simulator

21st century

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In January 2007 a 13-ton control box fell eight to twelve inches and caused an unexpected shutdown. This control box was located in the condenser room of the turbine building and contained valves which controlled steam pressure. Emergency response teams at the station deemed that the event was likely caused by inadequate welds at the time of installation and fatigue due to vibrations over the life of the plant.[citation needed]

Construction of the on-site independent spent fuel storage installation (ISFSI) pad began in June 2007. The target date for the completion of the pads was December 2007 with insertion of the first ten dry storage containers (holding spent fuel assemblies ) into horizontal storage modules (HSMs) in mid-2008. Initially, 12 HSMs will be placed on the storage pad. Each HSM—a thick, reinforced, pre-cast concrete structure about the size of a single car garage—has the capacity to hold 61 fuel bundles.[citation needed]

On September 11, 2008, a cable fault tripped the transformer which supplied power to the site. This resulted in a loss of off-site power and the plant automatically shut down.[15]

On September 18, 2008, an employee for a rental equipment company was electrocuted by one phase of the 115-kV power line outside of the plant due to a lack of situational awareness. The individual was raising a bucket lift without watching overhead and contacted one phase of the 115-kV line. The plant was offline at the time due to the forced outage described above.[16]

In February 2011, the site's plant officials determined that four control rod blades could be affected by a potentially substantial safety hazard. Vice President Tim O'Connor indicated that the blades would be replaced in March.[17][18]

In 2006, Xcel Energy proposed a series of upgrades to the plant in order to increase its output and extend its life for an additional 20 years. In December 2013, the Nuclear Regulatory Commission approved [19] the license amendment allowing the unit to increase output from 600 MWe to 671 MWe. However, final project implementation costs significantly outstripped initial estimates by more than $400 million. In 2015, the Minnesota Public Utilities Commission denied full cost recovery and determined that, while Xcel Energy could include the additional cost in customer rates, it could not earn a return on those costs. Xcel Energy would record a greater than $100 million loss in 1Q 2015 as a result and recouped $27 million less than expected from the project.[citation needed]

In March 2013, the plant was shut down for a routine refueling. During this time, workers replaced several original plant components. This increased the plant's electrical output from the original 600 MWe to 671 MWe. In early August, the plant was brought back online with the new equipment. Refueling outages as such increase the population of the plant's workforce by the thousands.[citation needed]

In November 2022, 400,000 gallons (more than 1500 cubic meters) of water contaminated with tritium leaked from a water pipe running between two buildings at the facility.[20] Only 25% of the released tritium was recovered as of March 16, 2023, with cleanup continuing.[21] Another leak of hundreds of gallons of tritium-laced water, originating from a short-term fix for the original leak, was discovered on March 22.[22] Xcel announced that the nuclear plant would be powered down on March 24, 2023, to cut out a leaking 50-year-old pipe to repair the ongoing leak. Xcel president Chris Clark said that "there is always a risk that it would spill over again and have more tritium enter the groundwater."[23][24][25][needs update]

In December 2023, Xcel Energy was fined $14,000 by the Minnesota Pollution Control Agency for not obtaining a permit before pumping contaminated groundwater into temporary holding tanks.[26]

Electricity Production

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Generation (MWh) of Monticello Nuclear Facility[27]
Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual (Total)
2001 440,695 340,547 -4,261 369,313 431,818 417,928 422,760 415,031 411,801 396,154 21,897 212,639 3,876,322
2002 349,057 396,128 438,866 423,484 438,208 409,953 421,673 423,789 416,914 434,384 424,937 438,164 5,015,557
2003 436,483 393,223 437,856 345,599 50,496 369,107 424,318 420,302 416,377 436,020 424,869 421,860 4,576,510
2004 433,230 408,757 440,422 424,219 423,616 350,104 420,318 425,000 412,488 436,433 423,677 436,618 5,034,882
2005 436,233 363,285 42,698 228,534 436,029 413,038 420,637 421,445 414,350 437,081 423,304 438,284 4,474,918
2006 437,266 393,609 437,954 421,222 433,091 407,403 411,732 419,876 414,853 437,102 423,707 434,736 5,072,551
2007 232,813 391,535 173,046 6,240 420,460 414,784 424,641 425,406 420,682 439,692 407,935 435,035 4,192,269
2008 440,240 411,395 439,697 425,502 436,396 415,071 422,351 421,789 170,136 436,652 423,091 435,696 4,878,016
2009 400,966 390,162 168,280 -2,230 247,583 413,210 421,814 420,893 410,568 420,808 418,648 431,762 4,142,464
2010 433,518 390,894 432,633 414,429 423,908 402,835 413,871 398,564 389,641 402,295 163,540 428,985 4,695,113
2011 434,903 391,689 49,550 -2,209 45,668 337,853 415,665 387,105 414,046 328,906 264,265 288,837 3,356,278
2012 434,444 404,751 431,898 418,218 426,910 404,834 410,886 307,057 367,237 431,231 420,039 432,869 4,890,374
2013 426,909 391,008 6,649 -1,399 -2,103 -1,208 71,069 412,756 408,379 431,803 419,876 429,835 2,993,574
2014 234,943 314,811 447,228 417,881 424,344 405,108 416,025 415,937 326,596 137,408 338,787 444,898 4,323,966
2015 462,652 420,166 465,432 156,356 2,466 418,819 470,732 477,996 462,826 492,735 357,253 476,462 4,663,895
2016 491,040 458,648 488,124 475,660 486,354 457,486 473,065 475,297 361,809 459,478 478,102 492,695 5,597,758
2017 486,644 443,965 480,983 175,184 252,980 449,491 473,963 478,975 464,544 490,160 475,734 486,997 5,159,620
2018 490,435 443,250 489,058 472,836 481,527 456,816 469,899 461,713 462,405 490,370 410,489 489,226 5,618,024
2019 469,517 392,464 387,120 132,626 263,845 460,683 469,176 473,507 463,668 488,998 474,910 488,061 4,964,575
2020 489,487 456,926 483,706 468,628 473,907 444,350 445,849 465,947 457,069 445,779 474,407 487,259 5,593,314
2021 479,432 435,017 439,966 203,430 157,540 454,863 464,321 480,624 465,120 484,214 473,243 485,088 5,022,858
2022 389,831 440,998 484,256 472,089 452,801 458,182 468,783 470,786 459,056 485,719 472,727 490,045 5,545,273
2023 487,762 440,350 341,230 158,956 246,782 456,685 469,864 470,532 399,936 380,577 474,207 466,618 4,793,499
2024 489,290 431,747 360,914 461,957 483,325 456,714 466,819 469,418 449,794 --

See also

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References

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  1. ^ "EIA - State Nuclear Profiles". www.eia.gov. Retrieved October 3, 2017.
  2. ^ "PRIS - Reactor Details". Archived from the original on October 5, 2013.
  3. ^ "NRC: Monticello Nuclear Generating Plant, Unit 1". United States Nuclear Regulatory Commission. Retrieved December 22, 2019.
  4. ^ Monticello Nuclear Generating Plant (January 2023). "Monticello Nuclear Generating Plant Unit 1 Subsequent License Renewal Application". NRC. {{cite web}}: Missing or empty |url= (help)
  5. ^ "NRC Makes Monticello Subsequent License Renewal Application Available for Public Inspection" (PDF). NRC. January 27, 2023. Retrieved March 4, 2024.
  6. ^ "NRC: Emergency Planning Zones". United States Nuclear Regulatory Commission. Retrieved December 22, 2019.
  7. ^ "What are the odds? US nuke plants ranked by quake risk". NBC News. March 16, 2011. Retrieved August 16, 2024.
  8. ^ "Archived copy" (PDF). Archived from the original (PDF) on May 25, 2017. Retrieved April 19, 2011.{{cite web}}: CS1 maint: archived copy as title (link)
  9. ^ "Nuclear neighbors: Population rises near US reactors". NBC News. April 14, 2011. Retrieved August 16, 2024.
  10. ^ Marohn, Kirsti (October 18, 2019). "In Monticello, a city at the center of the nuclear energy debate". MPR News. Retrieved December 22, 2019.
  11. ^ "NSP to delay atom discharges". The Minneapolis Star. November 24, 1971. p. 23. Retrieved December 17, 2023.
  12. ^ "Radioactive discharge fits state standards". Star Tribune. December 21, 1971. p. 16. Retrieved December 17, 2023.
  13. ^ "A-water released by NSP". The Minneapolis Star. December 29, 1971. p. 29. Retrieved December 17, 2023.
  14. ^ "Reactor leak 'no threat'". The Montreal Gazette. May 5, 1982. Retrieved March 24, 2011.
  15. ^ [1] Archived October 24, 2008, at the Wayback Machine
  16. ^ [2] Archived October 24, 2008, at the Wayback Machine
  17. ^ "Possible fuel rod hazard at Xcel's Monticello nuclear plant". Star Tribune. February 16, 2011. Archived from the original on February 21, 2011. Retrieved March 24, 2011.
  18. ^ Gram, Dave (February 17, 2011). "Possible fuel rod hazard seen at some nuke plants". BusinessWeek. Archived from the original on October 26, 2012.
  19. ^ "NRC: Package ML13316C459 - Monticello Nuclear Generating Plant - Issuance of Amendment No. 176 to Renewed Facility Operating License Regarding Extended Power Uprate (TAC No. MD9990)".
  20. ^ Karnowski, Steve (March 17, 2023). "400,000 gallons of radioactive water leak from nuclear plant". WKRC. Associated Press. Retrieved March 18, 2023.
  21. ^ Henry, Allen (March 16, 2023). "Xcel Energy cleaning up radioactive leak at Monticello nuclear generating plant". CBS Minnesota.
  22. ^ "Radioactive water leaks at Minn. nuclear plant for 2nd time". AP News. March 24, 2023.
  23. ^ Ortiz, Erik (March 24, 2023). "A nuclear plant that leaked 400,000 gallons of radioactive water will be shut down after second incident". CNBC.
  24. ^ Ahmed, Trisha; Daly, Matthew (March 24, 2023). "Minnesota nuclear plant shuts down for leak; residents worry". AP News.
  25. ^ Marohn, Kirsti (July 20, 2023). "Leaked tritium may have reached Mississippi River". MPR News. Retrieved July 21, 2023.
  26. ^ "Xcel Energy fined $14,000 after leaks of radioactive tritium from its Monticello plant in Minnesota - CBS Minnesota". www.cbsnews.com. December 15, 2023. Retrieved January 9, 2024.
  27. ^ "Electricity Data Browser". www.eia.gov. Retrieved January 7, 2023.

footnote number 6:

Nuclear Regulatory Commission, Preliminary Notification – Region III, Sept. 15, 2008, Preliminary Notification Of Event Or Unusual Occurrence – PNO-III-08-009; <http://pbadupws.nrc.gov/docs/ML0825/ML082590668.pdf>

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