Monticello Nuclear Generating Plant
Encyclopedia
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 613 megawatts, but studies are ongoing to uprate it to 700 MWe.
Currently the plant is both owned and operated by Xcel Energy
The reactor was originally licensed to operate until 2010, however on November 8, 2006, it was extended to operate until 2030. The plant has had a solid operating history and is one of only two plants in the United States to never have received an Enforcement Action from the Nuclear Regulatory Commission
, the other facility is North Anna Nuclear Generating Station
.
defines two emergency planning zones around nuclear power plants: a plume exposure pathway zone with a radius of 10 miles (16.1 km), concerned primarily with exposure to, and inhalation of, airborne radioactive contamination, and an ingestion pathway zone of about 50 miles (80.5 km), concerned primarily with ingestion of food and liquid contaminated by radioactivity.
The 2010 U.S. population within 10 miles (16.1 km) of Monticello was 62,976, an increase of 36.5 percent in a decade, according to an analysis of U.S. Census data for msnbc.com. The 2010 U.S. population within 50 miles (80.5 km) was 2,977,934, an increase of 8.6 percent since 2000. Cities within 50 miles include Minneapolis (38 miles to city center) and St. Paul (45 miles to city center).
in an incident in 1982.
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.
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 is 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.
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.
On September 17, 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.
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.
Nuclear power plant
A nuclear power plant is a thermal power station in which the heat source is one or more nuclear reactors. As in a conventional thermal power station the heat is used to generate steam which drives a steam turbine connected to a generator which produces electricity.Nuclear power plants are usually...
located in Monticello, Minnesota
Monticello, Minnesota
Monticello is a city in Wright County, Minnesota, United States. Monticello was founded in 1856 and celebrated its 150th anniversary in 2006. The population was 12,759 at the 2010 census. The name Monticello is derived from the Italian word for "Little Mountain," it translates literally to...
, along the Mississippi River
Mississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...
. The site, which began operating in 1971, has a single nuclear reactor
Nuclear reactor
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid , which runs through turbines that power either ship's...
(boiling water reactor
Boiling water reactor
The boiling water reactor is a type of light water nuclear reactor used for the generation of electrical power. It is the second most common type of electricity-generating nuclear reactor after the pressurized water reactor , also a type of light water nuclear reactor...
) of the General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...
BWR-3 design generating 613 megawatts, but studies are ongoing to uprate it to 700 MWe.
Currently the plant is both owned and operated by Xcel Energy
Xcel Energy
Xcel Energy, Inc. is a public utility company based in Minneapolis, Minnesota, serving customers in Colorado, Michigan, Minnesota, New Mexico, North Dakota, South Dakota, Texas, and Wisconsin. Primary services are electricity and natural gas...
The reactor was originally licensed to operate until 2010, however on November 8, 2006, it was extended to operate until 2030. The plant has had a solid operating history and is one of only two plants in the United States to never have received an Enforcement Action from the Nuclear Regulatory Commission
Nuclear Regulatory Commission
The Nuclear Regulatory Commission is an independent agency of the United States government that was established by the Energy Reorganization Act of 1974 from the United States Atomic Energy Commission, and was first opened January 19, 1975...
, the other facility is North Anna Nuclear Generating Station
North Anna Nuclear Generating Station
The North Anna Nuclear Generating Station is a nuclear power plant on a site in Louisa County, Virginia. The site is operated by Dominion Generation company and is jointly owned by the Dominion Virginia Power corporation and by the Old Dominion Electric Cooperative .The plant has two Westinghouse...
.
Surrounding population
The Nuclear Regulatory CommissionNuclear Regulatory Commission
The Nuclear Regulatory Commission is an independent agency of the United States government that was established by the Energy Reorganization Act of 1974 from the United States Atomic Energy Commission, and was first opened January 19, 1975...
defines two emergency planning zones around nuclear power plants: a plume exposure pathway zone with a radius of 10 miles (16.1 km), concerned primarily with exposure to, and inhalation of, airborne radioactive contamination, and an ingestion pathway zone of about 50 miles (80.5 km), concerned primarily with ingestion of food and liquid contaminated by radioactivity.
The 2010 U.S. population within 10 miles (16.1 km) of Monticello was 62,976, an increase of 36.5 percent in a decade, according to an analysis of U.S. Census data for msnbc.com. The 2010 U.S. population within 50 miles (80.5 km) was 2,977,934, an increase of 8.6 percent since 2000. Cities within 50 miles include Minneapolis (38 miles to city center) and St. Paul (45 miles to city center).
Incidents & Updates
Roughly 1300 gallons of radioactive water accidentally leaked from the plant into the Mississippi RiverMississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...
in an incident in 1982.
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.
Construction of the on-site independent spent fuel storage
Dry cask storage
Dry cask storage is a method of storing high-level radioactive waste, such as spent nuclear fuel that has already been cooled in the spent fuel pool for at least one year.. These casks are typically steel cylinders that are either welded or bolted closed. When inside, the fuel rods are surrounded...
installation (ISFSI) pad began in June 2007. The target date for the completion of the pads is 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.
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.
On September 17, 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.
In February 2011, the site's plant officials determined that four control rod
Control rod
A control rod is a rod made of chemical elements capable of absorbing many neutrons without fissioning themselves. They are used in nuclear reactors to control the rate of fission of uranium and plutonium...
blades could be affected by a potentially substantial safety hazard. Vice President Tim O'Connor indicated that the blades would be replaced in March.