Monticello

Monticello Nuclear Generating Plant

Monticello Nuclear Generating Plant is a single unit boiling water reactor located on the banks of the Mississippi River, about 40 miles northwest of the Twin Cities and about three miles northwest of Monticello, Minn. The plant received its operating license from the U.S. Nuclear Regulatory Commission (NRC) in September 1970. More than 500 people are employed full time at Monticello. Xcel Energy also owns the Prairie Island Nuclear Generating Plant near Red Wing, Minn.

General Background Information

• The plant is situated on land acquired from the Rum River Boom Company, a logging business. Additional buffer land around the plant site was purchased from private landowners into the 1980s. The plant property now totals about 2,150 acres.
• Plant generating capacity is 600 megawatts, enough electricity to serve about 500,000 homes.
• In a boiling water reactor, water flows through the reactor and picks up heat released by the fissioning of uranium atoms. The water boils to steam, which then is directed to the turbine-generator to produce electricity.
• The reactor core holds 484 fuel assemblies. Each assembly is about 14 feet long and is a square array of individual fuel rods about the diameter of a finger.
• Approximately every 22 months, the plant is shut down and one-third of the used fuel assemblies are removed from the core and replaced with new ones. The term “cycle” refers to the 22-month period of operation between refuelings.

Plant Operational Facts

• NRC ratings for the Monticello plant are at the highest ranking (green) for all 18 indicators monitored by the NRC.
• Monticello generated a record 5.03 million megawatts hours of electricity in 2004, slightly more than the record set in 2002. In January 2006, Monticello reached 637 consecutive days of operation, the longest run in plant history.

Spent Fuel Storage

• When used fuel is moved from the reactor, it is stored in a pool inside the plant.
• In the 1980s, Monticello shipped 1,058 spent fuel assemblies to a General Electric facility in Illinois; that facility is full.
• Monticello safely built a dry cask storage facility in 2007 – 08. Ten canisters, each holding 61 fuel assemblies, were safely transferred to the concrete storage bunkers in the fall of 2008.

Plant Life

• In fall 2004, the Xcel Energy Board of Directors authorized pursuing license renewal for up to 20 years for the Monticello and Prairie Island plants. The NRC renewed Monticello’s operating license in late 2006, allowing that plant to operate for an additional 20 years to 2030. Xcel Energy submitted the application to renew Prairie Island’s operating licenses in April 2008.

Extended Power Uprate

• Plans are underway to increase the power output from the Monticello plant by approximately 70 megawatts. The project, scheduled to be complete in 2011, will replace several key plant components.

Contact Information:

• To request a speaker on nuclear power issues, call 651-388-1121, ext. 4967.