Dive Brief:

• The Minnesota Public Utilities Commission on Thursday voted unanimously to allow Xcel Energy to store additional spent nuclear fuel at the 571-MW Monticello Nuclear Generating Plant, clearing the way for operations to continue through at least 2040.
• The plant’s current license allows it to operate until 2030, and Xcel has asked the U.S. Nuclear Regulatory Commission for a two-decade extension. A decision is expected in late 2024, the company said.
• Xcel in March temporarily ceased operations at Monticello to fix a second radioactive water leak, four months after an initial repair failed to fix the problem. In July the utility said low concentrations of leaked tritium did not pose a risk to public health.

Dive Insight:

Leaked tritium reached the edge of the Mississippi River but remains undetected in river water and does not exceed safe drinking water limits, Xcel said. The utility’s nuclear fleet, which also includes the Prairie Island plant, is safe and reliable and a key to reaching Minnesota’s goal of 100% emissions-free electricity by 2040, according to the utility.

Both plants are located about 40 miles from the Minneapolis–Saint Paul metropolitan area.

Nuclear generation is a “foundation of the company’s future,” Shawn Hafen, site vice president of the Monticello plant, said in a statement. The Monticello and Prairie Island nuclear plants supply more than 30% of the electricity used by Xcel’s customers in the upper Midwest, according to the company. In 2022, the two plants produced nearly 14,700 GWh.

Work has also been done to improve the efficiency of the Monticello plant, officials said, and its operating costs have been reduced by 35% over the past decade.

Xcel estimated approximately 14 additional spent fuel canisters would be needed to continue operations at the Monticello plant through 2040, assuming federal regulators approve its relicensing request. The utility plans to construct a pad and modular concrete storage system that will be capable of storing an additional 36 canisters, however. 

“The extra space can be used for the existing technology or a different welded canister system, depending on which is selected,” Xcel said in its application. The utility plans to use a competitive bidding process to select the canister technology and vendor for the project.