Monticello power uprate approved

Wednesday, 11 December 2013

An increase in power output of some 10% at Xcel Energy's single-unit Monticello nuclear power plant in Minnesota has been approved by the US nuclear regulator.

Monticello (Image: Xcel)

In early 2008, the company announced plans to increase the gross generating capacity of the 600 MWe boiling water reactor by 10% - some 71 MWe - through an 'extended power uprate'. This involves significant modifications to major plant equipment, such as replacing steam turbines.

Xcel submitted an application to the US Nuclear Regulatory Commission (NRC) for the uprate in November 2008. Following a delay in the project, Xcel restarted the Monticello plant in early August 2013, after the work was completed.

The NRC has now given the plant permission to increase the maximum core thermal power level from 1775 MWt to 2004 MWt.

Xcel will begin incrementally increasing power at the reactor by the end of this month. However, certain modifications will be required to handle increased flows, heat transfer and power utilization. The company said it awaits an NRC decision in early 2014 that will allow more operator flexibility before the plant reaches the full 671 MWe.

Dave Sparby, president and CEO of Xcel subsidiary Northern States Power Company-Minnesota, said: "The Monticello plant currently generates about 10% of the electricity we provide customers in our Upper Midwest service territory, and it's carbon-free energy. The increased output will provide additional low-cost energy to our customers."

The Minnesota Public Utilities Commission has ordered an investigation into delays and cost overruns in the Monticello uprate project. Xcel estimated the cost of the project to be $320 million when it began in 2008, but the actual cost came to $655 million.

Monticello has been in operation since 1970. Xcel has a licence to operate the unit until 2030, after a 2006 decision to extend the licence by 20 years.

Researched and written
by World Nuclear News