26 August 2020


Storm Damage Prompts Early Closure of Duane Arnold Nuclear Reactor in the U.S.

WNISR, 26 August 2020

As a result of storm damage incurred on 10 August 2020, the 622 MW Duane Arnold-1 reactor will not return to service and will instead be permanently closed, the plant’s majority owner, NextEra Energy Resources announced 25 August 2020. It was previously scheduled for closure on 30 October 2020.

This is the second reactor closure in the U.S. and the fourth in the world since the beginning of 2020, with Indian Point-2 shuttered in the U.S. and Fessenheim-1 and -2 in France earlier in the year.

The single unit General Electric (GE) designed Mark-1 Boiling Water Reactor (BWR), the same as Fukushima Daichi unit 1, is located in Palo, 13 km northwest of Cedar Rapids and is the only commercial reactor in the mid-west U.S. state of Iowa. The reactor cooling towers were significantly damaged in strong winds from a derecho, a straight-line wind storm of up to hurricane force, which caused off-site power loss and automatic reactor shutdown.

Duane Arnold-1: The End
Photo: NextEra

“The strong storms that hit the area on Aug. 10 caused extensive damage to Duane Arnold’s cooling towers, and our evaluation found that replacing those towers before the site’s previously-scheduled decommissioning on Oct. 30, 2020, was not feasible,” stated NextEra Energy.

The 46 year old reactor, was connected to the grid in May 1974. In 2010, the NRC granted an additional 20 year operating license permitting operation until 2034. In July 2018, NextEra Energy announced that it would shut Duane Arnold in 2020 after renegotiation of a power purchase agreement that terminated a contract with the reactor as of October this year. Under the agreement, Nextra agreed to supply electricity to the Iowa grid from its lower cost wind energy capacity, which will save customers US$300 million in electricity costs, on a net present value basis, over 21 years, according to NextEra.