NextEra initiates regulatory process to restart Duane Arnold

Wednesday, 29 January 2025

The single-unit 615 MWe boiling water reactor plant was shut down after more than 45 years of operation. The plant was the only operating nuclear unit in Iowa and had been producing around 9.2% of the state's electric generation and 19% of its emission-free electricity, but the decision to close it was made in 2018 when utility Alliant Energy and owner NextEra Energy agreed to shorten their existing power purchase agreement by five years, ending in 2020 rather than 2025. The plant had been scheduled to shut in October 2020, but did not return to service after a severe storm in August that year damaged its cooling towers. The reactor itself was not damaged.

The reactor has been defuelled - all of its fuel is now in an on-site dry storage facility - but the buildings are not scheduled to be demolished until 50 years have passed. This deferred approach to decommissioning, with the facility placed into a safe storage configuration with eventual dismantling and decontamination activities taking place after residual radioactivity has decayed, is sometimes referred to as SAFESTOR.

In July last year, NextEra CEO John Ketchum confirmed the company was looking into restarting the plant.

"Nuclear continues to be a much longer term option in our opinion due to first-of-a-kind risks and uncertainty, with near-term opportunities centred on recommissioning and operating projects," Ketchum said during a webcast on 24 January to discuss the company's Q4 and full-year 2024 financial results. "Nuclear power plants across the country are already serving existing demand and there are only a few nuclear plants that can be recommissioned in the near-term and in an economic way."

"Recently, the company filed notice with the Nuclear Regulatory Commission to request a licensing change - an important first step in establishing the regulatory pathway to restore the facility's operating licence and potentially restart plant operations as early as the end of 2028.

"While this is just one part of a broader effort with regulators, government officials, potential customers, and other stakeholders, we are encouraged by the positive responses we have received so far from all parties involved."

The threat of premature closure of US nuclear generating capacity - and the resulting loss of its carbon-free generation attributes - has led to policy reforms and support mechanisms at the state and federal level to ensure that plants that might otherwise shut down can continue to operate.

Of those plants that have already closed, one - Palisades, in Michigan - is being prepared for a restart by now-owner Holtec International, with support from federal loan guarantees. Palisades is set to be the first power reactor to be returned to commercial operation after its being declared shut down, but may not be the last: Constellation Energy CEO Joe Dominguez also did not rule out a restart of the shut-down unit 1 at the Three Mile Island, which closed in 2019 in comments to investors last year.