Holtec’s Efforts to Reopen Palisades Nuclear Reactor

By Timothy Gardner
WASHINGTON (Reuters) – Holtec, the company seeking to reopen the Palisades nuclear reactor in Michigan, reported that corrosion cracking in the steam generators “far exceeded” estimates, according to a document published by the U.S. nuclear power regulator on Wednesday.

President Joe Biden’s administration recently finalized a $1.52 billion conditional loan guarantee for the Palisades plant as part of an initiative to support nuclear energy. This effort aims to generate nearly emissions-free electricity to combat climate change and accommodate the rising electricity demand driven by technologies such as artificial intelligence, electric vehicles, and digital currency.

Palisades, which ceased operations under a previous owner in 2022, aspires to be the first modern U.S. nuclear power plant to resume operations after being fully shut down.

A summary from an early September call between the U.S. Nuclear Regulatory Commission (NRC) and Holtec disclosed that stress corrosion cracking in the tubes of both steam generators at Palisades “far exceeded estimates based on previous operating history.” The inspection revealed that 1,163 steam generator tubes showed signs of stress cracking out of more than 16,000 tubes in the units.

Steam generators are delicate components requiring careful maintenance, and they represent some of the most expensive parts of a nuclear facility.

Holtec aims to return the plant to operation by late next year. Patrick O’Brien, a company spokesperson, noted that the inspection results were somewhat anticipated as the standard maintenance procedure was not properly followed during shutdown. However, he emphasized that the plan to reopen Palisades remains on track and that Holtec intends to repair rather than replace the steam generators, which are expected to last an additional 30 years post-repair.

The proposed repair strategy involves “unplugging” around 300 tubes per steam generator that were plugged during the original installation, followed by addressing the tubes identified in the inspections. This will include plugging approximately 20% of tubes that are challenging to repair and using sleeving, a common repair method, for the remaining 80%.

Holtec still requires permits from the NRC. According to an NRC spokesperson, “Holtec must ensure the generators will meet NRC requirements if the agency authorizes returning Palisades to operational status.”

Last month, the NRC reported preliminary inspection results “identified a large number of steam generator tubes with indications that require further analysis and/or repair.”

Issues with steam generators can create significant challenges for nuclear power plants. For instance, parts of the San Onofre Nuclear Generating Station in California were shut down in 2012 due to leaked steam generators with design flaws, leading to the plant’s closure in 2013 due to ongoing problems with the new generators.