Holtec has successfully developed an innovative embodiment of Palisades cooling water heat exchanger system that is being manufactured at Holtec’s own fabrication plant (courtesy of Holtec)
US-based Holtec International reported that, as a part of the ongoing melioration of the Palisades NPP, an innovative embodiment of the plant’s cooling water heat exchanger system has been developed and is being manufactured at Holtec’s own fabrication plant (the Holtec Manufacturing Division) in Pittsburgh.
The power output from plants that rely for cooling from nearby bodies of water, such as a lake, sea, or river, has been steadily eroding as temperatures increase as a result of global warming, Holtec noted. The temperature of Lake Michigan, which supplies cooling water to the Palisades NPP has been increasing and is expected to continue rising in the coming decades during its projected service life. The plant is currently undergoing refurbishment and upgrades, pending restart.
The single-unit 800 MWe pressurised water reactor began commercial operation in 1971. Operator Entergy announced in 2016 plans to close the plant. In 2021 the Nuclear Regulatory Commission (NRC) approved transfer of the licence from Entergy to Holtec in preparation for its decommissioning. The reactor was defueled and its sale to Holtec was completed in June 2022. Holtec then announced that it was applying for federal funding to allow restart of the plant. The US Department of Energy (DOE) through its Loan Programs Office (LPO) made a conditional offer of up to $1.52bn as a loan guarantee to restart the plant and to upgrade it to produce power until at least 2051.
The main challenge in development of the heat exchanger was the extremely congested space where the existing unit is located (typical of power plants). To meet the projected rising lake water temperature, the new unit needed to be more than twice as large in heat transfer surface area as the existing unit, but had to fit in the same space. “It was like asking to put two gallons of milk in a one-gallon carton,” said Edward Bell, Director of Holtec’s Heat Transfer Division.
The upgraded heat exchanger set will be installed within the next 12 months to support the planned restart of Palisades at the end of 2025. Holtec said the cooling system upgrade will require very little civil/structural work, which may reduce the project cost by over 50% compared with the initial projection.
“We are pleased to report this technical achievement to the industry to make other plant developers aware of what is possible to combat the adverse effect of global warming on nuclear and other power plants,” said Joy Russell, Holtec’s Chief Communications Officer.
