US-based Holtec International has launched a programme to build two SMR-300 reactor units at the Palisades NPP site in Michigan. Holtec said it is encouraged by the state’s “commitment to expand in-state carbon-free generation as well as by the broad-based federal, state, and community support for repowering the Palisades NPP”.
In October, Holtec said it had submitted a filing with the US Nuclear Regulatory Commission (NRC) to begin the process of seeking federal reauthorisation of power operations at the Palisades NPP. The single-unit 800 MWe pressurised water reactor at Palisades began commercial operation in 1971. Operator Entergy announced in 2016 announced plans to close the plant in 2021and NRC approved transfer of the licence from Entergy to Holtec in preparation for its decommissioning. The reactor was removed from service by Entergy in May 2022, and was defuelled. 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.
Holtec says the Palisades plant “refurbished with an array of enhancements is on track to be restarted by the end of 2025 and is designed to provide decades of safe and reliable service”. The addition of two Holtec SMRs will nearly double the site’s generation capacity. The filing of the Construction Permit Application (CPA) for the SMRs is targeted for 2026, shortly after the Palisades NPP returns to service, Holtec noted. Target commissioning date for the first SMR-300 plant is mid-2030, subject to NRC’s r reviews and oversight.
“Siting the first two SMR-300 units at Palisades eliminates the delays associated with erecting the plant at an undeveloped property and confers the many benefits of synergy that accrue from the presence of a co-located operating plant – including shared infrastructure and operational expertise, enhancements to grid stability, and resource optimisation,” said Holtec’s CEO Dr Kris Singh.
“By building at our own site with our own credit and our own at-risk funds, we hope to deliver the dual-unit SMR-300 plant within schedule and budget – an outcome that has eluded our industry for a long time. We thank our federal, state, and community partners for their critical support, which have made the Palisades re-start and our pioneering SMR-300 construction in Michigan feasible,” he noted.
Holtec’s SMR has been in development since 2011 undergoing several design evolutions. The SMR-160 advanced SMR is a pressurised light-water reactor, generating 160MWe (525MWt) using low-enriched uranium fuel, with flexibility to produce process heat for industrial applications and hydrogen production. The design has completed the first phase of the Canadian Nuclear Safety Commission's three-phase pre-licensing vendor design review and is undergoing pre-licensing activities with NRC. Holtec has also applied for a Generic Design Assessment of the SMR-160 in the UK.
The larger SMR-300 design is intended to be deployable in virtually any terrain, including those with significant seismic loadings. The Plant is also readily adaptable for diverting all or some of its cycle steam for other purposes such as hydrogen production and industrial thermal needs. The most recent design evolution is the incorporation of forced flow capability overlayed on gravity-driven flow in the plant’s primary system.
The addition of booster pumps for normal operations does not change the plant’s essential safety features, as the pumps are not relied upon for safe shutdown operations. Holtec says the SMR-300 remains “walk-away safe” with its redundant passive safety systems that operate without any operator action nor any external source of electricity or cooling water. The power uprate “has the added critical benefit of aligning the reactor’s embodiment with the existing US Code of Federal Regulations, eliminating the need for certain exemptions from them, and thus making the uprated plant more conducive to timely licensing by the NRC and other overseas regulatory authorities”.
Holtec’s 700-acre Oyster Creek site in Central New Jersey is alsobeing considered for early SMR-300 deploymen. The 600 MWe NPP shut down in 2018 and has been substantially decommissioned The focus for deployment of the SMR-300 at Oyster Creek is hydrogen production given ongoing electricity market dynamics, Holtec noted. The technical assessments will advance deployment of SMR-300s at Oyster Creek to accord with the mission of a recent DOE award to the Mid-Atlantic Regional Clean Hydrogen Hub (MACH2), of which Holtec is a member.
Image: Artist's impression of Holtec's two-unit SMR-300 plant (courtesy of Holtec)