From Plant Startups to Advanced Reactors, Nuclear Heats Up

Nuclear power has long been a reliable fixture of the U.S. electricity mix, accounting for nearly 20% of utility-scale generation. Several newsworthy items spell promise for the sector’s expansion in 2024, from regulatory milestones and new fuel technologies to state-level advanced reactor incentives.

Here’s what engineers need to know.

 

Unit 4 at the Vogtle nuclear plant in Georgia has reached initial criticality. Image used courtesy of Georgia Power

 

Nuclear Reactor in Georgia Moves Closer to Operation

The fourth nuclear reactor at Georgia Power’s Plant Vogtle has reached initial criticality, meaning the unit is now firing a self-sustaining nuclear fission reaction and splitting atoms to create nuclear heat, which will produce steam and generate electricity. 

The next stage of startup testing for Unit 4 will integrate the primary coolant and steam supply systems and slowly raise the power to 100%. It will begin commercial operation next quarter. 

This testing milestone comes after Unit 4’s sister reactor, Unit 3, came online last summer. Both are Westinghouse AP1000 pressurized water reactors (PWRs) with a combined 2.2 GW of capacity. The next-generation model brings enhanced features, including passive safety systems enabling emergency shutdown without operator intervention or external power sources. AP1000 also offers a simpler design with fewer pumps, control cables, safety valves, and other components.

 

The layout of Units 3 and 4 at Plant Vogtle. Image used courtesy of Georgia Power

 

The new reactors join Units 1 and 2, which came online in the 1980s. Both are Westinghouse four-loop PWRs with 2.4 GW of generating capacity combined. 

Units 3 and 4 will produce electricity for about 1 million homes and businesses combined — nearly half of Georgia Power’s customer base of 2.7 million. Once completed, Plant Vogtle will be America’s largest nuclear station. 

 

Illinois Nuclear Plant Seeks License Renewal

Constellation, a Maryland-based company producing about 10% of the nation’s clean energy, has filed license renewal paperwork with the Nuclear Regulatory Commission (NRC) for its Clinton Clean Energy Center in central Illinois. 

Nuclear facilities are initially licensed to operate for a 40-year term. The NRC allows licensees to file renewals up to 20 years after the first four decades. The single-unit Clinton plant entered commercial service in 1987, and its license expires in April 2027. Renewal would keep it running through 2047. 

The plant generates up to 1.08 GW of electricity through a General Electric boiling water reactor (BWR), powering more than 800,000 homes. If renewed, Clinton would provide Illinois with 179 TWh of additional electricity over two decades. 

 

The single-reactor Clinton Clean Energy Center in Illinois. Image used courtesy of Constellation 

 

Constellation stated the Clinton plant’s continued operations were supported by the federal nuclear production tax credit enacted in the 2022 Inflation Reduction Act. State legislation also played a role, as the 2016 Illinois Future Energy Jobs Act previously rescued the facility from early closure under its previous owner. 

Later this year, Constellation plans to file a second license renewal for two units at its three-reactor Dresden Clean Energy Center in Morris, about 100 miles north of Clinton. 

 

GE Vernova’s Secures Approval to Ship Enriched Uranium 

GE Vernova’s nuclear fuel business, Global Nuclear Fuel (GNF), has secured NRC approval to manufacture and ship nuclear fuel with Uranium-235 material enriched up to 8 weight percent (wt%). The NRC also authorized topical reports enabling GNF to analyze fuel performance with enrichments above 5 wt%, the current limit for low-enriched uranium (LEU) fuel. While GNF’s 8 wt% expansion exceeds the LEU limit in power reactor fuels, it still meets the NRC’s 10% bar for fuel cycle facilities. 

GNF is developing the technology as an accident tolerant fuel (ATF) under the Department of Energy. ATFs boost reactors’ resistance to safety incidents and reduce electricity losses. Higher enrichment fuels support power uprates for existing BWRs and emerging technologies like advanced nuclear reactors. 

The move makes GNF’s manufacturing facility in Wilmington, North Carolina, the first to hold a license for fabricating 8 wt% fuel enrichments, a market advantage targeting the increased demand for shipping higher enrichments. According to the World Nuclear Association, GNF’s Wilmington plant is one of only three fuel fabrication facilities in the U.S. converting enriched uranium oxide into solid pellets for fuel rods. 

 

A diagram of the RAJ-II shipping container (from a filing dated October 2007). Image used courtesy of GNF (Page 2) 

 

By increasing the payload content parameters of its RAJ-II shipping container, GNF can now transport higher uranium fuel bundles. RAJ-II, which features inner and outer enclosures made of stainless steel, was licensed as a type B fissile material container for shipping unirradiated BWR fuel assemblies and loose rods with uranium carbide and fuel from generic PWR/BWR designs. 

 

Presentation slides (dated February 2022) summarizing the RAJ-II regulatory amendment with a higher enrichment fuel bundle. Image used courtesy of GNF (Pages 3 and 5) 

 

Small Modular Reactors Gain Policy Support in Virginia 

The Virginia House and Senate passed two pieces of legislation permitting the state’s largest utilities to recover certain costs in deploying small modular reactors (SMRs). The bills are intended to incentivize future SMR adoption by allowing utilities to adjust rates to cover expenses. 

SMRs operate similarly to traditional utility-scale nuclear power plants but at a smaller scale, with under 300 MW of generating capacity. This sub-market of nuclear fission technology has attracted industry attention because the modest physical footprint allows more land use flexibility with minimal on-site preparation, thus speeding up construction. 

House Bill 1491 applies to Appalachian Power, a regional subsidiary of American Electric Power. The legislation allows the firm to recover project development costs, including design, engineering, permitting, environmental review, and other site-related activities. However, construction permits and NRC licensing expenses are excluded. At any time before applying for SMR construction, the utility can request the Virginia State Corporation Commission (SCC) to review its project development costs and consider whether any can be recovered through a rate adjustment clause. 

Senate Bill 454, which applies to Appalachian Power and Dominion Energy, focuses on recouping equipment and federal regulatory costs. The utilities can petition the SCC to review costs they plan to recover from customers via raising rates. 

Both utilities are interested in deploying SMRs in Virginia. Dominion’s 2023 integrated resource plan (IRP) anticipates they could be a feasible supply-side resource in the 2030s, earmarking the technology in its longer-term plans starting in 2040. Appalachian Power’s latest IRP (2022) also mentioned SMRs as a potential resource option. 

Several SMR designs are under development in the U.S., but economic gaps persist. Rising construction costs and interest rates have posed significant challenges to SMR commercialization.