Table of Contents
- TLDR
- Comanche Peak vs. South Texas Project
- Why Texas Only Has Two Plants
- What Nuclear Actually Does for the Texas Grid
- The Part Nobody Puts on the Brochure
- The Next Wave: Small Modular Reactors
TLDR
Texas runs two nuclear power plants: South Texas Project near Bay City and Comanche Peak near Glen Rose. Four reactors total, roughly 5,100 megawatts of combined capacity, and about 8 to 10 percent of the electricity ERCOT sends out on any given day. That’s it. No third plant, despite Texas producing more energy than any other state in the country. The short reason is money — both plants ran wildly over budget in the 1980s, and nobody’s wanted to relive that fight since. The long reason involves cheap natural gas, a waste problem the federal government still hasn’t solved, and a new push toward small modular reactors that’s further along here than in almost any other state.
Comanche Peak vs. South Texas Project
These two plants get lumped together so often that people assume they’re basically the same thing. They’re not. Different owners, different reactor designs, different decades of drama.
South Texas Project sits in Matagorda County, about 90 miles southwest of Houston, and cools its reactors with water pumped from a 7,000-acre man-made reservoir instead of a river — a workaround for a stretch of Texas coastline that doesn’t have a reliable freshwater source nearby. Comanche Peak sits in Somervell County, roughly 60 miles southwest of Fort Worth, on Squaw Creek Reservoir, and its distinctive cooling towers are visible from the highway well before the plant itself comes into view.
| South Texas Project | Comanche Peak | |
|---|---|---|
| Location | Matagorda County (near Bay City) | Somervell County (near Glen Rose) |
| Reactors | 2 (Units 1 & 2) | 2 (Units 1 & 2) |
| Combined capacity | ~2,700 MW | ~2,430 MW |
| Operator | STP Nuclear Operating Company | Vistra Corp |
| Reactor type | Pressurized water reactor | Pressurized water reactor |
| Online since | 1988 (Unit 1), 1989 (Unit 2) | 1990 (Unit 1), 1993 (Unit 2) |
| Owners | NRG, CPS Energy, Austin Energy | Vistra (fully merchant-owned) |
The ownership split matters more than it looks. South Texas Project is partly owned by two municipal utilities, CPS Energy in San Antonio and Austin Energy, which means it was built to guarantee cheap, stable power for those two cities specifically. Comanche Peak is a straight commercial asset — Vistra sells its output into the ERCOT market like any other generator. Same technology, different reason for existing.
Why Texas Only Has Two Plants
This is the question that actually deserves an answer, because on paper it makes no sense. Texas produces and consumes more energy than any other state, has the physical space, has the money, and has a political class that generally likes big industrial projects. So why stop at two?
Both plants answer the question themselves, just not in a flattering way. Comanche Peak was originally budgeted around $779 million. It ended up costing more than $11 billion, and construction dragged on for nearly two decades after a wave of whistleblower complaints about welding and quality-control shortcuts forced a management shakeup and years of added regulatory scrutiny. South Texas Project had its own version of the same story — original estimates near $1 billion, a final bill closer to $6 billion, and lawsuits between the co-owners over who’d eat the overage.
Utilities remember that math for a long time. By the time Comanche Peak’s second reactor finally came online in 1993, natural gas was cheap, deregulation was reshaping how Texas utilities made money, and nobody with a checkbook wanted to be the next cautionary tale. The pattern held for three decades: gas plants are fast to build and hard to lose money on, wind and solar got subsidized and dirt-cheap per megawatt, and nuclear stayed the thing everyone agreed was useful in theory and too risky to actually greenlight. Georgia’s Plant Vogtle expansion, which came in seven years late and roughly $21 billion over its original estimate before finally finishing in 2024, did nothing to change anyone’s mind in Austin.
What Nuclear Actually Does for the Texas Grid
Here’s the number that surprises people: nuclear covers around 8 to 10 percent of ERCOT’s generation mix, a share that’s held fairly steady for two decades even as total demand has climbed. According to the U.S. Energy Information Administration, Texas’s roughly 5,000 megawatts of nuclear capacity has stayed essentially flat since the 1990s — new demand gets met almost entirely by gas, wind, and solar, not by nuclear.
What makes that 8 to 10 percent disproportionately valuable is that it’s the least weather-dependent chunk of the mix. Wind output swings hard by season and time of day; solar disappears every night; gas plants can trip on fuel supply issues during a cold snap, which is exactly what happened during Winter Storm Uri in 2021. Nuclear plants run at close to full output around the clock for 18-to-24-month stretches between refueling outages, which is why grid operators treat that baseload slice as closer to guaranteed than almost anything else on the system. It’s a small percentage doing an outsized job of keeping the lights on during the hours everything else underperforms.
The Part Nobody Puts on the Brochure
Most write-ups on Texas nuclear stop at capacity numbers and grid percentages. Worth sitting with the parts that don’t make it into the boosterism.
Nuclear waste is the one nobody has a real answer for. Every gram of spent fuel either plant has ever produced is still on-site, because the federal government still hasn’t opened a permanent national repository — the Yucca Mountain project in Nevada has been politically stalled for decades. Both plants moved from pool storage into steel-and-concrete dry casks once their pools started filling up, a method the Nuclear Regulatory Commission has approved as safe since 1986 and continues to require heavy security around. That’s a permanent-feeling solution to what was supposed to be a temporary problem, and it’s not unique to Texas — it’s the same story at nearly every nuclear site in the country.
Cost and timeline risk is the other one. Comanche Peak and South Texas Project both proved it decades ago, and nothing about new nuclear construction since then has settled that risk. If Texas ever does build a large conventional reactor again, the honest expectation, based on every comparable U.S. project in the last twenty years, is a budget and schedule that both slip hard before the first kilowatt ships.
Emergency preparedness gets less attention than either of those, mostly because it’s boring until it isn’t. Both plants sit inside NRC-mandated 10-mile emergency planning zones with evacuation drills and sheltering protocols, and both zones have grown more populated as Houston and Dallas-Fort Worth sprawl outward. Neither has had an incident worth the term “close call,” but the zones are bigger than the original plant designs anticipated, purely because the surrounding land filled in with subdivisions nobody predicted in the 1970s.
The Next Wave: Small Modular Reactors
This is where the actual momentum is, and it’s a genuinely different bet than the last one. Small modular reactors, or SMRs, are built in factory-standardized pieces instead of poured and welded on-site over a decade, which is supposed to break the cost-overrun pattern that killed Texas’s appetite for reactor number three.
In 2025 the Texas Legislature passed House Bill 14, creating a $350 million Texas Nuclear Development Fund and a new state agency, the Texas Advanced Nuclear Energy Office, housed directly in the Governor’s office. It’s the largest state-level financial commitment to nuclear development anywhere in the country, and it’s aimed squarely at SMRs and microreactors rather than another large plant.
Two projects are already ahead of the announcement stage. Natura Resources is building the first new advanced research reactor licensed in the U.S. in almost 40 years, a molten-salt design housed at Abilene Christian University and backed by roughly $120 million in private funding plus a matching legislative appropriation. Separately, Texas A&M’s RELLIS campus near College Station has invited four companies — Natura, Aalo Atomics, Kairos Power, and Terrestrial Energy — to build demonstration reactors on-site, effectively trying to become a testing ground where multiple SMR designs run side by side. As the Texas Tribune reported, that cluster approach is now drawing more active reactor-siting interest than any other state has managed to attract in one place.
None of that means a wave of new plants by 2030. Every one of these projects is still in research, demonstration, or early construction phases, and SMR economics haven’t been proven at commercial scale anywhere in the U.S. yet. But it’s a real change from three decades of Texas treating nuclear as a settled question. The Texas Comptroller’s office has started tracking advanced nuclear alongside the state’s traditional energy sectors for the first time — not because two plants suddenly became more interesting, but because the state that builds everything else finally decided it’s worth trying to build this again, differently.
