Nuclear Energy Readiness - Small Modular Reactors for Denver

The Problem

Denver Needs Firm, Clean Baseload Power - And Doesn’t Have It

Denver faces an energy trilemma: the grid is unreliable (see Power Reliability & Municipal Energy), demand is surging, and climate targets require eliminating fossil fuels. Wind and solar are essential - but they are intermittent. Colorado wind farms produce power roughly 35% of the time; solar panels roughly 25% (EIA, 2024). The other 65-75% of the time, something else has to keep the lights on.

Right now, that “something else” is natural gas. Colorado generated 46% of its electricity from natural gas in 2023 (EIA State Electricity Profile). Every megawatt-hour of gas generation produces approximately 0.4 metric tons of CO2. Replacing gas with renewables alone requires either massive battery storage - which does not yet exist at the scale needed - or accepting continued fossil fuel dependence for decades.

Nuclear power operates at 93%+ capacity factor - it runs around the clock, regardless of weather, season, or time of day. A single Xe-100 small modular reactor produces 80 MW continuously. A 4-pack produces 320 MW - enough firm, zero-carbon baseload for approximately 240,000 homes, roughly 75% of Denver’s households.

Data Center Demand Is Overwhelming the Grid

Xcel Energy has 5.8 GW of pending data center applications in Colorado - nearly matching its entire existing 6.2 GW capacity. Xcel projects 8.5 GW of data center demand by 2040 (Colorado Sun, 2025). These facilities require 24/7 uninterruptible power. If this demand is met with natural gas, Colorado’s climate targets are dead on arrival. If it is met only with wind and solar, the storage requirements are staggering and the cost is unknown.

This is not a hypothetical problem. Amazon Web Services has already committed $500 million to X-energy to deploy Xe-100 reactors specifically for data center power. Microsoft, Google, and Meta have all signed nuclear power agreements. The market has spoken: data centers need nuclear.

The question for Denver is whether this clean energy infrastructure gets built here - creating local jobs, tax revenue, and grid resilience - or whether Denver exports its power demand to reactors built in other states.

Colorado Just Opened the Door

In April 2025, Governor Polis signed HB25-1040, classifying nuclear energy as clean energy under Colorado law. This is a fundamental shift. Nuclear power is now eligible for:

• Clean energy project financing at the city and county level
• Counting toward Colorado’s clean energy targets (100% clean electricity by 2040)
• Inclusion in utility integrated resource plans alongside wind and solar
• State tax incentives available to other clean energy technologies

Denver International Airport has already begun responding. In August 2025, DIA issued an RFP for a $1.25 million SMR feasibility study - recognizing that the airport’s 45 MW current load (projected to exceed 85 MW) could be served by a single 80 MW Xe-100 module (American Nuclear Society, 2025). The study was paused for community input but signals serious institutional interest.

Why the Xe-100 Specifically

Not all small modular reactors are equal. The Xe-100, designed by X-energy, has specific advantages relevant to Denver and Colorado:

Passive safety through physics, not mechanical systems. The Xe-100 uses TRISO (Tri-structural Isotropic) pebble fuel - uranium encased in layers of carbon and ceramic that can withstand temperatures far exceeding any reactor condition. TRISO fuel is physically incapable of melting down. There is no containment failure scenario analogous to Three Mile Island, Chernobyl, or Fukushima. The reactor shuts itself down through the laws of physics if cooling is lost.

Helium-cooled, not water-cooled. This is critical for Colorado. The state receives 14-17 inches of precipitation per year - half the national average - and faces a megadrought on the Colorado River (see Water Security & Conservation). Light-water reactors consume enormous quantities of water for cooling. The Xe-100 uses helium gas as its coolant, requiring minimal water. In a drought-prone state, this is not a minor advantage - it is a prerequisite.

Modular and factory-built. Each 80 MW module is designed for factory fabrication and road transport to the site. This avoids the massive on-site construction that has historically driven nuclear cost overruns. Modules can be added incrementally - start with one, add more as demand warrants and costs are proven.

High-temperature output (750°C). Beyond electricity, the Xe-100 can provide industrial process heat for hydrogen production, desalination, district heating, and manufacturing. This versatility increases the economic case and creates applications beyond the electric grid.

60-year design life at 95%+ capacity factor. This is not a 20-year wind turbine or a 25-year solar panel. A single installation provides firm power for two generations.

The Cautionary Tale: NuScale’s Failure

Honesty requires acknowledging what went wrong with the only other US SMR project that reached the customer stage.

NuScale Power’s Carbon Free Power Project with the Utah Associated Municipal Power Systems (UAMPS) was canceled in November 2023 after costs ballooned from $5.3 billion to $9.3 billion - a 75% increase. The per-kilowatt cost reached $20,139/kW, roughly equal to the Vogtle conventional nuclear plant that itself became a cautionary tale. The target electricity price rose from $55/MWh to $89/MWh, and UAMPS could only secure commitments for 26% of the plant’s output (Clean Air Task Force, 2023).

What went wrong - and what Denver must learn from it:

1. NuScale’s design required massive on-site civil works. The light-water SMR modules sat in a large underground pool, incurring enormous fixed construction costs regardless of the number of modules. The Xe-100 avoids this - modules are self-contained, factory-built units that do not require a shared containment pool.

2. Wrong first customer. UAMPS was a consortium of small municipal utilities with no nuclear experience and no ability to absorb cost risk. Denver - if it pursues nuclear through a municipal utility or a franchise requirement - would bring far greater institutional capacity and financial depth.

3. Initial cost estimates were not trustworthy. NuScale’s costs more than doubled from $9,964/kW in 2015 to $21,561/kW by cancellation. This is not unique to NuScale - it is a pattern across nuclear projects globally. Any Denver nuclear proposal must include binding cost protections and off-ramps.

4. Premature commitment. NuScale launched the project before completing NRC design certification. Denver should not commit capital until the Xe-100 completes design certification and demonstrates costs at the Dow Seadrift facility in Texas.

What Denver Currently Does

Nothing. Denver has no nuclear energy policy, no integration of nuclear into clean energy planning, and no position on HB25-1040’s implications for city energy strategy. The DIA feasibility study - paused after community pushback - is the only institutional activity, and it was an airport initiative, not a city energy policy.

Our Solution

1. Denver Nuclear Energy Readiness Plan

Commission a comprehensive Nuclear Energy Readiness Plan examining:

• Site identification: Evaluate potential locations for SMR deployment in or near Denver, including DIA, industrial zones, former Superfund sites with existing infrastructure, and brownfield sites along the South Platte corridor. Coordinate with Adams County, Arapahoe County, and neighboring jurisdictions.
• Grid integration analysis: Model how 80-320 MW of firm nuclear baseload integrates with Denver’s existing renewable energy portfolio and Xcel’s grid - including how nuclear complements intermittent wind and solar rather than competing with it.
• Demand matching: Identify the specific loads best served by nuclear: data centers, DIA, water treatment plants, hospitals, district heating systems, and industrial hydrogen production.
• Regulatory pathway: Map the NRC licensing timeline, state permitting requirements under HB25-1040, and local land-use approvals needed for SMR deployment.
• Cost benchmarking: Establish transparent cost targets based on Xe-100 performance at Dow Seadrift and other early deployments - not on developer projections alone. Include binding ratepayer protection mechanisms.
• Workforce development: Partner with Community College of Denver, Emily Griffith Technical College, and Colorado School of Mines to develop nuclear technician and engineering training programs in advance of deployment.

Timeline: Commission study in 2027, complete by mid-2028, aligned with Xe-100 design certification timeline and DIA feasibility study results.

2. Support and Expand the DIA Feasibility Study

• Lift the pause on DIA’s $1.25 million SMR feasibility study with a structured community engagement process - not cancellation
• Expand the study scope beyond airport operations to evaluate SMR potential for the broader Denver metro area, including shared infrastructure with the city grid
• Require the study to evaluate the Xe-100 specifically (helium-cooled, TRISO fuel, no water cooling requirement) alongside other SMR designs
• Include an honest public comparison: nuclear vs. gas peakers vs. battery storage for meeting DIA’s projected 85+ MW load around the clock

3. Integrate Nuclear into Denver’s Clean Energy Framework

• Amend Denver’s climate action planning to include nuclear as a clean energy source, consistent with HB25-1040
• Include nuclear in any future municipal utility integrated resource plan (cross-reference: Power Reliability & Municipal Energy)
• Set a target: 50% of Denver’s electricity from firm, zero-carbon sources by 2040 - counting nuclear alongside hydropower and geothermal, distinct from intermittent wind and solar
• Require Xcel (or any successor utility) to evaluate nuclear as part of its Colorado resource plan filings with the PUC

4. Ratepayer Protection and Cost Accountability

The NuScale failure teaches that nuclear cost estimates cannot be taken on faith. Denver must build cost discipline into any nuclear commitment:

• No ratepayer exposure until technology is commercially proven. Denver should not fund first-of-a-kind construction risk. The Dow Seadrift demonstration and early commercial deployments must establish real-world costs before Denver commits capital.
• Fixed-price power purchase agreements (PPAs) - if Denver contracts for nuclear power, lock in a price per MWh with the developer bearing construction cost overrun risk, not ratepayers
• Milestone-based commitments with off-ramps at each stage: feasibility study → site selection → NRC licensing → construction start → commercial operation. Each stage requires demonstrated cost performance before proceeding.
• Independent cost verification at each milestone by a third-party engineering firm, not the reactor developer
• Transparent public reporting of all costs, timelines, and performance metrics

5. Address Rocky Flats History Directly

Denver’s relationship with nuclear technology is uniquely complicated. Rocky Flats produced plutonium triggers for nuclear warheads 16 miles from downtown Denver from 1952-1992, contaminating soil and groundwater with radioactive materials that will persist for 24,000 years (see Climate & Environmental Justice). Any nuclear energy proposal that ignores this history will - and should - face fierce opposition.

The response is not to avoid the conversation. It is to have it honestly:

• SMRs are fundamentally different from weapons production. Rocky Flats enriched weapons-grade plutonium and uranium with minimal safety culture in an era of Cold War secrecy. The Xe-100 uses low-enriched uranium (below 20% U-235, vs. 90%+ for weapons) in TRISO fuel that is physically incapable of melting. These are different technologies with different risk profiles. Acknowledging Rocky Flats’ legacy and making this distinction clearly is essential.
• Community consent is non-negotiable. No SMR siting in the Denver metro area without genuine, informed community engagement - not after-the-fact PR, but structured deliberation before any site selection. Frontline communities, including those affected by Rocky Flats, must have meaningful voice and veto power.
• Independent safety oversight. Any Denver-area SMR must be subject to independent environmental monitoring by a community-appointed panel - not just NRC oversight, but local accountability. Continuous public reporting of all radiological data.
• Rocky Flats accountability first. Denver should not embrace nuclear energy while the Rocky Flats contamination remains unresolved. Demanding independent assessment of Rocky Flats (as proposed in our Climate & Environmental Justice platform) and demanding accountability for SMR safety are complementary positions, not contradictory ones. A city that takes nuclear safety seriously does both.

6. HALEU Fuel Supply Chain

The Xe-100 requires High-Assay Low-Enriched Uranium (HALEU) enriched to just under 20% U-235. Russia was historically the primary global supplier, but the US banned Russian uranium imports in 2024. Domestic supply is being built but is not yet at scale:

• Centrus Energy (Piketon, Ohio) has produced over 920 kg of demonstration HALEU through mid-2025 and is scaling production under a DOE contract extended through June 2026 (Power Magazine, 2025)
• Nusano (Utah) targets initial commercial HALEU samples by Q4 2026, with large-scale production beginning Q1 2027 and 350 metric tons/year capacity by 2029
• DOE has committed $2.7 billion over ten years for domestic uranium enrichment expansion and $700 million from the Inflation Reduction Act specifically for the HALEU Availability Program

Denver’s readiness plan should track HALEU supply milestones as a gating factor - the reactor is only viable if domestic fuel supply is secured. By the time Denver would realistically deploy an SMR (early-to-mid 2030s), multiple domestic HALEU suppliers are expected to be operational.

International and Domestic Evidence

How We Pay For It

• Nuclear Energy Readiness Plan (feasibility study): $3-5M one-time. Funded through Denver Climate Protection Fund and DOE cost-share grants under the ARDP and advanced reactor programs. This is planning and analysis - not construction commitment.
• DIA feasibility study expansion: $1-2M incremental (on top of existing $1.25M RFP). Airport enterprise fund - no general fund impact.
• Workforce development programs: $2-3M/year for 5 years. Funded through DOE workforce development grants, Colorado Department of Higher Education, and employer partnerships with reactor developers. Nuclear technician jobs pay $60,000-100,000/year - this is economic development investment.
• SMR construction (if pursued, 2030s): A 4-pack Xe-100 (320 MW) is estimated at $1.5-2.5 billion based on current projections - but this number is uncertain and must be validated by real-world deployments. Financed through revenue bonds repaid by electricity sales (the standard model for utility infrastructure), federal production tax credits ($15/MWh under the Inflation Reduction Act for zero-carbon generation), DOE loan guarantees, and potentially private capital from data center operators who need firm clean power.
• What Denver does NOT pay for: First-of-a-kind construction risk. The Dow Seadrift and AWS/Energy Northwest projects will bear demonstration costs. Denver deploys proven technology, not experimental projects.

Net cost to Denver through 2030: $8-15M for planning, studies, and workforce development. Construction capital (2030s) financed through revenue bonds and federal incentives - not taxpayer funds.

Frequently Asked Questions

“After Rocky Flats, how can you propose nuclear energy for Denver?” Rocky Flats was a nuclear weapons plant that enriched weapons-grade plutonium with a reckless safety culture during the Cold War. An Xe-100 small modular reactor uses low-enriched uranium in TRISO fuel that is physically incapable of melting down, cooled by inert helium gas, with passive safety systems that shut the reactor down through the laws of physics - no operator action required. These are fundamentally different technologies. Acknowledging Rocky Flats’ contamination (which we demand be independently investigated - see Climate & Environmental Justice) and supporting modern nuclear energy are not contradictory. A city that takes nuclear safety seriously does both: demands accountability for past harm and insists on the highest safety standards for future technology.

“Aren’t renewables cheaper? Why not just build more wind and solar?” Wind and solar are cheaper per MWh when the wind blows and the sun shines. But electricity demand is 24/7, and Colorado wind produces power ~35% of the time, solar ~25%. The remaining hours require either battery storage (which does not exist at the scale needed and adds $50-150/MWh to the effective cost of renewables), natural gas (which defeats climate targets), or firm zero-carbon power like nuclear. The honest answer is that Denver needs both: renewables for the cheapest clean MWh when available, and nuclear for the firm baseload that keeps the lights on the other 65-75% of the time. This is not either/or. It is both/and.

“What about nuclear waste?” A single Xe-100 module produces approximately 3.5 cubic meters of spent fuel per year - roughly the size of a large desk. Compare this to the millions of tons of CO2 emitted annually by the gas plants nuclear would replace, or the thousands of acres of land required for equivalent wind and solar capacity. Used TRISO fuel is solid ceramic - it does not leak, flow, or dissolve in water. Long-term disposal is a federal responsibility under the Nuclear Waste Policy Act. The waste challenge is real but manageable and far smaller in scale than the waste streams from fossil fuels.

“SMRs are unproven. NuScale just failed.” NuScale’s failure was specific and instructive: a light-water design requiring massive on-site civil works, sold to a consortium of small utilities with no nuclear experience, launched before design certification was complete, with costs that doubled. The Xe-100 is a different reactor type (helium-cooled HTGR vs. light-water), with a different construction approach (factory-built modular units vs. site-built pool), backed by different customers (Amazon, Dow Chemical vs. small municipal co-ops). This does not guarantee success - which is exactly why our proposal is phased readiness, not immediate construction. Denver should prepare now and commit capital only after real-world deployment proves the economics.

“Can Denver afford this?” Denver cannot afford not to plan for this. The city faces 5.8 GW of pending data center demand, a failing Xcel grid, coal plant retirements, and a 2040 clean energy target. If the answer is “only wind, solar, and gas,” then either the climate targets fail or the grid fails. Nuclear is the missing piece of firm, clean baseload. The readiness plan costs $3-5M - less than 0.1% of Denver’s annual budget. The question is not whether Denver can afford to study this. It is whether Denver can afford to be unprepared when the technology is ready.

“What about the water issue? Colorado is in a drought.” This is one of the strongest arguments for the Xe-100 specifically. Conventional nuclear reactors are water-cooled and consume enormous quantities of water. The Xe-100 uses helium gas as its coolant, requiring minimal water - a critical advantage in a state that receives half the national average precipitation and faces megadrought on the Colorado River. Not all reactors are equal on this dimension, and Denver should insist on low-water or zero-water cooling designs.

“Is the fuel supply secure?” Not yet - but it will be by the time Denver would deploy. The Xe-100 requires HALEU fuel, which is currently in limited domestic supply. However, Centrus Energy is producing demonstration quantities in Ohio, Nusano targets commercial production by Q1 2027 with 350 metric tons/year by 2029, and DOE has committed $2.7 billion for domestic enrichment expansion. Denver’s realistic deployment timeline (early-to-mid 2030s) aligns with projected domestic HALEU availability. The readiness plan tracks fuel supply as a gating milestone.

References

• Colorado General Assembly. (2025). HB25-1040: Classify Nuclear Energy as Clean Energy. Signed by Governor Polis, April 2025.
• U.S. Energy Information Administration. (2024). Colorado State Electricity Profile. (46% natural gas, 30% wind, 8% solar generation mix, 2023.)
• U.S. Energy Information Administration. (2024). Electric Power Monthly. (Nuclear capacity factor 93.1%, wind 34.6%, solar 24.9%, 2023.)
• Colorado Sun. (2025, August 18). “Xcel has $22 billion in data center power demands.” (5.8 GW pending applications, 8.5 GW projected by 2040.)
• Colorado Sun. (2025, December 10). “Data center power demands in Colorado.”
• X-energy. (2025). Xe-100 reactor specifications. (80 MWe per module, 200 MWt, helium-cooled HTGR, TRISO pebble fuel, 60-year design life.)
• American Nuclear Society. (2025, August 7). “Denver airport may go nuclear.” (DIA $1.25M SMR feasibility study RFP.)
• Denver7. (2025). “After pushback, Denver International Airport temporarily grounds plan to study nuclear energy.”
• Clean Air Task Force. (2023, November). “Lessons learned from the recently cancelled NuScale-UAMPS project.” (Cost escalation from $5.3B to $9.3B, 26% subscription rate.)
• IEEFA. (2023). “Eye-popping new cost estimates released for NuScale small modular reactor.” ($20,139/kW cost, $89/MWh target price.)
• Power Magazine. (2025). “Centrus completes 900-kg HALEU delivery to DOE.” (Domestic HALEU production milestone.)
• Nusano. (2025, June). “Breakthrough HALEU program expected to produce up to 350 metric tons annually.” (Q4 2026 initial production, 2029 full-scale target.)
• U.S. Department of Energy. (2026, January). $2.7 billion commitment for domestic uranium enrichment expansion.
• U.S. Department of Energy. HALEU Availability Program. ($700M IRA funding for domestic HALEU supply chain.)
• World Nuclear Association. (2025). “Small Modular Reactors.” (SMR LCOE range $50-100/MWh, capacity factor data.)
• ScienceDirect. (2023). “Techno-economic analysis of advanced small modular nuclear reactors.” (Gas-cooled SMR LCOE estimated at $81.5/MWh.)
• CPR News. (2025, April 1). “Nuclear is now ‘clean energy’ in Colorado.”
• Amazon/X-energy. (2024). $500M investment announcement. Energy Northwest partnership for 320 MW initial Xe-100 deployment.
• Dow Chemical / X-energy. ARDP demonstration project at Seadrift, TX. (First Xe-100 commercial deployment.)
• American Public Power Association. (2024). Municipal utility performance data.
• Colorado PUC. (2025). Xcel Energy reliability performance briefing. (352 min average outage, 2024.)