Small Modular Reactors: The Future of Nuclear?

The energy sector is currently witnessing a paradigm shift. For decades, the nuclear industry operated on the philosophy that bigger is better. However, massive cost overruns at traditional plants like Georgia’s Plant Vogtle have pushed investors and governments to look for alternatives. Enter Small Modular Reactors (SMRs). These “mini” nuclear plants promise to be cheaper, safer, and easier to build. But as recent project cancellations and supply chain issues show, the path to commercial viability is steep.

What Are Small Modular Reactors?

Small Modular Reactors are advanced nuclear reactors that have a power capacity of up to 300 MW(e) per unit. This is roughly one-third of the generating capacity of traditional nuclear power reactors. The definition relies on two distinct features:

  • Small: Physically smaller footprints allow them to be sited in locations not suitable for larger nuclear plants, such as retiring coal plants or remote industrial hubs.
  • Modular: This is the critical business differentiator. SMR components are factory-assembled and transported as a unit to a location for installation.

The goal is to move nuclear construction from a “custom civil engineering project” model to a “manufacturing” model. Companies like GE Hitachi and Holtec International argue that factory standardization will drive down costs significantly over time.

The Business Case: Why Investors Are Interested

The renewed interest in nuclear power is not just about climate goals. It is driven by the insatiable energy demand of artificial intelligence and data centers. Tech giants require 24⁄7 baseload power that wind and solar cannot provide without massive battery storage.

  • Grid Flexibility: SMRs can load-follow (adjust output based on demand) more effectively than traditional large reactors.
  • Safety Profiles: Many designs, such as the NuScale Power Module, utilize passive safety systems. In an emergency, these systems shut down and cool the reactor without the need for operator intervention or external power.
  • Repurposing Infrastructure: There is a strategic business case for placing SMRs at the sites of decommissioned coal plants. TerraPower, founded by Bill Gates, is currently pursuing this strategy in Kemmerer, Wyoming. This allows the new plant to utilize existing transmission lines and water cooling rights.

The Economic Reality Check

While the theory is sound, the financial reality has proven difficult. The premise of SMRs relies on “economies of numbers” rather than economies of scale. To make them cheap, you need to build them in mass quantities. However, you cannot build them in mass quantities until the first few are built and proven, which is incredibly expensive.

The NuScale Setback

The most prominent example of this economic friction is the recent cancellation of NuScale Power’s Carbon Free Power Project (CFPP) in Idaho. NuScale is currently the only SMR design to receive certification from the U.S. Nuclear Regulatory Commission (NRC).

Despite this regulatory win, the project collapsed in late 2023. The estimated cost for power from the plant jumped from $58 per megawatt-hour (MWh) to $89 per MWh. This price hike spooked the Utah Associated Municipal Power Systems (UAMPS), the coalition of utilities that had agreed to buy the power. When they could not secure enough subscribers for the higher price, the project was terminated.

This event highlighted a critical risk: First-of-a-kind (FOAK) costs are punishingly high.

Regulatory and Supply Chain Hurdles

Beyond simple economics, SMR developers face two massive logistical walls: regulation and fuel.

1. The NRC Approval Process

The U.S. Nuclear Regulatory Commission is known as the gold standard for safety, but their process is slow and expensive. Getting a design certified can take over five years and cost upwards of $500 million in fees and engineering hours.

While NuScale has crossed this finish line, competitors like X-energy and Westinghouse (with their AP300 SMR) are still navigating the process. The NRC is working to streamline rules for SMRs (Part 53 rulemaking), but the regulatory framework was originally built for massive, custom-built reactors, making the adaptation process sluggish.

2. The HALEU Bottleneck

This is arguably the most immediate threat to the industry. Many advanced SMR designs (including TerraPower’s Natrium reactor) require High-Assay Low-Enriched Uranium (HALEU).

Currently, Russia is the only commercial supplier of HALEU globally.

Due to the geopolitical situation following the invasion of Ukraine, relying on Russian supply chains is no longer viable for Western companies. This forced TerraPower to delay the launch of its Wyoming plant by at least two years, pushing the start date to 2030. The U.S. government is rushing to subsidize domestic HALEU production through companies like Centrus Energy, but scaling this production will take years.

Leading Competitors to Watch

Despite the hurdles, several companies are moving forward with significant backing:

  • TerraPower: Backed by Bill Gates, they are constructing the Natrium reactor in Wyoming. It uses liquid sodium for cooling rather than water, which operates at lower pressures and increases safety.
  • GE Hitachi: Their BWRX-300 design is gaining traction because it is based on existing, licensed fuel technology (not HALEU). This simplifies the supply chain. Ontario Power Generation has selected this model for deployment at their Darlington site, with a target completion around 2028-2029.
  • Rolls-Royce SMR: The British engineering giant is leveraging its history of building nuclear reactors for submarines. They are heavily supported by the UK government and aim to deploy units by the early 2030s.

The Outlook for 2030

Small Modular Reactors are likely the future of nuclear energy, but “future” is the operative word. We are currently in a “valley of death” between design certification and the first successful commercial operation.

For investors and industry watchers, the critical metrics to watch over the next 24 months are not just design announcements. Instead, look for:

  1. Domestic HALEU production targets being met by Centrus Energy.
  2. Firm order books rather than non-binding memorandums of understanding.
  3. Construction start dates for the GE Hitachi project in Ontario, which is currently the mostly likely candidate to prove the concept works in North America.

Frequently Asked Questions

How much does an SMR cost to build? Estimates vary wildly depending on the design. NuScale’s cancelled project was estimated at roughly $9.3 billion for a 462 MW plant. The industry goal is to get overnight capital costs down to $3,000 to $4,000 per kilowatt once factory production scales up.

Are SMRs safer than traditional reactors? Generally, yes. Most SMR designs incorporate “passive safety” features. This means they rely on natural physics (gravity and convection) to cool the reactor core in the event of a power failure, rather than requiring active pumps and human intervention.

When will the first SMR be online in the US? While NuScale aimed for 2029, that timeline has slipped. TerraPower is now targeting 2030 for its Wyoming demonstration plant, contingent on fuel availability.

What is the difference between SMRs and Microreactors? SMRs generally produce between 50 MW and 300 MW. Microreactors are even smaller, typically producing 1 MW to 20 MW. Microreactors are designed for very remote applications, such as military bases, islands, or mining operations.