How Will X-energy's XE-100 Deployment Change PJM's Energy Mix?

X-energy has signed a Letter of Intent with Talen Energy to assess deploying multiple XE-100 small modular reactors across Pennsylvania and the broader PJM Interconnection market. The partnership targets X-energy's 80 MWe High Temperature Gas-Cooled Reactor design, which uses TRISO fuel and helium coolant for enhanced safety characteristics.

The agreement positions Talen Energy, which operates 10.8 GW of generation capacity across PJM, as a potential major customer for X-energy's commercial reactor fleet. PJM's 65 million customer base across 13 states represents the largest power market in North America, making this partnership strategically significant for SMR deployment at scale. X-energy's XE-100 design received $1.23 billion in DOE Advanced Reactor Demonstration Program funding and is targeting commercial operation by 2030.

The assessment will evaluate specific Pennsylvania sites and broader PJM opportunities where the XE-100's load-following capability and 60-year operating license could complement Talen's existing fossil fuel fleet. This marks X-energy's first major utility partnership announcement since completing its merger with GO Public in 2024.

X-energy's XE-100 Technology Profile

The XE-100 represents X-energy's flagship High Temperature Gas-Cooled Reactor design, rated at 200 MWth and 80 MWe per module. The reactor uses TRi-structural ISOtropic (TRISO) fuel pellets containing uranium dioxide kernels coated in carbon and silicon carbide layers, enabling operation at temperatures up to 750°C without fuel failure.

Key technical specifications include:

• Helium gas coolant operating at 7 MPa pressure
• Graphite moderator with prismatic fuel blocks
• High-Assay Low-Enriched Uranium fuel enriched to 15.5%
• 60-year design life with six-year refueling cycles
• Passive safety systems requiring no external power or operator action

The reactor's decay heat removal relies entirely on conduction, radiation, and natural convection, eliminating the need for active cooling systems during accident scenarios. X-energy projects TRISO fuel manufacturing capability of 40 metric tons annually by 2030 through partnerships with BWXT.

Talen Energy's Strategic Position in PJM

Talen Energy operates a diverse 10.8 GW portfolio across PJM, including 6.2 GW of natural gas, 3.7 GW of coal, and 890 MW of nuclear capacity at Susquehanna Steam Electric Station. The company's Pennsylvania footprint includes major facilities like the 1,884 MW Montour combined-cycle plant and 829 MW Brunner Island coal station.

PJM's capacity market structure provides revenue certainty for baseload power resources, potentially supporting XE-100 economics through Base Residual Auctions. The regional transmission operator's 2023 capacity auction cleared at $269.92/MW-day for the 2026-2027 delivery year, establishing benchmark revenue streams for new nuclear resources.

Talen's existing nuclear experience at Susquehanna, combined with established transmission interconnections across Pennsylvania, positions the utility to evaluate XE-100 deployment at existing fossil plant sites. Coal plant retirements in PJM totaled 4.8 GW in 2023, creating replacement generation opportunities for clean baseload resources.

Regulatory and Market Dynamics

X-energy submitted its XE-100 design for NRC review under 10 CFR Part 52, targeting design certification completion by 2027. The company received NRC acceptance for its Topical Report on TRISO fuel qualification in 2024, establishing regulatory precedent for prismatic High Temperature Gas-Cooled Reactor fuel licensing.

Pennsylvania's nuclear policy environment supports advanced reactor deployment through Act 87 of 2022, which established a state-level advanced nuclear working group. The legislation directs regulatory streamlining for SMR projects and potential state-level financial incentives complementing federal tax credits.

PJM's minimum offer price rules (MOPR) were modified in 2021 to accommodate state-subsidized resources, reducing barriers for SMR deployment supported by state clean energy policies. The market operator projects 40 GW of coal and oil retirements through 2030, creating substantial replacement capacity needs across the footprint.

Commercial and Financial Implications

The X-energy-Talen partnership represents a critical commercial milestone for HTGR technology deployment beyond DOE demonstration projects. Talen's investment-grade credit rating (BBB-/Baa3) and established customer relationships across PJM provide financial stability for multi-unit XE-100 development.

Industry analysts estimate XE-100 LCOE at $55-75/MWh for First of a Kind units, improving to $45-60/MWh for subsequent deployments. PJM energy prices averaged $34.70/MWh in 2025, requiring XE-100 projects to capture additional revenue from capacity markets and state clean energy programs.

X-energy's ARDP funding supports construction of the first commercial XE-100 at Dow Chemical's Seadrift facility in Texas, providing operational data to support Pennsylvania deployment economics. The company projects construction timelines of 42-48 months for subsequent units, significantly faster than large nuclear plant schedules.

Key Takeaways

• X-energy and Talen Energy signed LOI to assess XE-100 SMR deployment across Pennsylvania and PJM market
• Partnership leverages Talen's 10.8 GW generation portfolio and established PJM presence
• XE-100 design offers 80 MWe capacity with TRISO fuel and passive safety systems
• PJM capacity market structure provides revenue certainty for baseload nuclear resources
• Pennsylvania's nuclear-friendly policy environment supports advanced reactor deployment
• Commercial operation timeline targets late 2020s following NRC design certification

Frequently Asked Questions

What makes the XE-100 reactor design different from other SMRs? The XE-100 uses TRISO fuel pellets and helium gas coolant in a high-temperature gas-cooled reactor design, operating at 750°C compared to 320°C for traditional PWRs. This enables higher thermal efficiency and passive safety systems that require no external power during accidents.

How large is Talen Energy's existing nuclear experience? Talen Energy operates the 2,542 MW Susquehanna Steam Electric Station in Pennsylvania, providing nuclear operations experience and established NRC relationships that could support XE-100 deployment.

When could the first X-energy reactor in PJM begin operation? X-energy targets NRC design certification by 2027 and commercial operation of its first XE-100 by 2030. Pennsylvania deployment would likely follow in the early 2030s pending site-specific licensing and construction.

What is PJM's role in SMR deployment economics? PJM's capacity market provides revenue certainty through Base Residual Auctions, while energy markets offer additional revenue streams. The regional operator projects 40 GW of fossil plant retirements through 2030, creating replacement capacity opportunities.

How does TRISO fuel affect reactor economics and safety? TRISO fuel enables the XE-100 to operate without active cooling systems during accidents, reducing safety system complexity and licensing requirements. The fuel's six-year cycle length also improves capacity factors compared to annual refueling schedules.