At Elemental, we're working to make reliable, customer-focused nuclear energy available on a practical timeline. In this update, David explains how the modular design of our ISTR + BCG systems could support a target of less than 12 months for site development and commissioning after NRC licensing approval. By carrying out much of the work in factories while site preparation progresses, we aim to simplify and shorten the on-site phase. The schedule will depend on licensing, supply-chain readiness and site conditions, as outlined below.
Modular construction enables Elemental's ISTR + BCG systems to target less than 12 months of site development and commissioning for behind-the-meter deployment once NRC licensing is approved, by shifting the bulk of work off-site into factories and minimizing on-site activities.
Core Enablers Specific to the ISTR + BCG Design
The ISTR is a compact (~25 MWt / 10 MWe), atmospheric-pressure, sodium-cooled system using proven U-ZrHₓ fuel. The BCG is an equally compact sCO₂ Brayton cycle power conversion unit. Together they avoid many of the large, complex, site-intensive structures of traditional nuclear plants (high-pressure vessels, large containment, extensive steam systems, large cooling towers). This supports a highly modular architecture in which major components and skids are factory-built, tested, and shipped for rapid integration.
How Modularity Compresses the Site Timeline
Factory fabrication of major modules in parallel with site work
Reactor vessel/core modules, primary sodium systems, intermediate heat exchangers, BCG turbomachinery skids, recuperators, compressors, turbines, and control/electrical packages can be manufactured, assembled, and pre-tested in controlled factory environments. Site preparation (grading, foundations, non-nuclear electrical and mechanical interconnects, security) proceeds simultaneously. Once licensing is in hand, pre-qualified modules are delivered and set rather than built from scratch on site.
Minimal civil and structural scope
Atmospheric-pressure operation and the high power density of sCO₂ reduce the need for massive reinforced-concrete structures or large containment buildings. Foundations and enclosures are simpler and smaller. Behind-the-meter siting on industrial, data-center, or remote sites often means existing infrastructure (power distribution, cooling interfaces, roads, security) can be leveraged, further cutting civil work.
Standardized, repeatable design
A standardized plant design reduces site-specific engineering. Modules are designed for "plug-and-play" interfaces. Factory quality control improves reliability of the modules that arrive on site and shortens the integration and testing phase.
Behind-the-meter advantages
No multi-year transmission interconnection queue or large grid upgrades are required. Power is delivered directly to the customer load. This removes a major external schedule risk and allows the project to focus purely on local site readiness and system integration.
Short commissioning path
Because key systems are factory-tested, on-site work concentrates on final connections, integrated system testing, fuel loading (if not already completed under a manufacturing license pathway), and startup. For systems of this scale, industry analyses of modular microreactor and small advanced reactor approaches indicate that site assembly and commissioning can be reduced to months rather than years once the design is licensed and modules are available.
Resulting Timeline Profile (Post-NRC Approval)
- Months 0–3/4Finalize site foundations and non-nuclear balance-of-plant while factory modules are completed and shipped.
- Months 3–8Module placement, mechanical/electrical integration, and system tie-ins.
- Months 8–12Integrated testing, commissioning, fuel loading/startup (as applicable), and commercial operation.
This pathway is consistent with the broader modular SMR and microreactor model (factory fabrication + parallel execution + reduced site scope) that studies show can cut construction durations substantially versus stick-built plants. Elemental's compact, atmospheric-pressure ISTR and high-density BCG architecture are particularly well suited to realizing the lower end of those timelines for behind-the-meter applications. Actual project schedules will depend on design maturity, supply-chain readiness, final regulatory framework details (including any manufacturing license or design certification pathway), and specific site conditions, but the modular approach is the primary mechanism that makes a sub-12-month post-licensing site deployment target feasible.
Our modular approach is designed to move more of the work into factories and allow site preparation to happen at the same time. As David explains, a deployment in under 12 months after licensing is a target, and the actual schedule will depend on the design, supply chain, regulatory pathway and site. We'll share further updates as the project progresses.