First-of-a-Kind deployment prospects for small modular reactors

Technical Summary: First-of-a-Kind Deployment Prospects for Small Modular Reactors

Problem Statement
Small modular reactors (SMRs) are increasingly promoted as a flexible, low-carbon energy source capable of faster and cheaper deployment than conventional gigawatt-scale reactors. However, their actual contribution to global nuclear expansion remains uncertain due to persistent technical setbacks, licensing delays, and cost overruns. A critical empirical challenge exists in estimating First-of-a-Kind (FOAK) deployment timelines: existing SMR projects have a limited operating record, project histories are often incomplete, and deployment prospects vary significantly across regions and technologies. Current capacity projections frequently rely on vendor-announced timelines and assumed commercial readiness, failing to adequately account for the schedule delays, attrition risks, and phase-specific uncertainties that govern whether and when FOAK deployment actually occurs.

Methodology
To address these gaps, the authors developed a design-level probabilistic framework that links project progression with pipeline evolution. The study is built upon a newly constructed database of 75 SMR designs spanning four decades, categorized into five sequential development phases: conceptual design, basic design, detailed design, licensing, and construction.

The framework consists of two integrated modules implemented within a Monte Carlo discrete-event simulation (10,000 iterations):

1. Project-Progression Module: Estimates FOAK timing for active designs by parameterizing phase durations from historical SMR and conventional nuclear project timelines. This module isolates timing divergence between vendor targets and modelled development paths without applying failure risks initially.
2. Pipeline-Evolution Module: Extends the analysis to simulate post-2025 design additions based on historical entry rates. Crucially, this module applies phase-specific failure risks (attrition) derived from observed project outcomes (cancellations, suspensions, and stalled developments) to both active and simulated designs.

The analysis compares two scenarios:

• Baseline: Uses empirically derived phase durations, design-entry rates, and attrition assumptions.
• Accelerated: Assumes faster progression through development phases (truncating the upper quartile of duration samples), higher design-entry rates, and lower phase-specific attrition, serving as a favourable bounding case rather than a specific policy pathway.

Key Contributions

• Probabilistic Framework: The paper introduces a method to estimate FOAK deployment that explicitly models uncertainty in project timing and completion, moving beyond deterministic vendor schedules.
• Comprehensive Database: The construction of a longitudinal database tracking 75 designs across five distinct development phases, allowing for systematic comparison of FOAK dynamics across different jurisdictions and reactor technologies.
• Quantification of the "Vendor-Ambition Gap": The study provides a rigorous quantification of the discrepancy between vendor-announced FOAK targets and modelled projections based on historical progression data.
• Differentiation of Technology and Region: The framework explicitly distinguishes between water-cooled designs and Advanced Modular Reactors (AMRs), and analyzes deployment trajectories across OECD and non-OECD regions.

Results

• Systematic Overambition: Vendor-announced FOAK timelines are systematically overambitious. Even under optimistic assumptions, the model projects that only a median of 13 additional designs (P10–P90: 11–16) will reach FOAK operation by 2035, far below the 34 implied by vendor announcements.
• Delay Magnitude: The median vendor-ambition gap is 10.5 years under the Baseline scenario and 4.8 years under the Accelerated scenario. Water-cooled designs show smaller gaps (6.9 years Baseline) compared to AMRs (13.5 years Baseline).
• Cumulative Deployment by 2050:
  • Baseline Scenario: Cumulative FOAK deployment reaches a median of 24 SMRs (P10–P90: 18–30).
  • Accelerated Scenario: Cumulative FOAK deployment reaches a median of 48 SMRs (P10–P90: 39–58).
• Regional and Technological Asymmetries:
  • Near-term: Deployment remains concentrated in China and Russia, driven by existing operational units and designs nearing construction.
  • Long-term: Growth shifts toward OECD markets (North America and Europe) from the mid-2030s onwards.
  • Technology: Water-cooled SMRs dominate early deployment. AMRs become increasingly important in later deployment, particularly under Accelerated assumptions, though they face higher attrition risks in early phases.
• Sensitivity Analysis: Results are sensitive to regulatory acceleration and pipeline health. "Stalled development" scenarios yield the most constrained outlook (median 17 by 2050), while "Current-phase completion" yields the most optimistic (median 32 by 2050) under Baseline assumptions.

Significance
The paper argues that its findings define the feasible starting conditions for subsequent scale-up (Nth-of-a-Kind deployment). By grounding deployment expectations in observed project progression rather than announced timelines, the framework helps distinguish plausible pathways from aspirational market narratives. The results suggest that market outlooks and policy timelines built around vendor schedules may substantially overstate the pace of near-term SMR deployment. Furthermore, the study clarifies that even optimistic FOAK outcomes leave a limited set of designs with sufficient time to progress from initial operation to serial production before mid-century, challenging the feasibility of net-zero-aligned pathways that assume massive SMR capacity (e.g., 150 GWe) by 2050 without rapid NOAK scale-up. The framework provides a foundation for analyzing early deployment uncertainty in emerging energy technologies characterized by long development cycles and high capital intensity.