A nuclear power primer: sized for every application

Research evidence excerpt

A nuclear power primer: sized for every application

Reactor Sizes

Nuclear power is not a single technology, but a set of reactor classes differentiated by

scale, deployment model, and end use. Large reactors, small modular reactors (SMRs),

and microreactors each provide firm, carbon-free generation, but differ in capital

intensity, construction approach, and market application.

These distinctions are important because they shape both economic characteristics

(cost, financing, build time) and deployment pathways across different customer

segments.

Key Distinctions Across Reactor Sizes

• Large reactors (≥1 GW): Designed for utility-scale baseload generation, serving as

long-duration, high-capacity assets within the core grid system

• Small modular reactors (SMRs) (~50–300 MW): Mid-scale systems intended for

modular deployment across utilities, industrial users, and large commercial loads,

with greater flexibility in siting and capacity expansion.

• Microreactors (≤20 MW): Small, highly distributed systems designed for niche or

off-grid applications where reliability, autonomy, or energy security are primary

considerations

Exhibit 1: Comparison of Scale, Economics, & Use Case for Reactor Types

Reactor Size Characteristics

Category Large Reactors SMRs Microreactors

Typical Size ≥1,000 MW ~50–300 MW ≤20 MW

Core Use Case Utility-scale baseload Flexible firm capacity Off-grid / niche

Role in System Grid backbone Mid-scale, modular Grid edge / beyond-grid

Target Customers Regulated utilities Utilities, industrials, data centers Military, mining, remote sites

Cost Profile Lowest $/kW (scale) Moderate, improving with repetition Highest $/kW

Capital Profile Very large upfront Smaller, phased build Smaller absolute capital

Deployment Timeline Longest (multi-year) Medium Shortest