Overview

The Global Nuclear Power Tracker is a comprehensive dataset providing insights into nuclear power throughout its history and across all statuses and geographies.

It tracks ~1,750 nuclear power units across all statuses, including operating, retired, prospective, and cancelled. While many sources focus on currently operating or historical plants, the GNPT reveals the full scope of all nuclear proposals ever announced, spanning over 1,500 gigawatts (GW) of total capacity, with cancellations alone representing 40%. This dataset covers the complete history of nuclear power around the world, from the first experimental power reactors whose construction began in the 1940s to modern plans for small modular reactors. The GNPT tracks buildouts, delays, and status changes across eight decades, illuminating critical patterns in deployment timelines relevant to long-term energy planning.

Historically, more proposed nuclear units have been cancelled than completed. 566 GW of nuclear power were cancelled before coming online, a trend driven by extended timelines, cost overruns, regulatory hurdles, or shifting energy priorities. While 538 GW of nuclear power have been operational at some point in time, the world’s operating fleet as of 2026 stands at ~401 GW across ~421 reactors, with another 81 GW under construction and 282 GW in earlier stages of development.

As governments, businesses, and civil society groups pursue climate and decarbonization goals amid rising electricity demand from data centers and AI, nuclear power remains under discussion as a low-carbon source of baseload electricity. Yet, its delivery challenges and attrition record continue to shape investment and policy choices. By mapping the history of nuclear power over time and across geographies, the GNPT helps business leaders, policymakers, researchers, and market participants assess its full history and future outlook.

Methodology

Frequently Asked Questions