Nuclear breakout time is the intelligence community's term for the number of days a country would need—from the moment it decided to pursue a nuclear weapon—to produce 25 kilograms of uranium enriched to 90% purity (weapons-grade). It does not include the additional one to two years typically required to design and build a deliverable warhead.
Under the JCPOA, Iran's breakout time was maintained at approximately 12 months. After the deal's collapse, Iran enriched uranium to 60% purity—far beyond the 3.67-5% needed for civilian reactors—reducing the technical work needed to reach weapons grade. By 2025, the Defense Intelligence Agency assessed Iran could produce enough weapons-grade uranium for one bomb in "probably less than one week."
The Arms Control Association and the Institute for Science and International Security both documented Iran's formal breakout timeline as effectively zero by 2025, making nuclear verification a central issue in the 2026 Geneva talks.