Overview

Iran's nuclear infrastructure is spread across multiple sites, each serving a specific function in the uranium fuel cycle. Three facilities dominate the discussion: Natanz, where the bulk of centrifuge enrichment takes place; Fordow, a fortified underground plant that has become the focus of proliferation concerns; and Isfahan, where raw uranium is converted into the gas that feeds centrifuges. Understanding what each site does is essential for evaluating the impact of military strikes, the feasibility of reconstruction, and the timeline for any potential weapons breakout.

In February 2026, US-led strikes targeted Iranian nuclear infrastructure across all three locations. While satellite imagery confirmed significant surface damage at Natanz and Isfahan, the underground halls at Fordow are harder to assess. The IAEA has requested access to verify operational status but has not yet received authorization to inspect the strike-affected areas.

This article explains the technical role of each site, its physical characteristics, and its significance in the broader context of Iran's enrichment capacity and international verification efforts.

What We Know

As of February 28, 2026, coverage on natanz fordow isfahan explained should prioritize primary documentation and high-credibility reporting. This section focuses on confirmed information and labels uncertainty directly.

Analysis

Natanz has been the backbone of Iran's declared enrichment program since its existence was revealed in 2002. The above-ground pilot enrichment plant was damaged by the Stuxnet cyberattack in 2010 and a sabotage incident in 2021. In response, Iran accelerated construction of underground centrifuge halls at the site, burying them under reinforced concrete and earth. Before the February 2026 strikes, IAEA reports indicated Natanz housed approximately 12,000 installed centrifuges, including advanced IR-6 and IR-8 models that enrich uranium significantly faster than the original IR-1 design.

Fordow presents a different challenge. Built inside a mountain near the city of Qom, the facility was constructed covertly and only disclosed under diplomatic pressure in 2009. Its depth -- estimated at 80 meters of rock overhead -- makes it extremely difficult to destroy with conventional munitions. Fordow had been enriching uranium to 60% purity, a level that is technically a short step from the 90% weapons-grade threshold. Whether the February strikes penetrated deep enough to disable Fordow's centrifuge cascades is one of the most consequential unanswered questions of the current conflict.

Isfahan's role is less dramatic but no less important. The uranium conversion facility there transforms yellowcake (U3O8) into uranium hexafluoride (UF6), the gaseous compound that centrifuges process. Without a functioning UCF, Iran cannot produce fresh feedstock for enrichment. However, existing UF6 stockpiles -- which the IAEA estimated at over 5,500 kg before the strikes -- could sustain enrichment operations for months even if Isfahan is fully offline.

The interplay between these three sites defines Iran's breakout timeline. If Fordow's underground cascades survived and Isfahan's UF6 stocks remain accessible, Iran could continue enrichment operations at reduced capacity even with Natanz substantially damaged. Conversely, if all three are degraded, the timeline for reconstitution depends on centrifuge manufacturing capacity at sites that may not be fully mapped by Western intelligence.

What's Next

Several developments will determine whether Iran's nuclear infrastructure can be reconstituted and on what timeline.

Why It Matters

The physical geography of Iran's nuclear program is not an abstract detail -- it directly determines what military strikes can accomplish and what they cannot. Natanz's above-ground facilities are vulnerable to air attack, but the program's most sensitive work has been progressively moved underground and dispersed. The hardened design of Fordow was specifically intended to survive the kind of strikes that occurred in February 2026, and whether it succeeded is the central question for nonproliferation analysts.

For policymakers, the distinction between these sites matters because destroying surface infrastructure at Natanz and Isfahan may delay but not prevent reconstitution. Iran has demonstrated the ability to manufacture advanced centrifuges domestically, and the knowledge base required to rebuild cannot be bombed. If Fordow's underground halls survived, the enrichment program's most dangerous component may be intact.

For the public, understanding these three facilities cuts through oversimplified narratives about whether strikes "worked." The answer depends entirely on which sites were hit, how deep the damage reached, and whether Iran retains the feedstock and equipment to resume operations. These are empirical questions that only IAEA inspections and sustained intelligence monitoring can answer.

Sources

  1. IAEA: Iran focus page. www.iaea.org/newscenter/focus/iran
  2. IAEA: Iran board reports. www.iaea.org/newscenter/focus/iran/iaea-and-iran-iaea-board-reports
  3. IAEA: Additional Protocol. www.iaea.org/topics/additional-protocol
  4. CRS IF12106. www.congress.gov/crs-products/product/pdf/IF/IF12106
  5. AP: IAEA unable to verify enrichment halt. apnews.com/article/ccf574a324504b985f4b158f9d3d6941
  6. UNODA: NPT text. disarmament.unoda.org/wmd/nuclear/npt/text/

Last updated: February 28, 2026. This article is revised when new evidence materially changes what can be stated with confidence.