What Is Iran's "Nuclear Dust"? The Dangerous Stockpile Trump Wants Handed Over

President Trump has repeatedly demanded that Iran surrender what he calls its "nuclear dust." Is he actually talking about “dust”? In reality, he is referring to hundreds of kilograms of highly enriched uranium buried beneath damaged nuclear facilities—a stockpile that could dramatically shorten Tehran's path to a nuclear weapon. Any deal with Iran must take this into consideration.

By Dan Feferman

AI generated image of Trump and one of its statements

Since the February 28 joint American-Israeli strikes on Iran's nuclear facilities, President Donald Trump has repeatedly insisted that Iran cannot be allowed to possess nuclear weapons.

As negotiations between Washington and Tehran continue, one issue has emerged as a major point of contention: what Trump has described as Iran's "nuclear dust."

Understanding what that term means—and why it matters—is critical to understanding the broader debate over Iran's nuclear ambitions.

What Is Trump's "Nuclear Dust"?

Trump has repeatedly referred to Iran's stockpile of highly enriched uranium as "nuclear dust."

In a Truth Social post, Trump wrote:

"The Enriched Uranium (Nuclear Dust!) will either be immediately turned over to the United States to be brought home and destroyed or, preferably...destroyed in place."

Of course, the term is not a technical one.

Contrary to the image suggested by the phrase, the material is not literally dust. It is believed to be enriched material stored in canisters in the form of uranium hexafluoride (UF6), a gaseous compound used in the uranium enrichment process.

The issue is not the physical form of the material. The issue is that it is highly enriched uranium—the essential ingredient needed to build a uranium-based nuclear weapon.

How Uranium Enrichment Works

Iran's chosen pathway to nuclear weapons capability has long centered on uranium enrichment using gas centrifuges.

After uranium is mined from the earth, it can either be processed into fuel for civilian nuclear reactors or enriched to much higher concentrations suitable for nuclear weapons.

According to the U.S. Department of Energy, natural uranium contains only about 0.7 percent uranium-235 (U-235), the isotope capable of sustaining a nuclear chain reaction.

Most civilian nuclear reactors require uranium enriched to less than 5 percent U-235.

Nuclear weapons, by contrast, generally require enrichment levels approaching 90 percent.

This distinction is critical because Iran has gone far beyond the enrichment levels required for peaceful civilian energy production.

Why Iran's Highly Enriched Uranium Matters

The International Atomic Energy Agency (IAEA) reported that by mid-2025, Iran had accumulated roughly 440 kilograms of uranium enriched to 60 percent purity.

While 60 percent is below weapons-grade uranium, nuclear experts note that the vast majority of the enrichment work required to reach weapons-grade levels has already been completed by that point.

In practical terms, moving from natural uranium to 60 percent enrichment is far more difficult than moving from 60 percent to 90 percent.

That is why Iran's highly enriched uranium stockpile has become the central issue in nuclear negotiations. Essentially, they’re “almost at the finish line”. 

Why Trump Wants the Uranium “Dust” Handed Over

For Trump and many nonproliferation experts, destroying centrifuges and enrichment facilities is not enough. The uranium itself matters at this point. Trump has made clear that any future agreement must address the fate of the stockpile.

In another public statement, he declared:

"There will be no enrichment of Uranium ... [we will] dig up and remove all of the deeply buried nuclear 'dust.'"

The comment reflects concerns that highly enriched uranium may remain buried beneath damaged nuclear facilities, particularly at Isfahan and possibly Fordow. Trump has also suggested that the United States is closely monitoring the sites to ensure the material is not moved or recovered.

The message is clear: even if enrichment facilities have been damaged, the uranium stockpile remains the most strategically important asset in Iran's nuclear program.

Iran's Long History of Nuclear Deception

Iran is a signatory to the Nuclear Non-Proliferation Treaty (NPT), which permits the peaceful use of nuclear energy in exchange for strict international oversight and transparency. Under the treaty, Iran is obligated to declare nuclear-related activities to the International Atomic Energy Agency.

Yet Iran has repeatedly concealed key elements of its nuclear program. In 2002, the regime was caught secretly constructing the uranium enrichment facility at Natanz. In response, the United Nations Security Council passed multiple resolutions demanding that Iran suspend enrichment activities. Iran, of course, refused.

For years, Tehran insisted that its nuclear program was solely for peaceful purposes. That claim suffered a devastating blow in 2018 when Israel's Mossad Intelligence Agency successfully seized Iran's secret nuclear archive from a warehouse in Tehran. The documents revealed extensive evidence that Iran had conducted organized work related to the development of nuclear weapons while publicly denying such efforts.

The Mossad Archive Changed the Debate

The archive demonstrated that Iran had undertaken activities associated with nuclear weapons design, testing, and weaponization. The discovery significantly undermined Tehran's longstanding claim that its nuclear program had always been exclusively peaceful.

Today, Iran possesses all three essential components required for a nuclear weapons capability:

• Highly enriched uranium.

• Weaponization knowledge and research.

• Long-range ballistic missile delivery systems.

The existence of all three components continues to fuel concerns among the United States, Israel, and much of the international community.

The Real Battle Is Over the Uranium

Ultimately, the debate over Trump's "nuclear dust" is not about dust at all. It is about Iran's stockpile of highly enriched uranium—the most critical ingredient required to build a nuclear weapon. Military strikes can damage centrifuges, laboratories, and underground facilities.

But if hundreds of kilograms of highly enriched uranium remain intact, Iran could retain a substantial portion of its nuclear capability. That is why the future of this material has become one of the most important issues in ongoing negotiations.

Any agreement that fails to address Iran's existing stockpile of highly enriched uranium—as well as its future enrichment capabilities—risks leaving the core problem unresolved.

Dan Feferman is the co-founder and co-editor of MiddleEast24 and MidEastJournal. He is a veteran analyst and policy scholar of MiddleEast affairs, antisemitism, narrative warfare and radical ideologies. You can follow him at @danfeferman