The recent series of strange mishaps at Iranian military sites is likely to have only minimal effects on Iranian weapon programs, including its nuclear efforts. The most headline-grabbing incident occurred at Iran’s most important, declared nuclear facility. On July 2, an accident or act of sabotage severely damaged what Iranian officials have called a “shed” at the Natanz uranium enrichment site, located 140 miles south of Tehran. The “shed” is actually the Iran Centrifuge Assembly Center, based on the sign on its main entrance (Note to Iranian nuclear officials: Obfuscation is pointless when state news videos and an article on the building, which include group pictures at the entrance, are publicly available). 

Sabotage of Iran’s Nuclear Program a Consideration

Iran used this centrifuge assembly building to research and develop components in advanced centrifuges. Centrifuges enrich uranium 235, one of two fissile materials used in nuclear weapons (plutonium 239, created in nuclear reactors, is the other fissile isotope). The New York Times reported that a Middle Eastern intelligence official said Israel was responsible for the attack, “using a powerful bomb.” Additionally, it was reported that an Islamic Revolutionary Guards Corps official confirmed the use of a bomb. If it was an act of sabotage, it could raise questions about the perpetrator’s cost versus benefit calculations if it does not measurably or significantly delay Iran’s nuclear program.

Level of Delay to Iran’s Nuclear Program

Regardless of what caused the considerable damage to the assembly building, reconstitution, or recuperation times can assist in determining how much this notable incident has delayed or disrupted Iran’s nuclear program. In its most simple form, reconstitution/recuperation is required for an entity to recover from damage or disruption in order to perform its functions. Reconstitution requirements are necessary to develop business continuity plans. And assessments of expected reconstitution times are also a best practice when deliberating offensive attacks — including sabotage — against adversary infrastructure and programs. Common business continuity concepts that can be useful in assessing the impact of this incident on Iran’s nuclear program:

Repair and Replacement Times

Repair and replacement times are affected by the level of damage, availability and skill of repair personnel, the availability and capability of their repair or construction equipment, the willingness to begin this repair/replacement and supply chain status. It took the Iranians five to six years to construct the centrifuge assembly building, according a spokesman for the Atomic Energy Organization of Iran (Iran’s nuclear agency) and commercial satellite imagery reviewed by the Institute for Science and International Security. It subsequently operated for two years or less before the fire or explosion in early July. Now the building can be considered destroyed based high-resolution satellite imagery released by Maxar Technologies; the U.S. military considers an adversary building to be destroyed if at least 50 percent of it is damaged. Because of the extent of damage and the fact that centrifuges are extremely sensitive to vibrations, we can write off any centrifuges that were inside the building — assuming explosives caused the damage (the aforementioned state media article from 2016 mentioned 60 centrifuges). In fact, a spokesman for the AEOI not only claimed that Iran plans to “rebuild the damaged shed at Shahid Ahmadi Roshan (Natanz) nuclear facility and a bigger shed with more advanced equipment is to [sic] replace it,” but also that the damaged equipment can no longer be used.

Recovery Point Objectives

RPO, used primarily for information technology, is the point to which information used by an activity must be restored to enable the activity to resume operations.  It can be thought of as the amount of data that will be lost in the event of data destruction or loss of access. For example, if the technicians at the centrifuge assembly building never backed up their R&D data (or if they stored all their backups only in the centrifuge assembly building), they would have had an RPO equivalent of 0, or no RPO at all. If they decided on an RPO of 24 hours, that means they decided to backup their data once per day. The incident occurred at 2 AM Tehran time. So, if they did data backups at 1 PM daily (The Dhuhr prayer, the second prayer of the day in Islam, occurs shortly after 1 PM in Natanz during July), they would have lost all data between approximately 1 PM Wednesday July 1 and the 2 AM incident — 13 hours of data if the centrifuge assemblies were spinning after hours. These are hypotheticals, but highlight one of the issues with which Iranian nuclear technicians are undoubtedly dealing.

Recovery Time Objectives

RTO is the time goal for the restoration and recovery of functions or resources to prevent an unacceptable impact to the entity. In terms of IT, RTO would be how quickly the Iranians planned to resume work after a cyber security incident — after they update software security patches, remove malware, and recover their R&D data (again, possibly a moot point if no backups are available). In terms of operational activity such as the R&D that occurred at the destroyed building, RTO would be substantial; factors include replacement time for the building and also restarting the R&D effort where it left off. But for the overall nuclear program, RTO might not be substantial or matter much. Iran already has over 6,600 centrifuges: 

  • 5,060 first-generation IR-1 centrifuges at the Natanz Fuel Enrichment Plant (FEP)’s deeply buried underground bunkers;
  • 553 advanced centrifuges of various models at Natanz’ above-ground Pilot Fuel Enrichment Plant (PFEP). These are most relevant to recovering from the July 2 incident, as the Iranians used the centrifuge assembly “shed” to work on advanced centrifuges;
  • 1,044 centrifuges at the Fordow Fuel Enrichment Plant (FFEP) located 60 miles southwest of Tehran;


Interdependencies exist where two or more departments, processes, functions, and/or third parties support one another. For example, the grid electrical power that services the Natanz installation is a key interdependence. There are no known interdependencies of relevance to the July 2 incident. But in the future, damage to the relevant substation or power plant in Isfahan province would affect not only the “bigger shed with more advanced equipment” that the Iranians have said will replace the building destroyed on July 2, but would also affect the entire Natanz installation. 

Despite the Event, Iran still has over 500 advanced centrifuges

Despite the July 2 loss of the Iran Centrifuge Assembly Center that took several years to build, the unknown number of advanced centrifuges inside, and the associated R&D data that might have been lost, Iran still has over 500 advanced centrifuges at the same Natanz complex. This assumes they were not damaged by the shockwaves from what seems like an explosion at the destroyed building. But Iran does not need the advanced centrifuges for uranium enrichment; the first-generation IR-1s just enrich at a much slower rate. In estimates of Iran’s “breakout time” — how long it would take the Iranians to scrap the nuclear deal from which the U.S. withdrew, then dash towards building a nuclear bomb — advanced centrifuges are sometimes not even factored in.

For these reasons, and based on the limited information available about the now infamous “shed”, the destruction of the centrifuge assembly plant delayed the Iranian nuclear program by 0 days to a few months only (possibly no more than two or three months). The low end of the estimate is derived from the assumption that although centrifuge assembly technicians will have to spend a few days assessing their loss and its impact, Iran continues to enrich uranium with its older centrifuges. 

On the high end, a few months delay might result from Iranian assessments of physical and cyber security, insider threat investigations, allocating technical expertise to design and build a new centrifuge assembly building, and allocating this expertise to restructure its R&D on advanced centrifuges by using some of the remaining 533 advanced centrifuges at the Natanz Fuel Enrichment Plant. But even in this case, they still would not need advanced centrifuges, and thus an advance centrifuge assembly building, for a “breakout” effort to quickly build a nuclear bomb.

If It was an Attack, Iran not Behind Their Nuclear Schedule

In other words, if the incident was an act of sabotage — whether physical or cyber — the measure of performance was great, if not perfect. The sabotage destroyed the building. But the attack receives poor grades for measure of effectiveness. While the advanced centrifuge program and thus Iran’s overall nuclear program were clearly disrupted, Iran’s ability to develop a nuclear weapon by using its first-generation centrifuges has been minimally affected — if affected at all. With this in mind, it seems the extremely limited benefits of this attack (if it was an attack) are outweighed by the potential costs, such as potential Iranian retaliation or even a more robust and more secure Iranian advanced centrifuge program.

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K. Campbell, CPP® is a security and intelligence professional with 25 years of experience and training in intelligence; risk, threat, and vulnerability assessments; executive protection; counterterrorism; and business continuity. He is a Certified Protection Professional, board certified in security management by ASIS International. During his prior career as a U.S. military intelligence officer, his responsibilities included protective intelligence operations; effects (degrade, disrupt, destroy, etc.) recommendations against non-state and state entities such as critical infrastructure and terrorist networks; business continuity/continuity of operations; and war and contingency planning.