Highlights

In imagery dated to late September and early October all three tunnel entrances show recent or ongoing activity to different extent.  However, the visible activity does not indicate a dash to remove possible centrifuge or enriched uranium stocks inside the tunnel complex; rather it points more towards preparing controlled and secure access to two of the three tunnel entrances, and hardening the entrances and utilities against future strikes.

While two of three tunnel entrances have now been largely cleared, and no visible damage remains to their doors, the extent of damage to the tunnels remains unclear.  The United States and Israel have not issued any statements about the damage done to the tunnel entrances by the many Tomahawk warheads used to attack the three tunnel entrances.  This is in contrast to Fordow, where the United States presented detailed information about the bombing of this site.

A question is whether more damaging Joint Multiple Effects Warhead System (JMEWS) warheads were included on the Tomahawk missiles that struck Esfahan.   These relatively newer warheads have blast-fragmentation capabilities and increased penetration capabilities giving them much greater bunker busting capabilities against hardened targets compared to standard high explosive warheads.  

In addition, Los Alamos National Laboratory has worked turning unused fuel in a Tomahawk to create a thermobaric explosion, which can act as an additional warhead, possibly more powerful than the main warhead itself, given sufficient leftover fuel.

The addition of these destructive capabilities could have caused much greater damage to the inside of the tunnel complex than reported so far publicly.

Northern Tunnel Entrance

As the Institute reported earlier, by the end of July, the northern most tunnel entrance was cleared and repaired after having suffered structural damage in addition to the collapse of the extending framework during the 12-Day War.  It is possible that at that point, regular vehicle access was established.  The portal shows no remaining visible damage, however, the extent of damage inside the tunnel cannot be determined.  Additionally, accessing the tunnel may not be safe.    

A September 30th image shows a backhoe in front of the northern tunnel entrance.  The backhoe seems to be piling rocks up next to the portal entrance (see Figure 1).  This is probably to prevent erosion and possibly a step towards hardening the entrance in the event of additional attacks in the near future.  Unidentified objects remain outside the tunnel entrance in imagery dated to October 7 and 12.

The Middle Tunnel Entrance

Multiple vehicles, including heavy machinery, are visible right outside the entrance on September 30th.  Most of the dirt has been cleared from the tunnel entrance, so the door is now visible (see Figure 3).  Nonetheless, the door is still visibly closed on October 12, and an  unidentified object remains outside of it.

The probable utility alcove is adjacent to the main middle portal and connected to it via a pre-existing duct running below grade.  The duct was not destroyed in June; imagery from July on show that parts of it were covered with earthen material.

The Southern Tunnel Entrance

There are no signs of the portal being cleared; it remains blocked by dirt in a September 30th image (see Figure 4) and unchanged as of October 12.  There has been no effort to clean up the damaged framework of the portal and the remnants of the adjacent ventilation building.  The only notable change is a replacement of the roadblock; where the road was previously blocked by two trucks, it is now blocked by a truck and bollards (see Figure 5).  On October 12, the truck is seen at a different angle, indicating that it had moved and the access road is being used.

Discussion

The northern and middle tunnel entrances show no remaining visible damage.  But heavy machinery blocking both entrances in late September and early October indicates that Iran is prioritising slow and safe access.  Iran may have gotten access inside the tunnel complex through the northern entrance but there is no visible evidence of regular access.  In addition, the damage inside the tunnel remains unknown but could be severe.

Figure 1.  A view of the northern entrance showing heavy machinery outside of the portal.  A backhoe is blocking the tunnel entrance and appears to be piling rocks on the adjacent slope.

Figure 2.  Unidentified objects remain outside the northern tunnel entrance.

Figure 3.  The above image shows the portal entrance before the dirt was removed on September 4.  The below image shows a view of the middle entrance with the dirt removed on September 30.  The portal door is visible and heavy machinery is in front of it.

Figure 4.  A view of the southern entrance showing the portal still blocked by dirt.

Figure 5.  A view of the road to the southern entrance showing that it is restricted.