Satellite images taken on July 5, 2025, have revealed a flurry of construction activity at Israel’s Shimon Peres Negev Nuclear Research Center near Dimona, reigniting debate and speculation about the country’s long-suspected nuclear weapons program. The images, captured by Planet Labs PBC and analyzed by a panel of seven nuclear weapons experts, show thick concrete retaining walls, cranes looming overhead, and what appears to be multiple underground floors forming the skeleton of a major new structure at the heart of Israel’s secretive nuclear complex.
According to The Associated Press, the unanimous verdict among these experts is that the new construction is directly linked to Israel’s nuclear weapons program. However, they were split on the facility’s exact purpose—a division that underscores the pervasive secrecy surrounding Israel’s nuclear activities. Three of the experts believe the site is likely a new heavy water reactor, capable of producing plutonium and tritium, both essential for manufacturing and enhancing nuclear warheads. The remaining four suggest it could be a facility for assembling nuclear weapons, though they caution that the early stage of construction makes definitive conclusions elusive.
“It’s probably a reactor—that judgement is circumstantial, but that’s the nature of these things,” said Jeffrey Lewis, a nonproliferation expert at the James Martin Center for Nonproliferation Studies, as quoted by Israel Hayom. “It’s very hard to imagine it being something else.” Lewis based his assessment on the satellite images and Dimona’s long history as the centerpiece of Israel’s nuclear program.
Other experts echoed his caution. Edwin Lyman, from the Union of Concerned Scientists, noted the absence of a visible containment dome—typically a hallmark of reactor design—but allowed that one could be added later or omitted by design. “Israel does not allow international inspections or verification of what it is doing, forcing the public to speculate,” Lyman told The Associated Press. Daryl G. Kimball, executive director of the Arms Control Association, added, “If this is a heavy-water reactor, they are seeking to preserve the ability to produce spent fuel that can then be reprocessed to extract plutonium for more nuclear weapons. Or they are building a facility to maintain their arsenal or manufacture additional warheads.”
The ongoing construction at Dimona is not an isolated event. It comes on the heels of a tense period in regional nuclear politics. In June 2025, Israel, joined by the United States, bombed multiple Iranian nuclear sites, including the heavy water reactor at Arak. These strikes, described by PressTV as “a blatant and unprovoked act of aggression,” resulted in the deaths of Iranian military commanders, nuclear scientists, and civilians. A week later, the U.S. launched its own attacks on three Iranian nuclear facilities, actions widely condemned as violations of international law and the Nuclear Non-Proliferation Treaty (NPT).
Experts say the timing of Israel’s construction, so soon after these strikes, could provoke international outcry. The project “could trigger international criticism, particularly given its timing—Israel and the U.S. bombed nuclear sites across Iran in June, fearing Tehran would use its highly enriched uranium to build nuclear weapons,” reported Israel Hayom. Among the targets was Iran’s heavy water reactor at Arak, a facility similar in function to Dimona’s reactor.
Secrecy is a hallmark of Israel’s nuclear policy. The country neither confirms nor denies possessing atomic weapons and bars international inspections of its military nuclear facilities. This policy of “nuclear ambiguity” has been in place since Israel began constructing the Dimona site in the late 1950s, in the shadow of the Holocaust and amid repeated wars with its Arab neighbors. The International Atomic Energy Agency (IAEA) in Vienna reiterated recently that Israel “is not obligated to provide information about other nuclear facilities in the country” outside of its Soreq research reactor.
Despite the lack of official acknowledgment, Israel is widely believed to possess between 90 and 400 nuclear warheads, according to estimates from organizations like the Bulletin of Atomic Scientists and various international reports. This makes Israel the only state in West Asia with a nuclear arsenal, a fact that has long shaped regional security dynamics. The country is one of only four in the world never to have signed the NPT, joining India, Pakistan, and North Korea. As a result, the IAEA has no authority to inspect Dimona or any other suspected military nuclear sites in Israel.
The technical details of the construction add to the intrigue. The structure’s height and the presence of multiple underground floors suggest it could house a reactor core, as noted by Lewis. The lack of a containment dome, however, leaves open the possibility that the building is intended for another purpose, such as weapons assembly. The current heavy water reactor at Dimona has been operational since the 1960s, far longer than most reactors of its generation, and experts say it will likely need replacement or major refurbishment soon.
Heavy water reactors are prized for their ability to produce plutonium as a byproduct—a critical material for nuclear bombs. Tritium, another byproduct, is used to boost the explosive yield of warheads but decays at a rate of about 5% per year. Lyman suggested that the new construction could be aimed at producing more tritium, rather than expanding Israel’s plutonium stockpile. “If they are building a new production reactor, it doesn’t necessarily mean they are seeking to expand their plutonium stockpile but rather to produce tritium,” he explained.
Adding to the atmosphere of surveillance and secrecy, Israel’s Defence Minister Israel Katz announced on September 4, 2025, the launch of a new spy satellite. According to Morning Star, Katz said the satellite would enhance Israel’s ability to collect images across the Middle East. During a 12-day war earlier this year, Israel reportedly gathered more than 12,000 satellite images over Iran, with Katz posting on social media, “This is also a message to all our enemies, wherever they may be—we are keeping an eye on you at all times and in all situations.”
The current wave of construction at Dimona has been underway for years. The Associated Press first reported on excavations at the site in 2021, when satellite images showed a massive pit being dug near the original reactor. The latest images show that the project has entered a new, more advanced phase, with concrete walls and underground chambers taking shape. The lack of transparency and the site’s military significance mean it is unlikely that the world will get definitive answers any time soon.
For now, the intensifying construction at Dimona stands as both a symbol of Israel’s enduring nuclear ambiguity and a flashpoint in the region’s already volatile security landscape. As new evidence emerges and regional tensions continue to simmer, the world’s eyes remain fixed on the desert south of Jerusalem, where secrets are being built—one concrete wall at a time.