barrels of nuclear waste
Sean Cate
Sean Cate
June 6, 2024 ·  3 min read

There is an enormous dome filled with lethal waste from U.S. nuclear blasts in the pacific – and its cracking 

A looming environmental disaster is silently unfolding in the vast expanse of the Pacific Ocean, amidst the beauty of remote islands. Deep within the Marshall Islands, a relic of the past is cracking under the weight of its deadly cargo. This article delves into the sinister legacy of U.S. nuclear tests in the Pacific and the precarious state of the Runit Dome, a concrete structure struggling to contain radioactive waste.

The Dark History of The Runit Dome1

On March 1, 1954, the sky over Bikini Atoll in the Marshall Islands was torn apart by an enormous red flash. This cataclysmic event marked the Castle Bravo test, the U.S. government’s first hydrogen bomb experiment. It yielded an explosion 1,000 times more powerful than Hiroshima, engulfing the nearby islands in radioactive ash.2

Between 1946 and 1958, the U.S. conducted a staggering 67 nuclear tests in the Marshall Islands, leaving an enduring legacy of radioactive contamination. The tranquil reefs and islands of this once-pristine region bore the brunt of these tests, causing irreparable damage to both the environment and the lives of the local population.

Read: Minutes to hours after a nuclear blast are critical for survival. Disaster experts explain how to protect yourself in a worst-case scenario.

Image Source: Public Domain | National Archives

The Runit Dome: A Fragile Containment

Rising incongruously on Runit Island, the Runit Dome, also known as the Cactus Dome or “The Tomb,” is a 45-centimeter thick concrete structure with a 115-meter diameter. It stands as an eerie testament to a troubled past.4

Originally conceived as a temporary containment measure, the Runit Dome has stood for decades. However, the passage of time has taken its toll, with investigations in 2019 revealing alarming cracks in the structure. These fissures, exacerbated by rising temperatures, signal a looming environmental catastrophe.

As if cracks in the dome were not enough, the encroachment of rising sea levels compounds the problem. The relentless erosion of Runit Island’s shores puts additional stress on the already fragile concrete structure, potentially releasing radioactive material into the Pacific Ocean.

Despite reassurances from experts like Ken Buesseler that the plutonium remains contained beneath the dome, the situation remains precarious. Factors such as future sea-level rise and the impact of storms and tides on water flow raise concerns about the potential release of radioactive materials. The stakes are high, and vigilance is paramount.

Unresolved Accountability

The consequences of the U.S. nuclear tests on the Marshall Islands are profound. Elevated cancer rates and forced relocations are grim reminders of the devastating impact on the local population. While the U.S. military withdrew from the region in 1986 and pledged assistance for affected individuals, many argue that these commitments have fallen short of addressing the scale of the devastation.

Two scientists from Columbia University have made a compelling case for urgent action. They call for independent research funded by the U.S. Congress to assess radioactive contamination in the Marshall Islands and formulate a comprehensive plan to address the impending crisis. The fate of the Runit Dome hangs in the balance, and time is of the essence.

The Pacific Ocean, once a theater of nuclear tests, now bears witness to the slow decay of the Runit Dome—a fragile shield protecting the world from a lethal radioactive legacy. The cracks in this “nuclear coffin” are not just a structural concern but a symbol of the unresolved accountability and responsibility surrounding nuclear testing in the Marshall Islands.

As we contemplate the precarious future of this concrete edifice, we must acknowledge the enduring suffering of the islanders and the urgent need for action. The world must unite to ensure that the Runit Dome and the radioactive specter it contains is secured before it’s too late. In this critical moment, humanity must grapple with the consequences of its past actions to safeguard a more hopeful future.

Keep Reading: How a Viable Nuclear Fusion Reactor Really Could Change the World


  1. The “Nuclear Coffin” On Runit Island Is Still Haunting The Pacific.” IFL Science. Tom Hale. March 3, 2023.
  2. The U.S. put nuclear waste under a dome on a Pacific island. Now it’s cracking open..” Washington Post. Kyle Swenson. March 20, 2019.
  3. Radioactive ‘Tomb’ in Pacific Filled With Nuclear Waste Is Starting to Crack.” Science Alert. Aria Bendix. November 12, 2019.
  4. The Story Of Runit Dome, The Concrete ‘Tomb’ In The Marshall Islands That’s Filled With Deadly Nuclear Waste.” All That Insteresting. Amber Breese. July 1, 2023.