The detonation of a 18-kiloton nuclear device by the United States military in 1958, an event codified as the ‘Cactus‘ experiment, created a significant void on a diminutive island in the Pacific Ocean.
Following the detonation on Runit Island in the Marshall Islands, military personnel undertook the task of interring the resultant contaminated earth and refuse, thereby establishing a containment structure for nuclear detritus, now recognized as the Runit Dome.
In the nearly five decades subsequent to the dome’s erection, scientific observers have voiced apprehension regarding anomalies within the concrete-encased radioactive repository, with fissures indicating its inherent fragility against the encroaching oceanic expansion upon the island’s constricted perimeter.
This expansive structure, spanning 115 meters (377 feet) in diameter and constructed between 1977 and 1980 as part of the military’s remediation initiatives, shields over 120,000 tons of material laden with radioactive isotopes from American nuclear detonations across Enewetak Atoll, including perilously high concentrations of plutonium.
The dome was conceived as a provisional measure to sequester materials relegated from the nuclear trials, certain of which surpassed the destructive capacity of Hiroshima and Nagasaki by a factor of one thousand.
However, since its inception, subterranean water sources have permeated the otherwise unlined excavation. Beneath this stratum lies a layer of permeable coral sediment. While this currently represents the primary conduit for leakage, concerns are mounting that sections of the dome designed to remain above the waterline may soon be submerged.
In the year 2020, subsequent to a comprehensive investigative report published by the Los Angeles Times, Ken Buesseler, a specialist in marine radioactivity at the Woods Hole Oceanographic Institute, stated in an interview for the institute’s periodical that the radioactive effluence emanating from the Runit Dome has, to date, been “relatively minimal.”
“Nevertheless, a significant determinant is future oceanic elevation and the impact of meteorological events such as tempests and elevated tidal cycles on the ingress and egress of water within the dome. At present, the contribution is minor, yet it necessitates more frequent observation to ascertain ongoing developments and to disseminate pertinent data directly to the impacted populations in the region.”
Ivana Nikolic-Hughes, a chemist affiliated with Columbia University and actively engaged in research concerning the enduring radioactive contamination of the Marshall Islands stemming from nuclear testing, recently communicated to journalist Kyle Evans of the Australian Broadcasting Corporation that she personally observed the dome’s structural fissures during a soil sampling excursion on the island in 2018.
Her investigations have revealed elevated radiation levels and substantial concentrations of five distinct radionuclides within soil samples collected from the island, external to the dome structure.
This finding could be indicative of leakage from the nuclear containment facility; conversely, it might also be attributable to the rudimentary execution of the cleanup operations, which also led to the disposal of considerable quantities of waste into the adjacent lagoon.
Irrespective of the origin, the presence of plutonium-239, a constituent element of nuclear armaments that retains its hazardous properties for over 24,000 years, engenders profound apprehensions regarding its susceptibility to rising sea levels and the pervasive effects of climate change.
“Considering the upward trend in sea levels and the observable escalation in storm intensity, we harbor concerns that the structural integrity of the dome could be compromised,” Nikolic-Hughes informed Evans.
“Runit Island is situated approximately 20 miles from populated areas, and the inhabitants utilize the lagoon; consequently, the potential ramifications are gravely concerning.”
In 2024, an inquiry conducted by the US Department of Energy’s Pacific Northwest National Laboratory investigated the potential consequences of climate change on the Runit Dome site. The findings indicated that storm surges and gradual sea level augmentation would indeed constitute the most significant factor in the dissemination of radionuclides throughout the atoll.
The majority of Runit Island lies at an elevation of merely 2 meters (6.5 feet) above the prevailing sea level.
From an elevated perspective, it is easily conceivable to visualize the profound impact that merely 1 meter of additional oceanic inundation could exert upon the atoll and the deteriorating nuclear containment structure on Runit Island. This represents the projected increment in sea level anticipated by climate scientists for the Marshall Islands by the terminus of the 21st century.
Nikolic-Hughes and her collaborator, Hart Rapaport, have previously implored the United States to assume accountability for the appropriate remediation of radioactive waste on the islands, as a fundamental step towards ensuring a secure future for the Marshallese populace.
As articulated by the United Nations special rapporteur Paula Gaviria Betancur in 2024: “The enduring consequences of nuclear experimentation and the appropriation of land for military purposes by an external power have resulted in the displacement of hundreds of Marshallese individuals across generations, while the deleterious effects of climate change pose a threat of displacing thousands more.”
Attribution: Kyle Evans, Australian Broadcasting Corporation
