List of military nuclear accidents


This article lists notable military accidents involving nuclear material. Civilian accidents are listed at List of civilian nuclear accidents. For a general discussion of both civilian and military accidents, see nuclear and radiation accidents.

Scope of this article

In listing military nuclear accidents, the following criteria have been adopted:
  1. There must be well-attested and substantial health damage, property damage or contamination.
  2. The damage must be related directly to radioactive material, not merely at a nuclear power plant.
  3. To qualify as "military", the nuclear operation/material must be principally for military purposes.
  4. To qualify as "accident", the damage should not be intentional, unlike in nuclear warfare.

    1940s

DateLocationTypeDescription
June 23, 1942Leipzig, Germany Steam explosion and reactor fire.Leipzig L-IV experiment accident: Shortly after the Leipzig L-IV atomic pile — worked on by Werner Heisenberg and Robert Doepel — demonstrated Germany's first signs of neutron propagation, the device was checked for a possible heavy water leak. During the inspection, air leaked in, igniting the uranium powder inside. The burning uranium boiled the water jacket, generating enough steam pressure to blow the reactor apart. Burning uranium powder scattered throughout the lab causing a larger fire at the facility.
August 21, 1945Los Alamos National Laboratory, Los Alamos, New Mexico, United StatesAccidental criticality.Harry Daghlian dropped a tungsten carbide brick onto a plutonium core, inadvertently creating a critical mass at the Los Alamos Omega site. He quickly removed the brick, but was fatally irradiated, dying September 15.
May 21, 1946Los Alamos National Laboratory, Los Alamos, New Mexico, United StatesAccidental criticality's criticality accident used to determine exposure of those in the room at the time.
While demonstrating his technique to visiting scientists at Los Alamos, Canadian physicist Louis Slotin manually assembled a critical mass of plutonium. A momentary slip of a screwdriver caused a prompt critical reaction. Slotin died on May 30 from massive radiation poisoning, with an estimated dose of 1,000 rads, or 10 grays. Seven observers, who received doses as high as 166 rads, survived, yet three died within a few decades from conditions believed to be radiation-related.
Slotin worked with the same bomb core as Daghlian which became known as the "demon core." It was later melted down and combined with existing weapons-grade material.

1950s

1960s

1970s

1980s

1990s

DateLocationTypeDescription
1997GeorgiaRadiological accidentSoldiers suffered radiation poisoning and burns. They were eventually traced back to training sources abandoned, forgotten, and unlabeled after the dissolution of the Soviet Union. One was a 137Cs pellet in a pocket of a shared jacket which put out about 130,000 times the level of background radiation at a distance.

2000s

DateLocationTypeDescription
February 2003Y-12 facility, Oak Ridge, TennesseeProcessing vessel explosion
During the final testing of a new saltless uranium processing method, there was a small explosion followed by a fire. The explosion occurred in an unvented vessel containing unreacted calcium, water and depleted uranium. An exothermic reaction in the vessel generated enough steam to burst the container. This small explosion breached its glovebox, allowing air to enter and ignite some loose uranium powder. Three employees were contaminated. BWXT Y-12, a partnership of Babcock & Wilcox and Bechtel, was fined $82,500 for the accident.

2010s

DateLocationTypeDescription
8 August 2019State Central Navy Testing Range near NyonoksaExplosive destruction of a nuclear power sourceMain article: Nyonoksa radiation accident.
According to the version presented by Russian officials, it was a result of a failed test of an "isotope power source for a liquid-fuelled rocket engine". Nonproliferation expert Jeffrey Lewis and Federation of American Scientists fellow Ankit Panda suspect the incident resulted from a test of the Burevestnik cruise missile. However, other arms control experts disputed the assertions; Ian Williams of the Center for Strategic and International Studies and James Acton of the Carnegie Endowment for International Peace expressed skepticism over Moscow's financial and technical capabilities to field the weapon, while Michael Kofman of the Wilson Center concluded that the explosion was probably not related to Burevestnik but instead to the testing of another military platform. According to CNBC, the Russians were trying to recover a missile from the seabed which was lost during a previously failed test.