The 1950 Rivière-du-Loup B-50 nuclear weapon loss incident refers to loss of a nuclear weapon near

Rivière-du-Loup Rivière-du-Loup (; 2021 population 20,118) is a small city (Quebec), city on the south shore of the Saint Lawrence River in Quebec. The city is the seat for the Rivière-du-Loup Regional County Municipality and the Judicial districts of Quebec ...

Quebec Quebec is Canada's List of Canadian provinces and territories by area, largest province by area. Located in Central Canada, the province shares borders with the provinces of Ontario to the west, Newfoundland and Labrador to the northeast, ...

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

, during the fall of 1950. The bomb was released due to engine troubles, and then was destroyed in a non-nuclear detonation before it hit the ground.

Background

Returning one of several US

Mark 4 nuclear bomb The Mark 4 nuclear bomb was an American implosion-type nuclear bomb based on the earlier Mark 3 Fat Man design, used in the Trinity test and the bombing of Nagasaki. With the Mark 3 needing each individual component to be hand-assembled by only ...

s secretly deployed at Goose Bay AFB in Labrador, a USAF

Boeing B-50 Superfortress The Boeing B-50 Superfortress is a retired American strategic bomber. A post–World War II revision of the Boeing B-29 Superfortress, it was fitted with more powerful Pratt & Whitney R-4360 radial engines, stronger structure, a taller tail fin ...

had engine trouble and jettisoned the weapon at . The crew released it over the

St. Lawrence River The St. Lawrence River (, ) is a large international river in the middle latitudes of North America connecting the Great Lakes to the North Atlantic Ocean. Its waters flow in a northeasterly direction from Lake Ontario to the Gulf of St. Lawren ...

where it conventionally detonated, presumably on impact. The non-nuclear explosion shook area residents and scattered nearly of

radioactive Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is conside ...

uranium ( U-238) used in the weapon's tamper. The

plutonium Plutonium is a chemical element; it has symbol Pu and atomic number 94. It is a silvery-gray actinide metal that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four ...

core (" pit"), which is the key component for a nuclear reaction and detonation, was not installed in the bomb at the time. The absence of the core probably was because of its high cost and relative scarcity at the time. Standard US Air Force protocol prohibited any aircraft carrying a nuclear device to land with the device if the aircraft was experiencing engine problems — it had to be jettisoned. Per standard protocol, the plutonium trigger was always removed prior to flight and shipped separately to prevent accidental nuclear activation. At the time of the incident, the aircraft was returning from Goose Bay AFB to

Davis–Monthan Air Force Base Davis–Monthan Air Force Base (DM AFB) is a United States Air Force base southeast of downtown Tucson, Arizona. It was established in 1925 as Davis–Monthan Landing Field. The host unit for Davis–Monthan AFB is the 355th Wing (355 WG) ass ...

. The troubled aircraft successfully diverted to

Loring Air Force Base Loring Air Force Base was a United States Air Force installation in northeastern Maine, near Limestone and Caribou in Aroostook County. It was one of the largest bases of the U.S. Air Force's Strategic Air Command during its existence, and was ...

in Maine. The incident was immediately covered up at the time, and explained away as military practice bombs being detonated. It was not until the 1980s that the Air Force confirmed it had been a nuclear incident.

References

{{DEFAULTSORT:1950 Riviere-du-Loup B-50 nuclear weapon loss incident Rivière-du-Loup Riviere du loup Riviere du loup Riviere du loup Riviere du loup Riviere du loup Riviere du loup Riviere du loup Canada–United States military relations Riviere du loup 1950 disasters in Canada November 1950 in Canada

Background

See also

References