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Stephen Schwartz

@AtomicAnalyst

8 Dec

Today in 1968, the United States conducted Schooner, a Project Plowshare experiment in which a 30-kiloton device was exploded 355 feet under the Nevada Test Site to study nuclear excavation techniques. This was the last US nuclear test to deliberately reach with the atmosphere.

Here is restored official footage of the Schooner explosion breaching the surface and the early formation of the resulting highly-radioactive dust cloud:

And here is a short official (but silent) film about the preparations for and execution of the Schooner test, including multiple views of the explosion and the very large dust cloud from the ground and the air.

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Stephen Schwartz

@AtomicAnalyst

8 Dec

OTD in 1964 at Bunker Hill AFB, Indiana, as aircraft were taxiing during an Operational Readiness Alert inspection exercise in icy weather, a B-58 carrying a 9Mt B53 bomb in a pod and four 70kt-1Mt B43 bombs skidded off the taxiway, suffered landing gear failure, and caught fire.

All three crew members abandoned the aircraft. The commander and defensive systems operated escaped with superficial burns. Navigator Manuel “Rocky” Cervantes, Jr., 29, was trapped and opted to use his escape capsule. Its parachute had no time to deploy. He landed hard and died.

When the landing gear collapsed, the B-58 crushed the pod beneath it, which carried both the B53 bomb _and_ 14,000 gallons of fuel. The fire caused the high explosives in all five bombs to detonate. The wreckage burned for two hours. Three of the five bombs were heavily damaged.

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Stephen Schwartz

@AtomicAnalyst

8 Dec

Today in 1953, President Dwight D. Eisenhower announced his “Atoms for Peace” plan at the UN General Assembly, which led to the creation of the International Atomic Energy Agency and unwittingly made it much easier for states to develop nuclear weapons. nsarchive.gwu.edu/briefing-book/…

Secretary of State John Foster Dulles believed that US and Soviet donations of fissionable material to an international agency—to fuel peaceful research and power reactors around the world—would actually decrease the amount of uranium and plutonium available for nuclear weapons.

But when Soviet Foreign Minister Vyacheslav Molotov told Dulles that such reactors could be used to make A-bomb fuel, Dulles completely failed to grasp that with “Atoms for Peace,” Ike had committed to disseminating nuclear technology without even a rudimentary risk assessment.

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Stephen Schwartz

@AtomicAnalyst

3 Dec

55 years ago today, the United States conducted the Sterling nuclear test inside Tatum Salt Dome 21 miles southwest of Hattiesburg, Mississippi. A 380-ton device was detonated at a depth of 2,715 feet inside the cavity created by the 5.3-kiloton Salmon test on October 22, 1964.

https://twitter.com/AtomicAnalyst/status/1451600297088925699?s=20

This was the second of two underground nuclear tests to determine whether decoupled nuclear explosions inside salt domes could be detected and their yields accurately measured. This was done in the context of assessing the verifiability a nuclear test ban.

https://twitter.com/AtomicAnalyst/status/1451600297088925699?s=20

Today, the site is marked with a granite monument erected by the Department of Defense explaining what happened there, along with a warning not to excavate, drill, or remove any materials from the area.

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Stephen Schwartz

@AtomicAnalyst

2 Dec

Tonight in 1949, the US AEC and Air Force conducted a secret experiment at the Hanford Reservation in Washington State, exposing thousands of people living downwind to dangerous levels of radioactive iodine-131 and xenon-133 from freshly-irradiated or “green” uranium fuel.

The purpose of the experiment was to determine if specially-instrumented aircraft could detect emissions from nuclear fuel production facilities by mimicking what were thought to be conditions inside the Soviet Union, in order to better assess Soviet atomic bomb production rates.

The fuel was dissolved in acid at the T Plant just 16 days after being removed from a reactor at Hanford (rather than the typical 90-day waiting period to allow the most dangerous radioactivity to decay to safer levels). In addition, filters on the high stack were disconnected.

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Stephen Schwartz

@AtomicAnalyst

2 Dec

@UChicago

79 years ago this afternoon (3:25pm), in an abandoned squash court beneath the West Stand of Stagg Field @UChicago, a team led by physicist Enrico Fermi used a secretly-built reactor (Chicago Pile 1) to achieve the world’s first artificial, self-sustaining nuclear chain reaction.

Three scientists—Leona Marshall, Herbert Anderson, and William Sturm—recorded measurements that day in a log book as control rods were slowly removed in order to achieve criticality. See the notation “We’re cookin!” at 3:42:30 Central War Time at the bottom of page 29.

Metallurgical Laboratory head Prof. Arthur Holly Compton called James Conant, chair of the National Defense Research Committee, to share the news in ad hoc code:

Compton—“The Italian navigator has landed in the New World.”
Conant—“How were the natives?”
Compton—“Very friendly.”

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