Castle Bravo
E290915
Castle Bravo was the United States’ first and most powerful dry-fuel thermonuclear (hydrogen) bomb test, conducted in 1954 and infamous for its unexpectedly massive yield and severe radioactive fallout.
All labels observed (4)
| Label | Occurrences |
|---|---|
| Castle Bravo canonical | 8 |
| Castle Bravo nuclear test | 1 |
| Castle Bravo test | 1 |
| Lucky Dragon No. 5 incident | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T2708223 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Castle Bravo Context triple: [Bikini Atoll, notableTest, Castle Bravo]
-
A.
Little Boy
Little Boy was the codename for the uranium-based atomic bomb dropped on Hiroshima, Japan, by the United States on August 6, 1945, marking the first use of nuclear weapons in warfare.
-
B.
Operation Crossroads
Operation Crossroads was a series of U.S. nuclear weapons tests conducted at Bikini Atoll in 1946 to study the effects of atomic bombs on warships and military equipment.
-
C.
Fission
"Fission" is a prominent track from Ludwig Göransson’s score for the film *Oppenheimer*, known for its tense, evolving soundscape that underscores the movie’s central themes of scientific breakthrough and moral conflict.
-
D.
Fat Man
Fat Man was the plutonium implosion-type nuclear bomb detonated over Nagasaki, Japan, in August 1945, contributing to the end of World War II.
-
E.
D Reactor
D Reactor was one of the early plutonium production reactors at the Hanford Site in Washington, built during the Manhattan Project to support the U.S. nuclear weapons program.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Castle Bravo Target entity description: Castle Bravo was the United States’ first and most powerful dry-fuel thermonuclear (hydrogen) bomb test, conducted in 1954 and infamous for its unexpectedly massive yield and severe radioactive fallout.
-
A.
Little Boy
Little Boy was the codename for the uranium-based atomic bomb dropped on Hiroshima, Japan, by the United States on August 6, 1945, marking the first use of nuclear weapons in warfare.
-
B.
Operation Crossroads
Operation Crossroads was a series of U.S. nuclear weapons tests conducted at Bikini Atoll in 1946 to study the effects of atomic bombs on warships and military equipment.
-
C.
Fission
"Fission" is a prominent track from Ludwig Göransson’s score for the film *Oppenheimer*, known for its tense, evolving soundscape that underscores the movie’s central themes of scientific breakthrough and moral conflict.
-
D.
Fat Man
Fat Man was the plutonium implosion-type nuclear bomb detonated over Nagasaki, Japan, in August 1945, contributing to the end of World War II.
-
E.
D Reactor
D Reactor was one of the early plutonium production reactors at the Hanford Site in Washington, built during the Manhattan Project to support the U.S. nuclear weapons program.
- F. None of above. chosen
Statements (51)
| Predicate | Object |
|---|---|
| instanceOf |
United States nuclear test
ⓘ
hydrogen bomb test ⓘ nuclear weapons test ⓘ thermonuclear weapon test ⓘ |
| actualYield |
15 megatons of TNT
ⓘ
approximately 15 Mt ⓘ |
| affectedArea |
Ailinginae Atoll
ⓘ
Marshall Islands region ⓘ Rongelap Atoll ⓘ Rongerik Atoll ⓘ Utirik Atoll ⓘ |
| affectedVessel | Daigo Fukuryu Maru ⓘ |
| casualties | one fatality on Daigo Fukuryu Maru from radiation sickness ⓘ |
| codename | Castle Bravo self-link ⓘ |
| consequence |
contributed to the movement toward a nuclear test ban
ⓘ
led to compensation claims by Marshall Islands residents ⓘ |
| controversy | triggered international concern over radioactive fallout ⓘ |
| country |
United States of America
ⓘ
surface form:
United States
|
| craterDepth | about 75 meters ⓘ |
| craterDiameter | about 1.9 kilometers ⓘ |
| date | 1954-03-01 ⓘ |
| deliveryMethod | surface detonation on a barge ⓘ |
| design | Teller–Ulam design ⓘ |
| deviceName | Shrimp ⓘ |
| distanceFromBikiniIsland | approximately 4.5 miles west of Bikini Island ⓘ |
| errorCause | underestimation of lithium-7 contribution to fusion reactions ⓘ |
| fallout |
caused extensive radioactive contamination
ⓘ
produced widespread radioactive fallout over inhabited atolls ⓘ |
| fuelType | dry lithium deuteride ⓘ |
| healthEffects |
caused acute radiation sickness among Marshallese inhabitants
ⓘ
caused long-term health problems including cancers in exposed populations ⓘ |
| location |
Bikini Atoll
ⓘ
Marshall Islands ⓘ |
| mushroomCloudHeight | about 40 kilometers ⓘ |
| mushroomCloudWidth | about 100 kilometers ⓘ |
| operator |
United States Atomic Energy Commission
ⓘ
Department of Defense ⓘ
surface form:
United States Department of Defense
|
| partOf | Operation Castle ⓘ |
| partOfSeries |
Pacific Proving Grounds
ⓘ
surface form:
Pacific Proving Grounds tests
|
| predictedYield |
5 megatons of TNT
ⓘ
approximately 5 Mt ⓘ |
| significance |
first U.S. test of a deliverable dry-fuel thermonuclear device
ⓘ
most powerful nuclear device ever tested by the United States ⓘ |
| stageCount | two-stage ⓘ |
| testSeriesNumber | first test in Operation Castle series ⓘ |
| testSite |
Bikini Atoll
ⓘ
surface form:
Bikini Atoll nuclear test site
|
| time | 06:45 local time ⓘ |
| weaponType |
dry-fuel thermonuclear bomb
ⓘ
hydrogen bomb ⓘ |
| year | 1954 ⓘ |
| yieldErrorFactor | about three times predicted yield ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Castle Bravo Description of subject: Castle Bravo was the United States’ first and most powerful dry-fuel thermonuclear (hydrogen) bomb test, conducted in 1954 and infamous for its unexpectedly massive yield and severe radioactive fallout.
Referenced by (11)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Castle Bravo nuclear test
this entity surface form:
Castle Bravo test
this entity surface form:
Lucky Dragon No. 5 incident