L Reactor
E104343
L Reactor was a heavy water–moderated nuclear production reactor at the Savannah River Site in South Carolina, historically used to produce materials such as plutonium and tritium for the U.S. nuclear weapons program.
All labels observed (1)
| Label | Occurrences |
|---|---|
| L Reactor canonical | 4 |
How this entity was disambiguated
This entity first appeared as the object of triple T842138 — 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: L Reactor Context triple: [Savannah River Site, formerFacility, L Reactor]
-
A.
R Reactor
R Reactor was one of the plutonium and tritium production nuclear reactors that operated at the U.S. Department of Energy’s Savannah River Site during the Cold War.
-
B.
P Reactor
P Reactor was a plutonium and tritium production nuclear reactor at the U.S. Department of Energy’s Savannah River Site in South Carolina, built during the Cold War to support the nation’s nuclear weapons program.
-
C.
H Reactor
H Reactor was one of the plutonium-producing nuclear reactors at the Hanford Site in Washington, built during the Cold War as part of the U.S. nuclear weapons program.
-
D.
B Reactor
B Reactor is the world’s first full-scale plutonium production reactor, built during the Manhattan Project at the Hanford Site in Washington State.
-
E.
F Reactor
F 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: L Reactor Target entity description: L Reactor was a heavy water–moderated nuclear production reactor at the Savannah River Site in South Carolina, historically used to produce materials such as plutonium and tritium for the U.S. nuclear weapons program.
-
A.
R Reactor
R Reactor was one of the plutonium and tritium production nuclear reactors that operated at the U.S. Department of Energy’s Savannah River Site during the Cold War.
-
B.
P Reactor
P Reactor was a plutonium and tritium production nuclear reactor at the U.S. Department of Energy’s Savannah River Site in South Carolina, built during the Cold War to support the nation’s nuclear weapons program.
-
C.
H Reactor
H Reactor was one of the plutonium-producing nuclear reactors at the Hanford Site in Washington, built during the Cold War as part of the U.S. nuclear weapons program.
-
D.
B Reactor
B Reactor is the world’s first full-scale plutonium production reactor, built during the Manhattan Project at the Hanford Site in Washington State.
-
E.
F Reactor
F 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 (49)
| Predicate | Object |
|---|---|
| instanceOf |
heavy water–moderated reactor
ⓘ
nuclear reactor ⓘ production reactor ⓘ |
| associatedRiver | Savannah River ⓘ |
| commissioned | 1954 ⓘ |
| constructionStart | 1951 ⓘ |
| coolant | light water ⓘ |
| coolingSystem | once-through river water cooling with cooling basins ⓘ |
| coreType | graphite-free, aluminum-clad fuel assemblies in heavy-water moderator ⓘ |
| country |
United States
ⓘ
linked to:
United States of America
|
| currentUse | non-operational, deactivated nuclear facility ⓘ |
| deactivationStart | late 1980s ⓘ |
| decommissioningStatus | permanently shut down ⓘ |
| designedElectricalOutput | none (non‑power production reactor) ⓘ |
| designedThermalPower | approximately 2,800 MWth ⓘ |
| environmentalConcern | radioactive releases to seepage basins and surrounding environment ⓘ |
| finalShutdown | 1988 ⓘ |
| firstCriticality | 1954 ⓘ |
| fuelType | natural uranium ⓘ |
| location | Savannah River Site ⓘ |
| militaryRole | strategic materials production for U.S. nuclear arsenal ⓘ |
| moderator | heavy water ⓘ |
| neighboringReactor |
C Reactor
ⓘ
K Reactor ⓘ P Reactor ⓘ R Reactor ⓘ |
| operator |
U.S. Atomic Energy Commission
ⓘ
linked to:
United States Atomic Energy Commission
U.S. Department of Energy ⓘ |
| ownership |
U.S. government
ⓘ
linked to:
United States government
|
| partOf |
Savannah River Site reactor complex
ⓘ
linked to:
Savannah River Site
|
| primaryMission | support of U.S. nuclear weapons program ⓘ |
| primaryUse |
production of tritium
ⓘ
production of weapons-grade plutonium ⓘ |
| producedIsotope |
other transuranic isotopes
ⓘ
plutonium-239 ⓘ tritium ⓘ |
| reactivated | 1985 ⓘ |
| reasonForFinalShutdown | end of Cold War production needs and safety/aging concerns ⓘ |
| regulatoryOversight | Defense Nuclear Facilities Safety Board ⓘ |
| relatedProgram |
U.S. Cold War nuclear weapons program
ⓘ
linked to:
United States nuclear weapons complex
|
| safetyEvent | experienced fuel assembly failures and leaks during operation ⓘ |
| safetyUpgrades | received upgrades prior to 1985 restart ⓘ |
| shutdown | 1968 ⓘ |
| siteCode | SRS L Reactor ⓘ |
| siteOperator |
DuPont
ⓘ
Westinghouse Savannah River Company ⓘ |
| state | South Carolina ⓘ |
| statusAfter1968Shutdown | standby ⓘ |
| wasteManagement | generated high-level and low-level radioactive waste ⓘ |
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: L Reactor Description of subject: L Reactor was a heavy water–moderated nuclear production reactor at the Savannah River Site in South Carolina, historically used to produce materials such as plutonium and tritium for the U.S. nuclear weapons program.
Referenced by (4)
Full triples — surface form annotated when it differs from this entity's canonical label.