Phenomenon · phenomenon:nuclear-fission

Nuclear fission

A heavy nucleus absorbing a neutron splits into fragments whose kinetic energy, ~200 MeV per event, thermalises into the surrounding fuel.

Nuclear physicsfirst reported 1938also: fission reactor, nuclear reactor, reactor core, fissioning plasma

Atlas record: 7 claims reference this phenomenon — 6 established and 1 demonstrated.

Explorerelations · matrix context · routes · sources · cite

conditions: above ~700 K

7claims71enumerated routes3routes with complete-composition evidence21candidate routes not searched4cited sources

Relations

drives · 1

Nuclear binding-energy difference—drives→Nuclear fissionestablished

for neutron-induced fission: a fissionable nuclide and an incident neutron in an energy range with non-zero fission cross-section
critical geometry is required only for a self-sustaining chain reaction; a moderator is reactor-design dependent

About 200 MeV per event, almost all as fragment kinetic energy (Frisch 1939); thermalisation is a separate step.

produces · 2

Nuclear fission—produces→Temperature gradientestablished

fragment and neutron kinetic energy thermalised in the fuel; the fuel runs hotter than the coolant

Nuclear fission—produces→Hot gasestablished

fission heating produces a vapour or gas working fluid in a DIRECTLY heated, same-circuit configuration: the reactor coolant itself boils in the vessel and its steam goes to the turbine (a boiling-water reactor), or the fissioning or fission-heated gas is the working medium (a gas-core or fissioning-plasma reactor)
not a pressurised-water reactor: there fission heats a pressurised liquid whose heat crosses a steam generator into a separate secondary circuit — the heat exchanger, not the core, makes the turbine's steam, and that topology belongs to the system layer, never hidden inside this claim (pass 38)

member of · 1

Nuclear fission—member of→Nuclear heatestablished

as a heat source for a conventional steam cycle

implemented by · 2

Nuclear fission—implemented by→Nuclear fission plantestablished

Nuclear fission—implemented by→Boiling-water reactor plantdemonstrated

governed by · 1

Nuclear fission—governed by→Strong nuclear interactionestablished

Matrix context

D = disequilibrium row · C = coupling family column. A cell reads the state of the atlas for that pair.

D.20 × C.27 · Nuclear binding-energy difference × Nuclear heat · Established

family: Nuclear heat (C.27)

Enumerated routes through this · 71 (showing 24)

PWR primary heat delivery5/5 est · demonstrated
Nuclear fission steam plant7/7 est · demonstrated
Boiling-water reactor direct-steam plant7/7 est · demonstrated
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Thermal emission → Light4/4 est · extends a recorded pathway
Nuclear binding-energy difference → Nuclear fission → Hot gas → Thermal emission → Light4/4 est · candidate
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Alkali-metal thermal-to-electric conversion → Ionic current → Electrical work3/5 est · extends a recorded pathway
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Ionic thermoelectric effect → Ionic current → Electrical work5/5 est · candidate
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Marangoni effect → Mechanical motion → Mechanical work5/5 est · extends a recorded pathway
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Thermal shape-memory effect → Mechanical motion → Mechanical work5/5 est · extends a recorded pathway
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Thermochemical redox cycle → Chemical fuel (H₂, CO, syngas) → Chemical fuel5/5 est · candidate
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Thermopolarization effect → Separated surface charge → Electrical work3/5 est · weakly supported
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Thermopolarization effect → Separated surface charge → Electrical work3/5 est · weakly supported
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Seebeck effect → Charge carriers → Electrical work5/5 est · extends a recorded pathway
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Heat conduction → Heat flow → Useful heat5/5 est · extends a recorded pathway
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Thermionic emission → Charge carriers → Electrical work5/5 est · extends a recorded pathway
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Thermogalvanic effect → Ionic current → Electrical work5/5 est · extends a recorded pathway
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Thermally regenerative electrochemical cycle → Ionic current → Electrical work3/5 est · extends a recorded pathway
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Nernst effect → Charge carriers → Electrical work5/5 est · extends a recorded pathway
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Anomalous Nernst effect → Charge carriers → Electrical work5/5 est · extends a recorded pathway
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Working-fluid expansion (heat-engine cycle) → Mechanical motion → Mechanical work5/5 est · extends a recorded pathway
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Ocean thermal energy conversion → Mechanical motion → Mechanical work3/5 est · candidate
Nuclear binding-energy difference → Nuclear fission → Hot gas → Magnetohydrodynamic generation → Charge carriers → Electrical work4/5 est · candidate
Nuclear binding-energy difference → Nuclear fission → Hot gas → Working-fluid expansion (heat-engine cycle) → Mechanical motion → Mechanical work5/5 est · extends a recorded pathway
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Thermo-osmosis → Streaming potential → Ionic current → Electrical work5/6 est · extends a recorded pathway

Cited sources · 4

[1]
O. R. Frisch. Physical evidence for the division of heavy nuclei under neutron bombardment (1939)
Nature 143, 276 · doi:10.1038/143276a0 · crossref ✓ 2026-09-19 · record
[2]
A. Bejan. Advanced Engineering Thermodynamics (4th ed.) (2016)
Wiley · doi:10.1002/9781119245964 · crossref ✓ 2026-09-19 · record
[3]
U.S. Nuclear Regulatory Commission. Boiling Water Reactors — how a typical commercial BWR works (2025)
nrc.gov · www.nrc.gov/reactors/power/bwrs · record
[4]
O. Hahn, F. Strassmann. Über den Nachweis und das Verhalten der bei der Bestrahlung des Urans mittels Neutronen entstehenden Erdalkalimetalle (1939)
Naturwissenschaften 27, 11–15 · doi:10.1007/BF01488241 · crossref ✓ 2026-09-19 · record

Cite this entity

Physical Transformation Atlas (2026). entity phenomenon:nuclear-fission: Nuclear fission. Dataset revision rbfbfcbb70e57 (hash of the canonical data). https://physical-transformation-atlas.wldud5192.workers.dev/phenomenon/nuclear-fission

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