plutonium-240

chemical isotope

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July 1, 2026

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Plutonium-240 is a radioactive isotope of plutonium, a synthetic chemical element with atomic number 94. While plutonium-239 is crucial for nuclear reactors and weapons due to its fissionable properties and long half-life, plutonium-240 is noted for its longer half-life compared to some other isotopes, making it valuable in chemical and metallurgical research. Plutonium-240, like all plutonium isotopes, is radioactive and emits alpha particles.12

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nuclear reactor
Fissile and fertile materials
…directly through neutron capture in plutonium-240, following the formula ²⁴⁰Pu + ¹n = ²⁴¹Pu.
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…directly through neutron capture in plutonium-240, following the formula ²⁴⁰Pu + ¹n = ²⁴¹Pu.
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nuclear weapon
Selecting a weapon design
…absorbed a neutron and became plutonium-240. This material underwent spontaneous fission, producing neutrons. Some neutrons would always be present in a plutonium assembly and would cause it to begin multiplying as soon as it “went critical” but before it reached supercriticality; the assembly would then explode prematurely and produce comparatively…
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…absorbed a neutron and became plutonium-240. This material underwent spontaneous fission, producing neutrons. Some neutrons would always be present in a plutonium assembly and would cause it to begin multiplying as soon as it “went critical” but before it reached supercriticality; the assembly would then explode prematurely and produce comparatively…
Read More