236 U
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236 U Stephan Winkler (Univ. of Vienna)
description
236 U. Stephan Winkler (Univ. of Vienna). Production of 236 U. Main Production channel in thermonuclear devices is (n,3n) of 14MeV neutrons on 238 U. ( Sakaguchi et al). (n,3n). Main Production in Reactors via (n, γ ) of thermal neutrons on 235 U. 236 U inventory. Natural - PowerPoint PPT Presentation
Transcript of 236 U
236U
Stephan Winkler(Univ. of Vienna)
Production of 236U
(n,3n)
Main Production channel in thermonuclear devices is (n,3n) of 14MeV neutrons on 238U.(Sakaguchi et al)
Main Production in Reactors via (n,γ) of thermal neutrons on 235U
[email protected] AMS-12, Wellington, NZ, 2011
236U inventoryNatural• Uranium ore: 236U/U typ. 4×10-11. In U ore recoverable: 1.5 kg 236U. • Typical deep lithosphere: equilibrium 236U/U = 2...5×10-14
Inventory of the topmost 1000 m: ~22 kg 236U• Cosmic radiation: ~0.5 at 236U cm-2 yr-1
(half of this in the upmost 1 m)Equilibrium inventory: 10 kg.Total transfer to rivers would rise the ratio in rivers by +5×10-14
• Signature of river water: 1...10×10-14 also valid for the global oceans(U residence time: several 105 years, well mixed)
• Natural 236U inventory in oceans: 0.2 kg (!)
Anthropogenic
• 236U produced by nuclear power reactors: ~106 kg (!)
• Global fall-out from nuclear weapons testing ~103 kg
• Leakage by reprocessing plants (e.g. Sellafield)
The HMF-1 236U and 14C record
Ocean Water Data So Far
Depth profiles from • Atlantic • Northern Seas• Sea of Japan
