3 ms·
Thorium has significantly less delayed neutrons [1], which means that the reactor is closer to prompt criticality. In addition, browsing the relevant parts of w
by yk 14y ago
Thorium has significantly less delayed neutrons [1], which means that the reactor is closer to prompt criticality. In addition, browsing the relevant parts of wikipedia [2], there seem to be some problem with the neutron economy. And to start an reactor you need to breed some U 233 from Thorium first ( Which will alter the reaction of the reactor to a given neutron flux). Since the neutron flux in the reactor is the main variable which controls the power output it seems, that a Thorium reactor is significantly harder to control than a Uranium one.
[1] .6 delayed neutrons per 100 fissions for U233 compared to 1.6 for U235.
http://www.reak.bme.hu/Wigner_Course/WignerManuals/Budapest/DELAYED_NEUTRON.htm#_ftnref3 http://www.reak.bme.hu/Wigner_Course/WignerManuals/Budapest/...
[2] Especially https://en.wikipedia.org/wiki/Liquid_fluoride_thorium_reactor#Disadvantages https://en.wikipedia.org/wiki/Liquid_fluoride_thorium_reacto...
- adam-f 14y agoI've heard this concern raised before, and the real question is whether the thermal expansion of the fuel salt acts as a strong enough negative coefficient of reactivity.
- KitemanSA 14y agoAnswer, yes it does. This was proven in the Molten Salt Reactor Experiment.
- KitemanSA 14y ago"Since the neutron flux in the reactor is the main variable which controls the power output it seems, that a Thorium reactor is significantly harder to control than a Uranium one." This is nonsense. LFTRs are self controlling with a significant negative coefficient. It really makes no more sense to think about putting Thorium in a solid fuel reactor than it does about using diesel in a spark ignition engine.