Nuclear features of thorium:

As remember above, interest in thorium as a contributor to the world's meaningful energy supply is based on its transmutability into the fissile isotope ²³³U.   The ease along with that this property could be utilized depends on the impact of the nuclear features of thorium on the several reactor systems in that it may be placed and also on the ability to fabricate thorium into suitable fuel elements  and,  after  irradiation,  to  separate  chemically  the  resultant  uranium. The nuclear features of thorium are briefly discussed below through comparing them along with ²³⁸U as a point of reference.

First one, a higher fissile material loading needs exists for initial criticality for a provided reactor system and fissile fuel while thorium is used than is the case for an otherwise comparable system using ²³⁸U.

Second one ,  on  the  basis of  nuclear  performance,  the  interval  among refueling  for  comparable thermal reactor systems could be longer while thorium is the fertile fuel.   Therefore, for a given reactor system, fuel element integrity might be the limiting factor in the depletion levels which could be achieved.

Third one, ²³³Pa (protactinium), that occurs in the transmutation chain for the conversion of thorium to ²³³U, acts as a power history dependent neutron poison within a thorium-fueled nuclear reactor. There is no isotope along with comparable properties present in a ²³⁸U fuel system.

Fourth one, for comparable reactor systems, the one using a thorium-base fuel will have a larger negative advice on neutron multiplication along with increased fuel temperature (Doppler coefficient) than will a ²³⁸U-fueled reactor.

Fifth one, for comparable reactor configurations, a ²³²Th/²³³U fuel system will have a greater stability associative to xenon-induced power oscillations than will a ²³⁸U/²³⁵U fuel system.   The stability is also enhanced through the larger Doppler coefficient for the ²³²Th/²³³U fuel system.

And last sixth, the effectual value of β for ²³²Th/²³³U systems is about half which of ²³⁵U-fueled reactors and about the similar as for plutonium-fueled reactors.  A little value of means in which the reactor is more responsive to reactivity modifications.

As result, the nuclear properties of thorium could be a source of vast energy production. As described through the Light Water Breeder Reactor Program, this production could be achieved in nuclear reactors utilizing proven light water reactor technology.