Thorium nuclear technology is a dead end
Thorium ‒ a better fuel for nuclear technology? Thorium ‒ a better fuel for nuclear technology? Nuclear Monitor, by Dr. Rainer Moormann 1 March 2018 An important, detailed critique of thorium by Dr. Rainer Moormann, translated from the original German by Jan Haverkamp. Dr. Moormann concludes:
“The use of technology based on thorium would not be able to solve any of the known problems of current nuclear techniques, but it would require an enormous development effort and wide introduction of breeder and reprocessing technology. For those reasons, thorium technology is a dead end.”
Author: Dr. Rainer Moormann, Aachen (r.moormann@gmx.de) Thorium is currently described by several nuclear proponents as a better alternative to uranium fuel.
Thorium itself is, however, not a fissile material. It can only be transformed into fissile uranium-233 using breeder and reprocessing technology. It is 3 to 4 times more abundant than uranium.
Concerning safety and waste disposal there are no convincing arguments in comparison to uranium fuel. A severe disadvantage is that uranium-233 bred from thorium can be used by terror organisations for the construction of simple but high-impact nuclear explosives. Thus development of a thorium fuel cycle without effective denaturation of bredfissile materials is irresponsible.
Introduction
Thorium Introduction
Thorium (Th) is a heavy metal of atomic number 90
(uranium has 92). It belongs to the group of actinides, is
around 3 to 4 times more abundant than uranium and is
radioactive (half-life of Th-232 as starter of the thorium
decay-chain is 14 billion years with alpha-decay). There
are currently hardly any technical applications. Distinctive
is the highly penetrating gamma radiation from its decaychain
(thallium-208 (Tl-208): 2.6 MeV; compared to
gamma radiation from Cs-137: 0.66 MeV). Over the past
decade, a group of globally active nuclear proponents is
recommending thorium as fuel for a safe and affordable
nuclear power technology without larger waste and
proliferation problems. These claims should be submitted
to a scientific fact check. For that reason, we examine
here the claims of thorium proponents.
Dispelling Claim 1: The use of thorium expands the
availability of nuclear fuel by a factor 400
Thorium ‒ a better fuel for nuclear technology? Nuclear Monitor, by Dr. Rainer Moormann 1 March 2018
Thorium itself is not a fissile material. It can, however, be
transformed in breeder reactors into fissile uranium-233
(U-233), just like non-fissile U-238 (99.3% of natural
uranium) can be transformed in a breeder reactor to fissile
plutonium. (A breeder reactor is a reactor in which more
fissile material can be harvested from spent nuclear fuel
than present in the original fresh fuel elements. It may be
sometimes confusing that in the nuclear vocabulary every
conventional reactor breeds, but less than it uses (and
therefore it is not called a breeder reactor).)
For that reason, the use of thorium presupposes the use
of breeder and reprocessing technology. Because these
technologies have almost globally fallen into disrepute, it
cannot be excluded that the more neutral term thorium is
currently also used to disguise an intended reintroduction
of these problematic techniques.
The claimed factor 400: A factor of 100 is due to the
breeder technology. It is also achievable in the uraniumplutonium
cycle. Only a factor of 3 to 4 is specific to
thorium, just because it is more abundant than uranium
by this factor.
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