Antinuclear

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.

March 5, 2018 - Posted by Christina MacPherson | General News