Thorium has potential advantages over uranium for nuclear energy production. It is more abundant and produces less long-lived radioactive waste. The document discusses how thorium energy works in a molten salt reactor where the thorium is dissolved in salts. This technology could provide clean, safe energy on grid or off grid applications. Small modular thorium reactors hold promise for uses such as power generation, marine transport, or providing rural electrification. The UK is well-positioned to participate in this emerging thorium energy market.

1. Basics of Thorium Energy
With the joint phenomena of CO2 emissions which lead
to climate change and the increasing cost of rhe fossil
fuels which create this problem, attention is now being
directed to wider use of nuclear fission power and,
in particular, to the use of thorium as a nuclear fuel.
The purpose of this summary is to explain how thorium
energy works, its many environmental and economic
advantages and its possible applications.
"Cheap and abundant nuclear energy is no
longer a luxury, it will eventually be a necessity
for maintenance of the human sondition."
Alvin Weinberg

2. HOW THORIUM CAN BE USED TO PRODUCE ENERGY
THORIUM ENERGY CYCLE
MOLTEN SALT REACTOR
Thorium is a metal somewhat heavier than lead
and you will find it (Th) in the extreme bottom left
hand corner of the following Periodic Table.
In the thorium cycle, fuel is formed when Thori-
um-232 (at the base of the diagram) captures a
neutron to become Thorium-233. This normally
emits an electron to become Protoactinium-233.
This then emits another electron to become Urani-
um-233 which is the fuel. U-233 then undergoes
spontaneous fission to produce energy with
further neutrons released to continue the cycle.
In all reactors using uranium the fuel is processed into solid rods or pellets. A disadvantage of this is
that these have to be re-processed before all the fuel is consumed. Thorium lends itself to the design
of reactors in which the fuel is not solid but a mixture of salts which are in a molten state at the tem-
perature of operation. Hence the term “molten salt reactor” or MSR. Another term commonly used to
describe this technology is the Liquid Fluoride Thorium Reactor of LFTR (pronounced “lifter”). In a
LFTR, the thorium salts are dissolved in carrier salts, forming a liquid fuel in which the process of
nuclear fission and release of heat energy occurs. The heat is then transferred to a steam turbine or
closed-cycle gas turbine. The kinetic energy so produced can be used directly for propulsion or to
drive a generator and hence produce electricity. Some of the energy is available as heat which can
be used for industrial processes such as desalination, cement or fertilizer production and liquid fuel
synthesis.
Its atomic number is 90 and its atomic weight 232.
On Earth, thorium is not a rare element, having an
abundance comparable to that of lead and molyb-
denum, twice that of arsenic, and thrice that of tin.
It is found in small amounts in most rocks and soils
which commonly contain an average of around 6
parts per million (ppm) of thorium.
Unlike uranium, it is not “fertile”. That is to say that
uranium contains a proportion of the radioactive
isotope uranium-235 which liberates neutrons
which are needed to initiate fission and the release
of energy. Thorium does not produce neutrons so in
order to initiate fission the neutrons must be
supplied from an “external” source. Thorium is
therefore described as “fissionable”
but not “fertile”
Fission
Transmutes to
D
ecaysto
D
ecaysto
Fission

3. SOURCE OF NEUTRONS
THESE ARE SOME OF THE BENEFITS OF THORIUM
MSRs AS AN ENERGY SOURCE:
As mentioned, thorium requires a source of
neutrons in order to undergo fission. Three main
such sources can be considered.
1. Uranium-235 or plutonium-239
2. An accelerator in which a beam of protons
strikes a heavy metal target to liberate
neutrons (“spallation”).
3. Nuclear fusion in which nuclei of the hydrogen
isotope deuterium (D-D fusion) or a mixture of
the isotopes deuterium and tritium (D-T fusion)
are fused to liberate neutrons.
It is a metal derived from minerals widely present in the Earthʼs crust.
One ton of Thorium produces the same amount of energy as 10 tons of Uranium, 3.5 million tons of
coal, 5 million barrels of oil or 5000 million cubic metres of gas. A mere 6,600 tonnes of thorium
could provide the energy equivalent of the combined global consumption of 5 billion tonnes of coal,
31 billion barrels of oil, 3 trillion cubic meters of natural gas, and 65,000 tonnes of uranium. Conti-
nental global reserves amount to over 4,000 million tons which would provide energy for a Million
years and hence Thorium is SUSTAINABLE and ABUNDANT in the long term.
Thorium energy is CARBON-FREE and its use would therefore eliminate CO2 emissions and halt
dangerous climate change.
In addition, it produces no oxides of nitrogen (NOx) or of sulphur (SOx) which are health hazards.
Thorium reactors dramatically reduce the long-term radiotoxicity of reactor wastes. About 83% of the
radioactive waste has a half-life in hours or days, with the remaining 17% requiring 300 year storage
in geologically stable confinement to reach background levels. This compares with the thousands of
years half-life of the actinide wastes from uranium fission.
They are air-cooled which means that they do not need to be located close to a source of cooling
water such as river, lake or ocean.
While there are areas in the world particularly rich in Thorium deposits, all areas of the world typical-
ly carry 26 grams per cubic metre of rock, sand or earth which can be extracted economically. This
improves international security by reducing competition and conflicts over scarce fossil fuel resources.

4. Thorium molten salt reactors (MSR) can be built on an assembly-line basis thus greatly reducing cost and
construction time as compared with uranium reactors.
MSRs could be sealed units which will operate for 10 – 20 years on a single charge. This would mean
that no re-fuelling would be required for the full lifetime of the reactor.
They can be made very small – as little as a few megawatts. Thus they are portable and can be used a
propulsion units for ships or high speed trains or could be carried on space vehicles to destinations such
as the moon or Mars
In addition to generation of electricity, thorium MSRs would produce high temperature steam suitable
for a range of in industrial applications, including cement production, desalination and liquid fuel
synthesis.
The first Thorium MSR was developed at Oak Ridge National
Laboratory, U.S.A. by Alvin Weinberg and went critical in
1965, running for 4 years and producing 7.4 megawatts of
thermal energy. It was closed down on the orders of President
Nixon for the reason that it could not produce weapons-grade
material.
Alvin Weinberg and his thorium reactor.
Since then a number of experimental thorium reactors have
been successfully operated, though all of the designs used
solid fuel elements rather than molten salts. For example, the
Dragon was a high temperature gas cooled reactor at Win-
frith in Dorset, England, operated by United Kingdom Atomic
Energy Authority (UKAEA.). Currently there is a solid fuel
thorium reactor in operation at Halden, Norway. It produces
electricity for the grid and superheated steam for the local
paper mill.
China is now working on large thorium-powered reactors and
so is India which has some of the richest thorium deposits in
the world.
The approach adopted by Smart Thorium LLP (www.smartthorium.co.uk )
is to design a reactor producing in the order of 5 megawatts.
This would be small enough to fit into a shipping container and hence
would be portable and modular.
A TRIED TECHNOLOGY
A SMALL MODULAR REACTOR AND
ITS APPLICATIONS

5. Manufacturing costs are low since thorium MSRs can be produced on an assembly-line basis. Fuel is
cheap and the cost of waste processing low since most of it requires no long-term storage. Electricity can
be produced from such reactors at a price lower than that from coal. Manufacturing of thorium reactors
could lead to a potential market of $1 trillion per annum.
The design favoured by Smart Thorium LLP would have an output of 2 megawatts. scalable to 5 mega-
watts. It would be relatively light and portable. Amongst its possible uses would be:
Power for local co-generation plants which supply electricity to the national grid or a local “mini-grid”.
The UK is facing a shortage of electricity generating capacity due to shutdown of old power stations. It
takes some four years to build new coal or gas-fired stations and somewhat longer for uranium fission
power stations. The UK is thus likely to face power cuts in future severe winters. Local co-generation
plants with output of 2 – 5 megawatts can be constructed in as little as 18 months. At present these run
on natural gas, but thorium MSRs would be an ideal power source since they are carbon-free.
There are 1.5 billion people in the world with no electrical supply, without which social and economic
advancement stagnates. The United Nations has launched the Sustainable Energy for All programme
which aims to provide every household with a minimum of 1 kilowatt of electricity. The criteria are that
such energy provision must be sustainable, carbon-free and, of course, safe and affordable. Except in
rare cases, renewables such as sun and wind cannot provide this but thorium MSRs would be an ideal
technology for this application .
Marine cargo ships produce more CO2 than air transport or the entire worldʼs fleet of cars. Moreover,
because of the heavy oil used in many cases, the output of health-hazardous oxides of nitrogen and
sulphur is high. Pressure is now coming from the International Maritime Organization to reduce CO2
emission. This can be done by reducing operating speed or by substituting heavy oil by low-sulphur fuel
or liquid natural gas. Many ports worldwide will not accept ships unless they are powered by such fuels,
this includes ports of the Mediterranean, North Sea, and Baltic.Such fuels are twice the cost of heavy
oil. Thorium MSRs would be ideal propulsion systems for the most common type of “handysize” cargo
ship of some 20,000 tons capacity which are currently powered by diesel engines of about 8 megawatts
output.
Calder Hall in Cumbria was the first nuclear power station in the world to provide electricity to the grid.
But from being leaders in the development of civil nuclear power the UK now has an almost non-existent
research and development programme in comparison with other major countries, even though public
opinion is increasingly growing in favour of electricity production from nuclear sources.
Considering the effort that is now going into development of thorium molten salt reactors in many coun-
tries, notably China and India, there can be no doubt that this technology will become possibly the
worldʼs most important source of energy with massive economic benefits to the countries involved in
manufacturing and marketing.
Opportunity exists for UK to have a £240bn share of this £1tr international nuclear market by 2030.
Thorium-fuelled MSRs can be developed in the UK to benefit from this market.
The choice is ours: do we produce and benefit or import and pay out?
ECONOMIC FEASIBILITY
OPPORTUNITIES FOR THE UNITED KINGDOM