Thorium reactor 2018: Terrorism & "environmentally friendly" and green nuclear power (Greenwashing – Wikipedia manipulation – nuclear lobby)


Thorium reactor 2018: Terrorism & "environmentally friendly" and green nuclear power



Current discussion 2018: Greenwashing – Wikipedia manipulation – nuclear lobby


Wikipedia web page on thorium-based nuclear power
The wikipedia article about thorium-based nuclear power includes very biased external links, which present thorium-based nuclear power in a very positive light.
Therefore, we tried to place an external link to our critical thorium page there. Only two minutes later, our link was checked and deleted. As a reason for this, they wrote that we tried to place a biased external link.
Actually, not our critical page based on scientific sources is biased, but the industrial directed Wikipedia article is it.
There, they list many possible benefits but only some possible disadvantages. And the external links are really biased too. Our external link, the only critical one, they deleted immediately.
Nowadays, Wikipedia manipulation is a popular PR instrument, which is used for instance by the nuclear lobby. In this case, the dangerous thorium-based nuclear power should be presented in a very positive light. This is called „Greenwashing“.

More information (in German) about "Greenwashing" here.



Recent discussions about thorium reactors (terrorism / danger - thorium-based nuclear power)



Due to the nuclear incidents of Chernobyl and Fukushima, the nuclear lobby seemed to be hidden and absent. Meanwhile, they are telling old lies again, but presented in a very positive light.

Nuclear power companies
plan to build small „environmentally friendly and green” thorium reactors distributed among the whole world. The research is also financed by EU-money.
The old pressurised water reactors and boiling water reactors should be replaced by many small thorium reactors. You call them also liquid fluoride thorium reactors.

But these companies don´t consider that only one of these mini-reactors emit a amount of radioactivity that is as high as the one of many Hiroshima bombs. An accident or a terroristic attack on one of these mini-reactors could destroy a whole city. Many of these small reactors are, inevitably, insecure targets. If there stood some of these reactors in countries like Syria or Iraq, terroristic organisations like the “IS (or ISIS)” could gain in power by building so-called “dirty bombs”.

The idea of distributing thorium reactors among the whole world is a nuclear nightmare and can be described as a global suicide programm. It´s another example of the destructive era of the “Anthropocene”.

There are many possible ways of nuclear terrorism.

In this case, there are three possible scenarios

1. They could use thorium to build nuclear explosive devices easily
2. They could distribute radioactive material to contaminate the environment
3. They could attack a reactor, a reprocessing plant or a nuclear waste transport directly.

Therefore, ten thousands of liquid fluoride reactors (thorium reactors) are potentially, incredibly endangered.

Thorium, protactinium and the building of nuclear bombs

The journal “Nature” describes in his article “Thorium fuel has risks” a big thorium problem very precisely:

Thus, only 1.6 tonnes of thorium metal would be required to produce the 8kg of
233U required for a weapon. This amount of 233U could feasibly be obtained by this process in
less than a year. The separation of protactinium from thorium is not new. We highlight two well-
known chemical processes — acid-media techniques and liquid bismuth reductive extraction
— that are causes for concern, although there may be others. Both methods use standard nuclear-lab equipment
and hot cells — containment chambers in which highly radioactive materials can be manipulated safely. Such apparatus is not necessarily subject to IAEA safeguards. […]

We have three main concerns:


Thorium bomb?
During the Second World War, when nuclear bombs hit the cities of Hiroshima and Nagasaki,
some people also planned to build thorium bombs:
Historian and Oppenheimer-biographer Martin Sherwin is convinced that if they had built thorium bombs, these bombs would have been kindled too.
If they had a thorium bomb, there would have been dropped altogether three during the Second World War, says historian Peter Kutznick from the American University Washington.

The exploitation of thorium
and the nuclear regeneration are harmful to the environment, make ill and at worst, they can be lethal. Even if the reactors work normally, they emit carcinogenic radioactivity. Thus, many people are exposed to radiation. Although, thorium reactors emit, on the one hand, less radioactivity than a boiling water reactor and for a shorter period, the radiation is, on the other hand, more intense.

To conclude, why should we support a dangerous and expensive technology, if we have cheaper, environmentally (more) friendly solutions?

The global public relations-campaign
for small nuclear power plants and thorium reactors is very active.
Greenwash and hidden PR, so-called “no-badge”- activities are standards of PR-campaigns. The extremely partial and one-sided articles of Wikipedia about small nuclear power plants and thorium reactors in many different languages are typical examples of the strategy of advertising agencys. Their functioning includes typically manipulated letter-to-the-editor-campaigns, one-sided opinion polls, spy on and slanden of reviewers, jubilation online-reports, articles in blogs and increasingly the use of “social bots”, opinion robots. Also industrial directed faked citizen`s action groups take part of the manipulation business of these groups, environmental destroyers and the nuclear lobby. The biggest advertising agency in the world “Burson-Marsteller” which played down over many years the dangers of smoking and denied the global climate change, advertised until autumn 2016 the “eco-friendly” nulclear power.
In this case, the environmental and anti-nuclear movements often work careless and barely oppose something.
If you enter the key-word “thorium reactor” in a search engine, you can see, who, unfortunately, has the power in the world wide web.

Axel Mayer, BUND-Regionalverband Südlicher Oberrhein (Friends of the Earth Germany)

Translation: Leon Sander




Terrorism & "Environmentally friendly and green” small thorium reactors



A critical website about this topic:
"Exposing the truth about Thorium Nuclear propaganda"


More critical articles about this topic:


PDF-documents:





















































1
Thorium
: Not ‘
green’
,
not ‘viable’, and not likely
1. Introduction
"With uranium
-
based nuclear power continuing its decades
-
long economic
collapse, it's awfully late to be thinking of developing a whole new fuel cycle
whose problems differ only in det
ail from current versions."
Amory Lovins, Rocky Mountain Institute, March 2009.
A number of commentators have argued that most of the problems associated with
nuclear power could be avoided by both:

using thorium fuel in place o
f
uranium or plutonium fue
ls

using ‘molten salt reactors’ (MSRs) in place of conventional solid fuel reactor
designs.
The combination of these two technologies is known as the Liquid Fluoride Thorium
Reactor or LFTR, because the fuel is in form of a molten fluoride salt of thorium
and
other elements.
In this
Briefing
,
we examine the validity of the optimistic claims made for thorium
fuel, MSRs and the LFTR in particular. We find that the claims do not stand up to
critical scrutiny
,
and that these technologies have significant dra
wbacks including:

the very high costs of technology development, construction and operation.

marginal benefits
for a
thorium fuel cycle over the currently utilised uranium /
plutonium fuel cycles

serious nuclear
weapons
proliferation hazard
s

the
danger
of
both
routine and
accidental releases of radiation
, mainly from
continuous
‘live’ fuel reprocessing
in MSRs

the very
long lead time for significant deployment of
LFTRs of
the
order of
half
a century

rendering it irrelevant in terms of addressing
current
o
r medium
term
energy supply
needs
1. Background
1.1 What is
t
horium
?
Thorium is a heavy metal named after Thor, the Nordic God of thunder.
The naturally
occurring isotope, 232Th,
is mildly radioactive with a very long half life of
14
billion
years
. Thorium present
s
a health hazard
mainly from inhalation of dust, and from
e
missions of the
powerfully
radioactive gas radon
(220Rn).
It occurs mainly in deposits of rare earth metals
.
. As it has few uses
requiring more
than minimal volumes of ma
terial
it is considered a
s
radioactive
waste

and requires
careful and expensive handling to prevent contamination. It is
three to
four times
2
more abundant in the Earth
’s
crust than uranium, and is
especially
plentiful
in
Australia, Norway, India, the US
A and China.
Although
t
horium can be used to make nuclear fuel, it is not fissi
le
.
But it is ‘fertile’
-
that is, it can transformed into fissile material. Under
neutron
irradiation,
typically
provided by the fission of uranium or plutonium
, it
breed
s
th
e fissile uranium isotope
233U. Thus any thorium fuel cycle needs to be initiated by an supply of existing
fissile material.
The thorium
-
uranium fuel cycle has some advantages over the dominant uranium
-
plutonium cycle,
in terms
for example,
of
the
reduce
d
production of long
-
lived
actinides and somewhat diminished radio
-
toxicity overall. However
,
it also creates
new hazards of its own. As far as radioactive fission products are concerned
,
there is
little to cho
ose between the two.
(see Appendix 1 for furt
her details)
1.2 What are
m
olten
s
alt
r
eactor
s?
Unlike conventional nuclear reactors which use solid fuel in the form of rods or
pellets, molten salt reactors (MSRs) use fuel in the form of a complex mixture of
fluoride salts in a molten state. T
he salt mixture includes the fissile material (fissile
isotopes of plutonium and/or uranium), together with any fertile material (such as
thorium or 238U) together with other elements.
The molten fluoride salt serves as the primary coolant, carrying hea
t away from the
reactor, and delivering it to a secondary cooling circuit and ultimately to the steam
turbines that generate electricity.
In principle, MSR’s offer several potential advantages over conventional reactor
designs:

the reactor and its cooling
circuits operate at near atmospheric pressure,
reducing the chance of any explosion

In the event of
a
reactor overheating, the fuel can simply drain out into a
secondary container and the f
ission chain reaction will halt, reducing the risk of
reactor mel
tdowns such as those experienced at Chernobyl and Fukushima
B
ut b
efore 'production' MSRs can be
built
,
there are significant technical prob
lems to
be overcome, among them:

the development of corrosion
-
resistant materials capable of surviving for
decades i
n a uniquely
hostile environment

highly corrosive and subject to
intense radiation including neutron bombardment

and,
the continuous fuel reprocessing that MSRs demand, requiring the
development of hazardous, complex and currently experimental pyro
-
proce
ssing
and electro
-
refining technologies on a production scale.
If these technologies are successfully developed
-
and
it
cannot be taken for granted
that they ever will

they are likely to be very expensive
. Moreover
,
reprocessing
will
always
represent
a weak link from a safety
and proliferation
perspective
.
3
(S
ee Appendix 2 for further details
)
2. Current State of Play
2.1 Actual
thorium
reactors
Thorium fuel has so far been used in about 30 operational reactors in conjunction with
fissile
uranium (235U /
233U
)
or
plutonium (
239Pu
)
to
initiate the fuel cycle
. Most of
these were located in the USA, Germany, Netherlands and India. A single example
operated in the UK, from 1965 to 1976: the Dragon Reactor at Winfrith, a helium
-
cooled test reac
tor evaluating fuel and
materials for the European high
-
temperature
reactor programme. It is currently partially decommissioned
.
Most thorium reactors have been of conventional designs originally intended for
uranium fuel, such as pressurised water reacto
rs, boiling water reactors and
pressurised heavy water reactors. But thorium has also been included in more exotic
designs, notably the molten salt breeder experiment (MRSE) reactor (see
2.3, below
),
the thermal breeder reactor (USA), and the liquid metal
fast reactor (India).
The only operational thorium reactors today are in India, which possesses abundant
thorium reserves but little uranium. These are all solid fuel reactors. As of 2010
,
India
had used only a small amount of thorium
-
approximately one
tonne
-
in its reactors.
2.2
P
lanned
thorium
reactors
In December 2011
,
India announced its plans for a new generation of Advanced
Heavy Water Reactors using a plutonium / uranium / thorium MOX (mixed oxide)
fuel. The programme would begin with
an initial test reactor whose construction could
commence in 2013. Again, this would not be a molten salt reactor but would use
conventional solid fuel.
Norw
ay’s
Thor Energy is also intending to develop a thorium
-
plutonium MOX
nuclear fuel, aimed at repl
acing conventional fuels in light water reactors (LWRs). It
is currently seeking investment to irradiate thorium
-
plutonium oxide fuel pins in
simulated LWR conditions in the Halden fuel
-
testing reactor. A separate project is to
optimise thorium
-
plutonium f
uels for boiling water reactors, while maximis
ing the
breeding of 233U. Thor E
nergy anticipates that 25
-
30% of power output could arise
from the thorium.
Proposals have been
made to construct LFTR reactors
in China, Japan and the US (see
2.3
). Initially
these would be research reactors and the first 'production' LFTR would
appear to be 20
-
30 years away (see
2.4
).
2.3
Actual
molten salt reactors
The molten salt reactor was
originated i
n the 1950s
as a potential power source for the
USAF’s fleet of high
altitude nuclear bomber aircraft. A working reactor was
produced
(
under the Airborne Reactor Experiment) programme, but never
commissioned
.
4
The technology was further developed at Oak Ridge
National Laboratory in the 1960
s
under its MSRE (Molten Salt Rea
ctor Experiment). The 7MW reactor employed
fluoride salts of uranium and plutonium as fuel. In the 1970s
,
Oak Ridge built its
Molten Salt Breeder Reactor (MSBR), which used as fuel fluoride salts of uranium,
thorium and plutonium
as its fuel
.
2.
4
Planned
molten salt reactors
There are a number of proposals to build MSRs:

In January 2011
,
the Chinese Academy of Sciences announced plans to develop
the LFTR technology into commer
ci
al reactors. But it warned that 20 to 30
years
of
research and development wou
ld probably be needed before an LFTR
was operational.

Flibe Energy was set up in 2011 to develop LFTR technology in the USA and
worldwide. Its initial intention is to build a small test reactor. Ultimately
,
it aims
to bring about a world with many thousand
s of LFTRs.

The FUJI LFTR project in Japan is attempting to raise £300 million to build a
10 MW 'MiniFUJI' research reactor. Following the 2011 Fukushima
catastrophe
,
the project has a low chance of attracting the necessary finance.

the UK's Weinberg Found
ation was established in September 2011 to act as a
communications, debate and lobbying hub to promote thorium energy and the
LFTR in particular. There are currently no plans in the UK to build an actual
LFTR.
Despite the resurgence of interest in the MSR
/ LFTR technology, there are no
concrete plans to build even a single such reactor. China currently appears most likely
to provide the funding necessary to develop LFTR technology due to that country's
relatively large nuclear programme and the government
's willingness to invest in new
energy generation technologies. But even there any production
-
scale LFTR is unlikely
to materialise for 20
-
30 years.
2.
5
New
-
found interests

why?
Several
factors
underlie the current vogue of interest in thorium reactors
. Perhaps the
most important is the desire for energy and nuclear independence in countries with
large thorium reserves and little uranium, or which have concerns about long
-
term
price of
uranium and
its
availability. This would appear to apply to India, C
hina, the
USA and Norway.
Noting the large volumes of surplus
thor
ium produced as waste in the mining of
valuable rare earth metals, there is also a clear commercial interest among the mining
companies concerned to give value to this waste. However
,
we h
ave no evidence of
any efforts by mining companies to drive forward the thorium project.
A more significant factor is perhaps a deeply
-
rooted techno
-
optimism in human
psychology

the desire to believe that one or other technolog
y provides ‘the answer’
to
deep
-
rooted problems. Faced with the prospect of ‘peak oil’ and
accelerating
climate change from the burning of fossil fuels, those who are sceptical about the
potential of renewable energy sources will naturally incline towards some other
answer. For som
e, it would seem that thorium fills that particular ‘desire gap’.
5
The established nuclear industry in the UK has little interest in thorium as such,
since
any use of thorium would create far more cost than it ever saved. However
,
the mere
idea that there
exists a
notionally
‘green’
version
of nuclear power could be seen by
the nuclear industry as positive in public relations terms, and
useful in promoting
the
persistence
of nuclear power
in the UK’s electricity mix.
3
.
Thorium claims

and the reality
Numerous advantages for
thorium as a nuclear fuel
and
for
the LFTR design
over
conventional solid fuel reactors ha
ve been claimed. In this section we consider each of
these claims in turn.
3.1
Abundance of thorium relative to uranium
Claim:
T
horium is se
veral times more abundant in
the Earth's crust than uranium.
Response:
T
horium (232Th) is indeed more abundant than uranium, by a factor of
three
to
four. But where
as
0.7% of uranium occurs as fissile 235U, none of the
thorium is fissile. The world already
pos
s
esses an estimated 1.2 million tonnes of
depleted uranium (mainly 238U), like thorium a
fertile but non
-
fissile material
.
So the
greater abundance of thorium than uraniu
m confer
s no
advantage
, other than a
very
marginal advantage in energy security to
those countries in which it is abundant.
3.2
Relative utility of thorium and uranium as fuel
Claim:
100% of the thorium is usable as fuel, in contrast to the low (~0.7%)
proportion of
fissile 235U in natural uranium.
Response:
Thorium must be subjected
to neutron irradiation to be transformed into a
fissile
material
suitable for nuclear fuel
(uranium, 233U)
. The same applies to the
238U that makes up depleted uranium, which as already observed
,
is
plentiful.
I
n
theory, 100% of either metal could be bred
into nuclear fuel.
However
,
uranium has a
strong head start, as 0.7% of it is fissile
(235U)
in its natural
ly
-
occurring
form.
3.3
Nuclear weapons proliferation
Claim:
thorium reactors do not produce plutonium, and so create little or no
proliferation ha
zard.
Response:
thorium re
actors do not produce plutonium.
B
ut
an LFTR could (by
including 238U in the fuel) be adapted to produce plutonium of a high purity well
above normal weapons
-
grade, presenting a major proliferation hazard.
Beyond that,
the main p
roliferation hazard
s
arise from:

the need for fissile material (plutonium or uranium) to
initiate
the thorium fuel
cycle, which could be diverted, and

the production of fissile uranium 233U.
Claim:
the fissile uranium (233U) produced by thorium reactors i
s not

weaponisable

owing to the presence of highly radiotoxic 232U as a contaminant.
Response:
233U was successfully used in a 1955 bomb test in the Nevada Desert
under the USA's Operation Teapot
and so is clearly weaponisable notwithstanding
6
any 232U pr
esent.
Moreover
,
t
he
continuous
pyro
-
processing / electro
-
refining
technologies
intrinsic to MSRs / LFTRs
could generate streams of 233U
very low in
232U
at
a purity
well above weapons grade as currently defined.
3.4
Safety
Claim:
LFTRs are intrinsicall
y safe, because the reactor operates
at
low pressure and
is and
incapable of
melt
ing down.
Response:
the design of molten salt reactors does indeed mitigate against reactor
meltdown and explosion. However
,
i
n an LFTR
the
main
danger ha
s been shifted
from t
he reactor
to the on
-
site continu
o
us fuel reprocessing operation

a
high
temperature process involving highly hazardous, explosive and intensely radioactive
materials.
A further serious hazard
lies in the potential
failure of the materials used for
reacto
r and fu
el containment in a highly corrosive chemical environment,
under
intense neutron and other radiation
.
3.5
State of technology
Claim:
t
he technology is already proven.
Response:
important elements of the LFTR technology were proven during the 1970
s
Molten Salt Breeder Reactor (MSBR) at Oak Ridge National Laboratory. However
,
this was a small research reactor
rated at
just
7MW
and there are huge technical and
engineering challenges in scaling up this experimental design to make a 'production'
reacto
r.
Specific challenges include
:

developing materials that can both resist corrosion by liquid fluoride salts
including diverse fission products, and withstand decades of intense neutron
radiation;

scaling up fuel reprocessing techniques to deal
safely and
reliably with large
volumes of
highly
radioactive ma
terial at very high temperature;

keeping radioactive releases from the reprocessing operation to an a
cceptably
low level;

achieving a full understanding of the thorium fuel cycle.
3.6
Nuclear waste
Cla
im:
LFTRs produce far less nuclear waste than c
onventional solid fuel reactors.
Response:
LFTRs are theoretically capable of a high fuel burn
-
up rate
,
but while this
may
indeed
reduce the volume of waste, the waste is more radioactive due to the
higher vol
ume of radioactive fission products. The continuous fuel reprocessing that
is characteristic of LFTRs will also produce hazardous chemical and radioactive waste
streams
,
and releases to the environment will be unavoidable.
Claim:
Liquid fluoride thorium r
eactors generate no high
-
level waste material
.
Response:
This claim, although
made
in the
report from the
House of Lo
rds, has no
basis in fact. High
-
level waste is an unavoidable product of nuclear fission. Spent fuel
from any LFTR will be intensely radioa
ctive and constitute high level waste. The
reactor itself, at the end of its lifetime, will constitute high level waste.
Claim:
the waste from LFTRs contains very few long
-
lived isotopes, in particular
transura
nic actinides such as plutonium.
7
Response:
th
e thorium fuel cycle does indeed produce very low volumes of
plutonium and other long
-
lived actinides so long as only thorium and 233U are used
as fuel. However
,
the waste contains many radioactive fission pro
ducts and will
remain dangerous for many hundre
ds of years. A particular hazard is the production
of 232U, with its highly radio
-
toxic decay chain.
Claim:
LFTRs can 'burn up' high level waste from conventional nuclear reacto
rs, and
stockpiles of plutonium.
Response:
if LFTRs are used to 'burn up' wast
e from conventional reactors, their fuel
now comprises 238U, 235U, 239Pu, 240Pu and other actinides. Operated in this way,
what is now a mixed
-
fuel molten salt reactor will breed plutonium (from 238U) and
other long lived actinides, perpetuating the pluton
ium cycle.
3.7
Cost of electricity
Claim:
the design of LFTRs tends towards low construction cost and very cheap
electricity.
Response:
while some elements of LFTR design may cut costs compared to
conventional reactors, other elements will add cost, not
ably the continuous fuel
reprocessing using high
-
temperature 'pyro
-
processing' technologies.
Moreover,
a
costly experimental phase of ~20
-
40 years duration will be required before any
'production' LFTR reactors can be built.
It is very hard to predict th
e cost of the technology that finally emerges, but the
economics of nuclear fuel reprocessing to date suggests that
the nuclear fuel produced
from breeder reactors is about 50 times more expensive than ‘virgin’ fuel. It therefore
appears probable that any
electricity
produced from LFTRs will be expensive.
We must also
consider the prospect
that
relatively
novel
or immature
energy
sources,
such as photovoltaic electricity and photo
-
evolved hydrogen, will have become well
established
as
low
-
cost technologies
long before
LFTRs are in the market.
3.8
Timescale
Claim:
Thorium and the LFTR offer a solution to current and medium
-
term energy
supply deficits.
Response:
The thorium fuel cycle is immature
. Estimates from the UK’s National
Nuclear Laboratory and the
Chinese Academy of Sciences (see 4.2 below) suggest
that 10
-
15 years of research will be needed before thorium fuels are ready to be
deployed in existing reactor designs. Production LFTRs will not be deployable on any
significant scale for 40
-
70 years.
4. T
horium
/ LFTR prospects
8
4.1 Timescales
for thorium fuel
The thorium fuel cycle is immature and unready for production
-
scale deployment.
Although thorium fuels have been used in approximately 30 reactors
,
their nuclear
dynamics and opera
tional performance remain poorly characterised.
India is already deploying thorium in its reactors as a component of mixed oxide
(MOX) fuels comprising plutonium / uranium, and plans more of the same in its
forthcoming Advanced Heavy Water Reactors. Howe
ver
,
Norway's Thor Energy and
the UK's National Nuclear Laboratory (NNL) both believe that considerable research,
development and testing lies ahead before thorium fuels will be ready for operational
use.
As the NNL states,
"Thorium reprocessing and wast
e management are poorly
understood. The thorium fuel cycle cannot be considered to be mature in any area."
It
estimates that 10
-
15 years work is required before thorium fuels will be ready for use
in current reactor designs, and that
their
use in new types
of reactor is at least 40 years
away.
[
The Thorium Fuel Cycle
-
An independent assessment
, NNL, August 2010]
4.2
LFTR lead time:
half a century
The assessment of the Chinese Academy of Sciences as it embarks on its LFTR
programme is that a production LF
TR is 20
-
30 years in the future

rather shorter than
the NNL’s estimate of 40 years (see 4.1)
.
Given the hazards, such as the potential failure of reactor materials under intense
neutron irradiation
and chemical corrosion
, risk
-
averse utilities and inve
stors would
want to observe the performance of any such full
-
scale LFTR for at least a decade and
probabl
y more, before
embarking on
any substantial LFTR programme. The lead time
for nuclear construction is of the order of a decade
,
so this could add a fur
ther 20
-
30
years before production LFTRs were de
ployed at full
scale.
The total lead time for LFTRs would therefore be a minimum of 40 years on the
shortest estimates,
or
70 years
based on
more conservative figures.
4.3
Thorium and LFTRs

investment
ou
tlook
The development of thorium / LFTR technologies represents a poor
investment for
national govern
ments, utilities and private investors given:

the marginal benefits to be derived from using thorium fuels in existing reactor
designs;

the very long
-
te
rm nature of any benefit t
hat may be realised from LFTRs, of
the order of half a century;

the uncertainty as to whether the
very
significant technical challenges of the
LFTR will ever be overcome;

the possibility that the materials used for reactor constr
uction may degrade more
rapidly than anticipated, causing early shut
-
down;

the
likely very
high cost of LFTR electricity

especially when compared
against the anticipated low future cost of electricity from renewable sources,
solar in particular, over the
applicable time frame
.
9
As NNL states:
“thorium is competing with the uranium/plutonium fuel cycle which is
already very mature. To progress to commercial deployment would demand major
investments f
rom fuel vendors and utilities ... L
WR and PHWR utilities w
ould be
unlikely to invest in thorium fuels to the levels required under current market
conditions. The potential savings that thorium fuels offer and other claimed benefits
are insufficiently demonstrated and too marginal to justify the technical risk tha
t the
utility would be exposed to.

We therefore
see little prospect that LFTRs will present a
n economic
solution
if and
when
they are
ever
read
y for large scale deployment. A
ny money invested in LFTRs
,
whether by governments, utilities or other investors
,
is likely to be wasted.
Far better to invest in the renewable technologies that are already shaping our national
and global future
, and whose cost is rapidly falling
-
in the process developing
valuable UK
-
based expertise and technologies, and accelera
ting the renewables
revolution.
Oliver Tickell, April / May 2012.
10
Appendix 1
-
The thorium fuel cycle
Thorium is not itself fissile, however it is 'fertile'. That is to say that, under neutron
irradiation, it can be used to breed fissile material. In
any thorium reactor, the
naturally oc
c
u
r
ring 232Th is irradiated with neutrons from fissile material (for
example, 235U, 233U or 239Pu). Some of the thorium nuclei capture
a
neutron
and
become
233Th. This isotope then undergoes beta decay to 233Pa (protact
inium 233)
which in turn beta decays to 233U, a fissile isotope of uranium.
So in a thorium reactor, the fissile material is in fact uranium. The 233U
behaves like
the more familiar
naturally occurring 235U. It has a fairly long half life of 160,000
years
, and like 235U, 233U is fissionable and can create and sustain a nuclear fission
chain reaction, in which the neutrons emitted by one fission event trigger further
fission events in other 233U nuclei. When 233U undergoes fission
,
it produces similar
fissi
on products as 235U, but in different proportions.
Thorium fuel does possess some advantages over conventional uranium / plutonium
fuels:

the 232Th is more likely than the 238U to capture thermal neutrons;

the resulting 233U is more likely to fission foll
owing neutron capture than is
239Pu;

fissioning 233U produces more neutrons to sustain the nuclear chain reaction.
These factors combine to create a more efficient 'neutron economy' for thorium than
for conventional nuclear fuels, making smaller reactors m
ore viable. They also
mitigate against the formation of long
-
lived transuranic isotopes such as plutonium.
There is also one important disadvantage: the breeding of 232U, a non
-
fissile but
strongly radioactive uranium isotope. This arises when the 233Pa a
bsorbs a neutron
before it decays to 233U. The resulting 234Pa may then expel a pair of neutrons to
make 232Pa, which then undergoes beta decay to 232U.
This isotope is typically present in small quantities with a 232U:233U ratio of well
under 1%. But it
presents a considerable hazard due to its short half life of under 70
years and the rapid decay chain which follows, culminating in an ultra
-
hard 2.6 MeV
gamma ray
-
capable of passing through a metre of lead. This powerful gamma
irradiation creates a haz
ard to personnel and to unshielded electronic control systems.
Consequently
,
thorium fuel requires far more shielding, and more strin
gent remote
handling techniques
than conventional nuclear fuels.
But the greatest problem with the thorium fuel cycle is o
ur relative inexperience of it,
compared to the conventional uranium / plutonium fuel cycle. According to the UK's
National Nuclear Laboratory,
"Thorium reprocessing and waste management are
poorly understood. The thorium fuel cycle cannot be considered to
be mature in any
area."
The NNL estimates that 10
-
15 years of research and development will be
required before thorium fuels are ready for production deployment in conventional
reactors:
"Starting from fabrication of a commercially
-
relevant mass of ThO2
fuel,
which might take 1 or 2 years, the subsequent irradiation to full burnup would
likely take 4 to 5 years. Subsequent post
-
irradiation examination might take