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Powering our Future
A Comparative Report on Nuclear Energy and Thorium
Power
By: Steve Scriver
Submitted to Jordan Berard,
In partial fulfillment of the requirements of ENL8720
Algonquin College
Electro Mechanical Engineering Robotics
Friday March 20th
Contents
List of Figures and Tables ............................................... 3
Glossary ......................................................................... 4
Introduction .................................................................. 5
Safety ............................................................................ 6
Uranium ........................................................................ 6
Thorium ......................................................................... 7
Abundance .................................................................... 8
Uranium ........................................................................ 8
Thorium ......................................................................... 9
Cost ............................................................................. 10
Uranium ...................................................................... 10
Thorium ....................................................................... 11
Conclusion ................................................................... 12
Sources ........................................................................ 13
List of Figures and Tables
Figure 1 Calandria .......................................................................................... 4
Figure 2 Recoverable Uranium [8] ............................................................... 8
Figure 3 Estimated thorium on Earth [7]..................................................... 9
Figure 4Cost of Uranium Aug2014-Feb2015............................................. 10
Glossary
Calandria – A large metal cylinder filled with heavy water.
MSR – Molten Salt Reactor
Actinides – rare earth metals
Tonnes – Metric unit of weight, 1000 lbs.
Figure 1 Calandria
Introduction
The purpose of my report is to compare the pros and cons of using uranium
(nuclear) power opposed to thorium. In the post Fukushima world scientists,
politicians, and citizens are looking for the proper outlet of energy to fuel our
future without the devastating effects of radiation.
As humanity makes a push to move away from uranium based energy, thorium has
been toted to be the new way, and the future of energy [1].
Though the uses of thorium are vast and seemingly unmatched by its predecessor
some people downplay what it can do for the world. These rebuttals by uranium
backers hinder the development and employment of the element to our modern
world.
At the end of this comparison I will have used research based on which element is
safest, most abundant, and most cost effective to back what should be or remain
the backbone to energy generation in North America and the foreign world.
Safety
For safety there are three critical points to examine when considering the use of
an element. These areas are control of reactivity, how to cool the fuel, and how to
contain radioactive substances [2].
Uranium
To control the reactivity in a uranium reactor the use of control rods are in place.
Essentially a control rod is what keeps fission triggering properly, it is represented
by the equation k = total number of fission events in a given generation divided by
total number of fission events in the previous generation [3]. This is key in keeping
the reactor regulated and without them the reactor would go into melt down.
To cool a uranium reactor a direct or “once-through” method is used. Since we live
in Canada, I will use the Darlington reactor as an example. It is considered to be a
pressurized heavy water reactor, what this means is that it is cooled via a calandria
that is filled with water containing higher amounts of hydrogen (2H20) and within
it are about 300 fuel channels [4]. The water is cycled in and acts as a heat sync to
keep the reactor stable.
Controlling the radioactive isotopes exists on three planes, low-level, intermediate-
level, and high-level. Since we are only examining reactors we will be looking at
High-level waste. Uranium has a very high half-life, in which when disposing of it if
not threw uranium depleted weapons has to decay in storage for 40-50 years.
From there the uranium is buried and after about 1000 years will have finally
decayed completely. But this is not the only precaution to burying uranium, we
also add layers of protection to create a “multiple barrier” disposal concept [5].
This barrier is made up of borosilicate glass, than put in a stainless steel container
to avoid corrosion where it is than surrounded by bentonite clay and buried in a
deep underground stable rock structure.
Thorium
Like uranium reactors thorium also uses control rods, but they are of a different
composition. In the beginning graphite was used as a moderator, but because of
swelling and damage teams of scientists have developed a way to speed up a
Molten Salt Reactor (MSR) to have it act as a fast neutron reactor, and with that
rids the use of a graphite moderator [6].
Thorium uses a method of cooling called molten salt, in it there are natural
protections from failure that is common to uranium reactors [6]. Should a power
failure happen, a “freeze plug” melts and the contents of the fuel-carrying salt will
be drained into a series of drain tanks that are being consistently cooled [6]. This
helps avoid disasters like Chernobyl and Fukushima, as well as Three Mile Island
[6].
For the disposal of waste created by thorium reactors, the same process would be
used as we would for uranium, the difference being the radioactivity in the waste
would only last a few hundred years opposed to 1000. Interestingly enough
thorium reactors also create an array of actinides [7].
After viewing the safety credentials of both elements, it appears that thorium
would have the upper hand in being the wise choice for future energy production.
Just because it is the safer of the two doesn’t mean that it is the best choice by
today’s standards. We still have to take into consideration the cost, and
abundance.
Abundance
Uranium
The statistic above shows that of the possible 5.9 million tonnes North America
accounts for 701,300 tons which is 11.88% of the world’s uranium [8].
Figure 2 Recoverable Uranium [8]
Thorium
The statistics on the chart above show the amount of thorium estimated to be in
the world. Of the 6.3 million tonnes North America has 767,000 tonnes which is
12% of the world’s abundance [7].
After viewing the abundance of the elements, once again thorium has come out on
top. Though not by much, the power generated by thorium is quite higher. With
that, my research only has left to show and compare the costs of the elements.
Figure 3 Estimated thorium on Earth [7]
Cost
For cost’s I will be analyzing the price of a kilogram of uranium and the costs of a
kilogram of thorium, as well as the refining costs for both elements.
Uranium
This figure represents the cost of a kilogram of uranium from August 2014 to
February 2015 [9].
At the start of February 2015, uranium had risen to a price of about $38 per
kilogram. A reactor uses about 1.4 tonnes or uranium a month, for a total of 17.5
tonnes a year [10]. This means that the cost per month just on fueling is
$482,622.80.
As for the refining cost of uranium, some sources say it’s about $60 US to refine
one tonne of ore. Though not a fully reliable source, 2 uncreditable sites have
reported this.
Figure 4Cost of Uranium Aug2014-Feb2015
Thorium
Thorium is a more expensive mineral, coming in at about $1,490 US dollars per 175
grams [11]. This means a kilogram of thorium is about $8,514 US dollars. Based on
the research of source 12, it’s estimated the funding for a year’s supply of thorium
would only be 1 million dollars [12] which roughly places the cost per month at
$117.45.
The price for refining thorium ore is hard to determine via todays statistics, but for
the comparison of costs since uranium is so high it would be a safe bet that
thorium even with refining costs is significantly lower than that of uranium use.
In the search for the prices of thorium it was very hard to determine accurate
results. My thoughts on this is that uranium backers or companies do not want
thorium facts to be readily available to researchers like myself.
Conclusion
Based upon the research I have done, my comparative research has found that
thorium should be the leading element in powering North America. After viewing
the safety components and how they are utilized thorium presents an effective
way of avoiding a meltdown, which in a post Fukushima world should be the
upmost concern of any citizen in the world.
Notably the money saved by investing in thorium reactors is quite considerable
and immediately pay themselves off. This money could be put back into budgets
and help to improve the standard of living for Canadians and Americans likewise.
Lastly the abundance of thorium native to Canada is substantial. There is enough
thorium to fuel North America and our vehicles for hundreds of years.
My recommendation after doing this research is to immediately invest in it as a
future keystone. Of course it wouldn’t hurt to research it a little more to hammer
out the quirks, but within 5 years North America could begin shutting down and
disposing the radioactive uranium and begin ushering in a new guideline to safe
energy.
Sources [1] D. Warmflash, 'Thorium Power Is the Safer Future of Nuclear Energy', The Crux, 2015. [Online].
Available: http://blogs.discovermagazine.com/crux/2015/01/16/thorium-future-nuclear-energy/#.VQh87eH_rDE.
2] World-nuclear.org, 'Safety of Nuclear Reactors', 2015. [Online]. Available: http://www.world-
nuclear.org/info/Safety-and-Security/Safety-of-Plants/Safety-of-Nuclear-Power-Reactors/.
[3]J. Grayson, 'Control Rods in Nuclear Reactors', Large.stanford.edu, 2015. [Online]. Available:
http://large.stanford.edu/courses/2011/ph241/grayson1/. [].
[4]2015. [Online]. Available: http://www.opg.com/generating-power/nuclear/how-it-
works/documents/HowDoes_NuclearPlantWork.pdf.]
[5] World-nuclear.org, 'Waste Management Overview', 2015. [Online]. Available: http://www.world-
nuclear.org/info/Nuclear-Fuel-Cycle/Nuclear-Wastes/Waste-Management-Overview/.
[6]P. Reinhardt, 'Thorium Reactors by Peter Reinhardt', Rein.pk, 2013. [Online]. Available:
http://rein.pk/thorium-reactors/.
[7] World-nuclear.org, 'Thorium', 2015. [Online]. Available: http://www.world-nuclear.org/info/Current-
and-Future-Generation/Thorium/.
[8] World-nuclear.org, 'Uranium Supplies: Supply of Uranium', 2015. [Online]. Available:
http://www.world-nuclear.org/info/Nuclear-Fuel-Cycle/Uranium-Resources/Supply-of-Uranium/.
[9] Indexmundi.com, 'Uranium - Monthly Price - Commodity Prices - Price Charts, Data, and News -
IndexMundi', 2015. [Online]. Available:
http://www.indexmundi.com/commodities/?commodity=uranium.
[10] World-nuclear.org, 'Nuclear Fuel Cycle Overview', 2015. [Online]. Available: http://www.world-
nuclear.org/info/Nuclear-Fuel-Cycle/Introduction/Nuclear-Fuel-Cycle-Overview/
[11] Science.energy.gov, 'Uranium and Thorium Ores Price List | U.S. DOE Office of Science (SC)', 2015.
[Online]. Available: http://science.energy.gov/nbl/certified-reference-materials/prices-and-
certificates/uranium-thorium-ores-price-list/. [Accessed: 19- Mar- 2015]
[12] Thorium.tv, 'Thorium Costs', 2015. [Online]. Available:
http://www.thorium.tv/en/thorium_costs/thorium_costs.php.