This report compares nuclear energy from uranium to thorium. Thorium has advantages in safety, abundance, and cost. Thorium reactors can be passively cooled if power is lost and produce less long-lived radioactive waste. The world has similar amounts of recoverable uranium and thorium, but thorium fuel costs far less. The report recommends investing in thorium reactor development to provide safer, more affordable nuclear energy.
In Thorium Breeder reactor Thorium-Uranium fuel cycle is used. The fertile material is thorium-232, the only naturally occurring isotope of thorium. The fissile material is uranium-233.
Transatomic Power (TAP) is developing an advanced molten salt reactor that generates clean, passively safe, proliferation-resistant, and low-cost nuclear power. This reactor can consume the spent nuclear fuel (SNF) generated by commercial light water reactors or use freshly mined uranium at enrichment levels as low as 1.8% U-235. It achieves actinide burnups as high as 96%, and can generate up to 75 times more electricity per ton of mined uranium than a light-water reactor.
Source: http://transatomicpower.com/white_papers/TAP_White_Paper.pdf
In Thorium Breeder reactor Thorium-Uranium fuel cycle is used. The fertile material is thorium-232, the only naturally occurring isotope of thorium. The fissile material is uranium-233.
Transatomic Power (TAP) is developing an advanced molten salt reactor that generates clean, passively safe, proliferation-resistant, and low-cost nuclear power. This reactor can consume the spent nuclear fuel (SNF) generated by commercial light water reactors or use freshly mined uranium at enrichment levels as low as 1.8% U-235. It achieves actinide burnups as high as 96%, and can generate up to 75 times more electricity per ton of mined uranium than a light-water reactor.
Source: http://transatomicpower.com/white_papers/TAP_White_Paper.pdf
Discuss the concept of breeder reactors. How do they breed fuel What.pdfsuresh640714
Discuss the concept of breeder reactors. How do they breed fuel? What type reactors can be
used as breeders? What are some problems/benefits of breeders?
Solution
(1) Conceptof breeder reactors :
A breeder reactor is a nuclear reactor that generates more fissile material than it consumes. These
devices achieve this because their neutron economy is high enough to breed more fissile fuel
than they use from fertile material, such as uranium-238 or thorium-232.Breeder reactors could,
in principle, extract almost all of the energy contained in uranium or thorium, decreasing fuel
requirements by a factor of 100 compared to widely used once-through light water reactors,
which extract less than 1% of the energy in the uranium mined from the earth.The high fuel
efficiency of breeder reactors could greatly reduce concerns about fuel supply or energy used in
mining. A \'breeder\' is simply a reactor designed for very high neutron economy with an
associated conversion rate higher than 1.0. In principle, almost any reactor design could possibly
be tweaked to become a breeder. An example of this process is the evolution of the Light Water
Reactor, a very heavily moderated thermal design, into the Super Fast Reactor concept, using
light water in an extremely low-density supercritical form to increase the neutron economy high
enough to allow breeding.
(2) breeder reactors breed fuel by-
A fast-breeder nuclear reactor produces more fuel than it consumes, while generating energy.
Conventional reactors use uranium as fuel and produce some plutonium. Breeders produce much
more plutonium, which can be separated and reused as fuel.
(3) reactors that can be used as breeders-
Aside from water cooled, there are many other types of breeder reactor currently envisioned as
possible. These include molten-salt cooled, gas cooled, and liquid metal cooled designs in many
variations. Almost any of these basic design types may be fueled by uranium, plutonium, many
minor actinides, or thorium, and they may be designed for many different goals, such as creating
more fissile fuel, long-term steady-state operation, or active burning of nuclear wastes.
For convenience, it is perhaps simplest to divide the extant reactor designs into two broad
categories based upon their neutron spectrum, which has the natural effect of dividing the reactor
designs into those designed to use primarily uranium and transuranics, and those designed to use
thorium and avoid transuranics.
(4) benifits/problems of breeders-
benifits:
Breeder reactors use highly enriched fuels, which pose the danger of critical accidents. They also
work at a very high temperature and a fast pace.
Plutonium persists for a long time in the environment, with a half-life of 24,000 years, and is
highly toxic, causing lung cancer even if a small amount is inhaled.
The construction and operation is very costly. Between $4 to $8 billion is required in the
construction alone.
The byproducts formed during the fission of plutonium h.
Detailed Report on Nuclear cold fusion Reaction and it's Future aspects
Powering our Futurelinkedin
1. 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
3. 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
4. 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
5. Introduction
The purposeof my reportis to comparethe prosand cons of using uranium
(nuclear) power opposed to thorium. In the post Fukushima world scientists,
politicians, and citizens are looking for the proper outletof energy to fuel our
futurewithout the devastating effects of radiation.
As humanitymakes a push to move away from uranium based energy, thorium has
been toted to be the new way, and the futureof energy [1].
Though the uses of thorium are vast and seemingly unmatched by its predecessor
some people downplaywhat it can do for the world. These rebuttals by uranium
backers hinder the development and employmentof 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 energygeneration in North America and the foreign world.
6. Safety
For safety there arethree critical points to examine when considering the use of
an element. These areasare controlof reactivity, howto cool the fuel, and how to
contain radioactive substances [2].
Uranium
To controlthe reactivity in a uranium reactor the use of controlrodsare in place.
Essentially a controlrod is what keeps fission triggering properly, itis represented
by the equation k = total number of fission events in a given generation divided by
total number of fission events in the previousgeneration [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 isused. Since we live
in Canada, I will use the Darlington reactor asan example. It is considered to be a
pressurized heavy water reactor, whatthis means is that it is cooled via a calandria
that is filled with water containing higher amountsof hydrogen (2H20) and within
it are about300 fuel channels [4]. Thewater is cycled in and acts as a heat sync to
keep the reactor stable.
Controlling the radioactive isotopes exists on threeplanes, low-level, intermediate-
level, and high-level. Since we are only examining reactorswe 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 about1000 yearswill have finally
decayed completely. But this is not the only precaution to burying uranium, we
also add layers of protection to create a “multiplebarrier” disposal concept [5].
This barrier is made up of borosilicate glass, than put in a stainless steel container
to avoid corrosion whereit is than surrounded bybentonite clay and buried in a
deep underground stablerockstructure.
7. Thorium
Like uranium reactorsthorium also uses controlrods, butthey are of a different
composition. In the beginning graphitewas used as a moderator, butbecause of
swelling and damageteams 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 graphitemoderator [6].
Thorium uses a method of cooling called molten salt, in it there are natural
protectionsfrom failurethat is common to uranium reactors[6]. Should a power
failurehappen, a “freeze plug” melts and the contents of the fuel-carrying salt will
be drained into a series of drain tanks that arebeing consistently cooled [6]. This
helps avoid disasters like Chernobyland Fukushima, as well as ThreeMile Island
[6].
For the disposal of waste created by thorium reactors, the same process would be
used as we would for uranium, the differencebeing the radioactivityin the waste
would only last a few hundred years opposed to 1000. Interestinglyenough
thorium reactorsalso create an arrayof actinides [7].
After viewing the safety credentials of both elements, it appearsthat thorium
would have the upper hand in being the wise choice for futureenergy production.
Just because it is the safer of the two doesn’tmean that it is the best choice by
today’s standards. Westill have to take into consideration the cost, and
abundance.
8. Abundance
Uranium
The statistic above shows that of the possible 5.9 million tonnes North America
accountsfor 701,300 tonswhich is 11.88%of the world’suranium [8].
Figure 2 Recoverable Uranium [8]
9. Thorium
The statistics on the chart above showthe amountof thorium estimated to be in
the world. Of the 6.3 million tonnes North America has 767,000 tonneswhich is
12%of the world’sabundance[7].
After viewing the abundanceof the elements, onceagain thorium has comeout on
top. Though not by much, the power generated by thorium is quite higher. With
that, my research only has left to show and comparethe costs of the elements.
Figure 3 Estimated thorium on Earth [7]
10. Cost
For cost’s I will be analyzing the priceof a kilogram of uranium and the costs of a
kilogram of thorium, aswell as the refining costs for both elements.
Uranium
This figurerepresents the cost of a kilogram of uranium from August2014 to
February2015 [9].
At the start of February2015, uranium had risen to a priceof about$38 per
kilogram. A reactor uses about1.4 tonnes or uranium a month, for a total of 17.5
tonnes a year [10]. Thismeans that the cost per month just on fueling is
$482,622.80.
As for the refining cost of uranium, somesources say it’s about$60 US to refine
one tonne of ore. Though not a fully reliable source, 2 uncreditablesites have
reported this.
Figure 4Cost of Uranium Aug2014-Feb2015
11. Thorium
Thorium is a more expensive mineral, coming in at about$1,490 US dollarsper 175
grams[11]. Thismeans 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 supplyof thorium
would only be 1 million dollars [12] which roughlyplaces the cost per month at
$117.45.
The price for refining thorium oreis hard to determinevia todays statistics, butfor
the comparison of costs since uranium is so high it would be a safe bet that
thorium even with refining costs is significantlylower than that of uranium use.
In the search for the pricesof thorium it was very hard to determine accurate
results. My thoughtson this is that uranium backersor companiesdo not want
thorium facts to be readily available to researcherslike myself.
12. Conclusion
Based upon the research I have done, my comparativeresearch has found that
thorium should be the leading element in powering North America. After viewing
the safety componentsand how they are utilized thorium presents an effective
way of avoiding a meltdown, which in a post Fukushima world should be the
upmostconcern of any citizen in the world.
Notably the money saved by investing in thorium reactorsis quite considerable
and immediately pay themselves off. This money could be putback into budgets
and help to improve the standard of living for Canadiansand Americanslikewise.
Lastly the abundanceof thorium native to Canada is substantial. There is enough
thorium to fuel North America and our vehicles for hundredsof years.
My recommendation after doing this research is to immediately invest in it as a
futurekeystone. Of courseit wouldn’thurtto research it a little moreto hammer
out the quirks, but within 5 years North America could begin shutting down and
disposing the radioactiveuranium and begin ushering in a new guideline to safe
energy.