Conference Session B10
Paper # 6161
Disclaimer — This paper partially fulfills a writing requirement for first year (freshman) engineering students at the University
of Pittsburgh Swanson School of Engineering. This paper is a student, not a professional, paper. This paper is based on
publicly available information and may not be provide complete analyses of all relevant data. If this paper is used for
any purpose other than these authors’ partial fulfillment of a writing requirement for first year (freshman) engineering
students at the University of Pittsburgh Swanson School of Engineering, the user does so at his or her own risk.
LITHIUM CERAMIC PEBBLES USED TO CREATE SUSTAINABLE
ENERGY FROM FUSION
Elan Anderson, eda24@pitt.edu, Lora 4:00
Aaron Woeppel, abw35@pitt.edu, Mahboobin 10:00
Revised Proposal— This paper will focus on lithium pebbles
that are used production of tritium, a radioactive isotope of
hydrogen, which serves as the main fuel for a fusion reactor.
In order to use fusion, the process of combining to lightweight
atomic nuclei to form a heavier atom, to create energy, an
abundant amount of fuel must be present to draw on. Fuel for
fusion consists of deuterium and tritium, isotopes of hydrogen.
While a near-endless supply of deuterium is present in sea
water, naturally occurring tritium is scarce. Therefore, in
order to make sustainable energy, fusion tritium must be manmade. Fortunately, tritium is produced in fusion when
neutrons escaping the plasma interact with lithium.
Considering this fact, lithium pebbles will be the main
component of a blanket of a fusion reactor. [1]
The pebbles must be a small diameter within a set range
to achieve an ideal set of properties such as a low thermal
energy. While there are many potential lithium compounds
that may be suitable for tritium breeding in a blanket, due to
certain chemical properties, lithium orthosilicate (Li4SiO4)
was chosen as the first potential material in a blanket referred
to Chinese Helium Cooled Pebble Bed Test Blanket Module.
[2]
We will examine many methods of producing lithium
pebbles such as the wet method and melting/spraying method.
The Plateau-Rayleigh Instability, which is observed every day
in cases such as dripping water, has also been found to be
effective in production of lithium pebbles. [3]
We will also examine the recovery of lithium from spent
pebbles. Mandel reports in the abstract of his paper that” at
the end of life, the pebbles (lithium titanate) will contain more
than 45% unused Li6 isotope.”[4] Since nearly half of the
usable lithium remains unused in spent pebbles, a fusion
reactor that did not include a method of lithium recovery
would be inefficient
As stated earlier, because tritium, a main fuel for fusion,
is not naturally abundant enough to produce energy, a
generator would have to be able to produce tritium. However,
a main concern is that tritium produced will leak into the
water, which could have negative ecological impacts. [5]
This topic is relevant to engineering because in perfecting
lithium pebble technology, society would be one step closer to
achieving a sustainable clean energy in the form of nuclear
University of Pittsburgh, Swanson School of Engineering 1
Submission Date 2016/01/25
fusion. In this paper, scholarly articles and reliable scientific
news articles will be used to assess lithium pebble technology
on its potential as a resource for tritium breeding and looking
in to the manufacturing economic viability of various methods
of lithium production.
REFERENCES
[1] ITER - the way to new energy. (n.d.). Retrieved
January 12, 2015.
http://www.iter.org/
[2] X. Gao. X. Chen. et al. (2012). “Fabrication and
characterization of Li4SiO4 ceramic pebbles by wet method.”
Journal of Nuclear Materials. (online article)
http://rt4rf9qn2y.scholar.serialssolutions.com/?sid=googl
e&auinit=X&aulast=Gao&atitle=Fabrication+and+character
ization+of+Li+4+SiO+4+ceramic+pebbles+by+wet+method
&id=doi:10.1016/j.jnucmat.2012.02.018&title=Journal+of+
nuclear+materials&volume=424&issue=1&date=2012&spag
e=210&issn=0022-3115
[3]P. Waibel. J. Matthes. et al. (2014). “High-Speed
Camera-Based Analysis of the Lithium Ceramic Pebble
Fabrication Process.” Chemical Engineering & Technology
(online article)
https://www.researchgate.net/publication/265514286_Hi
gh-Speed_CameraBased_Analysis_of_the_Lithium_Ceramic_Pebble_Fabricati
on_Process
[4] D..Mandal. (2013). “Recovery and recycling of
lithium value from spent lithium titanate (Li2TiO3) pebbles.”
Journal of Nuclear Materials. (Online article)
[5] S. Dingwall. C. Mills. N. Phan. K. Taylor. (2011).
“Human Health and the Biological Effects of Tritium In
Drinking Water: Prudent Policy Through Science-Addressing
the Odwac New Recommendation” Dose-Response (Online
article)
http://rt4rf9qn2y.scholar.serialssolutions.com/?sid=google&
auinit=S&aulast=Dingwall&atitle=Human+health+and+the+
biological+effects+of+tritium+in+drinking+water:+prudent+
policy+through+science%E2%80%93addressing+the+ODW
AC+new+recommendation&id=doi:10.2203/doseresponse.10-048.Boreham&title=Dose-
Elan Anderson
Aaron Woeppel
response&volume=9&issue=1&date=2011&spage=dose&iss
n=1559-3258
common details that an engineer may look for in the quality
of pebbles they produce.
ANNOTATED BIBLIOGRAPHY
R.Knitter, M.M.H Kolb, U.Kauffman, A.A Goraieb.
(2013, Nov 15). “Fabrication of modified lithium orthosilicate
pebbles by addition of titania.” Journal of Nuclear Materials.”
(online article).
http://www.engineeringvillage.com/search/doc/abstract.u
rl?pageType=quickSearch&searchtype=Quick&SEARCHID
=34359697M6e02M408cMa964Me5128cc0aba4&DOCIND
EX=6&database=3&format=quickSearchAbstractFormat&d
edupResultCount=&SEARCHID=34359697M6e02M408cM
a964Me5128cc0aba4
Written as part of a presentation during the Fifteenth
International Conference on Fusion Reactor Materials, this
article delves into lithium orthosilicate, one of the main
components used in tritium breeding. While it exhibits ideal
qualities, it has several flaws, the biggest of which being the
defects that manifest during prolonged use. However, this
article proposes a method to help enhance the mechanical
properties of the pebbles. By adding titania to the process the
final products, lithium titanate, exhibits smaller pores, thus
decreasing the chance of defects. This source is being used to
demonstrate methods that can help improve our current
technology and make more efficient products in the long run.
R.K Annabattula, M. Kold, Y. Gan, R. Rolli, M. Kamlah.
(2014, March 20). “Size-Dependent Crush Analysis of
Lithium Orthosilicate Pebbles”. Fusion Science and
Technology. (article).
http://dx.doi.org/10.13182/FST13-737
This article, written by researchers at the Indian Institute
of Technology, discusses lithium orthosilicate’s physical
properties and thermo-mechanical integrity, which is vital for
materials used in a fusion reactor. In order to identify the
pebbles’ strength, several samples of spherical OSi with
varying diameter were put under pressure. The results of the
studies showed that pebbles with larger diameters, as well as
more opacity were more durable. This article will be used in
order to help establish the material our project is centered on.
X. Chen ,X. Gao. et al. (2012, February 18). “Fabrication
and characterization of Li4SiO4 ceramic pebbles by wet
method.”Journal of Nuclear Materials. (Online article).
doi:10.1016/j.jnucmat.2012.02.018
This article, published in the Journal of Nuclear Materials,
compares production of pebbles by an expensive method to
those produced by a more affordable alternative. This article
will be presented in the paper as not only an example of a
method used to create lithium pebbles, but also an example as
to how an engineer would need to consider the cost of
production along with the quality of the product.
D..Mandal. (2013, September
9). “Recovery and
recycling of lithium value from spent lithium titanate
(Li2TiO3) pebbles.” Journal of Nuclear Materials. (Online
article)
doi:10.1016/j.jnucmat.2013.04.028
Published in the Journal of Nuclear Materials this article
studies the recovery of lithium from spent Li2TiO3 a potential
lithium ceramic that could be used in tritium breeding due to
some of its attractive properties. Previous literature has that a
great deal of lithium remains unused and thus must be
recovered. This article will be used to explain the importance
of recovering used lithium when trying to economically
produce tritium.
S. Dingwall, C.E. Mills, N. Phan, K. Taylor. 2011, 6
September. “Human Health and the Biological Effects of
Tritium in Drinking Water: Prudent Policy Through ScienceAddressing the ODWAC New Recommendation”.DoseResponse.(Article).
This article focuses on the ethical side of nuclear fusion.
Tritium, one of the byproducts in fusion, is considered to be
a potential danger to humans because if its carcinogenic
qualities. Even in minuscule amounts, it poses a threat to
humans if it isn’t properly contained. This article will be used
to view nuclear fusion from a humanitarian angle.
P. Waibel, J. Matthes, O. Leys, M. Kolb, R. Knitter, H.
Keller. (2014, September 10). “High-Speed Camera-Based
Analysis of the Lithium Ceramic Pebble Fabrication Process”.
Chemical Engineering and Technology. (Research article).
http://onlinelibrary.wiley.com/doi/10.1002/ceat.2013007
69/pdf
This paper, which was published by researchers at the
Institute for Applied Computer Science (IAI), Karlsruhe
Institute of Technology (KIT), uses a new method to delve
into the process of creating lithium ceramic pebbles. Using
nozzles which ranged from 200-400 µm, and internal pressure
of up to 400 mbar, it was proven that the diameter tended to
fall within the desired diameter desired for maximum
efficiency.
Y. Huang. H. Tang. J. Li. Et al. (2012, November 13)
“Preparation of Lithium Orthosilicate Ceramic Pebbles by
Molten Spray Method Process” Advanced Materials
Research Vol. 412, pp. 111-115, Nov. 2011 (Article)
This article published in Advanced Material Research studies
the process of producing lithium orthosilicate with the method
referred to in the paper as the molten spray method. The
article later includes details regarding the finished pebbles.
This article will be used to explain another example of a
method in producing lithium pebbles along with some
2
Elan Anderson
Aaron Woeppel
C. Xiao. X. Gao et al. (2013, July 8). “Tritium release
kinetics in lithium orthosilicate ceramic pebbles irradiated
with low thermal-neutron fluence” Journal of Nuclear
Materials. (Online article)
doi:10.1016/j.jnucmat.2013.02.069
Published in the Journal of Nuclear Materials this article
studies the release of tritium for lithium orthosilicate pebble.
Tritiated water vapor was found to be the main form of
released tritium. The kinetics of the tritiated water vapor was
well interpreted as a diffusion process in grains of the lithium
orthosilicate pebbles. This article will help allow us to give a
basic explanation behind the chemistry involved in tritium
production.
N. Zaccari, D. Aquaro. 2009, 30 April. “Experimental
characterization of ceramic pebble beds”. Journal of Nuclear
Materials. (article).
http://web.b.ebscohost.com/ehost/detail/detail?sid=c7220
94f-86f0-4cac-bb3851db7f161d7c%40sessionmgr112&vid=0&hid=115&bdata=
JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#AN=37824467&db
=aph
Originating in the Department of Mechanical Engineering
of the University of Pisa, this article compiles the results of
various mechanical tests on lithium orthosilicate and lithium
metanitate. These tests, which subjected samples to thermal
stresses, direct shearing and a tri-axial test, were used to gain
quantitative data. In turn, the data presented here could be
utilized in future simulations to aid in replicating scenarios.
This source is being used in order to support the viability of
the two aforementioned materials with numerical data.
3