Session A10
Paper 6139
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.
LIQUID SODIUM AS A COOLANT FOR FAST BREEDER REACTORS
Siddharth Lakshman, sil37@pitt.edu, Mahboobin 10:00, Zheng Guo, zhg18@pitt.edu , Mahboobin 4:00
Revised Proposal — Fast Breeder Reactors (FBRs) are the
future of nuclear reactors. Non-fast nuclear reactors can’t
produce energy with U-238 because it’s too heavy, thus lowenriched uranium is required which is comprised of 3-4% U235 [1]. FBRs counter this issue by having no neutron
moderator so the reactor can break down U-238 and doesn’t
need to enrich the uranium as fuel. The U-238 undergoes
fission and becomes plutonium; the plutonium can be reused
as a fuel source. Eventually an FBR becomes self-sustaining
and doesn’t require any fuel [2]. Consequently a high amount
of heat is produced and a coolant is needed.
Historically, water, liquid-metal, gas, and fluid fuels have
been used as coolants. Non-fast reactors use water as a
coolant because it’s also a neutron moderator, but FBRs
avoid neutron moderators. Thus, Liquid-sodium is the
optimal type of coolant for FBRs due to its thermophysical
and neutronic properties. The FBR’s temperature does not
exceed the boiling point of sodium, therefore a high
pressurized system isn’t needed. Unlike water, sodium’s
melting point to boiling point range is high [1]. If sodium
undergoes beta absorption, the half-life of the radiated
sodium is fifteen hours and does not pose a threat versus
other molten metals such as lead which produces polonium, a
highly radioactive element [3]. Another advantage is that
sodium does not react with the metals used to construct
nuclear reactors, therefore preventing any infrastructure
damage. Liquid sodium is a significant component to FBRs
solving one of the major problems associated with them.
At the same time, there are some risks to liquid sodium
such as the high reactivity with water and air. Sodium will
combust when exposed to water or start a fire when exposed
to air [3]. As long as the coolant isn’t exposed to water or
air, it is extremely efficient as proven by the Experimental
Breeder Reactor II (EBR II) in the US. The EBR II submerged
the reactor core in molten sodium and an experiment was
done shutting off the coolant from the reactor core and
leaving the reactor on maximum power. The result was the
sodium pool expanded and absorbed the heat, cooling the
reactor to near zero in about 300 seconds without any
significant damage done to the coolant or reactor core [4].
Using research conducted by nuclear chemists and real
like implications of liquid sodium, we will explore the nuclear
reactions that occur with liquid-sodium as a coolant. Then we
University of Pittsburgh Swanson School of Engineering 1
1/29/2016
will discuss the neutronic and thermophysical properties of
sodium as a coolant versus other coolants researched such as
lead or gas cooled reactors. Lastly, we will present real life
evidence to support the efficiency of using liquid sodium in
various other reactors such as the EBR II.
REFERENCES
[1] S. E. Bays, H. Zhang, H. Zhao. (2009). “The Industrial
Sodium Cooled Fast Reactor.” Idaho National Laboratory.
(Online
article).
https://inldigitallibrary.inl.gov/sti/4363828.pdf
[2] R. L. Garwin. (2010). “Fast Breeder Reactors.”
Federation of American Scientists. (Online article).
https://fas.org/rlg/3_15_2010%20Fast%20Breeder%20Reacto
rs%201.pdf
[3] T.H.Fanning. (2007). “Sodium as a Fast Reactor
Coolant.”
Argonne
National
Laboratory.
(Online
presentation).
http://www.sustainablees.com/asme/Shanahan_Fast_Reactors
_3.pdf
[4] S. Squassoni. (2009). “The US Nuclear Industry: Current
Status and Prospects under the Obama Administration.”
Carnegie Endowment for International Peace. (Online
article).
http://carnegieendowment.org/files/Nuclear_Energy_7_0.pdf
ANNOTATED BIBLIOGRAPHY
S. E. Bays, H. Zhang, H. Zhao. (2009). “The Industrial
Sodium Cooled Fast Reactor.” Idaho National Laboratory.
(Online
article).
https://inldigitallibrary.inl.gov/sti/4363828.pdf
This article is about the enrichment process in sodium cooled
fast reactors. The article is significant to this paper because
there are multiple statistics about cost, efficiency, and
electricity output from tested sodium cooled fast reactors.
There is also mentions of safety about SFRs.
R. L. Garwin. (2010). “Fast Breeder Reactors.” Federation of
American
Scientists.
(Online
article).
Siddharth Lakshman
Zheng Guo
https://fas.org/rlg/3_15_2010%20Fast%20Breeder%20Reacto
rs%201.pdf
This article illustrates effects of fast breeder reactors and the
nuclear fission reactions that take place inside the reactor.
There’s also mention of efficiency and using plutonium as a
fuel source and it’s compared to other types of nuclear
reactors that exist today.
be. Using certain gases in pipes to react with leakage, the
situation can be neutralized and controlled.
T.H.Fanning. (2007). “Sodium as a Fast Reactor Coolant.”
Argonne National Laboratory. (Online presentation).
http://www.sustainablees.com/asme/Shanahan_Fast_Reactors
_3.pdf
This source is a presentation presented by a professional
engineer from U.S. Department of Energy and U.S. Nuclear
Regulatory Commission, introducing why sodium is a good
coolant in fast reactors. It compares liquid sodium with
coolants such as lead and helium, including their
thermophysical, material and neutronic properties, and
identifies why sodium is preferred. These information will
help us understand the potential of further studying on
sodium cooled fast reactor.
I. Kazumi, M. Hiroyuki, O. Yoshiyuki, et al. (2014).
“Applications of hafnium hydride control rod to large sodium
cooled fast breeder reactor.” Ebscohost. (Online article).
http://search.ebscohost.com/login.aspx?direct=true&db=aph
&AN=98665837&site=ehost-live
This article is mainly about the implication of a special type
of control rod in sodium cooled fast reactors specifically. The
control rod is made of hafnium hybrid in order to prevent
reaction between the liquid sodium and the control rod. In
addition the safety issue is addressed and minimized by using
this type of control rod.
T. B. Cochran, H. A. Feiverson, F. V. Hippel. (2009). “Fast
Reactor Development in the United States.” Science &
Global Security. (Online article).
https://www.princeton.edu/sgs/publications/sgs/archive/17-23-Cochran-Feiv-vonHip.pdf
This writers of this article are from Natural Resources
Council and Program on Science and Global Security of
Princeton University. It chronicles the rise and fall of fast
reactor study in the United States. It can help us make a clear
introduction of the fast reactor and then get into the focus
which is liquid sodium coolant is the fast reactor.
S. Squassoni. (2009). “The US Nuclear Industry: Current
Status and Prospects under the Obama Administration.”
Carnegie Endowment for International Peace. (Online
article).
http://carnegieendowment.org/files/Nuclear_Energy_7_0.pdf
This article is written by a professional engineer from The
Centre for International Governance Innovation for the
purpose of future nuclear energy study. It describes the
history, current nuclear energy government programs in US
under the Obama administration. This article includes a big
amount of details of the U.S nuclear industries now that is
very important to real life applications of SFR we will talk
about in our conference paper.
R. Schaller, R. Chawla, J. Krepel, et al. (2012). “Analysis of
Advanced Sodium-cooled Fast Reactor Core Designed with
Improved Safety Characteristics.” Lausanne Federal
Polytechnic.
(Online
article).
http://infoscience.epfl.ch/record/181222/files/EPFL_TH5480.
pdf
This article shows further experiments and tests with sodium
cooled fast breeder reactors to prove the point that liquid
sodium is the ideal coolant. Specific code is used for the fast
reactor fuel cycles and it’s from the European framework.
This addresses how sodium becomes even more efficient
under an equilibrium closed fuel cycle.
N. K. Sinha, B. Raj. (2014). “Leakage limits for inflatable
seals of sodium cooled fast breeder reactor.” Ebscohost.
(Online
article).
http://search.ebscohost.com/login.aspx?direct=true&db=aph
&AN=93348320&site=ehost-live
This article talks purely about the leakage issued with sodium
cooled fast breeder reactors. The limitations of the leakage
are how dangerous a leakage can be and how minute they can
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