New INL project
tackles nuclear fuel recycling science
A new research project at Idaho National Laboratory and
Argonne National Laboratory will use an innovative approach to learn how to get
more use from nuclear fuel.
INL has won a competitive research grant that could help nuclear
fuel be recycled or used for longer periods of time to produce more energy. The
INL team in Idaho will collaborate with
scientists at the Argonne Tandem Linac Accelerator System (ATLAS) user facility
in Illinois.
The project demonstrates the U.S. Department of Energy's commitment
to conduct more basic research on nuclear fuel recycling. Thanks to $2 million in
funding from DOE's Office of Science, INL researcher Gilles Youinou aims to
give nuclear scientists a better understanding of how elements within fuel rods
respond to neutron irradiation.
"If we're going to recycle nuclear fuel or burn it
longer, we need a clearer understanding of how the daughter products respond to
neutron irradiation," said Youinou.
During the fission process, uranium emits neutrons as it splits
into daughter atoms. Within the fuel rods, those neutrons will interact to
produce either more fissions or heavier elements (i.e., "actinides"
such as neptunium, plutonium or americium). As nuclear scientists consider recycling
nuclear fuel to use more of the fissionable uranium, they would like more
information about how prolonged neutron bombardment affects such actinide
elements.
That's where INL's new project comes in. Youinou and his
team propose putting pure samples of common actinides — neptunium, americium
and curium — into INL's Advanced Test Reactor. The ATR lets researchers subject
materials to concentrated neutron irradiation in relatively short periods of
time.
After a mere 20 to 40 days in the ATR, the samples will be
removed and sent to the ATLAS facility for analysis. Argonne
collaborators Filip Kondev and Richard Pardo will oversee accelerator mass
spectroscopy analysis at ATLAS, which will be able to detect miniscule amounts of
material within a small sample size.
The analysis will provide precise measurements of rare
isotopes that build up during the irradiation process, which allows researchers
to infer fundamental nuclear characteristics of these elements. This is the
first time post-irradiation work has been done using this approach or the ATLAS
facility.
The project, originally conceived several years ago by
senior advisor Massimo Salvatores, has several advantages. It uses a unique
combination of expertise to offer quick and low-cost irradiation, high
precision and fewer uncertainties than similar experiments have achieved.
This high-quality actinide data will enable more precise
nuclear reactor simulations than are possible with current data. This type of
information is required to reliably assess fuel performance in advanced nuclear
systems. Such systems, which minimize waste and reduce proliferation risk, will
be a fundamental asset of future sustainable nuclear energy development.
New INL project will
improve nuclear reactor simulations
A new project at Idaho National Laboratory and Brookhaven
National Laboratory will improve the way scientists model the inner workings of
nuclear reactors.
Researchers from the Idaho
and New York
labs, led by INL's Giuseppe Palmiotti, won a competitive grant from the
Department of Energy's Office of Science. The researchers will use the money to
develop more accurate, and more universally applicable, reactor simulations. As
a result, engineers should be able to design better, more efficient reactors
down the road.
INL and BNL scientists will use data from experiments
already performed at nuclear facilities around the world to test and calibrate
their models of nuclear reactions at the atomic level. This will enable them to
integrate data from the meter scale (humans and their machines) with outcomes
at the femtometer scale (the atomic nucleus). The research will cover an
unprecedented 15 orders of magnitude, equivalent to the range between a single
footstep and a light year.
This approach is novel, because reactor engineers and
nuclear physicists occupy separate, rarely intersecting realms, according to
Palmiotti.
"This will create a bridge between the nuclear physics
community and the reactor community," he said. "The exchange of
information between the two will be beneficial to both sides."
INL researchers, including project leader Palmiotti, Massimo
Salvatores and Hikaru Hiruta, will take charge at the meter scale. Using INL's
supercomputer facility, they will analyze data from experiments investigating
the behavior and performance of materials inside reactors. These experiments
are broad and varied. Some have measured reaction rates and critical masses for
fissionable substances such as uranium and plutonium; others have looked at how
neutrons propagate through iron and sodium.
Meanwhile, BNL scientists Michal Herman and Pavel Oblozinsky
will use supercomputers to improve models at the nuclear physics level. The two
groups will feed off each other, testing the simulations they develop against
information from actual experiments.
The new simulations should be more accurate than those
currently in use, which have not been tested in this way. And, because the
researchers are looking at such a wide range of materials and experiments,
their models should also be more broadly applicable.
This project, which received $1.05 million over three years,
is one of two INL proposals funded by DOE's Office of Science. The other, which
Palmiotti also works on and INL physicist Gilles Youinou leads, could help
reveal how to get more use from nuclear fuel. While the two efforts differ
substantially in their details, they share common goals.
"Both projects look at improving our knowledge of
fast-reactor physics and increasing the accuracy of our simulation
efforts," Palmiotti said. Fast reactors employ a nuclear chain reaction
powered by especially fast-moving neutrons.
Projects are unusual
for INL
This project is one of two INL proposals funded by DOE's
Office of Science. The two grant awards represent a unique accomplishment for
INL, which receives the bulk of its research funding for applied engineering
work rather than basic research projects such as these. Further, the two
projects together received about $3 million, meaning that INL received 10
percent of the funds the Office of Science estimates will be available in this
round of Recovery Act funding.
"INL is using a science-based approach to obtain better
data and to better design future reactors," said Phillip Finck, INL associate
laboratory director for Nuclear Science & Technology. "Basically,
we're using scientific tools to get better engineering data."
Both projects began operation on Oct. 1.
Original articles here
and here.
Advanced Test Reactor
website
SOURCE: Idaho
National Laboratory