Page 58 from: Out now: Recycling Technology 2021!
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2021
Technolab
R
ecycling very sensitive materials is rarely
easy. The nuclear industry currently re-
cycles up to 95% of spent fuel from reac-
tors but the remaining 5% has to be stored for
hundreds of thousands of years.
In the USA today, 98 commercially-oper-
ated nuclear power reactors produce nearly
20% of the country’s electricity. These gener-
ate around 2000 tonnes of used nuclear fuel
annually, with the result that almost 80 000
tonnes of such waste has accumulated nation-
wide. At the current rate, the total US inven-
tory will reach 126 000 tonnes by 2040.
36-step process
Scientists at the US Department of En-
ergy’s Argonne National Laboratory are in-
creasingly using 3D printed parts from recy-
cled materials. This may help trim these last
few percent of non-recycled spent nuclear
fuel, according to Argonne nuclear chemist
Andrew Breshears. He proposes closing the
cycle to recover minor actinides (including
neptunium, americium and curium) using a
‘simplified’ minor actinide lanthanide separa-
tion process paired with sustainable additive
manufacturing.
The starting point is the highly radioactive
liquid solution generated after the recovery
of uranium, neptunium and plutonium from
the dissolved fuel by extraction with tri-butyl
phosphate. Extraction of minor actinides has
been performed by contacting the extracting
organic phase with aqueous phases for 10
minutes using a vortex mixer at the maximum
intensity setting. Exact details of the 36-step
process have been published in the journal
Nature Research and can be found online.
Less stored, more energy
The scientists explain how ‘expanded low-
carbon baseload power production through
the use of nuclear fission can be enabled by
recycling long-lived actinide isotopes within
the nuclear fuel cycle’. This approach enables
the recovery of an additional 2% of the nu-
clear material.
‘Rather than store 5% for hundreds of
thousands of years, the remaining 3% needs to
be stored at a maximum of about 1000 years,’
says Breshears. ‘Breaking down that nuclear
material in a next-generation fast reactor
would generate additional electricity.’
99.9% separation
The scientists achieved their goal by sepa-
rating americium and curium from rare earth
lanthanides; ultimately, they succeeded in
separating 99.9% of the actinides from the
lanthanides. In redesigning the processes that
divide the elements, the researchers were able
to 3D print centrifugal contactors – initially
with a 1.25 cm rotor diameter.
Because the performance of these centrifu-
gal contactors scales well with increased rotor
diameter, successful implementation with 1.25
cm contactors would be expected to translate
to larger, industrially-relevant contactors.
‘Taken together, this work opens the door
for a simplified means to recycle the tran-
suranic actinide elements in the nuclear fuel
cycle, helping to enable the expansion of low-
carbon nuclear power production,’ Breshears
concludes.
For more information, contact Andrew Breshears
at: [email protected]
Author:
Kirstin Linnenkoper
HigHLigHts
Research:
Nuclear fuel waste recycling
Pioneer:
Argonne National Laboratory, USA
Led by:
Andrew Breshears
A recycling win for nuclear
fuel processing
There is a growing connection between 3D printing and nuclear fuel recycling,
explain scientists at the US Department of Energy’s Argonne National Laboratory
who say this novel application fits into a circular economy for spent fuel.
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