| dc.description.abstract | The current waste management strategy for spent nuclear fuel (SNF) mandated by the
U.S. Congress is the disposal of high-level waste (HLW) in a geological repository at
Yucca Mountain. Ongoing efforts on closed-fuel cycle options and difficulties in
opening and safeguarding such a repository have led to investigations of alternative
waste management strategies. One potential strategy would make use of fuels containing
transuranic (TRU) nuclides in nuclear reactors. This would prolong reactor operation on
a single fuel loading and by doing so, would reduce current HLW stockpiles. The
analysis has already shown that high-temperature gas-cooled reactors (HTGRs) and their
Generation IV extensions, very-high-temperature reactors (VHTRs), have encouraging
performance characteristics that will allow for prolonged operation with no intermediate
refueling, as well as for transmutation of TRUs.
The objective of this research was to show that TRU-fueled VHTRs have the possibility
of prolonged operation on a single fuel loading while retaining their Generation IV safety
features. In addition, this research evaluated performance characteristics, and identified
operational domains of these systems, as well as the possibility of HLW reduction.
A whole-core, 3-D model of a power size prismatic VHTR with a detailed temperature
distribution was developed for calculations with the SCALE 5.1 code package. Results
of extensive criticality and depletion calculations with multiple fuel loadings showed that
VHTRs are capable and suitable for autonomous operation when loaded with TRU fuel. | en |
