ALCF Science 1 - Argonne National Laboratory

argonne leadership computing facility
Energy Technologies
Improving Light Water Reactor Fuel Reliability
Via Flow-Induced Vibration Simulations
Vibrations at the heart of fuel rod failures
Failures of the fuel rod elements used to power U.S. nuclear power
plants are rare. When they do fail, however, one of the most common
causes is flow-induced vibration of fuel assembly components. In
fact, the Electric Power Research Institute reports that more than
70 percent of all fuel failures in pressured water reactors are due to
grid-to-rod fretting.
Recent advances and state-of-the-art resources set stage for success
Using resources at the Argonne Leadership Computing Facility,
scientists are investigating vibrations caused by turbulent flow in
the core of light-water reactors—the major cause of fuel failure and
a recognized bottleneck to optimal fuel utilization. This research
is especially well timed, given recent advances in high-fidelity
computational fluid dynamics that make multi-pin large-eddy
simulations (LES) computationally within reach, coupled with fluid/
structural codes that have reached a state of maturity far beyond what
existed a decade ago.
Homegrown code, Nek5000,
used to demystify forces in
vibration
Researchers will conduct LES
simulations using the Argonnedeveloped
code Nek5000 to better
understand vibration-driven forces
resulting from the turbulent fluid
flow in multi-pin configurations
of realistic LWR fuel assembly
geometries. These simulations
will then be loosely coupled to
the highly scalable finite-element
structural mechanics simulator,
Diablo.
ALCC Allocation:
75 Million Hours
ASCR LEADERSHIP
COMPUTING CHALLENGE
23
Velocity distribution in a 217-pin
reactor subassembly.
Contact Andrew Siegel
Argonne National Laboratory | siegela@mcs.anl.gov