Seminar Series
2025
September 9
Liquid Lead Suspended Fuel Subcritical Fission Blanket for Nuclear Waste Transmutation
Taek K. Kim, Argonne National Laboratory
2:00 p.m., Mechanical Engineering Building Room 218
Zoom: https://unm.zoom.us/j/95290856939
Meeting ID: 952 9085 6939
Passcode: NE_501 (need to sign in to Zoom)
Abstract: A transformational transmutation technology is proposed to the ARPA-E Newton program for transmuting the entire U.S. minor actinides (MAs) stockpile and selected intermediate- and long-lived fission products (FPs). The transmutation system consists of a proton accelerator, a subcritical fission blanket containing liquid lead and nanometersized suspended MA transmutation targets, and an innovative separation system based on centrifugal force. The fission blanket system utilizes a liquid-lead-based nanofluid as a carrier for the transmutation targets, a coolant for heat transfer, and a spallation target. The lead-based nanofluid can substantially simplify spallation target design and enhance material resilience against frequent beam trips and temperature variations. The MA transmutation targets are irradiated in the form of nanometer-sized particles, aiming at homogenous suspension in the liquid lead, improvement of heat transfer capability, and emission of FPs from transmutation targets due to their recoil distance longer than the nanoparticle size. An innovative online separation technology is proposed to separate nanoparticles and FPs suspended in the liquid lead. Gaseous FPs bubble out, and other FPs in liquid lead are separated using a centrifugal force-based separation system such as a centrifugal contactor or centrifuge. The proposed transmutation technologies will be demonstrated through numerical simulations and experiments utilizing the nanoparticle manufacture and irradiation capabilities of national labs and universities.
Bio: Dr. Taek K. Kim is a Senior Nuclear Engineer, the Manager of the Nuclear Systems Analysis Department, Nuclear and Science Engineering Division at Argonne National Laboratory, and the National Technical Director of the Systems Analysis and Integration (SA&I) Campaign of the Office of Nuclear Energy, Department of Energy. He got a PhD in Nuclear Engineering from Seoul National University in 1995 and joined Argonne in 2001. At Argonne, he is responsible for providing technical leadership and programmatic guidance on various activities, including nuclear fuel cycle performance analysis, reactor physics, modeling and simulation of advanced reactor cores, and development of advanced reactor and transmutation concepts. In addition, Dr. Kim is leading the DOE-NE’s SA&I Campaign, which is the multi-national labs R&D program to develop strategies to improve the economic, technical, and social sustainability of nuclear energy.
April 15
Monte Carlo Neutron Transport on Exascale Computers
Steven Hamilton, Oak Ridge National Laboratory
2:00 p.m., Student Lounge inside Farris Engineering Center
Room 1026, Centennial Engineering Center
Zoom: https://unm.zoom.us/j/91510871864
Meeting ID: 915 1087 1864
Passcode: NE_501 (need to sign in to Zoom)
Abstract: The world's largest supercomputers have become increasingly focused on GPU-based computing architectures. This trend is driven by both the higher energy efficiency of GPUs relative to CPU platforms and the growing interest in applications of artificial intelligence. Researchers wishing to leverage high performance computing platforms for challenging problems must adapt their codes to the unique GPU programming paradigm. This talk presents an overview of the process of porting ORNL's Shift Monte Carlo radiation transport solver to execute efficiently GPUs as part of the DOE Exascale Computing Project. Several of the unique challenges encountered in the porting process will be highlighted. A central theme is that strategies known to be efficient on traditional CPU architectures may encounter unexpected challenges when running on GPUs. A few areas requiring particular algorithmic advances include continuous-energy nuclear data, isotopic depletion, flexible computational geometry, and multiphysics coupling. Simulation results on both Nvidia and AMD GPUs will be presented, including a series of multiphysics calculations on ORNL's Frontier supercomputer that was named a finalist for the 2023 ACM Gordon Bell Prize.
Bio: Steven Hamilton is a Senior R&D staff member in the HPC Methods for Nuclear Applications Group at Oak Ridge National Laboratory. He received BS and MS degrees in Nuclear Engineering from Georgia Tech and a PhD in Computational Mathematics from Emory University. He is a developer on both the Shift Monte Carlo radiation transport code and the Denovo deterministic transport solver, both part of ORNL's SCALE nuclear analysis suite. His research interests are in porting and optimizing scientific software for high performance computing platforms as well as the development of linear and nonlinear solvers for radiation transport and fluid flow problems.