Nuclear Physics Seminar: Dr. Alexander M. Long, Los Alamos National Laboratory


Location: 127 Nieuwland Science Hall (View on map )

Neutron PIE: Accelerating Post-Irradiation Examination with Advanced Neutron Imaging for Next-Gen. Nuclear Reactor Materials

Dr. Alex Long (ND PhD 2016)
Material Science and Technology
Los Alamos National Laboratory

As the US nuclear energy sector strives to meet the escalating demand for clean, reliable energy, the Department of Energy's Office of Nuclear Energy (DOE-NE) is actively investing in programs to mature and demonstrate innovative reactor technologies and designs. With the development of new reactor designs under these initiatives, the licensing and qualification of nuclear fuel materials necessitate a thorough understanding of their performance under both nominal and transient conditions.  Traditionally, fuel irradiations followed by post-irradiation examination (PIE) techniques have been pivotal in qualifying nuclear fuels, providing essential insights into the material's behavior and integrity under extreme conditions. However, conventional PIE techniques, both destructive and non-destructive, can be costly and time-consuming, especially when examining fuels after extended irradiation periods. This necessitates more innovative and efficient approaches.

Advanced neutron imaging techniques, such as energy resolved neutron imaging (ERNI), offer a potential non-destructive PIE capability that can expedite the PIE-based material qualification process. ERNI's capacity to accurately image and record neutron absorption resonances on a pixelated basis enables precise three-dimensional spatial quantification of isotopic information within irradiated materials. This capability is particularly valuable for understanding isotopic distributions, both pre- and post-irradiation, providing critical data for fuel performance modeling and simulations. Furthermore, this technique marks a significant advancement in PIE capabilities, as ERNI measurements on  specific irradiated materials can inform and guide subsequent PIE analysis, enabling more detailed and comprehensive characterization of the materials for licensing and qualification.

In this presentation, I will showcase our progress in establishing ERNI capabilities at the Los Alamos Neutron Science Center (LANSCE) as a potential PIE tool. Our efforts range from deploying novel neutron imaging detectors based on TIMEPIX technology, crucial for overcoming the challenges associated with imaging highly radioactive nuclear materials; to developing automated tools for neutron resonance analysis, enhancing the efficiency and accuracy of ERNI measurements; to designing and fabricating containment systems for neutron measurements of samples with radiation levels up to 900R/hr. Ultimately, our goal is to develop a comprehensive ERNI program capable of handling and examining highly radioactive irradiated fuels, while fostering a knowledgeable and engaged user community that can advance the frontiers of PIE measurements to meet the needs of the nuclear energy community.

Hosted by Dr. deBoer