AVS 57th International Symposium & Exhibition
    Actinides and Rare Earths Topical Conference Tuesday Sessions
       Session AC-TuA

Paper AC-TuA2
Memory Effects of UF6 Adsorption and Reaction at Metallic Surfaces

Tuesday, October 19, 2010, 2:20 pm, Room Isleta

Session: Science and Technology of Actinides and Rare Earths
Presenter: M.T. Paffett, Los Alamos National Laboratory
Authors: M.T. Paffett, Los Alamos National Laboratory
D.P. Moore, Los Alamos National Laboratory
J.D. Farr, Los Alamos National Laboratory
R.K. Schulze, Los Alamos National Laboratory
K.D. Ianakiev, Los Alamos National Laboratory
Correspondent: Click to Email
In this study we explore memory effects that arise from the reactivity of UF6 with surface hydroxyls (and other entities with a reactive H bond) that may be present at metallic surfaces. These chemical interactions are noted to leave behind low but measurable quantities of uranium oxy fluorides (UO2F2, UOF4 and related extended solids). Uranium re-depositions are noted to occur following sequential exposures to varying isotopic content in the UF6 gas stream. We explore the role that additional fluorinating agents (HF, ClF3) play in promoting uranium surface re-fluorination and memory effects in these deposits. The primary surface and radiochemical characterization techniques utilized in this study and include x-ray photoelectron spectroscopy, Auger electron spectroscopy depth profiling, static SIMS and alpha emission spectroscopy. The importance of these memory effects in enabling higher accuracy isotopic determinations and in forensic knowledge