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Bridges to the Doctorate Program Seminar-Dr. Daniel Rios, 10

PostPosted: Mon Oct 24, 2016 9:11 am
by rcrews
[center]BRIDGES TO THE DOCTORATE PROGRAM SEMINAR

Capture and Identification of the "Elusive" Chlorine-Containing
Gases Emitted from Impure Pu0[sub]2[/sub]

Daniel Rios

Los Alamos National Laboratory
Los Alamos, NM, U.S.A.
drios@lanl.gov

October 26th 2016, 3:00 - 4:00 PM
Science II Rm 109


The U.S. Department of Energy (DOE) stores excess plutonium-bearing materials in double nested 304L stainless steel containers. These containers were designed to safely store plutonium for 50 years. Recent observations of general and pitting corrosion inside the headspace region of some of these containers packaged with impure Pu0[sub]2[/sub] (Pu0[sub]2[/sub] mixed with hydrated salts) have raised the question as to whether or not these container could fulfill their life expectancy. Chlorine- containing gases (Cb, HClO and HCI) are believed to be responsible for this corrosion but up to this point have not been identified. Here we present the successful capture and identification of chlorine-containing gases emitted from impure PUO[sub]2[/sub].

Energy dispersive x-ray (EDX) analysis of deposits near corrosion pits in the inner container closure weld region found chloride (Cl) but no metal cations from the impure PuO[sub]2[/sub] (Na, K, Ca, Mg, or Pu) that would indicate particulate transport of the Cl to that location. These results indicate transport of G to the headspace was achieved via chlorine-containing gases. Once in the headspace, these chlorine- containing gases could be adsorbed onto the surface of the inner container closure weld region and initiate pitting and stress corrosion cracking. Chlorine-containing gases have different redox potentials and consequently different reactivity towards stainless steel. Therefore it is of great importance to identify the different chlorine-containing gases being emitted by impure PuO[sub]2[/sub] to better evaluate the risk for stress corrosion cracking in packaged containers.

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