Premium
Plasma Decontamination Of Depleted Uranium Oxide From Stainless Steel Surfaces a
Author(s) -
VEILLEUX JOHN M.,
ELGENK MOHAMED S.,
CHAMBERLIN E. P.,
MUNSON C.,
FITZPATRICK J.
Publication year - 1999
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.1999.tb08764.x
Subject(s) - depleted uranium , uranium , plasma , etching (microfabrication) , human decontamination , oxide , chemistry , glow discharge , materials science , uranium oxide , radiochemistry , metallurgy , nanotechnology , layer (electronics) , physics , quantum mechanics , nuclear physics
A series of single effect, RF plasma, glow discharge experiments were conducted using NF 3 gas to decontaminate depleted uranium dioxide from stainless‐steel substrates. In the experiments, the plasma absorbed power was varied from 25 to 210 W, the pressure from ∼10 to 40 Pa, and the NF 3 flow rate from 3 to 18.5 SCCM. Results demonstrated that UO 2 can be completely removed from stainless‐steel substrates after several minutes processing at under 100 W with initial etch rates ranging from 0.2 to 7.4 μm/min. A primary etch mechanism is proposed in which F atoms created in the plasma diffuse to the surface UO 2 and react to form successive intermediates of uranium fluorides and/or oxyfluorides with reactions continuing to form the volatile UF 6 which desorbs into the gas phase to be pumped away. Ions created in the plasma are too low in concentration to be the primary etch mechanism, yet they can deliver enough energy to enhance the reaction process. UO 2 etching is a self‐limiting process due to the formation of non‐volatile uranium oxyfluorides and fluorides which form over the UO 2 , slowing or completely blocking the reaction to UF 6 .