Determination of preferential binder oxidation in HTGR matrix material subjected to high temperature steam

JOURNAL OF NUCLEAR MATERIALS

卷:544

Article

Montoya, Katherine I.¹  Moczygemba, Cole J.¹  Brigham, Brian A.¹  Spano, Tyler L.²  Campbell, Anne A.³  Gerczak, Tyler J.⁴  Sooby, Elizabeth S.¹ 

[1] Univ Texas San Antonio, Dept Phys & Astron, San Antonio, TX 78249 USA

[2] Oak Ridge Natl Lab, Nucl Nonproliferat Div, Oak Ridge, TN 37831 USA

[3] Oak Ridge Natl Lab, Mat Sci & Technol Div, Oak Ridge, TN 37831 USA

[4] Oak Ridge Natl Lab, Reactor & Nucl Syst Div, Oak Ridge, TN 37831 USA

关键词: Steam oxidation;    Raman Spectroscopy;    Graphitic matrix material;    High Temperature Gas Reactors;   

DOI  :  10.1016/j.jnucmat.2020.152674

来源: Elsevier

【 摘 要 】

Graphitic matrix material encapsulates tristructural isotropic (TRISO) coated fuel particles and is a structural component for both pebble and cylindrical fuel compacts in high temperature gas reactor (HTGR) designs. In an off-normal event involving steam exposure, the matrix material is exposed to oxidants, leading to degradation of the fuel compact and subsequent exposure of the TRISO particle fuel to oxidizing species. This study presents microstructural characterization of matrix material after exposure to high temperature (1200 degrees C), 48 kPa steam in which the evolved microstructure demonstrated nonuniform degradation. Subsequent Raman spectroscopy determined the nature of the remaining material post-exposure. The electron microscopy characterization suggests and Raman spectroscopic analysis confirms, under off-normal conditions, the carbonized phenolic resin binder is preferentially oxidized ahead of the graphite flake filler and is responsible for the nonuniform degradation and enhanced depth of attack. (C) 2020 Elsevier B.V. All rights reserved.

【 授权许可】

Free