Abstract

The next generation of nuclear reactors (Generation IV) are specified to use graphite as the choice material for neutron moderation and structural components. For this reason, study of diffusion behavior of the fission product, ruthenium (Ru), in the candidate graphite grades, POCO AXF-5Q & ZXF-5Q, IG-110, NBG-18 and PCEA, is necessary. Diffusion data for Ru in these grades is absent due to the lack of prior studies and this work aims to fill this void and begin the study of this metallic fission product's diffusion behavior. By utilizing physical vapor deposition (PVD), dynamic secondary ion mass spectroscopy (SIMS), and the thin film solution to the diffusion equation coupled with a short circuit diffusion correction term, the diffusivities and Arrhenius temperature dependence are determined in the range of 500-1000°C and reported for the first time. Diffusion of Ru in this range is slow, with both lower activation energies and diffusion coefficients than other metallic fission products. Simulations of Ru diffusion on a graphene plane give activation energies similar to those acquired in this study. This is consistent with Ru behaving as an intercalating species and using the region in between graphene-like basal planes of graphite to travel through the lattice.

Graduation Date

2020

Semester

Fall

Advisor

Sohn, Yongho

Degree

Master of Science in Materials Science and Engineering (M.S.M.S.E.)

College

College of Engineering and Computer Science

Department

Materials Science and Engineering

Degree Program

Materials Science and Engineering

Format

application/pdf

Identifier

CFE0008330

Language

English

Release Date

December 2020

Length of Campus-only Access

None

Access Status

Masters Thesis (Open Access)

Share

COinS