Author ORCID Identifier

https://orcid.org/0009-0000-3620-322X

Defense Date

2024

Document Type

Thesis

Degree Name

Master of Science

Department

Mechanical and Nuclear Engineering

First Advisor

Dr. Braden Goddard

Abstract

This thesis uses MCNP simulations to evaluate the performance of a radiation shielding material consisting of Hafnium Diboride (HfB2) powder in an epoxy matrix. Comparing the results to previously measured data against both gamma and neutron sources, suitability for other applications can be confirmed. The model simulated the epoxy material with different weight percentages of HfB2 and thicknesses. It was compared to other shielding materials such as pure epoxy and 5% Borated High Density Polyethylene (HDPE-B). The HfB2-epoxy composite was tested against a wide energy range gamma spectrum from a 152Eu source, and neutrons from an Americium-241/Beryllium source. It was then used in simulations of combined gamma/neutron emitters: an Americium-241/Lithium research source, and Plutonium-238 Dioxide inside a housing for use in a Radioisotope Thermoelectric Generator.

Overall, the models show strong fidelity to previously captured laboratory data. The models very closely align with the gamma measurements (simulated results at 97% of laboratory measurements), and have a somewhat weaker correlation with neutron counting measurements (simulated results at 114% of laboratory measurements). Allowing for uncertainties of neutron measurements compared to gamma measurements, this is considered acceptable. The simulated HfB2-epoxy composite compares well to both lead and 5% HDPE-B for gamma and neutron shielding, respectively. Additionally, the HfB2-epoxy composite is effective at shielding both gammas and neutrons simultaneously. Further investigation is warranted into the generation of secondary radiation from scattering reactions, but HfB2-epoxy composite should be considered as an alternative to traditional shielding.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

8-5-2024

Available for download on Wednesday, August 05, 2026

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