Defense Date

2020

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Mechanical and Nuclear Engineering

First Advisor

Dr. Braden Goddard

Second Advisor

Dr. Supathorn Phongikaroon

Third Advisor

Dr. Ravi Hadimani

Fourth Advisor

Dr. William Newmann

Fifth Advisor

Dr. Milos Manic

Abstract

Decreasing the material attractiveness of uranium and plutonium materials is crucial to nuclear nonproliferation. The International Atomic Energy Agency (IAEA) implements safeguards across the world on a limited budget. Not only does decreasing material attractiveness reduce the possibility of proliferation, but also may lighten the financial burden on the IAEA if safeguards can be reduced. Two particular isotopes that have negative material attractiveness traits are 238Pu and 232U. Without isotopic separation technology, these isotopes cannot be removed from plutonium and uranium materials respectively. Both 238Pu and 232U produce large quantities of heat by alpha decay. High decay heat is considered one of the primary impacts on material attractiveness. This decay heat causes major issues during weaponization and can render the high explosives in a weapon useless and cause failure in the materials if high enough temperatures are reached. In addition to high alpha decay heat, 238Pu has a high spontaneous fission neutron generation rate, which can lead to a reduction in the yield of a nuclear weapon. 232U’s daughter products give a relatively high dose rate over time. Both the dose rate and heat generation increase over time, reaching a maximum after 10 years. 232U will also create difficulty during the enrichment process. Considering 232U is lighter than 235U, its concentration will increase at a higher rate during enrichment. The decay of 232U in gaseous UF6 can destroy UF6 molecules creating a variety of lighter molecules that must be separated from the enrichment stream. This study will evaluate the effects of 238Pu and 232U on material attractiveness. The material attractiveness of these materials will be quantified using multiple methods in an attempt to make a broad statement about their attractiveness. In order to better understand the feasibility of the introduction of 232U into a civilian nuclear fuel cycle, the effects on safety, security, and safeguards will also be explored.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

11-23-2020

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