SULI - CSE - Rowles, Soren - 3.06.26

Argonne National Laboratory • Lemont, IL

2d

About The Position

This project supports a broader effort to develop an experimentally validated understanding of the surface chemistry and reactivity of plutonium oxide nanoparticles (PuO2 NPs) under highly alkaline, high-ionic-strength conditions relevant to Hanford tank waste. Motivated by evidence that a substantial fraction of Hanford plutonium exists as PuO2 NPs rather than dissolved species, this work examines how colloidal particles (including PuO2 NPs) interact with solid phases present in the tanks, particularly Al- and Zr-bearing materials. These interactions may drive particle retention, aggregation, or mobilization, contributing to uncertainty in plutonium fate during waste storage and treatment. The SULI student will synthesize CeO2 nanoparticles as a non-radioactive surrogate for PuO2 and use CeO2 NPs–Al2 O3 and CeO2 NPs–ZrO2 as model systems for tank-relevant Al- and Zr-phases. Using a combination of microscopy (AFM, SEM) and X-ray scattering methods (SAXS, SXRD), the student will quantify nanoparticle association with solids and measure changes in size distributions of immobilized aggregates as a function of electrolyte composition, e.g., hydroxide concentration and salt identity/ionic strength. The results will provide mechanistic insight into colloid–surface interactions under extreme chemical conditions and help constrain models of actinide nanoparticle behavior in complex waste environments such as at Hanford.

Requirements

• The entirety of the appointment must be conducted within the United States.
• Currently enrolled in undergraduate or graduate studies at an accredited institution.
• Graduated from an accredited institution within the past 3 months; or
• Actively enrolled in a graduate program at an accredited institution.
• Must be 18 years or older at the time the appointment begins.
• Must possess a cumulative GPA of 3.0 on a 4.0 scale.
• Must be a U.S. citizen or Legal Permanent Resident at the time of application.

Responsibilities

• synthesize CeO2 nanoparticles as a non-radioactive surrogate for PuO2
• use CeO2 NPs–Al2 O3 and CeO2 NPs–ZrO2 as model systems for tank-relevant Al- and Zr-phases
• quantify nanoparticle association with solids and measure changes in size distributions of immobilized aggregates as a function of electrolyte composition, e.g., hydroxide concentration and salt identity/ionic strength using a combination of microscopy (AFM, SEM) and X-ray scattering methods (SAXS, SXRD)

What This Job Offers

• Job Type: Full-time
• Career Level: Intern
• Education Level: No Education Listed
• Number of Employees: 1,001-5,000 employees