UT Resource Center, 1201 Oak Ridge Turnpike, Oak Ridge, or view online via Zoom.
Doors open at 11:15 a.m. for socializing and eating lunch (light lunch will be available for a donation). Scroll down for details of the location, lunch, and Zoom.

Abstract

Oak Ridge National Laboratory is the only place in the western world capable of producing the radioisotope californium-252, an essential material for nuclear reactor startup. Californium-252 from ORNL was used to start up reactors at Georgia Power’s Alvin W. Vogtle Electric Generating Plant, the nation’s largest nuclear power plant which houses the first new nuclear reactors built in the United States in more than 30 years.

Production of this rare and valuable isotope takes expertise, teams of trained professionals, and ORNL’s unique facilities, including the High Flux Isotope Reactor (HFIR), the strongest reactor-based neutron source in the United States, and the Radiochemical Engineering Development Center, which has an array of shielded hot cells to allow experts to safely handle radioactive materials. Cf-252 is also used in the creation of new elements, in some medical applications, and in the oil drilling industry.

Curium (Cm) is at the heart of californium (Cf) and heavy element production as it is the feedstock material for the HFIR targets irradiated by the reactor’s neutrons that produce elements such as berkelium, californium, einsteinium, and fermium (i.e. transcurium elements). This critical use makes Cm a precious commodity to the Department of Energy Isotope Program and to many scientists around the world. 

Unfortunately, the nation’s Cm supply is dwindling, and no future production is planned. In the next few years, curium-containing Mk-18A targets from Savannah River National Laboratory will provide ORNL with the last known large inventory of heavy Cm (rich in ²⁴⁶Cm, ²⁴⁷Cm, and ²⁴⁸Cm). Because Cm is rare, understanding and thoroughly characterizing its properties are important for fabricating HFIR targets that will enable robust transcurium element production.  

This talk will focus on ORNL’s efforts to better understand the curium oxide, or CmO_x (x = 1.5 or 2), used in target fabrication and the way it ages in solid matrices over time. Understanding these changes and their possible effects on thermophysical and thermochemical properties, such as volume, density, and materials packing, could provide an estimate of the material lifetime and help to improve Cm target fabrication to increase the production of heavy elements by up to 40%. To reach this goal, our group has performed characterizations of both curium-containing material and surrogates using powder X-ray diffraction, X-ray absorption spectroscopy, and microscopy. I will discuss our results and the future work we plan to perform on this unique material.

Biographical sketch
Dr. Samantha Schrell, previously known as Samantha Cary, received her B.S. degree in chemistry from Ithaca College in 2012 and her Ph.D. in inorganic chemistry from Florida State University in 2015. Her doctoral research, conducted under the direction of Professor T. E. Albrecht, focused on the structure and bonding of late actinide systems. During this time, she developed expertise in handling and manipulating relatively large quantities (on the scale of 5-100 milligrams) of highly radioactive materials, including neptunium, plutonium, americium, curium, berkelium, and californium in support of coordination chemistry studies.

In 2015, she received the Innovations in Fuel Cycle Research Award for her work with californium. In 2016, she joined Los Alamos National Laboratory as an Agnew National Security Postdoctoral Fellow under the guidance of Dr. Stosh A. Kozimor. In January 2017, she was awarded the Marie Curie Distinguished Postdoctoral Fellowship, through which her research broadly encompassed actinide intermetallics, coordination chemistry, solid-state synthesis, and separations.

In July 2018, she transitioned to a staff scientist position in the Metal Production Group at Los Alamos National Laboratory. In fall 2019, she was hired as a research scientist at Oak Ridge National Laboratory, where she continues to advance and improve californium production. She currently serves as the manager of the Cf-252 Program and director of the Glenn T. Seaborg Institute at ORNL.

Event Details
The UT Resource Center is at 1201 Oak Ridge Turnpike between Dairy Queen and Applebee's Grill. Use the entrance at the southwest (back) corner of the building. 
A light lunch (half sandwich, chips, cookie, and a drink) will be available for a $10 donation (cash, check or IOU) starting about 11:15 a.m. on a first-come, first-served basis.   Attendees may also bring food to eat.
 
Meeting Agenda

11:15 a.m.  – Arrive at UT Resource Center to grab a light lunch or chat with colleagues
11:50 a.m.  – Zoom attendees may login online until noon
12:00 p.m. – Talk begins following a few announcements and introduction of the speaker.
 
Zoom available about 11:50 a.m.
https://us02web.zoom.us/j/85031487666?pwd=hoWLDmg9aZkvPCkKqwbCqn2VNb0vab.1
 Meeting ID: 850 3148 7666
Passcode: 110299