The Transient Reactor Test (TREAT) facility, located at Idaho National Laboratory, restarted transient operations in 2018 following an extended shutdown. It is of interest to establish a methodology and capability to obtain an accurate estimate of the total number of fissions produced in a fissionable test item during a transient at TREAT. Uranium wires were irradiated in TREAT as part of a transient prescription test program, and gamma-ray spectrometry was performed on the wires following irradiation using a high-purity germanium detector. Many fission products are useful for estimating the number of fissions produced in a sample using gamma-ray spectrometry; at TREAT with the time periods used for analysis, the isotopes of interest include Zr-95, Nb-95, Ru-103, Ba-140, and La-140. The number of fissions per gram of U-235 determined from these measurements establishes an estimate for future experiments to be performed in the core when a similar configuration is used with a similar transient prescription.
