b'Microwave-assistedMicrowave-assisted digestion enables reliable, high efficiency, and high digestion of non-irradiatedthroughput nuclear materials digestion prior to chemical analysis.nuclear materials M ost analytical instrumentation used for isotopic and elemental determination in nuclear fuels and correlated materials require the sample to be in solution form. Microwave-assisted digestion procedures have been applied for several matrixes, such as alloys, ores, environmental samples and organic materials. However, the literature regarding applications to nuclear materials is scarce. To fill this gap, this research developed and validated microwave-assisted digestion methods for several nuclear materials and correlated samples. PROJECT NUMBER:Microwave-assisted digestion has clear advantages when compared to open 21A1050-004FP systems, including lower sample preparation times (significantly increasing sample TOTAL APPROVED AMOUNT:throughput), better recovery for volatile elements, and enhanced reproducibility of $284,000 over 3 years the analytical results. All these advantages are attributed to the high temperature and high pressure environment that is created inside the digestion vessel. As the PRINCIPAL INVESTIGATOR:microwave heating affects only the sample and acid mixture due to ionic migration Luiza Gimenes Rodrigues Albuquerque and dipole rotation effects, the vessel walls remain at a much lower temperature. CO-INVESTIGATORS: This creates a reflux condition that greatly increases the efficiency of the digestion Beau Ballard, INL process, reduces the loss of volatile analytes, and continuously regenerates the acid Vivian Monted de Oca Carioni, INL mixture. In this work, steels, alloys, and uranium oxide certified reference materials were digested using the open system digestion and microwave-assisted digestion procedure. These materials acted as surrogates prior the digestion of real samples. Several parameters for both procedures were compared, such as element recoveries, acid quantities used, and analytical blank values. The recoveries ranged from 80120% for all samples, the digestion times were reduced from two weeks to two hours, and the acid weight required per gram of sample was reduced to 75% for some samples. Once the digestion methods were stablished, cladding and uranium materials were successfully digested.A) Microwave digestion system; B) uranium samples dissolved using the microwave system; C) elemental 64 recoveries for certified reference materials.'