Search NASA⌕ Search

Engineering topics

Dry, Donald E.

Publications and source records attributed to Dry, Donald E..

R-Value Measurements Performed on Actinide Targets Irradiated using the GODIVA IV Critical Assembly in FY22

The separation and characterization of two irradiated uranium targets, a depleted uranium (DU) and a highly enriched uranium (HEU) target as well as a plutonium (Pu) target, was conducted in April of 2022. The three targets were assembled at Los Alamos National Laboratory (LANL) and irradiated using the GODIVA critical assembly at the National Criticality Experiments Research Center (NCERC). Splits of the dissolved targets were received by Pacific Northwest National Laboratory (PNNL) after which the PNNL and LANL teams chemically separated the solutions using independent separation schemes and analyzed the separated fractions for short lived actinides and fission products. Chemical separations were traced with stable or radioactive tracers to allow for the determination of chemical yields, analyzing using either inductively coupled plasma optical emission spectroscopy (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS) or gamma emission analysis (GEA) depending on the nature of the tracer. The Pu target solution was traced with stable elements at LANL to follow elemental fractionation during a Pu removal step. Many analytical techniques were used by PNNL including kinetic phosphorescence analysis (KPA), ICP-OES, ICP-MS, GEA, and thermal ionization mass spectrometry (TIMS) depending on the analyte’s need.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

June 2019 Depleted Uranium Irradiation

Three different irradiations were performed at the Annular Core Research Reactor (ACRR) at Sandia National laboratory on June 4-6, 2019. Each target assembly included two or three depleted uranium targets, as well as a bismuth target and dosimetry packets. In July 2019, the target assemblies were received at TA-48 RC-1, unpackaged, and radiochemical analyses were performed. The analyses included autoradiography and gamma counting of the whole depleted uranium targets, gamma counting of the activation foils, and dissolution of six of the depleted uranium targets, followed by separated radiochemical analysis for a suite of fission products. This report describes the details of the radiochemical analysis and provides final results for the fission and activation product concentrations.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

Final Results for 99 Mo, 111 Ag, 147 Nd, 140 Ba

Seven depleted uranium targets were irradiated at the ACRR reactor in three different irradiations occurring on June 4th, 5th, and 6th, 2019. The targets were received at LANL on July 10, 2019, unpackaged, and analyzed by autoradiography and gamma-ray spectrometry. Table 1 shows a chart of the Target ID, target mass, time the irradiation occurred, and the corresponding LANL sample ID. Six of the targets were dissolved and chemically separated radiochemical analyses were performed for a suite of radionuclides on four of the targets. The final results of the radiochemical separation and analysis of 99 Mo, 111 Ag, 147 Nd and 140 Ba for depleted U samples 4416-01, 4417-01, 4418-01 and 4418-03 are presented in Table 2. Associated errors represent 1σ uncertainty.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

Countroom Overview

This document describes the countroom operations at LANL, participants, and instrumentation.

99 GENERAL AND MISCELLANEOUS↗