PNNL

Abstract

A system was developed to quantify the emanation fraction from samples ranging in size from powder to small rocks. Various rock types were crushed and sieved to various grades before being encapsulated in quartz ampoules. The samples were then irradiated at the Device Assembly Facility at the Nevada National Security Site before being returned to PNNL where the argon gas, produced via neutron activation of calcium, was extracted on a custom apparatus and cryogenically trapped. The extracted gas was then processed to separate the argon and load it into a proportional counter for counting. The emanation fraction of argon gas was then calculated by comparing the measured and predicted activities.