Actinide Removal Process October 2014 Sample Analysis

Abstract

Filtration within the Actinide Removal Process (ARP) currently limits the throughput in interim salt processing at the Savannah River Site. In this process, batches of salt solution with Monosodium Titanate (MST) sorbent are concentrated by crossflow filtration. The filtrate is subsequently processed to remove cesium in the Modular Caustic Side Solvent Extraction Unit (MCU) followed by disposal in saltstone grout. The concentrated MST slurry is washed and sent to the Defense Waste Processing Facility (DWPF) for vitrification. During past ARP processing, there has been a degradation of filter performance manifested as the inability to maintain high filtrate flux throughout a multi-batch cycles during Salt Batches 6, 5 and 4. The objectives of the current effort for Salt Batch 7 samples, which are similar to the most recent ARP sample analysis from 2013, were to characterize the feed streams, to determine if solids (in addition to MST) are precipitating and causing the degraded performance of the filters, and to assess the particle size and rheological data to address potential filtration impacts. The samples from the LWPT and LWHT were obtained from several stages of processing of Salt Batch 7B, Cycle 1, Batch 67.