26 research outputs found
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Characterization, Leaching, and Filtration Testing for Tributyl Phosphate (TBP, Group 7) Actual Waste Sample Composites
.A testing program evaluating actual tank waste was developed in response to Task 4 from the M-12 External Flowsheet Review Team (EFRT) issue response plan. The bulk water-insoluble solid wastes that are anticipated to be delivered to the Waste Treatment and Immobilization Plant (WTP) were identified according to type such that the actual waste testing could be targeted to the relevant categories. Eight broad waste groupings were defined. Samples available from the 222S archive were identified and obtained for testing. The actual waste-testing program included homogenizing the samples by group, characterizing the solids and aqueous phases, and performing parametric leaching tests. The tributyl phosphate sludge (TBP, Group 7) is the subject of this report. The Group 7 waste was anticipated to be high in phosphorus as well as aluminum in the form of gibbsite. Both are believed to exist in sufficient quantities in the Group 7 waste to address leaching behavior. Thus, the focus of the Group 7 testing was on the removal of both P and Al. The waste-type definition, archived sample conditions, homogenization activities, characterization (physical, chemical, radioisotope, and crystal habit), and caustic leaching behavior as functions of time, temperature, and hydroxide concentration are discussed in this report. Testing was conducted according to TP-RPP-WTP-467
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Pretreatment Engineering Platform Phase 1 Final Test Report
Pacific Northwest National Laboratory (PNNL) was tasked by Bechtel National Inc. (BNI) on the River Protection Project, Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to conduct testing to demonstrate the performance of the WTP Pretreatment Facility (PTF) leaching and ultrafiltration processes at an engineering-scale. In addition to the demonstration, the testing was to address specific technical issues identified in Issue Response Plan for Implementation of External Flowsheet Review Team (EFRT) Recommendations - M12, Undemonstrated Leaching Processes.( ) Testing was conducted in a 1/4.5-scale mock-up of the PTF ultrafiltration system, the Pretreatment Engineering Platform (PEP). Parallel laboratory testing was conducted in various PNNL laboratories to allow direct comparison of process performance at an engineering-scale and a laboratory-scale. This report presents and discusses the results of those tests
Demonstration of an Advanced TALSPEAK Process for Actinide(III)/Lanthanide(III) Separation
Multivariate Analysis To Quantify Species in the Presence of Direct Interferents: Micro-Raman Analysis of HNO<sub>3</sub> in Microfluidic Devices
Microfluidic devices are a growing
field with significant potential
for applications to small scale processing of solutions. Much like
large scale processing, fast, reliable, and cost-effective means of
monitoring streams during processing are needed. Here we apply a novel
micro-Raman probe to the online monitoring of streams within a microfluidic
device. For either macro- or microscale process monitoring via spectroscopic
response, interfering or confounded bands can obfuscate results. By
utilizing chemometric analysis, a form of multivariate analysis, species
can be accurately quantified in solution despite the presence of overlapping
or confounding spectroscopic bands. This is demonstrated on solutions
of HNO<sub>3</sub> and NaNO<sub>3</sub> within microflow and microfluidic
devices
Development of Online pH Monitoring for Lactic, Malonic, Citric, and Oxalic Acids Based on Raman Spectroscopy Using Hierarchical Chemometric Modeling
Online spectroscopic measurements can be used to provide
unique
insight into complex chemical systems, enabling new understanding
and optimization of chemical processes. A key example of this is discussed
here with the monitoring of pH of various acid systems in real-time.
In this work the acids used in multiple chemical separations processes,
such as TALSPEAK (Trivalent Actinide-Lanthanide Separation by Phosphorus
reagent Extraction from Aqueous Komplexes) and oxalate precipitation,
were characterized. Raman spectroscopy, a robust optical approach
that can be integrated in corrosive processes, was used to follow
the unique fingerprints of the various protonated and deprotonated
acid species. This data was analyzed using a hierarchical modeling
approach to build a consolidated model scheme using optical fingerprints
from all weak acids to measure pH associated with any of the weak
acid systems studied here. Validation of system performance included
utilizing Raman spectroscopy under dynamic flow conditions to monitor
solution pH under changing process conditions in-line. Overall, the
Raman based approach provided accurate analysis of weak acid solution
pH
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Fiscal Year 2010
During FY 2010, work under the Spectroscopy-Based Process Monitoring task included ordering and receiving four fluid flow meters and four flow visible-near infrared spectrometer cells to be instrumented within the centrifugal contactor system at Pacific Northwest National Laboratory (PNNL). Initial demonstrations of real-time spectroscopic measurements on cold-stream simulants were conducted using plutonium (Pu)/uranium (U) (PUREX) solvent extraction process conditions. The specific test case examined the extraction of neodymium nitrate (Nd(NO3)3) from an aqueous nitric acid (HNO3) feed into a tri-n-butyl phosphate (TBP)/ n-dodecane solvent. Demonstration testing of this system included diverting a sample from the aqueous feed meanwhile monitoring the process in every phase using the on-line spectroscopic process monitoring system. The purpose of this demonstration was to test whether spectroscopic monitoring is capable of determining the mass balance of metal nitrate species involved in a cross-current solvent extraction scheme while also diverting a sample from the system. The diversion scenario involved diverting a portion of the feed from a counter-current extraction system while a continuous extraction experiment was underway. A successful test would demonstrate the ability of the process monitoring system to detect and quantify the diversion of material from the system during a real-time continuous solvent extraction experiment. The system was designed to mimic a PUREX-type extraction process with a bank of four centrifugal contactors. The aqueous feed contained Nd(NO3)3 in HNO3, and the organic phase was composed of TBP/n-dodecane. The amount of sample observed to be diverted by on-line spectroscopic process monitoring was measured to be 3 mmol (3 x 10-3 mol) Nd3+. This value was in excellent agreement with the 2.9 mmol Nd3+ value based on the known mass of sample taken (i.e., diverted) directly from the system feed solution