FY-2010 Process Monitoring Technology Final Report

Orton, Christopher R. ; Bryan, Samuel A. ; Casella, Amanda J. ; Hines, Wes ; Levitskaia, Tatiana G. ; henkell, J. ; Schwantes, Jon M. ; Jordan, Elizabeth A. ; Lines, Amanda M. ; Fraga, Carlos G. ; Peterson, James M. ; Verdugo, Dawn E. ; Christensen, Ronald N. ; Peper,

关键词: process monitoring;    spectroscopy-based monitoring;    multi-isotope process monitor;   

DOI  :  10.2172/1008246
RP-ID  :  PNNL-20022
PID  :  OSTI ID: 1008246
Others  :  Other: NN4003010

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来源: SciTech Connect

【 摘 要 】

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.