Real-Time Chord Length Analysis of Strontium and Manganese Precipitates Formed from Hanford Tank 241-AN-107 Simulant

KING, WILLIAMD

Savannah River Site (S.C.)

关键词: Alpha-Bearing Wastes;    Filtration;    Liquid Wastes;    Radioactive Waste Processing;    Strontium Compounds;   

DOI  :  10.2172/822239
RP-ID  :  WSRC-TR-2002-00364 SRT-RPP-2002-00194
RP-ID  :  AC09-96SR18500
RP-ID  :  822239

美国|英语

来源: UNT Digital Library

【 摘 要 】

Removal of radioactive strontium and transuranic elements from Hanford Envelope C waste solutions can be accomplished by the sequential addition of sodium hydroxide, strontium nitrate, and sodium permanganate solutions. This multistep precipitation process is the baseline technology in the River Protection Project -Waste Treatment Plant (RPP-WTP) for the removal of these radioactive species from Hanford Waste Tanks. Decontamination targets are easily met using these precipitation technologies and current work in this area focuses on optimization to minimize reagent levels. Downstream treatment processes require filtration of the precipitate slurry. In order to avoid further precipitation after filtration, it is necessary to know the precipitation reaction time-scale. In addition, precipitate slurry filter flux is a primary parameter of interest to plant design personnel. Optimization of the filtration process is benefited by an understanding of the parameters that impact particle size distribution. Filter cake packing and, hence, filter flux are often sensitive to small changes in the particle size distribution. However, traditional methods of particle size analysis often are not sufficiently sensitive to develop correlations to filterability. Focused Beam Reflectance Measurements (FBRM) are a relatively new chord length analysis method with extremely high sensitivity. The method is suited for continuous monitoring of chord length distributions in the process medium. The instrument is equipped with statistical data analysis software for the identification of small shifts in the population. Reported herein are the results of FBRM analysis of strontium and manganese precipitation tests with Hanford AN-107 simulant. The objectives of the testing were to: (1) evaluate the impacts of precipitation parameters (temperature and reagent levels) upon the strontium and manganese particle chord length distributions; (2) evaluate the stability of the particles under shear; (3) determine the general time-scale of the precipitation reactions; (4) identify correlations of the chord length distribution statistics to other measured experimental parameters such as slurry filterability; (5) monitor the filtered samples for post-filtration precipitation in order to identify the parameters that lead to solids formation