Small Column Ion Exchange Testing of Superlig 644 for Removal of 137Cs from Hanford Tank Waste Envelope C (Tank 241-AN-107)

Kurath, DE ; Blanchard, DL ; Bontha, JR

Pacific Northwest National Laboratory (U.S.)

关键词: Ion Exchange Materials;    Removal;    12 Management Of Radioactive Wastes, And Non-Radioactive Wastes From Nuclear Facilities;    Liquid Wastes;    Hanford Reservation;   

DOI  :  10.2172/757282
RP-ID  :  PNWD-3039
RP-ID  :  AC06-76RL01830
RP-ID  :  757282

美国|英语

来源: UNT Digital Library

【 摘 要 】

The current BNFL Inc. flowsheet for the pretreatment of the Hanford high-level tank wastes includes the use of Superlig{reg_sign} materials for removing {sup 137}Cs from the aqueous fraction of the waste. The Superlig materials applicable to cesium removal include the cesium-selective Superlig 632and Superlig 644. These materials have been developed and supplied by IBC Advanced Technologies, Inc., American Fork, Utah. This report describes the testing of the Superlig 644 ion exchange material in a small dual-column system. The bed volume of the lead column was 18.6 mL (L/D = 7), and the bed volume of the lag column was 15.9 mL (L/D = 6) during the loading phase. The sample processed was approximately 1.6 L of diluted waste ([Na{sup +}] = 4.84 M) from Tank 241-AN-107 (Envelope C). This sample had been previously treated for removal of Sr/transuranic (TRU) values and clarified in a single tube cross-flow filtration unit. All ion exchange process steps were tested, including resin-bed preparation, loading, feed displacement, water rinse, elution, eluant rinse, and resin regeneration. A summary of performance measures for both columns is shown in Table S1. The Cs {lambda} values represent a measure of the effective capacity of the SL-644 resin. The Cs {lambda} of 20 for the lead column is much lower than the estimated 150 obtained by the Savannah River Technology Center during Phase 1A testing. Equilibrium data obtained with batch contacts using the AN-107 Cs IX feed predicts a Cs {lambda} of 183. A Cs {lambda} for the lag column could not be determined due to insufficient breakthrough, but it appeared to work well and removed nearly all of the cesium not removed by the lead column. The low value for the lead column indicates that it did not perform as expected. This may have been due to air or gas in the bed that caused fluid channeling or blinding of the resin. The maximum decontamination factor (DF) for {sup 137}Cs listed in Table S1 is based on {sup 137}Cs concentration in the first samples collected from each column and the {sup 137}Cs concentration in the feed. The composite DF for {sup 137}Cs was 1,760, which provided an effluent with a {sup 137}Cs concentration of 8.7E-02 Ci/m{sup 3}. The {sup 137}Cs concentration is below the basis of design limit and is 7.2% of the contract limit for {sup 137}Cs.