Removal of technetium-99 from simulated Oak Ridge National Laboratory Newly-Generated Liquid Low-Level Waste
- Oak Ridge K-25 Site, TN (United States)
- Oak Ridge National Lab., TN (United States)
We report laboratory investigations on treatment options for the removal of the radionuclide {sup 99}{Tc} (as the pertechnetate anion, {Tc}O{sub 4}{sup {minus}}) from simulated Oak Ridge National Laboratory Newly Generated Liquid Low-Level Waste. The waste stimulant is alkaline (pH 12-13), containing sodium carbonate ({approximately}0.10 mot/L) and sodium hydroxide ({approximately} 0.125 mol/L), plus a modest concentration of sodium nitrate ({approximately}0.06 mol/L). Several organic resin anion exchange media were tested; Dowex{trademark} 1-X-8 and Reillex{trademark} HPQ resins were notably effective (with equilibrium distribution coefficients {approximately}2,000 mL/g, as-received basis). We also tested steel wool as a reagent to chemically reduce and sorb {sup 99}Tc. At pH values above {approximately}10, the iron surface was passivated and became ineffective as a reagent for technetium; however, as the test solution pH value was adjusted to near-neutrality (e.g., pH 8-9), the steel was noted to be more effective than the organic resins tested. In dynamic flow conditions, steel wool packed in a column was noted to continuously leak {approximately}1--3% of the amount of {sup 99}{Tc} activity in the feed solution, although no additional increase in eluent activity was noted for the duration of the testing ({approximately}1200 bed volumes of {approximately}0.11 mg/L {sup 99}{Tc} flowed at a rate equivalent to {approximately}0.5 gal/min/ft{sup 2} of column cross sectional area). Although no breakthrough was noted (other than the 1--3 % continuous ``bleed`` noted previously) during the column operation ({approximately} 2 weeks), the steel in the column was deteriorated, causing plugging and erratic flow toward the end of the testing interval.
- Research Organization:
- Oak Ridge K-25 Site, TN (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 95161
- Report Number(s):
- K/TCD-1141; ON: DE95014419; TRN: 95:018499
- Resource Relation:
- Other Information: PBD: Jun 1995
- Country of Publication:
- United States
- Language:
- English
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