Distribution and Retention of 137Cs in Sediments at the Hanford Site, Washington
{sup 137}Cesium and other contaminants have leaked from high level waste (HLW) single-shell storage tanks (SSTs) at the Hanford Site in southeastern Washington. {sup 137}Cesium and other contaminants have leaked from single-shell storage tanks (SSTs) into coarse-textured, relatively unweathered unconsolidated sediments. Contaminated sediments were retrieved from beneath a leaky SST to investigate the distribution of adsorbed {sup 137}Cs{sup +} across different sediment size fractions. All fractions contained mica (biotite, muscovite, vermiculatized biotite), quartz, and plagioclase along with smectite and kaolinite in the clay-size fraction. A phosphor-plate autoradiograph method was used to identify particular sediment particles responsible for retaining {sup 137}Cs{sup +}. The Cs-bearing particles were found to be individual mica flakes or agglomerated smectite, mica, quartz, and plagioclase. Of these, only the micaceous component was capable of sorbing Cs{sup +} strongly. Sorbed {sup 137}Cs{sup +} could not be significantly removed from sediments by leaching with dithionite citrate buffer or KOH, but a fraction of the sorbed {sup 137}Cs{sup +} (5?22%) was desorbable with solutions containing an excess of Rb{sup +}. The small amount of {sup 137}Cs{sup +} that might be mobilized by migrating fluids in the future would likely sorb to nearby micaceous clasts in downgradient sediments.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1033476
- Report Number(s):
- PNNL-SA-33709; ESTHAG; EY3542301; TRN: US201202%%775
- Journal Information:
- Environmental Science and Technology, Vol. 35, Issue 17; ISSN 0013-936X
- Country of Publication:
- United States
- Language:
- English
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