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Title: Significant volume reduction of tank waste by selective crystallization: 1994 Annual report

Technical Report ·
DOI:https://doi.org/10.2172/10189056· OSTI ID:10189056

The objective of this technology task plan is to develop and demonstrate a scaleable process of reclaim sodium nitrate (NaNO{sub 3}) from Hanford waste tanks as a clean nonradioactive salt. The purpose of the so-called Clean Salt Process is to reduce the volume of low level waste glass by as much as 70%. During the reporting period of October 1, 1993, through May 31, 1994, progress was made on four fronts -- laboratory studies, surrogate waste compositions, contracting for university research, and flowsheet development and modeling. In the laboratory, experiments with simulated waste were done to explore the effects of crystallization parameters on the size and crystal habit of product NaNO{sub 3} crystals. Data were obtained to allows prediction of decontamination factor as a function of solid/liquid separation parameters. Experiments with actual waste from tank 101-SY were done to determine the extent of contaminant occlusions in NaNO{sub 3} crystals. In preparation for defining surrogate waste compositions, single shell tanks were categorized according to the weight percent NaNO{sub 3} in each tank. A detailed process flowsheet and computer model were created using the ASPENPlus steady state process simulator. This is the same program being used by the Tank Waste Remediation System (TWRS) program for their waste pretreatment and disposal projections. Therefore, evaluations can be made of the effect of the Clean Salt Process on the low level waste volume and composition resulting from the TWRS baseline flowsheet. Calculations, using the same assumptions as used for the TWRS baseline where applicable indicate that the number of low level glass vaults would be reduced from 44 to 16 if the Clean Salt Process were incorporated into the baseline flowsheet.

Research Organization:
Westinghouse Hanford Co., Richland, WA (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC06-87RL10930
OSTI ID:
10189056
Report Number(s):
WHC-SD-WM-TI-643; ON: DE95001408; BR: 35AF11201/35AF11202; TRN: 94:021157
Resource Relation:
Other Information: PBD: 27 Sep 1994
Country of Publication:
United States
Language:
English