Extended Leach Testing of Simulated LAW Cast Stone Monoliths

Serne, R. Jeffrey¹  Westsik, Joseph H.¹  Williams, Benjamin D.¹  Jung, H. B.¹  Wang, Guohui¹ 

[1]Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

关键词: LEACHING;    LIQUID WASTES;    IODIDES;    SIMULATION;    WATER;    COMPARATIVE EVALUATIONS;    TESTING;    ABUNDANCE;    TECHNETIUM;    CYLINDERS;    WASTE FORMS;    LOW-LEVEL RADIOACTIVE WASTES;   

DOI  :  10.2172/1208783
RP-ID  :  PNNL--24297
PID  :  OSTI ID: 1208783
Others  :  Other: 830403000
Others  :  TRN: US1500331

学科分类：核能源与工程

美国|英语

来源: SciTech Connect

【 摘 要 】

This report describes the results from long-term laboratory leach tests performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate the release of key constituents from monoliths of Cast Stone prepared with four simulated low-activity waste (LAW) liquid waste streams. Specific objectives of the Cast Stone long-term leach tests described in this report focused on four activities: 1. Extending the leaching times for selected ongoing EPA-1315 tests on monoliths made with LAW simulants beyond the conventional 63-day time period up to 609 days reported herein (with some tests continuing that will be documented later) in an effort to evaluate long-term leaching properties of Cast Stone to support future performance assessment activities. 2. Starting new EPA-1315 leach tests on archived Cast Stone monoliths made with four LAW simulants using two leachants (deionized water [DIW] and simulated Hanford Integrated Disposal Facility (IDF) Site vadose zone pore water [VZP]). 3. Evaluating the impacts of varying the iodide loading (starting iodide concentrations) in one LAW simulant (7.8 M Na Hanford Tank Waste Operations Simulator (HTWOS) Average) by manufacturing new Cast Stone monoliths and repeating the EPA-1315 leach tests using DIW and the VZP leachants. 4. Evaluating the impacts of using a non-pertechnetate form of Tc that is present in some Hanford tanks. In this activity one LAW simulant (7.8 M Na HTWOS Average) was spiked with a Tc(I)-tricarbonyl gluconate species and then solidified into Cast Stone monoliths. Cured monoliths were leached using the EPA-1315 leach protocol with DIW and VZP. The leach results for the Tc-Gluconate Cast Stone monoliths were compared to Cast Stone monoliths pertechnetate.