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Polly Tsai

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  1. Dear Jiang Wang, I would like to know the relationship of input parameters of DDL (dielectric double layer) of SCM (surface complex model) betwen Phreeqc and GWB. As shown in the arrachment (File nmae: Phreeqc DDL model input parameters), only Debye length is needed to input. However, if the constant capacitance is slected in the sorbing surface of GWB, I don't know the relationship between Debye length (default value: 1.0E-08 m, for ionic strength=0.001) and capacitance. The potential data can be obtained from Phreeqc output (Phreeqc output_potential) and if the data was input in the GWB, the Kd values were almost the same between GWB and Phreeqc. I am curious about it and your response will be highly appreciated. Polly Tsai
  2. Dear Jia Wang, I would like to transfer the NEA_TDB formatted with Phreeqc, the other geochemical code to the format of GWB. However, SIT (Specific ion Interaction) theory is used to calculate activity coefficients in the NEA TDB; whereas, to the best of my knowledge, the Debye-Hückel or Pitzer equations are employed in the GWB. Is it possible to find any SIT dataset in other module of GWB? If any, can you demonstrate a right input format for me? Please refer to the attached text file [NEA_TDB_phreeqc_Nov2018 (UOH5 remove)]. Thanks for your kind assistance in dealing with my question. Best regards, Polly Tsai NEA_TDB_phreeqc_Nov2018(UOH5 remove).dat
  3. Dear Jia Wang, I would like to reproduce the modeling results of sorption of Am(III), Tc(IV), and U(IV) on MX 80 bentonite according to the themodynamic dataset (Tables 2 & 3) of attached reference paper (B. Grambow et al., 2006). Enclosed please find the React script, thermo dataset, sorbing surfaces files. However, the results log K values for Am (III), Tc (IV) and U (IV) were far from the literature where kd is defined as " sorbed (mg/kg)/ in fluid (mg/kg=mg/L)" . In addition, if the sorbate of iteration from config. was not chosen, the script could be run. If the sorbate was chosen, it could not be run and the result showed "Newton-Raphson did not converge after 999 iterations, maximum residual = 2.03e+183, Xi = 0.0000". I don't know why. I would appreciate any recommendation to understand the problem Thanks in advance! Polly 2006 B. Grambow sorption on bentonite.pdf Paper case study (U Kd)_1090330.rea thermo_phreeqc_Polly.tdat MX-80 IonEx (Grambow, 2006)_Polly.sdat MX-80 SCM (Grambow, 2006)_Polly.sdat
  4. Dear Brian, Thanks so much for your response. I have already revised surface complexation dataset and changed the file name as AlOH_Polly because the sorbing mineral was montmorillionate of MX-80 bentonite and the complexing site was AlOH. However, the results showed "Residuals too large, 645-th interation". How do I solve the problem?Enclosed please find the script, thermo dataset and sorbing surface. By the way, if I cancelled Cl as charge balance (system default), there was a result, but I could not make sure it was correct or not. Good luck, Polly SKB pore water calculation.rea AlOH_Polly.sdat IonEx_Polly.sdat thermo_phreeqc_Polly.tdat
  5. Dear Brian, I performed some calculations to obtain the initial chemical composition of pore water in bentonite (MX-80) using GWB code. These calculations have been done by equilibrating the Forsmark groundwater (Table 5.4 in the ppt file) with bentonite with a porosity of 43%, including equilibrium with bentonite accessory minerals as gypsum and quartz (equilibrium with carbonate minerals have also been calculated when considering the MX-80 bentonite), and exchange and surface reactions (Table 5.3 in the ppt file). Table 5-3 and Table 5-4 shows the thermodynamic data used. And according to the above description, enclosed please find the attachments of script, thermo data set and sorbing surface. However, I don’t know why the error message was shown as “bad surface reaction” after running. The other question is how to select SiO2 (aq) or Si(OH)4(aq) in the base pane based on the known concentration of Si in Forsmark groundwater for this case. Thanks for your kind assistance in dealing with my questions. Best regards, Polly Query_about_porewater_chemistry_to_Brian_20200218.pptx SKB pore water calculation.rea thermo_phreeqc_Polly.tdat SOH_Polly.sdat IonEx_Polly.sdat
  6. Dear Brian, Thanks for your kind response. I have already saved as a .tdat file in replace of .lnk file (a shortcut). Please refer to the attachment. Yes, I also ensured that the dataset and spreadsheet were using the same exact set of reactions and log K values. Can you explain why you’ve set your calculation up with trace quantities of all your basis entries, then titrated large amounts of all your minerals of interest? à The trace quantities of radionuclides need to be input in the dialog box as reminder before calculation. Actually, the concentrations of radionuclides within the spent nuclear fuels are quite low in case of copper canister corrosion resulted from the groundwater intrusion. The input values in the basis entries were just hypothetical and indicated very low concentrations of nuclides and “0 (zero)” value was not allowed for solubility calculation. Thanks for your further understanding. Best regards, Polly thermo_phreeqc_Polly.tdat
  7. Dear Brian, Recently, I calculated the solubility limits of nuclides and compared the results with simple function of Excel by SKB. However, there was a significant difference (~3 orders) for Se (selenium). Please refer to the ppt file (Solubility calculation_20191022). The species and chemical reactions with log k values (25C) in the Excel file (simple functions_atrisk_goethite_magnetite_temperate_fix_GW_110209, please refer to the link: https://drive.google.com/open?id=1ZoDivTdFTa7RzS1I1-SHCXzBM4_r9Kas) that I used and I also edited all of them in the thermo data file using Phreeqc template of TEdit. Please refer to the file (thermo_phreeqc_Polly). The script of React module was also attached and please refer to the file (U, Sr, Pa, Zr, Nb, Ra,Tc, Ni, Pd, Sn, Se, Th, Np, Pu, Am, Cm, Pb solubility_25C_SKB.rea). The overall calculation results were summarized compared with SKB (simple function) in the ppt file (Solubility calculation_20191022). The value marked as red color indicated “Big difference” and the values marked as blue color meant 2-3 folds difference between GWB (INER) and Simple function (SKB). I don’t know why there were some differences between them even I used the same thermo database as SKB. In addition, in the basis pane, why very trace amount of nuclide concentrations need to be input in the initial condition? The water compositions in the initial conditions were used as input parameters by following the SKB data (in the DON’T TOUCH spreadsheet of Excel file) and the reactants were selected using amorphous solid phases shown as blue color of solubility limits in each element spreadsheet of Excel file. Thanks for your kind response to answer my questions in advance!! Polly Solubility calculation_20191022.pptx thermo_phreeqc_Polly.lnk U, Sr, Pa, Zr, Nb, Ra,Tc, Ni, Pd, Sn, Se, Th, Np, Pu, Am,Cm, Pb solubility_25C_SKB.rea
  8. Dear Brian, I think you might misunderstand my question. I simply would like to directly export the text file of thermo dataset. Please refer to the attached example. Polly llnl TDB (example).txt
  9. Dear Brian, As title posted, how to export text file from thermo data, e.g., thermo.com.V8.R6+? Thanks for your kind response. Polly
  10. Dear Brian, Thanks for your previous response. Based on your instruction, I repeated to run the UO2 solubility calculation by addiding uraninite to the Basis pane. The result was almost the same as that of technical report (a little bit difference of GW conditions between two sites), please refer to the attached script file (UO2 solubility_32C.rea). However, when I performed Se solubility calculation using the above same method (1.0 fee mol/l) or even I input the other arbitrary values (0.001, 0.01, 0.01...) for Se , the result showed "Newton-Raphson did not converge after 999 iterations,....". What is wrong in this case? Thanks for your further response. Polly Se solubility_32C.rea UO2 solubility_32C.rea
  11. Dear Brian, Thanks for your instruction. Based on your previous reply, the calculation result of UO2 solubility and input parameters (i.e., field data) of the groundwater conditions were shown in the attached script of React module. However, I still have the following questions. 1. The total concentration of uranium is 9.923e-07 M at the bottom of view results. Is it also a solubility value? 2. I can not see the trend chart of solubility v.s pH or pe (examples of Figs.1 and 2 in the word file) in this case. 3. The result seems significant difference, 9.923e-07 M for UO2 compared to the table 1 in the attached word file. Could you please let me know what's wrong in this case? Thanks for your further response. Polly UO2 solubility_32C.rea Regarding mineral solubility calculation_to Brian 20190609.docx
  12. Dear Brian, I would like to plot the uraninite (UO2) solubility chart with the function of pH or pe at temperatures of 25, 32 and 80°C, just like the examples in Figs. 1 and 2 captured in the technical report. When the plots have been done, the raw data should be summarized in the Table 1. Please refer to the attachment. Should I use the Tact module to perform them? Please also refer to the script of Tact. Thanks for your kind instruction. Best regards, Polly Regarding mineral solubility calculation_to Brian 20190609.docx Solubility of uraninite.tac
  13. Hi, Brian, Thanks so much for your instruction. The pH/Eh diagram at 80C has been successfully plotted after selecting the "alter logk" of config. I wondered GWB would automatically calculate the species. All the best, Polly
  14. Dear Brian, Thanks for your response. Yes, my plot without consideration of gas fugacity is not the same as that of the above technical report. Please refer to the attached plot and raw data. As to the termo dataset, ver.8.0 of GWB was used in the technical report, while mine is ver.12.0. Is it possible for different version of thermo dataset? In addition, you can find the it's also not the same plot for 25C and 80C in the technical report. Please refer to the two figures of Technical report_25C and 80. So, I think they should consider the logk value in their 80C. So far, I still don't know how to do in the next step. Polly Plot without fugacity.docx U_80C in pure water_pH vs pe_wo fugacity.ac2
  15. Dear Brian, I am not sure what the value of gas fugacity (like CO2) at high temperature (80C) in pure water (no presence of complexing ions) should be input for uranium (UO2) pH/Eh diagram? I tried to input fugacity of CO2 <-> HCO3- using arbitary data, like 1, 0.8...0.3 and the plot was not the same as that of technical report. Please refer to the attached Act2 raw data and the technical report. Thanks again for your kind help. Polly U_80C in pure water_pH vs pe.ac2
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