Precipitates/Salts Model Calculations for Various Drift Temperature Environments REV 00

CAL-EBS-PA-000012  

December 13, 2001 

1. PURPOSE
The objective and scope of this calculation is to assist Performance Assessment Operations and 
the Engineered Barrier System (EBS) Department in modeling the geochemical effects of 
evaporation within a repository drift. This work is developed and documented using procedure 
AP-3.12Q, Calculations, in support of Technical Work Plan For Engineered Barrier System 
Department Modeling and Testing FY 02 Work Activities (BSC 2001a). 
The primary objective of this calculation is to predict the effects of evaporation on the abstracted 
water compositions established in EBS Incoming Water and Gas Composition Abstraction 
Calculations for Different Drift Temperature Environments (BSC 2001c). A secondary objective 
is to predict evaporation effects on observed Yucca Mountain waters for subsequent cement 
interaction calculations (BSC 2001d). The Precipitates/Salts model is documented in an 
Analysis/Model Report (AMR), In-Drift Precipitates/Salts Analysis (BSC 2001b). 
2. METHOD 
The Precipitates/Salts model was used to perform the calculations in this document. This model, 
explained in detail in In-Drift Precipitates/Salts Analysis (BSC 2001b, Section 6.4), is 
summarized in Section 4, as are the methods of calculation. Any deviations from these methods 
are explained in detail in Sections 3 and 5. The control of electronic management of data was 
accomplished in accordance with methods specified in the Technical Work Plan (TWP) (BSC 
2001a). 
3. ASSUMPTIONS 
The model assumptions for this calculation are identical to assumptions described in Section 5 of 
In-Drift Precipitates/Salts Analysis (BSC 2001b) and Section 3 of Precipitates/Salts Model 
Results for THC Abstraction (CRWMS M&O 2001). All model assumptions are used in 
Sections 5 and 6. 
Assumptions were also made for the input data sets listed in Table 1 and Table 2. These input 
assumptions are described in detail in the following subsections. 
3.1 NITRATE CONCENTRATIONS 
Nitrate was added to the waters listed in Table 1. These waters have no reported nitrate 
concentrations. The concentration of nitrate added was determined based on an assumed nitrate 
to chloride molar ratio. 
Assumption 3.1.1. The molar ratio of nitrate to chloride for the first twelve waters listed in 
Table 1 is assumed to be 0.1. 
Rationale: This molar ratio is justified based on a rounded average of the molar ratios in the four 
Topopah Spring welded hydrogeologic unit (TSw) pore water samples listed in Table 6 of 
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Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
CRWMS M&O (2000, pp. I-17 and I-19). No further confirmation is required for this 
assumption. 
Assumption 3.1.2. The molar ratio of nitrate to chloride for the last four waters listed in Table 1 
is assumed to be 1.0. 
Rationale: This molar ratio is justified based on a rounded average of the molar ratios in the 
seven UZ-14 perched water samples having measurements for both nitrate and chloride in Table 
8 of CRWMS M&O (2000, pp. I-22). No further confirmation is required for this assumption. 
3.2 CARBON DIOXIDE FUGACITY 
The carbon dioxide fugacity was fixed in each simulation for the inputs in Table 1. For the 
crown seepage waters, the fugacity was fixed at the value provided by DTN: 
MO0110SPAEBS13.038. However, for some of the invert waters simulated for the 
Supplemental Science and Performance Analyses (SSPA) (BSC 2001e, Section 6.3.3), the 
carbon dioxide fugacities of the corresponding crown seepage waters were assumed. This was 
done to prepare the outputs for the mixing model presented in the SSPA (BSC 2001e, Section 
6.3.3). 
Assumption 3.2.1. Several of the invert waters (specifically, cases HLi, HHi, LLi, and LHi in 
Table 1) were assumed to have the carbon dioxide fugacities of the corresponding crown seepage 
waters (i.e., cases HLc, HHc, LLc, and LHc, respectively). 
Rationale: This assumption is justified because the corresponding carbon dioxide fugacities are 
always within a factor of three and nearly always within a factor of two (DTN: 
MO0110SPAEBS13.038). These differences are within the range of uncertainty of the THC 
model predictions. No further confirmation is required for this assumption. 
3.3 MINERAL SUPPRESSIONS 
Mineral suppressions are addressed in Section 5.4 of In-Drift Precipitates/Salts Analysis (BSC 
2001b). For a subset of the simulations presented below, several of the minerals were not 
suppressed because they were performed for SSPA prior to ICN 03 of In-Drift Precipitates/Salts 
Analysis (BSC 2001b). Instead of rerunning these files with the new suppressions, an 
assumption was made that these additional suppressions do not considerably affect the qualified 
outputs of the model. This approach also allows for qualified documentation of the model 
predictions previously performed for the SSPA. 
Assumption 3.3.1. Excluding talc, chrysotile, and magnesite from the list of suppressed 
minerals does not considerably affect the qualified outputs (i.e., pH, chloride concentration, and 
ionic strength) for those simulations in which these minerals were not suppressed (specifically, 
cases HLi, HHi, LLi, LHi, HLc, HHc, LLc, and LHc in Table 1). 
Rationale: This assumption is justified by the results. Of these three minerals, only talc 
precipitated. Section 6.6 presents the results of rerunning case HHi with talc, chrysotile, and 
magnesite suppressed. The results show that qualified model outputs (i.e., pH, chloride 
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Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
concentration, and ionic strength) are not considerably affected, and the differences are within 
the range of model uncertainty. No further confirmation is required for this assumption. 
3.4 LOW RELATIVE HUMIDITY SALTS MODEL 
The low relative humidity (LRH) salts model was used to predict ionic strength and chloride 
concentration below a relative humidity of 85 percent for the HHi and LHi cases of the 
sensitivity THC model abstraction (Table 1). An assumption was made to extend these 
calculations to other THC model sensitivity abstractions. 
Assumption 3.4.1. The LRH salts model results for the HHi and LHi cases in Table 1 are 
assumed to adequately approximate the results for the HLi, HHc, HLc, LLi, LHc, and LLc cases. 
Specifically, the HHi case results are applied to the HLi, HHc, and HLc cases, and the LHi case 
results are applied to the LLi, LHc, and LLc cases. 
Rationale: This assumption is justified by: 1) the similarity of the results of the HHi and LHi 
cases (Section 6.2.1); 2) the small effects of CO2 fugacity (Section 6.2.1); 3) the small 
differences in results between seepage wicking into the invert and seepage at the crown of the 
drift (Section 6.1); and 4) the level of uncertainty (factor of ten) in the accuracy of the LRH 
model (BSC 2001b, Section 6.5.2). No further confirmation is required for this assumption. 
3.5 PERCHED WATER COMPOSITION 
Assumption 3.5.1. Because perched water is a subset of ambient fluids that could contact 
cementitious materials located in and around a potential repository drift, a potential fluid 
composition representing perched water has been selected for Precipitates/Salts model 
evaporation calculations that feed sensitivity calculations performed in Seepage Grout 
Interactions Model Calculations (BSC 2001d, Table 6-1.7). The assumed representative perched 
water composition is identical to a perched water sample collected on 8/3/1993 from borehole 
USW UZ-14 within the Topopah Spring welded unit. This composition is documented in Table 
8 of CRWMS M&O (2000, p. I-22). This assumption is used in Section 6.7. 
Rationale: The assumed representative perched water composition is corroborated by other 
perched water sample measurements listed in Table 8 of CRWMS M&O (2000, p. I-22). This 
composition has been used in previous sensitivity studies using previous versions of the 
Precipitates/Salts model (Mariner 2001). The use of this assumed input allows for direct 
comparison to previous sensitivity calculations. Because results for sensitivity studies are not 
generally used as direct input into TSPA models, this composition is sufficient to evaluate the 
representative potential effects. Therefore, this assumption is justified and requires no further 
confirmation. 
3.6 DRIFT-SCALE HEATER TEST WATER COMPOSITION 
Assumption 3.6.1. Because Drift-Scale Heater Test waters are a potential subset of thermally 
perturbed waters that could contact cementitious materials located in and around a potential 
repository drift, a potential fluid composition representing Drift-Scale Heater Test water has 
been selected for Precipitates/Salts model evaporation calculations that feed sensitivity 
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Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
calculations performed in Seepage Grout Interactions Model Calculations (BSC 2001d, Table 6-
1.8). The assumed representative composition of Drift-Scale Heater Test water is a Drift-Scale 
Heater Test water sample collected on 1/26/1999 from borehole 60-3. This composition is 
documented in DTN: LL990702804244.100. This assumption is used in Section 6.7. 
Rationale: This water composition is corroborated by other Drift-Scale Heater Test water 
compositions reported in DTN: LL990702804244.100 and has been used in previous sensitivity 
studies using previous versions of the Precipitates/Salts model (Mariner 2001). The use of this 
assumed input allows for direct comparison to previous sensitivity calculations. Because results 
for sensitivity studies are not generally used as direct input into TSPA models, this composition 
is sufficient to evaluate the representative potential effects. Therefore, this assumption is justified 
and requires no further confirmation. 
4. USE OF COMPUTER SOFTWARE AND MODELS 
All computer calculations were performed on a Hewlett Packard Pavilion 7410P, an IBM-
compatible personal computer, serial number US72352516. This computer uses a Microsoft 
Windows 95 operating system and is located in Colorado Springs, Colorado. 
4.1 MODELS 
The Precipitates/Salts model, developed and validated in In-Drift Precipitates/Salts Analysis 
(BSC 2001b), was used to perform the calculations in this document. The model incorporates 
two submodels, the Low Relative Humidity (LRH) model and the High Relative Humidity 
(HRH) model. Use of the Precipitates/Salts model in this calculation is justified because the 
model was specifically designed to perform these calculations (BSC 2001b). 
4.2 SOFTWARE 
The HRH salts model calculations were performed using the code EQ3/6 v7.2b [CSCI: URCL-
MA-110662, Wolery 1992a and 1992b, Wolery and Daveler 1992, CRWMS M&O 1998a] with 
the solid-centered flow-through addendum [EQ6 V7.2bLV, STN: 10075-7.2bLV-00, CRWMS 
M&O 1999a and 1999b]. These software were obtained from Configuration Management and 
installed on the IBM-compatible computer identified at the beginning of Section 4. They were 
appropriate for the application and were used only within the range of validation in accordance 
with AP-SI.1Q Software Management and the Precipitates/Salts AMR (BSC 2001b). The 
Precipitates/Salts AMR restricts the use of these codes to a water activity of about 0.85 and 
higher. 
MathSoft Mathcad7 Professional, a commercially-available software package for technical 
calculations, was used to perform and display the routine algebraic calculations of the LRH salts 
model. Every equation and calculation is displayed in the referenced Mathcad7 worksheets. 
Calculated values are represented graphically in the worksheets and have been hand-checked 
using a calculator to verify the software provided correct results. Because the software requires 
every equation to be displayed sequentially and in detail, a qualified individual can reproduce 
these calculations from worksheet displays without recourse to the originator. No macros or 
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Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
software routines were developed for, or used by, this software, and consequently it is an exempt 
software application in accordance with Section 2.1 of AP-SI.1Q. 
Microsoft Excel 97 SR-2, a commercially-available spreadsheet software package, was used to 
chart data and to calculate the ionic strength approximation (ISa) and concentration factor 
(C/Co). Spreadsheet calculations were validated by hand calculations using the equations 
presented in Section 5.2, and charts were validated by visual inspection. These actions confirm 
that the spreadsheet application provided correct results. No macros or software routines were 
developed for, or used by, this software, and consequently it is an exempt software application in 
accordance with Section 2.1 of AP-SI.1Q. 
5. CALCULATION 
Section 5.1 describes the input to the calculations while Section 5.2 describes the calculations 
performed. 
5.1 INPUT 
The calculations required the following types of input: 1) thermodynamic constants for 
potentially important ground-water constituents, and 2) values for model input variables. 
5.1.1 Thermodynamic Database 
Two thermodynamic databases were used in the evaporation calculations. The PT5v1 Pitzer 
thermodynamic database (DTN: MO0110SPAPT545.016) was used for cases HLi, HHi, LLi, 
LHi, HLc, HHc, LLc, and LHc in Table 1. These calculations were originally performed prior to 
the development of the PT5v2 database. The PT5v2 database (DTN: MO0110SPAPT245.017) 
was used in the rest of the simulations. The only difference between the two databases is that 
nesquehonite is not included in the PT5v1 database. These databases are developed and 
discussed in the Precipitates/Salts AMR (BSC 2001b). 
5.1.2 Input Variables 
The input variables for the simulations include temperature, pH, fugacity of CO2, redox 
potential, and initial concentrations of the aqueous components. Table 1 and Table 2 list the 
sources of the acquired input data used in the EQ3/6 input files in this calculation. 
Not all waters identified in Table 1 and Table 2 have a complete set of values for input variables. 
Values were entered for redox potential, but they did not affect the results because no redox 
reactions were simulated. Waters in Table 2 were evaporated at 96C and were evaporated at 
three different values for CO2 fugacity: 10-1, 10-3, and 10-6. Nitrate was added to the waters in 
Table 1 as described in Section 3.1, and CO2 fugacity was modified for four of the Table 1 
waters as described in Section 3.2. Minerals were suppressed for each water as explained in 
Section 3.3. 
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Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
Table 1. References for REV 01 THC Model Abstraction Data Used in EQ3/6 Input Files 
Case Description 
Case 
Abbreviation Reference 
Base Case THC Model Abstraction for Seepage at the Crown of the 
Drift in the Tptpmn Lithology 
Bmc BSC 2001c, Table 4 
Base Case THC Model Abstraction for Seepage Wicking into the Invert 
in the Tptpmn Lithology 
Bmi BSC 2001c, Table 5 
Base Case THC Model Abstraction for Seepage at the Crown of the 
Drift in the Tptpll Lithology 
Blc BSC 2001c, Table 6 
Base Case THC Model Abstraction for Seepage Wicking into the Invert 
in the Tptpll Lithology 
Bli BSC 2001c, Table 7 
High Temperature and Low Carbon Dioxide Partial Pressure Case for 
Seepage at the Crown of the Drift in the Tptpll Lithology 
HLc BSC 2001c, Table 8 
High Temperature and High Carbon Dioxide Partial Pressure Case for 
Seepage at the Crown of the Drift in the Tptpll Lithology 
HHc BSC 2001c, Table 9 
Low Temperature and Low Carbon Dioxide Partial Pressure Case for 
Seepage at the Crown of the Drift in the Tptpll Lithology 
LLc BSC 2001c, Table 10 
Low Temperature and High Carbon Dioxide Partial Pressure Case for 
Seepage at the Crown of the Drift in the Tptpll Lithology 
LHc BSC 2001c, Table 11 
High Temperature and Low Carbon Dioxide Partial Pressure Case for 
Matrix Imbibition into the Invert in the Tptpll Lithology 
HLi BSC 2001c, Table 12 
High Temperature and High Carbon Dioxide Partial Pressure Case for 
Matrix Imbibition into the Invert in the Tptpll Lithology 
HHi BSC 2001c, Table 13 
Low Temperature and Low Carbon Dioxide Partial Pressure Case for 
Matrix Imbibition into the Invert in the Tptpll Lithology 
LLi BSC 2001c, Table 14 
Low Temperature and High Carbon Dioxide Partial Pressure Case for 
Matrix Imbibition into the Invert in the Tptpll Lithology 
LHi BSC 2001c, Table 15 
High Temperature and High Carbon Dioxide Partial Pressure Case for 
Seepage at the Crown of the Drift in the Tptpll Lithology, Initialized 
Using Water Composition of UZ-14 Perched Water 
HHcp BSC 2001c, Table 16 
High Temperature and High Carbon Dioxide Partial Pressure Case for 
Matrix Imbibition into the Invert in the Tptpll Lithology, Initialized Using 
Water Composition of UZ-14 Perched Water 
HHip BSC 2001c, Table 17 
Low Temperature and High Carbon Dioxide Partial Pressure Case for 
Seepage at the Crown of the Drift in the Tptpll Lithology, Initialized 
Using Water Composition of UZ-14 Perched Water 
LHcp BSC 2001c, Table 18 
Low Temperature and High Carbon Dioxide Partial Pressure Case for 
Matrix Imbibition into the Invert in the Tptpll Lithology, Initialized Using 
Water Composition of UZ-14 Perched Water 
LHip BSC 2001c, Table 19 
DTN: MO0110SPAEBS13.038 
Table 2. References for Additional EQ3/6 Input Files 
Case Description Reference 
Chemical composition of perched water sample collected from borehole Assumption 3.5.1 
USW UZ-14 within the Topopah Spring welded unit on 8/3/1993 
Chemical analysis of Drift-Scale Heater Test water sample from Assumption 3.6.1 
borehole 60-3 on 1/26/1999 
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Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
5.2 CALCULATIONS 
The calculations involved both submodels of the Precipitates/Salts model, the high relative 
humidity (HRH) salts model and the low relative humidity (LRH) salts model. 
5.2.1 High Relative Humidity (HRH) Salts Model 
Each HRH salts model evaporation calculation was performed using EQ3/6 according to the 
procedures described in Section 6.4.2.1 of the Precipitates/Salts AMR (BSC 2001b). Water was 
evaporated by declaring it a special reactant with a rate constant of -1.0. The maximum 
reaction progress was iteratively adjusted to achieve a final water activity of 0.85. Before each 
evaporation simulation, the water composition was electrically balanced by allowing EQ3/6 to 
adjust the Na, Cl, or other major ion concentration, depending on which ions concentration 
would be changed the least to achieve electrical balance. 
Model predictions were exported to text files using the EQ3/6 postprocessor (PP.EXE) included 
in the EQ6 software package. These text files were imported into Excel worksheets where the 
ionic strength approximation (ISa) and concentration factor (C/Co) could be calculated and the 
results plotted. C/Co was calculated by dividing the total nitrate concentration by the initial 
nitrate concentration. Nitrate does not precipitate in the high relative humidity range modeled by 
the HRH salts model. 
The ionic strength approximation (ISa) parameter of the Precipitates/Salts model is not the true 
ionic strength. Instead, it is an approximation of the true ionic strength (I) according to the 
following equation: 
ISa = CNa + CK + 4(C + CMg ) (Eq. 1)
Ca 
where Ci is the molality of component i, and i represents sodium (Na), potassium (K), calcium 
(Ca), or magnesium (Mg). This approximation is included in the results because it is identical to 
the approximation used by the colloids model (CRWMS M&O 1998b, Section 4.4.3.3.1) and 
Precipitates/Salts model (BSC 2001b, Section 6.3.2). 
5.2.2 Low Relative Humidity (LRH) Salts Model 
The LRH salts model was used to predict ionic strength and chloride concentration below a 
relative humidity of 85 percent for the HHi and LHi cases of the sensitivity THC model 
abstraction (Table 1). These results were extended to the HLi, HHc, HLc, LLi, LHc, and LLc 
cases as described in Assumption 3.4.1 (Section 3.4). 
LRH salts model calculations were performed as described in Section 6.4.1 of the 
Precipitates/Salts AMR (BSC 2001b). Additional assumptions relevant to the LRH calculations 
are documented in Section 3 of the REV 00 THC model abstraction evaporation calculation 
(CRWMS M&O 2001). The effective solubility of the non-nitrate salts was adjusted between 
3.3 and 4.2 molal to provide a smooth transition between the LRH and HRH model results. 
This submodel was designed for waters that evaporatively evolve into a sodium nitrate brine. 
Section 6.8 describes the uncertainties and limitations of results of this submodel. 
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Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
6. RESULTS
In this section, the results of the calculations are presented. Section 6.1 presents the HRH model 
results for the base case REV 01 THC model abstraction, and Section 6.2 presents the HRH 
model results for the sensitivity cases of the REV 01 THC model abstractions. Section 6.3 
compares and summarizes the results of Sections 6.1 and 6.2. The LRH model results are 
presented in Section 6.4 and the lookup tables for TSPA in Section 6.5. Section 6.6 discusses 
the sensitivity of certain mineral suppressions. Evaporation calculations performed as input to 
the Seepage Grout Interactions Model are described in Section 6.7. Finally, Section 6.8 
discusses important uncertainties and limitations of the calculations. 
The calculations performed for this work are documented in the set of DTNs referenced in Table 
3. Each case in Table 1 is divided into 5 or 6 abstraction periods. To simplify comparisons and 
identification of results, these periods are numbered in the document and output files as 
described in Table 4. 
Results from selected output files are plotted in Figures 1 through 89.
Table 5 provides a cross-reference of the output files associated with each figure in this
document. A complete set of output files is found in the output DTNs listed in Table 3.
Table 3. Cross-Reference of Outputs and Their DTNs 
Case Abbreviation or Description Output File DTN 
Bmc, Bmi, Blc, Bli, HHcp, HHip, LHcp, MO0112MWDTHC12.024 (EQ3/6 input/output files) 
LHip (Table 1) 
HLc, HHc, LLc, LHc, HLi, HHi, LLi, LHi MO0111MWDVAR12.021 (EQ3/6 input/output files) 
(Table 1) MO0111MWDSEE12.022 (LRH model output files) 
MO0111SPAPSM12.023 (Lookup tables) 
Perched Water (Table 2), Drift Scale MO0111MWDHRH12.019 (EQ3/6 input/output files) 
Test Water (Table 2) 
Table 4. Key to Abstraction Time Periods Cited in This Report 
Abstraction 
Time Period Base Case a 
High Temperature 
Operating Mode b 
Low Temperature 
Operating Mode c 
1 0-50 years 0-50 years 0-300 years 
2 51-1,200 years 51-1,500 years 301-10,000 years 
3 1,201-2,000 years 1,501-4,000 years 10,001-30,000 years 
4 2,001-20,000 years 4,001-25,000 years 30,001-100,000 years 
5 20,001-100,000 years 25,001-100,000 years 100,001-1,000,000 years 
6 100,001-1,000,000 years 100,001-1,000,000 years not applicable 
DTN: MO0110SPAEBS13.038 
NOTE: a Cases Bmc, Bmi, Blc, and Bli in Table 1 
b Cases HLc, HHc, HLi, HHi, HHcp, and HHip in Table 1 
c Cases LLc, LHc, LLi, LHi, LHcp, and LHip in Table 1 
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Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
Table 5. Cross-Reference of Figures and Their Output Files 
Water a Figures Output Files Output DTN 
Bmc Figure 1 & Figure 2 
Figure 3 & Figure 4 
Figure 5 & Figure 6 
Figure 7 & Figure 8 
Figure 9 & Figure 10 
Figure 11 & Figure 12 
MC1.6O 
MC2.6O 
MC3.6O 
MC4.6O 
MC5.6O 
MC6.6O b 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
Bmi Figure 13 & Figure 14 
Figure 15 & Figure 16 
Figure 17 & Figure 18 
Figure 19 & Figure 20 
Figure 21 & Figure 22 
Figure 23 & Figure 24 
MI1.6O 
MI2.6O 
MI3.6O 
MI4.6O 
MI5.6O 
MI6.6O 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
Blc Figure 25 & Figure 26 
Figure 27 & Figure 28 
Figure 29 & Figure 30 
Figure 31 & Figure 32 
Figure 33 & Figure 34 
Figure 35 & Figure 36 
LC1.6O 
LC2.6O 
LC3.6O 
LC4.6O 
LC5.6O 
LC6.6O 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
Bli Figure 37 & Figure 38 
Figure 39 & Figure 40 
Figure 41 & Figure 42 
Figure 43 & Figure 44 
Figure 45 & Figure 46 
Figure 47 & Figure 48 
LI1.6O 
LI2.6O 
LI3.6O 
LI4.6O 
LI5.6O 
LI6.6O 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
Hli Figure 49 Figure 50 HLI1.6O HLI2.6O MO0111MWDVAR12.021 
Figure 51 Figure 52 HLI3.6O HLI4.6O MO0111MWDVAR12.021 
Figure 53 Figure 54 HLI5.6O HLI6.6O MO0111MWDVAR12.021 
HHi Figure 55 Figure 56 HHI1.6O HHI2.6O MO0111MWDVAR12.021 
Figure 57 Figure 58 HHI3.6O HHI4.6O MO0111MWDVAR12.021 
Figure 59 Figure 60 HHI5.6O HHI6.6O MO0111MWDVAR12.021 
LLi Figure 61 Figure 62 
Figure 63 Figure 64 
Figure 65 
LLI1.6O LLI2.6O 
LLI3.6O LLI4.6O 
LLI5.6O 
MO0111MWDVAR12.021 
MO0111MWDVAR12.021 
MO0111MWDVAR12.021 
LHi Figure 66 Figure 67 LHI1.6O LHI2.6O MO0111MWDVAR12.021 
Figure 68 Figure 69 LHI3.6O LHI4.6O MO0111MWDVAR12.021 
Figure 70 LHI5.6O MO0111MWDVAR12.021 
HHip Figure 71 Figure 72 HHIP1.6O HHIP2.6O MO0112MWDTHC12.024 
Figure 73 Figure 74 HHIP3.6O HHIP4.6O MO0112MWDTHC12.024 
Figure 75 Figure 76 HHIP5.6O HHIP6.6O MO0112MWDTHC12.024 
LHip Figure 77 Figure 78 
Figure 79 Figure 80 
Figure 81 
LHIP1.6O LHIP2.6O 
LHIP3.6O LHIP4.6O 
LHIP5.6O 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
MO0112MWDTHC12.024 
LHi1 (LRH) Figure 82 LHI1.MCD MO0111MWDSEE12.022 
LLi1 (LRH) Figure 83 LLI1.XLS MO0111SPAPSM12.023 
HHi Figure 84 Figure 85 HHI1EVAP.6O HHI2EVAP.6O MO0112MWDTHC12.024 
(Mineral Figure 86 Figure 87 HHI3EVAP.6O HHI4EVAP.6O MO0112MWDTHC12.024 
Sensitivity) Figure 88 Figure 89 HHI5EVAP.6O HHI6EVAP.6O MO0112MWDTHC12.024 
a Case abbreviations are defined in Table 1. LHi1 and LLi1 refer to period 1 of the LHi and LLi cases (see Table 4). 
b The input for this run is mistakenly from the invert instead of the crown. However, the differences in these inputs 
are small (BSC 2001d, Tables 4 and 5) and easily within the range of uncertainty in the derived abstracted input 
values (BSC 2001d, Section 6.3). The crown seepage values are within 2 percent of the invert values, except for 
Mg, which is nearly 10 percent higher in the invert seepage (BSC 2001d, Tables 4 and 5). 
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6.1 RESULTS FOR BASE CASE THC MODEL ABSTRACTION 
The base case THC model abstractions include the Bmc, Bmi, Blc, and Bli cases in Table 1. The 
Bmc and Bmi cases are for seepage in the middle nonlithophysal zone of the crystal-poor 
member of the Topopah Spring tuff (i.e., Tptpmn). The Blc and Bli cases are for seepage in the 
lower lithophysal zone of the crystal-poor member of the Topopah Spring tuff (i.e., Tptpll). The 
Tptpmn and Tptpll results are presented in Sections 6.1.1 and 6.1.2, respectively. These 
subsections are further subdivided by seepage source, i.e., seepage from the crown of the drift or 
imbibed into the invert. 
Figure 1 through Figure 48 present HRH salts model predictions of the evaporative evolution of 
these base case waters for each time period. For each case and time period, plots of the predicted 
aqueous and mineral evaporative evolutions are presented. The parameter IS represents the true 
ionic strength predicted by EQ3/6. As described in Section 5.2.1, ISa is the calculated ionic 
strength approximation. The concentration factor (C/Co) on the x-axis is the total nitrate 
concentration divided by the nitrate concentration prior to evaporation. The plotted results span 
the range of concentration factors corresponding to water activities of 0.85 and higher. 
The entire set of EQ3/6 input and output files for the Bmc, Bmi, Blc, and Bli cases are 
documented in DTN: MO0112MWDTHC12.024. 
CAL-EBS-PA-000012 REV 00 23 December 2001 

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0024December 20016.1.1Tptpmn Lithology6.1.1.1Seepage at the Crown of the Drift (Case Bmc)
456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 1. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpmn Lithology (Bmc), Period 1456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHChalcedonyNontronite-CaSepioliteCalciteMontmor-MgFluoriteGypsumMontmor-NaNontronite-NaAlbite_lowGlauberite 
DTN: MO0112MWDTHC12.024Figure 2. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpmn Lithology (Bmc), Period 1

Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
4 
5 
6 
7 
8 
9 
10 
11 
12 
pH 
pH 
IS 
Al 
C 
Ca 
Cl 
F 
Fe 
K 
Mg 
N 
Na 
S 
Si 
1.E-9 
1.E-8 
1.E-7 
1.E-6 
1.E-5 
1.E-4 
1.E-3 
1.E-2 
1.E-1 
1.E+0 
1.E+1 
Molality 
ISa 
1 10 100 1000 10000 
Concentration Factor 
DTN: MO0112MWDTHC12.024 
Figure 3. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at the 
Crown of the Drift in the Tptpmn Lithology (Bmc), Period 2 
4 
5 
6 
7 
8 
9 
10 
11 
12 
pH 
pH Chali1.E-12 
1.E-11 
1.E-10 
1.E-9 
1.E-8 
1.E-7 
1.E-6 
1.E-5 
1.E-4 
1.E-3 
1.E-2 
1.E-1 
1.E+0 
Moles Precipitated 
cedony Sepiolte Gypsum Sellaite 
1 10 100 1000 10000 
Concentration Factor 
DTN: MO0112MWDTHC12.024 
Figure 4. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at the 
Crown of the Drift in the Tptpmn Lithology (Bmc), Period 2 
CAL-EBS-PA-000012 REV 00 25 December 2001 

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0026December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 5. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpmn Lithology (Bmc), Period 3456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHChalcedonyNontronite-CaSepioliteCalciteMontmor-CaFluoriteGypsumAlbite_lowNontronite-Na 
DTN: MO0112MWDTHC12.024Figure 6. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpmn Lithology (Bmc), Period 3

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0027December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 7. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpmn Lithology (Bmc), Period 4456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHCalciteChalcedonyNontronite-CaMontmor-MgFluoriteMontmor-NaNontronite-NaGypsumClinoptilolite-hy-NaSepioliteAlbite_lowGlauberite 
DTN: MO0112MWDTHC12.024Figure 8. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpmn Lithology (Bmc), Period 4

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0028December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 9. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpmn Lithology (Bmc), Period 5456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHCalciteChalcedonyNontronite-CaNontronite-MgFluoriteMontmor-MgNontronite-NaMontmor-NaGypsumClinoptilolite-hy-NaSepioliteSellaiteGlauberite 
DTN: MO0112MWDTHC12.024Figure 10. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpmn Lithology (Bmc), Period 5

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0029December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 11. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpmn Lithology (Bmc), Period 6456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHCalciteChalcedonyNontronite-CaNontronite-MgFluoriteMontmor-MgNontronite-NaMontmor-NaGypsumClinoptilolite-hy-NaSellaiteSepioliteGlauberite 
DTN: MO0112MWDTHC12.024Figure 12. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpmn Lithology (Bmc), Period 6

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0030December 20016.1.1.2Water Imbibed into the Invert (Case Bmi)
456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 13. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for SeepageWicking into the Invert in the Tptpmn Lithology (Bmi), Period 1456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHCalciteChalcedonyNontronite-MgSepioliteMontmor-MgFluoriteGypsumMontmor-NaNontronite-NaAlbite_lowGlauberite 
DTN: MO0112MWDTHC12.024Figure 14. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage Wickinginto the Invert in the Tptpmn Lithology (Bmi), Period 1

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0031December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 15. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for SeepageWicking into the Invert in the Tptpmn Lithology (Bmi), Period 2456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHChalcedonySepioliteGyroliteAlbite_lowFluorite 
DTN: MO0112MWDTHC12.024Figure 16. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage Wickinginto the Invert in the Tptpmn Lithology (Bmi), Period 2

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0032December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 17. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for SeepageWicking into the Invert in the Tptpmn Lithology (Bmi), Period 3456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHChalcedonyNontronite-CaSepioliteCalciteFluoriteMontmor-CaGypsumAlbite_low 
DTN: MO0112MWDTHC12.024Figure 18. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage Wickinginto the Invert in the Tptpmn Lithology (Bmi), Period 3

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0033December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 19. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for SeepageWicking into the Invert in the Tptpmn Lithology (Bmi), Period 4456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHCalciteChalcedonyNontronite-CaFluoriteMontmor-MgMontmor-NaNontronite-NaGypsumClinoptilolite-hy-NaSepioliteAlbite_lowGlauberite 
DTN: MO0112MWDTHC12.024Figure 20. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage Wickinginto the Invert in the Tptpmn Lithology (Bmi), Period 4

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0034December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 21. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for SeepageWicking into the Invert in the Tptpmn Lithology (Bmi), Period 5456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHCalciteChalcedonyNontronite-CaNontronite-MgFluoriteMontmor-MgNontronite-NaMontmor-NaGypsumClinoptilolite-hy-NaSepioliteSellaiteGlauberite 
DTN: MO0112MWDTHC12.024Figure 22. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage Wickinginto the Invert in the Tptpmn Lithology (Bmi), Period 5

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0035December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 23. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for SeepageWicking into the Invert in the Tptpmn Lithology (Bmi), Period 6456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHCalciteChalcedonyNontronite-CaNontronite-MgFluoriteMontmor-MgNontronite-NaMontmor-NaGypsumClinoptilolite-hy-NaSellaiteSepioliteGlauberite 
DTN: MO0112MWDTHC12.024Figure 24. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage Wickinginto the Invert in the Tptpmn Lithology (Bmi), Period 6

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0036December 20016.1.2Tptpll Lithology6.1.2.1Seepage at the Crown of the Drift (Case Blc)
456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 25. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpll Lithology (Blc), Period 1456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHChalcedonyNontronite-MgMontmor-MgSepioliteFluoriteGypsumSellaiteAlbite_lowNontronite-Na 
DTN: MO0112MWDTHC12.024Figure 26. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpll Lithology (Blc), Period 1

Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
4 
5 
6 
7 
8 
9 
10 
11 
12 
pH 
pH 
IS 
Al 
C 
Ca 
Cl 
F 
K 
Mg 
N 
Na 
S 
Si 
1.E-9 
1.E-8 
1.E-7 
1.E-6 
1.E-5 
1.E-4 
1.E-3 
1.E-2 
1.E-1 
1.E+0 
1.E+1 
Molality 
ISa 
1 10 100 1000 10000 
Concentration Factor 
DTN: MO0112MWDTHC12.024 
Figure 27. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at the 
Crown of the Drift in the Tptpll Lithology (Blc), Period 2 
4 
5 
6 
7 
8 
9 
10 
11 
12 
pH 
pH Sellai1.E-12 
1.E-11 
1.E-10 
1.E-9 
1.E-8 
1.E-7 
1.E-6 
1.E-5 
1.E-4 
1.E-3 
1.E-2 
1.E-1 
1.E+0 
Moles Precipitated 
Chalcedony Sepiolite Gypsum te 
1 10 100 1000 10000 
Concentration Factor 
DTN: MO0112MWDTHC12.024 
Figure 28. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at the 
Crown of the Drift in the Tptpll Lithology (Blc), Period 2 
CAL-EBS-PA-000012 REV 00 37 December 2001 

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0038December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 29. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpll Lithology (Blc), Period 3456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHCalciteChalcedonyNontronite-CaSepioliteFluoriteGypsumMontmor-CaAlbite_lowNontronite-Na 
DTN: MO0112MWDTHC12.024Figure 30. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpll Lithology (Blc), Period 3

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0039December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 31. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpll Lithology (Blc), Period 4456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHCalciteChalcedonyNontronite-CaFluoriteMontmor-CaMontmor-MgMontmor-NaGypsumNontronite-NaClinoptilolite-hy-NaSepioliteAlbite_lowGlauberite 
DTN: MO0112MWDTHC12.024Figure 32. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpll Lithology (Blc), Period 4

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0040December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 33. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpll Lithology (Blc), Period 5456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHCalciteChalcedonyNontronite-CaFluoriteMontmor-MgNontronite-MgNontronite-NaMontmor-NaGypsumClinoptilolite-hy-NaSepioliteGlauberite 
DTN: MO0112MWDTHC12.024Figure 34. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpll Lithology (Blc), Period 5

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0041December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 35. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpll Lithology (Blc), Period 6456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHCalciteChalcedonyNontronite-CaFluoriteMontmor-MgMontmor-NaNontronite-NaGypsumClinoptilolite-hy-NaSepioliteAlbite_lowGlauberite 
DTN: MO0112MWDTHC12.024Figure 36. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage at theCrown of the Drift in the Tptpll Lithology (Blc), Period 6

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0042December 20016.1.2.2Water Imbibed into the Invert (Case Bli)
456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 37. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for SeepageWicking into the Invert in the Tptpll Lithology (Bli), Period 1456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHCalciteChalcedonyNontronite-MgSepioliteFluoriteMontmor-MgGypsumMontmor-NaNontronite-NaAlbite_lowGlauberite 
DTN: MO0112MWDTHC12.024Figure 38. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage Wickinginto the Invert in the Tptpll Lithology (Bli), Period 1

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0043December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 39. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for SeepageWicking into the Invert in the Tptpll Lithology (Bli), Period 2456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHChalcedonySepioliteSellaiteFluoriteGypsumMontmor-Mg 
DTN: MO0112MWDTHC12.024Figure 40. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage Wickinginto the Invert in the Tptpll Lithology (Bli), Period 2

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0044December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 41. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for SeepageWicking into the Invert in the Tptpll Lithology (Bli), Period 3456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHChalcedonyNontronite-CaSepioliteFluoriteMontmor-CaGypsumMontmor-MgNontronite-Mg 
DTN: MO0112MWDTHC12.024Figure 42. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage Wickinginto the Invert in the Tptpll Lithology (Bli), Period 3

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0045December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 43. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for SeepageWicking into the Invert in the Tptpll Lithology (Bli), Period 4456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHCalciteChalcedonyNontronite-CaFluoriteMontmor-CaGypsumMontmor-NaNontronite-NaClinoptilolite-hy-NaAlbite_low 
DTN: MO0112MWDTHC12.024Figure 44. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage Wickinginto the Invert in the Tptpll Lithology (Bli), Period 4

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0046December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 45. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for SeepageWicking into the Invert in the Tptpll Lithology (Bli), Period 5456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHCalciteChalcedonyNontronite-CaFluoriteMontmor-MgMontmor-NaNontronite-NaClinoptilolite-hy-NaGypsumSepioliteGlauberite 
DTN: MO0112MWDTHC12.024Figure 46. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage Wickinginto the Invert in the Tptpll Lithology (Bli), Period 5

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0047December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 47. Aqueous Evaporative Evolution for the Base Case THC Model Abstraction for SeepageWicking into the Invert in the Tptpll Lithology (Bli), Period 6456789101112110100100010000Concentration FactorpH1.E-121.E-111.E-101.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+0Moles PrecipitatedpHCalciteChalcedonyNontronite-CaFluoriteMontmor-MgMontmor-NaNontronite-NaGypsumClinoptilolite-hy-NaAlbite_lowSepioliteGlauberite 
DTN: MO0112MWDTHC12.024Figure 48. Mineral Evaporative Evolution for the Base Case THC Model Abstraction for Seepage Wickinginto the Invert in the Tptpll Lithology (Bli), Period 6

Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
6.2 RESULTS FOR SENSITIVITY THC MODEL ABSTRACTIONS 
The sensitivity THC model abstractions include the HLi, HHi, LLi, LHi, HLc, HHc, LLc, LHc, 
HHcp, HHip, LHcp, and LHip cases in Table 1. Each of these cases is for seepage in the lower 
lithophysal zone of the crystal-poor member of the Topopah Spring tuff (Tptpll). The results are 
divided into two subsections corresponding to the composition of the water used to initialize the 
THC model grid blocks. Section 6.2.1 presents and/or references the results of the cases in 
which Topopah Spring tuff pore water was used as the initial water (i.e., cases HLi, HHi, LLi, 
LHi, HLc, HHc, LLc, and LHc). Section 6.2.2 presents and/or references the results of the cases 
in which UZ-14 perched water was used as the initial water (i.e., cases HHcp, HHip, LHcp, and 
LHip). Sections 6.2.1 and 6.2.2 are further subdivided by a combination of operating 
temperature mode (high or low) and carbon dioxide soil gas condition (high or low). 
The HRH salts model predictions of the aqueous evaporative evolution of waters derived from 
cases HLi, HHi, LLi, and LHi are presented in Figure 49 through Figure 70. Predictions for 
waters derived from cases HHip and LHip are presented in Figure 71 through Figure 81. 
Results for seepage at the crown of the drift are not plotted. Differences in the evolution of 
invert and crown waters are discussed in Section 6.3. 
The entire set of EQ3/6 input and output files for the HLi, HHi, LLi, LHi, HLc, HHc, LLc, and 
LHc cases are documented in DTN: MO0111MWDVAR12.021. The EQ3/6 input and output 
files for cases HHcp, HHip, LHcp, and LHip are documented in DTN: 
MO0112MWDTHC12.024. 
CAL-EBS-PA-000012 REV 00 48 December 2001 

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0049December 20016.2.1Initial Water Composition (Pore Water)
6.2.1.1High Temperature, Low CO2 Partial Pressure (Case HLi)
456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 49. Aqueous Evaporative Evolution for the High Temperature and Low Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (HLi), Period 1456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 50. Aqueous Evaporative Evolution for the High Temperature and Low Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (HLi), Period 2

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0050December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 51. Aqueous Evaporative Evolution for the High Temperature and Low Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (HLi), Period 3456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 52. Aqueous Evaporative Evolution for the High Temperature and Low Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (HLi), Period 4

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0051December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 53. Aqueous Evaporative Evolution for the High Temperature and Low Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (HLi), Period 5456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 54. Aqueous Evaporative Evolution for the High Temperature and Low Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (HLi), Period 6

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0052December 20016.2.1.2High Temperature, High CO2 Partial Pressure (Case HHi)
456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 55. Aqueous Evaporative Evolution for the High Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (HHi), Period 1456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 56. Aqueous Evaporative Evolution for the High Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (HHi), Period 2

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0053December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 57. Aqueous Evaporative Evolution for the High Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (HHi), Period 3456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 58. Aqueous Evaporative Evolution for the High Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (HHi), Period 4

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0054December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 59. Aqueous Evaporative Evolution for the High Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (HHi), Period 5456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 60. Aqueous Evaporative Evolution for the High Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (HHi), Period 6

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0055December 20016.2.1.3Low Temperature, Low CO2 Partial Pressure (Case LLi)
456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 61. Aqueous Evaporative Evolution for the Low Temperature and Low Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (LLi), Period 1456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 62. Aqueous Evaporative Evolution for the Low Temperature and Low Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (LLi), Period 2

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0056December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 63. Aqueous Evaporative Evolution for the Low Temperature and Low Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (LLi), Period 3456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 64. Aqueous Evaporative Evolution for the Low Temperature and Low Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (LLi), Period 4

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0057December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 65. Aqueous Evaporative Evolution for the Low Temperature and Low Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (LLi), Period 56.2.1.4Low Temperature, High CO2 Partial Pressure (Case LHi)
456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 66. Aqueous Evaporative Evolution for the Low Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (LHi), Period 1

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0058December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 67. Aqueous Evaporative Evolution for the Low Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (LHi), Period 2456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 68. Aqueous Evaporative Evolution for the Low Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (LHi), Period 3

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0059December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 69. Aqueous Evaporative Evolution for the Low Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (LHi), Period 4456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0111MWDVAR12.021Figure 70. Aqueous Evaporative Evolution for the Low Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology (LHi), Period 5

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0060December 20016.2.2Initial Water Composition (UZ-14 Perched Water)
6.2.2.1High Temperature, High CO2 Partial Pressure (Case HHip)
456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 71. Aqueous Evaporative Evolution for the High Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology, Initialized Using WaterComposition of UZ-14 Perched Water (HHip), Period 1456789101112110100100010000100000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 72. Aqueous Evaporative Evolution for the High Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology, Initialized Using WaterComposition of UZ-14 Perched Water (HHip), Period 2

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0061December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 73. Aqueous Evaporative Evolution for the High Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology, Initialized Using WaterComposition of UZ-14 Perched Water (HHip), Period 3456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 74. Aqueous Evaporative Evolution for the High Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology, Initialized Using WaterComposition of UZ-14 Perched Water (HHip), Period 4

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0062December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 75. Aqueous Evaporative Evolution for the High Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology, Initialized Using WaterComposition of UZ-14 Perched Water (HHip), Period 5456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 76. Aqueous Evaporative Evolution for the High Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology, Initialized Using WaterComposition of UZ-14 Perched Water (HHip), Period 6

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0063December 20016.2.2.2Low Temperature, High CO2 Partial Pressure (Case LHip)
456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 77. Aqueous Evaporative Evolution for the Low Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology, Initialized Using WaterComposition of UZ-14 Perched Water (LHip), Period 1456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 78. Aqueous Evaporative Evolution for the Low Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology, Initialized Using WaterComposition of UZ-14 Perched Water (LHip), Period 2

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0064December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 79. Aqueous Evaporative Evolution for the Low Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology, Initialized Using WaterComposition of UZ-14 Perched Water (LHip), Period 3456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 80. Aqueous Evaporative Evolution for the Low Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology, Initialized Using WaterComposition of UZ-14 Perched Water (LHip), Period 4

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0065December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 81. Aqueous Evaporative Evolution for the Low Temperature and High Carbon Dioxide PartialPressure Case for Seepage Wicking into the Invert in the Tptpll Lithology, Initialized Using WaterComposition of UZ-14 Perched Water (LHip), Period 56.3SUMMARY OF HIGH RELATIVE HUMIDITY SALTS MODEL RESULTSComparison of Figures 1 through 81 provide insight into the effects of various parameters onmodel outputs. The following subsections summarize the effects observed as they pertain to theevaporation calculations.
6.3.1Effects of Lithology (Tptpmn vs. Tptpll)
The effects of lithology can be evaluated by comparing the Bmc and Bmi case results for theTptpmn (Figures 1 through 24) with the Blc and Bli case results for the Tptpll (Figures 25through 48). For the most part, there is little difference in the evaporation of these waters.
However, several of the comparisons suggest that the pH might be lower in the Tptpll (e.g.,
Figure 1 vs. Figure 25 and Figure 17 vs. Figure 41). This appears to be especially true forevaporation in the invert, where the pH for the Tptpmn can rise to about 10 while the pH fallsbelow 6 for the Tptpll (Figure 15 vs. Figure 39).
The lower pH values in the Tptpll appear to correlate fairly strongly with lower Na:Cl molarratios in the Tptpll. That is, for those cases in which the pH is considerably lower in the Tptpll,
the Na:Cl molar ratio is also considerably lower. This observation may be important becauselower Na:Cl molar ratios enhance the probability of developing a chloride brine instead of anitrate brine (BSC 2001f, Section 6.1.3).

Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
6.3.2 Effects of Seepage Location (Crown vs. Invert) 
The effects of seepage location can be evaluated by comparing the Bmc and Blc case results 
(Figures 1 through 12 and 25 through 36) with the Bmi and Bli case results (Figures 13 through 
24 and 37 through 48), respectively. For the Tptpmn lithology, the pH is generally lower in the 
crown than the invert for the early periods. This is especially apparent in the boiling period of 
the Tptpmn (Figure 3 versus Figures 15). 
A relationship between pH and seepage location is not clear for the Tptpll results. While the last 
two periods show almost no differences, the pH differences in the earlier time periods are mixed. 
Period 1 shows pH values about one unit lower in the crown than the invert while period 3 shows 
the opposite results. For the other four periods, the pH differences between seepage locations are 
small in comparison. 
Lower Na:Cl molar ratios are observed in the invert than in the crown in the early periods of 
Tptpll cases and in period 3 of the Tptpmn cases. These results reflect the ratios observed in the 
incoming seepage composition abstractions and not the effects of further evaporation. 
6.3.3 Effects of Thermal Operating Mode (High vs. Low) 
Comparison of results in Figures 49 through 60 with the results in Figures 61 through 70 suggest 
that seepage waters from the higher temperature operating mode have a greater probability of 
producing lower pH values during the first several thousand years. They also suggest that the 
higher temperature operating mode has a higher probability of having a Na:Cl molar ratio that 
falls below one. Ratios falling below one do not occur in the lower temperature operating mode 
abstractions. Such low ratios enhance the probability of developing a chloride brine instead of a 
nitrate brine (BSC 2001f, Section 6.1.3). 
It is possible, however, that the observed differences in the high and low temperature operating 
mode abstractions are an artifact of the discretization schemes. That is, it is possible that the 
discretizations in DTN: MO0110SPAEBS13.038 might not have captured potentially low Na:Cl 
molar ratios in the lower temperature operating mode because the lower temperature operating 
mode abstraction was not as highly discretized around the boiling and cool down periods as the 
higher temperature operating mode abstraction. Reanalysis of the source data for DTN: 
MO0110SPAEBS13.038 would clarify this issue. 
6.3.4 Effects of Carbon Dioxide Fugacity (High vs. Low) 
The effects of the carbon dioxide fugacity values used to bound the THC model can be evaluated 
by comparing the results of the HLi and LLi cases (Figures 49 through 54 and 61 through 65) 
with the results of the HHi and LHi cases (Figures 55 through 60 and 66 through 70). The pH 
tends to be slightly lower in the higher carbon dioxide fugacity cases. Other than these small 
differences, the results appear to be fairly insensitive to the range of bounding carbon dioxide 
fugacity values used in the simulations. 
CAL-EBS-PA-000012 REV 00 66 December 2001 

Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
6.3.5 Effects of Starting Water Composition (Pore Water vs. Perched Water) 
The effects of the starting water composition used to initialize the THC model can be evaluated 
by comparing the results of the HHi and LHi cases (Figures 55 through 60 and 66 through 70) 
with the results of the HHip and LHip cases (Figures 71 through 81). Initializing the water 
composition using UZ-14 perched water as in the HHip and LHip cases causes considerable 
changes in predicted seepage water compositions and how they evolve upon further evaporation. 
Instead of the pH tending to remain in the neutral range or fall into the acid range, the pH of the 
waters in the HHip and LHip cases tends to increase upon further evaporation, sometimes to 
values in the 9 to 10 range. These waters tend to be dominated by Na and CO3 and have Na:Cl 
molar ratios that exceed at least three. Also, because of the increased NO3:Cl molar ratio as 
explained in Section 3.1, the seepage waters from cases HHip and LHip have a considerably 
greater probability of developing into sodium nitrate brines (BSC 2001f, Section 6.1.3). 
6.4 SUMMARY OF LOW RELATIVE HUMIDITY SALTS MODEL RESULTS 
The LRH model results for this calculation are documented in DTN: MO0111MWDSEE12.022. 
They include cases HHi and LHi, which are extended to cases HHc, HLi, HLc, LHc, LLi, and 
LLc according to Assumption 3.4.1 (Section 3.4). 
Figure 82 shows the predicted chloride and ionic strength molalities as a function of relative 
humidity (RH) for the preclosure period of the LHi case. The results are similar for each of the 
other periods and cases simulated. 
As shown in Sections 6.1 and 6.2, the results of the high relative humidity model show that 
during early time periods when the temperature is elevated, the Na:Cl molar ratio can 
occasionally fall below one. This is important because this enhances the probability of a chloride 
brine developing due to predicted chemical divides (BSC 2001f, Section 6.1.3). This possibility 
is not captured in the low relative humidity model. Future development of the low relative 
humidity model will focus on predicting and incorporating the possibility of generating a 
chloride brine. Other important limitations of the model and uncertainties in the results are 
discussed in Section 6.8. 
CAL-EBS-PA-000012 REV 00 67 December 2001 

Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
Molality 
100 
10 
1 
0.1 
0.01 
40% 50% 60% 70% 80% 90% 
ISa (m) 
Cl (m) 
RH 
DTN: MO0111MWDSEE12.022 
Figure 82. Low Relative Humidity Salts Model Predictions of Ionic Strength and Chloride Concentration 
for the Low Temperature and High Carbon Dioxide Partial Pressure Case for Seepage Wicking into the 
Invert in the Tptpll Lithology (LHi), Period 1 
6.5 LOOKUP TABLES 
The HRH and LRH model results are summarized in a set of lookup tables for the HLi, HHi, 
LLi, LHi, HLc, HHc, LLc, and LHc cases. These tables are documented in DTN: 
MO0111SPAPSM12.023. Though the tables are only qualified for pH, ISa, and Cl technical 
product output, they also include predictions for true ionic strength, total concentrations of CO3, 
F, K, NO3, Na, SO4, Al, Ca, Fe(III), Mg, and Si, and individual species concentrations of HCO3-, 
-
CO32-, OH-, H+, H2SiO42-, H3SiO4 , and MgOH+. 
Figure 83 and Table 6 show values for selected model output parameters from the lookup table 
for the preclosure period of the LLi case. As explained in Sections 4.1.3 and 6.4.2 of the 
Precipitates/Salts model AMR (BSC 2001b), Res is the ratio of the evaporation flux (Qe) to 
seepage flux (Qs). At steady state, Res is related to the concentration factor by the following 
equation 
C 1 
= (Eq. 2)
es
C 1 - R
o 
where the concentration factor (C/Co) is the ratio of the steady state nitrate concentration in the 
cell divided by the nitrate concentration in the incoming seepage. Thus, when (1 -Res) is equal 
to 0.001, 0.01, 0.1, 1.0 and 10 at steady state, then C/Co is equal to 1000, 100, 10, 1.0, and 0.1, 
respectively. A concentration factor of 0.1 implies a ten-fold dilution. 
CAL-EBS-PA-000012 REV 00 68 December 2001 

Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
5 
6 
7 
8 
9 
10 
pH 
pH l Cl 
l N 
H+ H3Si1.E-8 
1.E-7 
1.E-6 
1.E-5 
1.E-4 
1.E-3 
1.E-2 
1.E-1 
1.E+0 
1.E+1 
1.E+2 
Molality 
ISa TotaTotal F 
TotaHCO3CO3 
2OHO4MgOH+
0.001 0.01 0.1 1 10 
1 -R es 
DTN: MO0111SPAPSM12.023 
Figure 83. Steady State Predictions of pH and Selected Aqueous Components and Species vs. (1  Res) 
for the Low Temperature and Low Carbon Dioxide Partial Pressure Case for Seepage Wicking into the 
Invert in the Tptpll Lithology (LLi), Period 1 
CAL-EBS-PA-000012 REV 00 69 December 2001 

CAL-EBS-PA-000012 REV 00 70 December 2001 
Table 6. Example Precipitates/Salts Model Lookup Table for Selected Outputs 
InputParametersa Precipitates/Salts Model Output for: Invert 
Low Temperature 
Low CO2 Preclosure Period (0-300 yr) 
Qualified Output Preliminary Unqualified Output 
RH 
(%) Qe/Qs pH 
ISa 
(molal) 
Total Cl 
(molal) 
Total F 
(molal) 
Total N 
(molal) 
HCO3 
-
(molal) 
CO3 
2-
(molal) 
OH-
(molal) 
H+ 
(molal) 
H2SiO4 
2-
(molal) 
H3SiO4 
-
(molal) 
MgOH+ 
(molal) 
< 50.3 NAb NA NA NA NA NA NA NA NA NA NA NA NA 
50.3 NA 7.30 2.61E+01 2.70E-02 NA NA NA NA NA NA NA NA NA 
51.0 NA 7.30 2.38E+01 3.72E-01 NA NA NA NA NA NA NA NA NA 
53.1 NA 7.30 1.49E+01 1.69E+00 NA NA NA NA NA NA NA NA NA 
55.2 NA 7.30 1.15E+01 2.20E+00 NA NA NA NA NA NA NA NA NA 
60.5 NA 7.30 6.26E+00 2.99E+00 NA NA NA NA NA NA NA NA NA 
65.7 NA 7.30 4.68E+00 3.22E+00 NA NA NA NA NA NA NA NA NA 
71.0 NA 7.30 4.32E+00 3.28E+00 NA NA NA NA NA NA NA NA NA 
76.2 NA 7.30 4.24E+00 3.29E+00 NA NA NA NA NA NA NA NA NA 
81.5 NA 7.30 4.33E+00 3.27E+00 NA NA NA NA NA NA NA NA NA 
85.0 NA 7.30 4.29E+00 3.17E+00 3.87E-04 3.17E-01 5.88E-04 2.17E-05 2.84E-06 2.24E-08 1.85E-10 4.18E-06 7.38E-08 
> 85 -9.00 6.75 9.62E-04 3.25E-04 4.54E-05 3.25E-05 6.99E-05 2.99E-08 3.28E-07 1.87E-07 1.85E-14 7.04E-08 1.74E-10 
> 85 0.00 7.71 9.63E-03 3.25E-03 4.54E-04 3.25E-04 6.88E-04 3.38E-06 3.24E-06 2.18E-08 2.06E-11 6.84E-06 1.22E-08 
> 85 0.90 7.53 7.46E-02 3.24E-02 3.18E-04 3.24E-03 5.23E-04 2.74E-06 2.51E-06 3.81E-08 1.64E-11 5.11E-06 2.20E-08 
> 85 0.99 7.44 5.34E-01 3.18E-01 3.42E-04 3.18E-02 5.58E-04 5.33E-06 2.61E-06 5.40E-08 3.35E-11 4.87E-06 3.83E-08 
> 85 0.999 7.38 3.92E+00 2.72E+00 4.47E-04 2.72E-01 7.10E-04 2.75E-05 3.24E-06 2.37E-08 2.25E-10 5.02E-06 6.37E-08 
> 85 > 0.999 7.30 4.29E+00 3.17E+00 3.87E-04 3.17E-01 5.88E-04 2.17E-05 2.84E-06 2.24E-08 1.85E-10 4.18E-06 7.38E-08 
DTN: MO0111SPAPSM12.023 (developed from MO0111MWDVAR12.021 [files: LLI1C900.6O, LLI1E000.6O, LLI1E900.6O, LLI1E990.6O, and LLI1E999.6O] and 
MO0111MWDSEE12.022 [file: LHI1.MCD]) 
a Qe
NOTE: /Qs is the evaporative flux divided by the seepage flux. 
b Not applicable to model (dry conditions at relative humidity less than 50.3 percent). 

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0071 December 20016.6SENSITIVITY OF MINERAL SUPPRESSIONSTo evaluate the sensitivity of three minerals permitted to precipitate in the HLi, HHi, LLi, LHi,
HLc, HHc, LLc, and LHc cases, the HHi cases were rerun with these minerals suppressed. Thethree minerals were talc, chrysotile, and magnesite. These minerals were not suppressed in theoriginal calculations performed for SSPA and documented in DTN: MO0111MWDVAR12.021and Section 6.2.1 above. As a result, talc precipitated in many of the simulations. Chrysotileand magnesite never did. The only other difference in how the HHi cases were rerun was thatthe PT5v2 database was used instead of the PT5v1 database. These two databases differ only bythe presence of nesquehonite in the PT5v2 database.
The aqueous evaporative evolution of the HHi waters as rerun using the PT5v2 database and theadditional mineral suppressions are presented in Figure 84 through Figure 89. Compared to theresults presented in Figures 55 through 60, they show only minor differences. The pH tends tobe higher, though less than about one pH unit, during periods 2 and 3 when the three minerals aresuppressed. The chloride and ionic strength approximations are approximately unchanged.
These results indicate that Assumption 3.3.1 is justified for the qualified outputs.
The entire set of EQ3/6 input and output files for the rerun HHi case is included in DTN:
MO0112MWDTHC12.024.456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 84. Aqueous Evaporative Evolution for the HHi Case Using the PT5v2 Thermodynamic Databaseand the Full List of Mineral Suppressions, Period 1

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0072 December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 85. Aqueous Evaporative Evolution for the HHi Case Using the PT5v2 Thermodynamic Databaseand the Full List of Mineral Suppressions, Period 2456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 86. Aqueous Evaporative Evolution for the HHi Case Using the PT5v2 Thermodynamic Databaseand the Full List of Mineral Suppressions, Period 3

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0073 December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 87. Aqueous Evaporative Evolution for the HHi Case Using the PT5v2 Thermodynamic Databaseand the Full List of Mineral Suppressions, Period 4456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 88. Aqueous Evaporative Evolution for the HHi Case Using the PT5v2 Thermodynamic Databaseand the Full List of Mineral Suppressions, Period 5

Precipitates/Salts Model Calculations for Various Drift Temperature EnvironmentsCAL-EBS-PA-000012 REV 0074 December 2001456789101112110100100010000Concentration FactorpH1.E-91.E-81.E-71.E-61.E-51.E-41.E-31.E-21.E-11.E+01.E+1MolalitypHISISaAlCCaClFFeKMgNNaSSi 
DTN: MO0112MWDTHC12.024Figure 89. Aqueous Evaporative Evolution for the HHi Case Using the PT5v2 Thermodynamic Databaseand the Full List of Mineral Suppressions, Period 66.7EVAPORATION CALCULATIONS FOR SEEPAGE GROUT INTERACTIONSMODEL INPUTSeveral additional evaporation calculations were performed to provide the Seepage GroutInteractions Model (BSC 2001d) with waters that had been subjected to evaporation by thePrecipitates/Salts Model. These included the Bmc case waters in Table 1 and the UZ-14 perchedwater and Drift-Scale Heater test water samples listed in Table 2. The two water samples inTable 2 are the same samples used in evaporation calculations documented in Precipitates/SaltsModel Sensitivity Calculations (BSC 2001f, Figures 13 through 18 and 25 through 30,
respectively).
Each of these waters was evaporated using the HRH salts model and PT5v2 Pitzer database to anionic strength of 0.5 molal. The Seepage Grout Interactions Model uses the B-dot equation toapproximate activity coefficients, so further evaporation would have provided model input nearor exceeding the ionic strength range of the B-dot equation. The UZ-14 perched water sampleand Drift-Scale Heater test water sample were evaporated at three different carbon dioxidefugicities: 10-1, 10-3, and 10-6.
The EQ3/6 input and output files generated for these calculations are documented in two DTNs.
The files for the Bmc case are included in DTN: MO0112MWDTHC12.024 (files: MCC1.6O,
MCC2.6O, MCC3.6O, MCC4.6O, MCC5.6O, and MCC6.6O). They provide the same results aspresented in Section 6.1 above for the Bmc case except that they do not include results at ionicstrength in excess of 0.5 molal. The corresponding files for the waters in Table 2 are

Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
documented in DTN: MO0111MWDHRH12.019. Like the Bmc case, they provide the same 
results presented elsewhere (Section 6.1.1.1) except that they do not include results at ionic 
strength in excess of 0.5 molal. The evaporation of the perched and Drift-Scale Heater Test 
water samples to a water activity of 0.85 is documented in Precipitates/Salts Model Sensitivity 
Calculations (BSC 2001f, Sections 6.1.2.3 and 6.1.2.5). 
6.8 UNCERTAINTY AND LIMITATIONS 
General model uncertainties and limitations are discussed in terms of model validation in Section 
7.3 of In-Drift Precipitates/Salts Analysis (BSC 2001b). Additional uncertainties and limitations 
associated with starting water composition, carbon dioxide fugacity, and mineral suppressions 
are addressed in sensitivity calculations presented in Precipitates/Salts Model Sensitivity 
Calculations (BSC 2001f, Sections 6.1, 6.2, and 6.3). Finally, the results in the current 
calculation provide insight into the uncertainties and potential effects associated with lithology, 
seepage location, operating temperature, carbon dioxide bounding conditions, and starting water 
compositions. 
Remaining unquantified uncertainties include uncertainties in the representation of processes that 
govern the evaporative evolution of seepage under repository conditions. These include the 
physical model representation (currently assumed to be a simple flow-through mixing cell), 
steady-state and equilibrium assumptions, chemical activity models, and thermodynamic 
database constants. For simple evaporation of synthesized J-13 well water and Topopah Spring 
tuff pore water in a beaker, uncertainties in thermodynamic constants, activity models, and 
equilibrium assumptions do not prevent reasonably accurate predictions of pH, chloride 
concentration, and ionic strength (BSC 2001b, Section 6.5). However, the question remains 
whether the uncertainties observed for these laboratory experiments are representative of the 
dominant evaporative processes in a repository. 
An important uncertainty in the LRH salts model calculations is the sensitivity of the starting 
water composition on the evaporative chemical evolution of water in the drift. The LRH salts 
model makes the assumption that nitrate salts will set the lower limit on the relative humidity at 
which liquid water is stable within the drift. The HRH salts model calculations presented in the 
current document suggest that this assumption may not be appropriate in some instances because 
occasionally, the Na:Cl molar ratio falls below one. A ratio less than one tends to cause the 
water to evaporatively evolve into a chloride brine instead of a nitrate brine (BSC 2001f, Section 
6.1.3). 
The uncertainty associated with the evolution of such a chloride brine is borne largely in the 
uncertainty of the starting water composition. Future efforts to quantify the uncertainty of 
developing a chloride brine must include quantification of the uncertainty of the input starting 
water composition. 
The model results for each water composition evaluated in this calculation are designated as 
qualified technical product output (TPO). The output DTNs produced or compared in this 
calculation are listed in Section 7.2.2 and Table 3. The waters listed in Table 1 use data from 
qualified DTNs as input. Their results are documented in DTN: MO0112MWDTHC12.024, 
MO0111MWDVAR12.021, MO0111MWDSEE12.022, and MO0111SPAPSM12.023. The 
CAL-EBS-PA-000012 REV 00 75 December 2001 

Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
waters in Table 2 (perched water and Drift-Scale Heater Test water) do not use data from 
qualified DTNs. Instead, they are qualified for use in sensitivity calculations using assumptions 
and corroborative data. The results for these two waters are documented in DTN: 
MO0111MWDHRH12.019. Currently, the Precipitates/Salts model is validated for predicting 
pH, chloride concentration, and ionic strength. 
Results of EQ6 evaporation runs sometimes provide final gas summaries with fugacities that 
seem unusual for nitrogen and oxygen gas when compared to partial pressures of these gases 
(~0.7 and ~0.2) at the drift altitude. This happens in evaporation calculations when the fugacities 
of oxygen and nitrogen are not constrained by the user. However, in the EQ6 runs documented 
in this calculation, these fugacities have no significant effect on the output of dissolved or 
precipitated species. The fugacity of oxygen remains high, ensuring that oxidizing conditions 
prevail (consistent with Assumption 5.2.2 (BSC 2001b)), and nitrogen gas does not oxidize, 
ensuring that total nitrate is conserved in the EQ6 calculations. 
CAL-EBS-PA-000012 REV 00 76 December 2001 

Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
7. REFERENCES 
7.1 DOCUMENTS 
BSC (Bechtel SAIC Company) 2001a. Technical Work Plan For Engineered Barrier System 
Department Modeling and Testing FY 02 Work Activities. TWP-MGR-MD-000015 Rev 01. Las 
Vegas, Nevada: Bechtel SAIC Company. URN-0993 
BSC 2001b. In-Drift Precipitates/Salts Analysis. ANL-EBS-MD-000045 REV 00 ICN 03. Las 
Vegas, Nevada: Bechtel SAIC Company. URN-0957 
BSC 2001c. EBS Incoming Water and Gas Composition Abstraction Calculations for Different 
Drift Temperature Environments. CAL-EBS-PA-000013 REV 00. Las Vegas, Nevada: Bechtel 
SAIC Company. ACC: MOL20011214.0126 
BSC 2001d. Seepage Grout Interactions Model Calculations. CAL-EBS-PA-000014 REV 00. 
Las Vegas, Nevada: Bechtel SAIC Company. URN-0967 
BSC 2001e. FY 01 Supplemental Science and Performance Analyses, Volume 1: Scientific Bases 
and Analyses. TDR-MGR-MD-000007 REV 00 ICN 01. Las Vegas, Nevada: Bechtel SAIC 
Company. ACC: MOL.20010801.0404; MOL.20010712.0062; MOL.20010815.0001. 
BSC 2001f. Precipitates/Salts Model Sensitivity Calculations. CAL-EBS-PA-000010 REV 00. 
Las Vegas, Nevada: Bechtel SAIC Company. URN-0955 
CRWMS M&O (Civilian Radioactive Waste Management Services Management and 
Operations) 1998b. "Near-Field Geochemical Environment." Chapter 4 of Total System 
Performance Assessment-Viability Assessment (TSPA-VA) Analyses Technical Basis Document. 
B00000000-01717-4301-00004 REV 01. Las Vegas, Nevada: CRWMS M&O. ACC: 
MOL.19981008.0004. 
CRWMS M&O 1999a. Addendum to: EQ6 Computer Program for Theoretical Manual, Users 
Guide, & Related Documentation. Software Change Request LSCR198. Las Vegas, Nevada: 
CRWMS M&O. ACC: MOL.19990305.0112. 
CRWMS M&O 2000. Analysis of Geochemical Data for the Unsaturated Zone. ANL-NBS-HS-
000017 REV 00. Las Vegas, Nevada: CRWMS M&O. ACC: MOL.20000725.0453. 
CRWMS M&O 2001. Precipitates/Salts Model Results for THC Abstraction. CAL-EBS-PA-
000008 REV 00 ICN 01. Las Vegas, Nevada: CRWMS M&O. ACC: MOL.20010125.0231. 
Mariner, P. 2001. "Informal Calculation Regarding Precipitates/Salts Model Sensitivity Analyses 
in Support of SSPA Volume 1." Memorandum from P. Mariner (BSC) to B. MacKinnon, May 
30, 2001, PROJ.05/01.075, with enclosure. ACC: MOL.20010531.0029. 
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Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
Wolery, T.J. 1992a. EQ3/6, A Software Package for Geochemical Modeling of Aqueous Systems: 
Package Overview and Installation Guide (Version 7.0). UCRL-MA-110662 PT I. Livermore, 
California: Lawrence Livermore National Laboratory. TIC: 205087. 
Wolery, T.J. 1992b. EQ3NR, A Computer Program for Geochemical Aqueous Speciation-
Solubility Calculations: Theoretical Manual, Users Guide, and Related Documentation 
(Version 7.0). UCRL-MA-110662 PT III. Livermore, California: Lawrence Livermore National 
Laboratory. ACC: MOL.19980717.0626. 
Wolery, T.J. and Daveler, S.A. 1992. Theoretical Manual, User's Guide, and Related 
Documentation, Version 7.0. Volume IV of EQ6, A Computer Program for Reaction Path 
Modeling of Aqueous Geochemical Systems. UCRL-MA-110662. Draft 1.1. Livermore, 
California: Lawrence Livermore National Laboratory. TIC: 238011. 
7.2 DATA, LISTED BY TRACKING NUMBER 
7.2.1 Input Data 
LL990702804244.100. Borehole and Pore Water Data. Submittal date: 07/13/1999. 
MO0110SPAEBS13.038. EBS Incoming Water and Gas Composition Abstraction Calculation 
Results. Submittal date: 10/16/2001. URN-0968 
MO0110SPAPT245.017. PT5 Pitzer Database for EQ3/6, Version 2. Submittal date: 10/04/2001. 
URN-0994 
MO0110SPAPT545.016. PT5 Database for EQ3/6. Submittal date: 10/10/2001. URN-0997 
7.2.2 Developed Data 
MO0111MWDHRH12.019. High Relative Humidity Salts Model Predictions For Cement 
Leachate Model. Submittal date: 11/01/2001. 
MO0111MWDSEE12.022. Low Relative Humidity Salts Model Mathcad Files for THC REV 01 
Seepage. Submittal date: 11/01/2001. 
MO0111MWDVAR12.021. High Relative Humidity Salts Model Input/Output Files for Various 
Thermal Operating Modes. Submittal date: 11/01/2001. 
MO0111SPAPSM12.023. Precipitates/Salts Model Lookup Tables for SSPA. Submittal date: 
11/06/2001. 
MO0112MWDTHC12.024. High Relative Humidity Salts Model Predictions for THC REV 01 
Using PT5v2 Thermodynamic Database. Submittal date: 11/28/2001. 
7.3 CODES, STANDARDS, REGULATIONS, PROCEDURES, AND SOFTWARE 
AP-3.12Q, Revision 0, ICN 4. Calculations. Washington, D.C.: U.S. Department of Energy, 
Office of Civilian Radioactive Waste Management. ACC: MOL.20010404.0008. 
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Precipitates/Salts Model Calculations for Various Drift Temperature Environments 
AP-SI.1Q, Rev. 3, ICN 2, ECN 1. Software Management. Washington, D.C.: U.S. Department
of Energy, Office of Civilian Radioactive Waste Management. ACC: MOL.20011030.0598.
CRWMS M&O 1998a. Software Code: EQ3/6. V7.2b. LLNL: UCRL-MA-110662.
CRWMS M&O 1999b. Software Code: EQ6, Version 7.2bLV. V7.2bLV. 10075-7.2bLV-00.
CAL-EBS-PA-000012 REV 00 79 December 2001