Saturated Zone In-Situ Testing Rev 00, ICN 00

ANL-NBS-HS-000039

December 2003

1. PURPOSE
The purpose of this scientific analysis is to document the results and interpretations of 
field
experiments that have been conducted to test and validate conceptual flow and 
radionuclide
transport models in the saturated zone (SZ) near Yucca Mountain. The test interpretations
provide estimates of flow and transport parameters that are used in the development of 
parameter
distributions for Total System Performance Assessment (TSPA) calculations. These 
parameter
distributions are documented in the revisions to the SZ flow model report (BSC 2003 
[162649]),
the SZ transport model report (BSC 2003 [162419]), the SZ colloid transport report (BSC 
2003
[162729]), and the SZ transport model abstraction report (BSC 2003 [164870]). 
Specifically,
this scientific analysis report provides the following information that contributes to the
assessment of the capability of the SZ to serve as a barrier for waste isolation for the 
Yucca
Mountain repository system:
* The bases for selection of conceptual flow and transport models in the saturated 
volcanics
and the saturated alluvium located near Yucca Mountain.
* Results and interpretations of hydraulic and tracer tests conducted in saturated fractured
volcanics at the C-wells complex near Yucca Mountain. The test interpretations include
estimates of hydraulic conductivities, anisotropy in hydraulic conductivity, storativities,
total porosities, effective porosities, longitudinal dispersivities, matrix diffusion mass
transfer coefficients, matrix diffusion coefficients, fracture apertures, and colloid
transport parameters.
* Results and interpretations of hydraulic and tracer tests conducted in saturated alluvium
at the Alluvium Testing Complex (ATC), which is located at the southwestern corner of
the Nevada Test Site (NTS). The test interpretations include estimates of hydraulic
conductivities, storativities, total porosities, effective porosities, longitudinal
dispersivities, matrix diffusion mass transfer coefficients, and colloid transport
parameters.
* Comparisons of sorption parameter estimates for a reactive solute tracer (lithium ion)
derived from both the C-wells field tracer tests and laboratory tests using C-wells core
samples.
* Sorption parameter estimates for lithium ion derived from laboratory tests using 
alluvium
samples from NC-EWDP-19D1 (one of the wells at the ATC) so that a comparison of
laboratory- and field-derived sorption parameters can be made in saturated alluvium if
cross-hole tracer tests are conducted at the ATC.
The comparisons between laboratory- and field-derived sorption parameter estimates for 
lithium
ion are used to assess whether sorption parameters determined in the laboratory can be 
used
reliably to predict field-scale transport. Favorable comparisons of lithium-ion sorption 
will lend
credibility to the Yucca Mountain Project's (YMP) use of laboratory-derived 
radionuclide
sorption parameters when modeling field-scale radionuclide transport. The use of 
laboratory
data for radionuclides is necessary because radionuclides cannot be tested in the field.
ANL-NBS-HS-000039, REV 00 28 December 2003
Saturated-zone geochemistry measurements, including Eh and pH, and water-level
measurements are not addressed in this scientific analysis because they can be used 
directly as
inputs (without intermediate analyses) in downstream analysis and model reports. 
Geochemistry
measurements are used extensively in the scientific analysis report Geochemical and 
Isotopic
Constraints on Groundwater Flow Directions and Magnitudes, Mixing, and Recharge at 
Yucca
Mountain, ANL-NBS-HS-000021, (BSC 2003 [162657], Section 6) to delineate flow 
pathways;
Eh and pH measurements are factored into the development of radionuclide Kd 
distributions in
Attachment I of the model report Site-Scale Saturated Zone Transport, MDL-NBS-HS-
000010,
(BSC 2003 [162419]) and in the model report Radionuclide Transport Models Under 
Ambient
Conditions, MDL-NBS-HS-000008, (BSC 2003 [163228]); and water-level 
measurements are
used as calibration targets in the model report Site-Scale Saturated Zone Flow Model, 
MDLNBS-
HS-000011, (BSC 2003 [162649]).
The work activities in this scientific analysis are governed by the work direction and 
planning
document Technical Work Plan for: Saturated Zone Flow and Transport Modeling and 
Testing,
TWP-NBS-MD-000002 (BSC 2003 [166034], Section 2.6), Work Package ASZM04. 
The
purpose and scope of these activities are to (1) document the basis for conceptual flow 
and
transport models in the SZ, (2) abstract transport parameters derived from SZ field testing 
for use
in TSPA analyses, and (3) assess whether sorption parameters determined in the 
laboratory can
be used reliably to predict field-scale transport.
The field and laboratory testing of the saturated fractured volcanics (e.g., C-wells and 
associated
laboratory tests) were completed prior to preparation of the TWP, so none of the 
investigations in
the fractured volcanics described in this scientific analysis are mentioned in the TWP.
Conversely, the TWP mentions some testing activities that are not reported in this 
analysis report
because they were deferred. These deferred activities include cross-hole tracer testing at 
the
ATC involving sorbing tracers and stable-isotope-tagged natural colloids, which is more 
fully
described in BSC (2002 [158198]).
The data and analyses documented in this report will be used as scientific supporting 
information
in other Project reports that are currently under revision, including:
* The SZ flow model report (BSC 2003 [162649])
* The SZ transport model report (BSC 2003 [162419])
* The SZ colloid transport scientific analysis report (BSC 2003 [162729])
* The SZ transport model abstraction report (BSC 2003 [164870]).
A potential limitation of this scientific analysis is that the bases for the conceptual models 
and
the estimates of flow and transport parameters are derived from tests conducted at only 
one
location in the saturated fractured volcanics (C-wells complex) and one location in the 
saturated
alluvium (ATC). The flow and transport characteristics at these locations may not 
necessarily be
representative of the characteristics at other locations along the flow pathway(s) from the
repository to the accessible environment. However, to compensate for this potential 
limitation,
several other sources of information are used to develop broader uncertainty distributions 
for
flow and transport parameters in the TSPA analyses than SZ in-situ testing data would 
indicate.
ANL-NBS-HS-000039, REV 00 29 December 2003
The development and bases of these distributions are documented in the SZ transport 
model
abstractions report (BSC 2003 [164870]), where it is shown that the overall parameter
distributions used in the TSPA analyses include considerations of literature data, expert
elicitation input, and peer review input. The only uncertainty distribution presented in this
analysis report is one for the north-south/east-west anisotropy ratio of horizontal 
hydraulic
conductivity in the fractured volcanics (Section 6.2.6).
This scientific analysis report does not provide the technical basis for inclusion of any of 
the SZ
features, events, and processes (FEPs). However, SZ FEPs that are included in the Total
Systems Performance Assessment for the License Application (TSPA-LA) and supported 
by the
results of this report are listed in Table 6.1-3. The rationale for excluding a FEP from the 
TSPALA
model will be given in the report Features, Events, and Processes in SZ Flow and 
Transport
REV 02 (BSC 2003 [163128]).
(NOTE: In this report, a unique six-digit numerical identifier (the Document Input 
Reference
System [DIRS] number) is placed in the text following the reference callout (e.g., BSC 
2003
[166034]). The purpose of the DIRS numbers is to assist the reader in locating a specific
reference in the DIRS database.)
ANL-NBS-HS-000039, REV 00 30 December 2003
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ANL-NBS-HS-000039, REV 00 31 December 2003
2. QUALITY ASSURANCE
Development of this scientific analysis report and the supporting analyses has been 
determined
to be subject to the Office of Civilian Waste Management (OCRWM) quality assurance 
(QA)
program (BSC 2003 [166034], Section 8), Work Package ASZM04. Approved QA 
procedures
identified in the technical work plan (BSC 2003 [166034], Section 4) have been used to 
conduct
and document the activities described in this scientific analysis report. The technical 
work plan
also identifies the methods used to control the electronic management of data (BSC 2003
[166034], Section 8), and these methods were implemented in the documentation of the 
activities
described in the TWP.
This analysis reports on the saturated zone, which is a natural barrier classified in the Q-
List
(BSC 2003 [165179]) as SC (Safety Category) because it is important to waste isolation, 
as
defined in AP-2.22Q, Classification Analyses and Maintenance of the Q-List. The results 
of this
report are important to the demonstration of compliance with the post-closure 
performance
objectives prescribed in 10 CFR 63.113 [156605]. The report contributes to the analysis 
and
modeling data used to support performance assessment; the conclusions do not directly 
impact
engineered features important to safety, as defined in AP-2.22Q.
ANL-NBS-HS-000039, REV 00 32 December 2003
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ANL-NBS-HS-000039, REV 00 33 December 2003
3. SOFTWARE
3.1 SOFTWARE TRACKED BY CONFIGURATION MANAGEMENT
The computer codes used directly in this scientific analysis are summarized in Table 3-1. 
The
qualification status of the software is indicated in the electronic DIRS database and in the
Software Configuration Management System Baseline Report. All software was obtained 
from
Software Configuration Management (SCM) and is appropriate for the application. 
Qualified
codes were used only within the range of validation as required by AP-SI.1Q, Software
Management.
Table 3-1. Software Used in Support of This Scientific Analysis
Software
Name and
Version (V)
Software
Tracking
Number
(STN)/DIRS
Number
Description Computer and Platform
Identification
2WELLS_2D
V 1.0
10665-1.0-00
[159067]
This software is used in the analysis of longitudinal
dispersivity in the Prow Pass Tuff C-wells field
tracer test. It is used to obtain predicted tracer
responses in homogeneous, isotropic, confined (2-
D) aquifers under partial recirculation conditions. It
has been used both to correct dispersioncoefficient
estimates for dispersion caused by a
dipole-flow pattern and for pre-test predictions of
ATC cross-hole tracer tests.
LANL, PC, Windows
2000/NT
2WELLS_3D
V 1.0
10667-1.0-00
[159036]
This software is used to obtain predicted tracer
responses in homogeneous, isotropic, confined
three-dimensional (3-D) aquifers under partial
recirculation conditions. It has been used both to
correct dispersion-coefficient estimates for
dispersion caused by a dipole-flow pattern and for
pre-test predictions of ATC cross-hole tracer tests.
LANL, PC, Windows
2000/NT
DIFFCELL
V 2.0
10557-2.0-00
[159063]
This software is used in the analysis of laboratory
diffusion cell experiments. It provides a numerical
solution to an equation describing one-dimensional
(1-D) diffusive transport through a rock wafer with
time-dependent concentration boundary
conditions.
LANL, PC, Windows
2000/NT
EQUIL_FIT
V 1.0
10668-1.0-00
[159064]
This software is used to obtain cation- exchange
coefficients, given experimental data on cation
sorption (both for sorbing and displaced cations)
and given independent cation-exchange-capacity
measurements.
LANL, PC, Windows
2000/NT
Filter.vi
V 1.0
10970-1.0-00
[162668]
This software uses the standard Butterworth filter
with standard coefficients. It is for filtering higherfrequency
diurnal pressure changes due to
barometric pressure changes and tidal effects.
USGS, PC, Windows
2000/NT, 4.0/98
ANL-NBS-HS-000039, REV 00 34 December 2003
Table 3-1 (Continued). Software Used in Support of This Scientific Analysis
Software
Name and
Version (V)
Software
Tracking
Number
(STN)/DIRS
Number
Description Computer and Platform
Identification
Injection_
Pump-back.vi
V 1.0
10675-1.0-00
[162749]
This software is used for tracer test analysis for
single-well testing. Analysis considers tracer
injection, drift, and pumpback.
USGS, PC, Windows
2000/NT
rcv2amos.exe
and
MOENCH.vi,
Function(1),
V 1.0
10583-1.0-00
[162750]
The software routine rcv2amos.exe is used to
analyze cross-hole tracer tests. In conjunction with
the use of rcv2amos.exe, the routine MOENCH.vi
was developed to serve as a user interface and to
display the results.
USGS, PC, Windows
2000/NT, 4.0/98
MOENCH.vi
Function(2)
V 1.0
10582-1.0-00
[162752]
This software is used for the analysis of cross-hole
tracer tests.
USGS, PC, Windows
2000/NT, 4.0/98
MULTRAN
V 1.0
10666-1.0-00
[159068]
This is a two-dimensional (2-D) numerical model
that uses an implicit-in-time, alternating-direction,
finite-difference method to solve the equations
describing multicomponent transport of sorbing and
nonsorbing solutes in a dual-porosity medium.
This software is used for analysis of laboratory
crushed-rock and alluvium column experiments. It
is also used for the analysis of the first peak in the
Bullfrog Tuff C-wells field tracer test and for
prediction and analysis of ATC tracer experiments.
LANL, PC, Windows
2000/NT
Neuman.vi
V 1.0
10972-1.0-00
[162754]
This software displays the standard and accepted
type curve for unconfined aquifers and allows the
fitting of the input data curves over the type curve.
The .vi extension displays the appropriate resulting
hydrologic parameters associated with the data
curve matching (transmissivity and storativity).
USGS, PC, Windows
2000/NT, 4.0/98
PEST
V 5.5
10289-5.5-00
[161564]
This software assists in data interpretation, model
calibration, and predictive analysis. PEST adjusts
model parameters and/or excitations until the fit
between model output and field or laboratory
observations is optimized in the weighted leastsquares
sense.
USGS, PC, Windows 2000
RECIRC.vi
V 1.0
10673-1.0-00
[164432]
This program is used for recirculating and partialrecirculation
cross-hole tracer test analysis.
USGS, PC, Windows
98/NT 4.0/2000
RELAP
V. 2.0
10551-2.0-00
[159065]
This software models tracer transport by
convoluting a Laplace-domain transfer function for
transport through dual-porosity media with transfer
functions that describe tracer injection, mixing in
the injection and production wellbores (or flow
manifolds in laboratory experiments), and
recirculation of the product fluid (in field
experiments only). It also performs curve fits to
field or laboratory tracer test data to obtain the
best-fitting transport parameter values.
LANL, PC, Windows
2000/NT
ANL-NBS-HS-000039, REV 00 35 December 2003
Table 3-1 (Continued). Software Used in Support of This Scientific Analysis
Software
Name and
Version (V)
Software
Tracking
Number
(STN)/DIRS
Number
Description Computer and Platform
Identification
RETRAN
V 2.0
10552-2.0-00
[159066]
This software models reactive transport in dualporosity
media with a general, nonlinear sorption
isotherm and with time-varying flow rates.
LANL, PC, Windows
2000/NT
Streltsova-
Adams.vi
V 1.0
10971-1.0-00
[162756]
This software displays the standard and accepted
Streltsova-Adams type curve for fractured aquifers
and allows the fitting of the input data curves over
this type curve. The .vi extension displays the
appropriate resulting hydrologic parameters
associated with the data curve matching
(transmissivity and storativity).
USGS, PC, Windows
2000/NT, 4.0/98
Theis.vi
V 1.0
10974-1.0-00
[162758]
This software displays the standard and accepted
Theis type curve and allows the fitting of the input
data curves over this type curve. The .vi extension
displays the appropriate resulting hydrologic
parameters associated with the data curve
matching (transmissivity and storativity).
USGS, PC, Windows
2000/NT, 4.0/98
3.2 EXEMPT SOFTWARE
Commercial, off-the-shelf software used in support of this scientific analysis report is 
listed in
Table 3-2. This software is exempt from the requirements of AP-SI.1Q, Software 
Management.
Table 3-2. Exempt Software Used in Support of This Scientific Analysis
Software Name
and Version (V) Description Computer and Platform
Identification
Microsoft Excel, 97
SR-1
The commercial software, Microsoft Excel, 97 SR-1, was used
for statistical analysis of data and plotting graphs. Only built-in
standard functions in this software were used. No software
routines or macros were used with the software to prepare this
report. The output was visually checked for correctness, and
the results of all calculations were hand-checked.
PC, Windows 2000/NT
Calculations and spreadsheets used in this analysis can be found in the Technical Data
Management System (TDMS) within data packages that have been assigned DTN 
numbers.
Alternatively, some calculations and spreadsheets can be found in scientific notebooks.
Calculations and spreadsheets are not included as attachments to this report because of 
their
voluminous nature.
ANL-NBS-HS-000039, REV 00 36 December 2003
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ANL-NBS-HS-000039, REV 00 37 December 2003
4. INPUTS
4.1 DATA AND PARAMETERS
The data used in interpretation of the hydraulic tests discussed in Section 6.2 have been
submitted as data packages (Table 4-1) to the TDMS. Data packages submitted to the 
U.S.
Department of Energy (DOE) are available for inspection at the DOE, Office of 
Repository
Development, Records Processing Center in Las Vegas, Nevada. The data and other 
technical
information providing input for the development of parameters documented in this 
scientific
analysis are identified in Table 4-1. The listed data and the technical information are 
appropriate
sources for the analyses documented in this report. A brief description of the data, the 
data
tracking number (DTN) used as input, or the source of the data are listed in Table 4-1. 
The table
is divided according to the sections in this analysis in which the data are used. The 
qualification
status of data input is indicated in the TDMS and in the DIRS database.
This document may be affected by technical product input information that requires
confirmation. Any changes to the document that may occur as a result of completing the
confirmation activities will be reflected in subsequent interim change notices or revisions.
Table 4-1. Input Data
Data Description Data Tracking Number (DTN) or Source
Section 6.1
Results of hydraulic tests in Miocene tuffaceous rocks
at the C-hole complex, 1995 to 1997, Yucca Mountain,
Nevada.
GS030508312314.003 [164425]
Revised bedrock geologic map of the Yucca Mountain
area.
GS980608314221.002 [107024]
Well completion information for NC-EWDP-19D1. MO0112DQRWLNYE.018 [157187]
Well completion information for NC-EWDP-19P. MO0112DQRWLNYE.014 [157184]
Stratigraphic and lithologic information for NC-EWDP-
19D1.
GS011008314211.001 [158690]
Well completion information for NC-EWDP-19IM1. MO0306NYE05259.165 [165876]
Well completion information for NC-EWDP-19IM2. MO0306NYE05260.166 [165877]
Hydraulic information from the C-hole complex and the
Yucca Mountain area.
GS930908312313.008 [166332]
Section 6.2
Results of hydraulic tests in Miocene tuffaceous rocks
at the C-hole complex, 1995 to 1997, Yucca Mountain,
Nevada.
GS030508312314.003 [164425]
Water-level altitude data from four wells in the
continuous network, May through December 1996.
GS970308312314.002 [161273]
Pump test data collected at the C-wells complex
5/7/96 - 12/31/96.
GS981008312314.003 [144464]
ANL-NBS-HS-000039, REV 00 38 December 2003
Table 4-1 (Continued). Input Data
Data Description Data Tracking Number (DTN) or Source
Section 6.2 (Continued)
Transducer, barometric pressure, and discharge data
collected from 4/18/98 in support of the ongoing
hydraulic tracer tests being conducted at the UE-25 Cwells
complex, Nevada.
GS990408312315.002 [140115]
UE-25 ONC-1 transducer pressures, April, 1995 to
December, 1997.
MO0212SPANYESJ.149 [161274]
Section 6.3
Results of hydraulic tests in Miocene tuffaceous rocks
at the C-hole complex, 1995 to 1997, Yucca Mountain,
Nevada.
GS030508312314.003 [164425]
Concentrations of 2,6 -DFBA and pyridone from tracer
test conducted at the C-wells complex, 1/8/97 -
7/11/97.
GS010508312315.001 [155860]
Data obtained from the analysis of the iodide tracer
test water samples collected during the 2/13/96
convergent tracer test conducted at the C-wells
complex.
GS960808312315.001 [159235]
Tracer recovery data from testing in the Prow Pass
interval.
GS990208312315.001 [159238]
Transducer, barometric pressure, and discharge data
collected from 4/18/98 in support of the ongoing
hydraulic tracer tests being conducted at the UE-25 Cwells
complex, Nevada.
GS990408312315.002 [140115]
Prow Pass reactive-tracer-test field data. LAPR831231AQ99.001 [140134]
Bullfrog reactive tracer test data. LA0007PR831231.001 [156043]
Injection and production flow rates for Prow Pass test. GS010799992315.001 [157067]
Mineral abundance data of C-well tuffs from UE-25
c#1 and c#2.
MO0012MINLCHOL.000 [153370]
Sorbing element concentration data of J-13 and C-3
well water from UE-25 c#1 and c#2.
MO0012SORBCHOL.000 [153375]
PFBA and bromide tracer diffusion in tuff from UE-25
c#1.
MO0012DIFFCHOL.000 [159243]
Porosity data for UE-25 c#1, c#2, and c#3. MO0012POROCHOL.000 [153376]
Permeability data for UE-25 c#1, c#2, and c#3. MO0012PERMCHOL.000 [153368]
Bromide and PFBA sorption data onto C-wells tuffs. LA0302PR831231.001 [162605]
Mineralogy data for Central Bullfrog Tuff from UE-25
c#2, 2406 ft (non-Q).
LA9909PR831231.004 [129623]
Bromide and lithium tracer movement in crushed tuff
columns for UE-25 c#2 tuff.
LA0301PR831231.001 [162603]
Cation exchange capacity data for lithium displacing
other cations from C-wells tuffs.
MO0012CATECHOL.000 [153371]
ANL-NBS-HS-000039, REV 00 39 December 2003
Table 4-1 (Continued). Input Data
Data Description Data Tracking Number (DTN) or Source
Section 6.3 (Continued)
Cation exchange capacity data for cesium displacing
other cations from C-wells tuffs.
LA0302PR831341.001 [162604]
Iodide concentrations in C-wells fractured core
experiments.
LA0212PR831231.001 [162607]
Lithium, bromide, and PFBA concentrations in C-wells
fractured core experiments.
LA0212PR831231.003 [162609]
Sodium and calcium concentrations in fractured core
experiments in all C-wells cores except for core UE-25
c#2, 1745 ft.
LA0212PR831231.002 [162608]
Sodium and calcium concentrations in fractured core
experiments in core UE-25 c#2, 1745 ft.
LA0212PR831231.005 [166215]
2,3,4,5 TeFBA Response in Prow Pass
from UE-25 c#1 to UE-25 c#2, 1998
MO0308SPATRCRC.000 [164821]
Pump test data collected at the C-wells complex
1/8/97 - 3/31/97.
GS981008312314.002 [147068]
Pumping test data collected at the C-wells complex,
5/7/96 - 12/31/96.
GS981008312314.003 [144464]
Results of flow surveys. GS930908312313.008 [166332]
Additional technical information for tracer tests. Reimus (2000 [165125]), Reimus (2000
[162855]), Reimus (2000 [162852]), Reimus
(2003 [165129], including Attachment A)
Section 6.4
NC-EWDP-19D, ATC single-hole hydraulic testing
associated with the July 7, 2000 to April 26, 2001
tracer study.
GS020708312316.001 [162678]
Flow rates, pressures, and temperatures for hydraulic
and tracer testing at the NC-EWDP-19D, NC-EWDP-
19IM1, and NC-EWDP-19IM2 Alluvial Testing
Complex from December 18, 2001 to March 22, 2002.
GS020908312316.002 [162679]
Background pressures and temperatures during
barometric monitoring at the NC-EWDP-19D, NCEWDP-
19IM1, and NC-EWDP-19IM2 Alluvial Testing
Complex from May 1, 2002 through July 3, 2002.
GS020908312316.003 [162680]
Grain size analysis of alluvium samples from wells
19D and 19P of the Alluvial Test Complex.
LA0201JS831421.001 [162613]
Section 6.5
Grain size distribution data for alluvium from NCEWDP-
19P and -19D.
LA0201JS831421.001 [162613]
2,6 DFBA and I concentrations in single-well tracer
test with 2-day rest period in NC-EWDP-19D1.
UN0102SPA008KS.003 [162614]
ANL-NBS-HS-000039, REV 00 40 December 2003
Table 4-1 (Continued). Input Data
Data Description Data Tracking Number (DTN) or Source
Section 6.5 (Continued)
Concentration data set for tracers (2,6-difluorobenzoic
acid and iodide) used for the 48 hour shut-in test at the
Alluvial Tracer Complex in Nye County, Nevada in
samples collected during the period 02/27/01 through
04/25/01.
UN0109SPA008KS.005 [162681]
2,4 DFBA and Cl concentrations in single-well tracer
test with 0.5-hr rest period in NC-EWDP-19D1.
UN0109SPA008IF.006 [162442]
PFBA concentrations in single-well tracer test with 30-
day rest period in NC-EWDP-19D1.
UN0109SPA008KS.007 [162615]
Bromide concentrations in single-well tracer test with
30-day rest period in NC-EWDP-19D1.
UN0109SPA008KS.008 [162616]
2,4 DFBA concentrations in single-well tracer test in
interval #4 of NC-EWDP-19D1.
MO0205UCC008IF.001 [162617]
Microsphere concentrations in single-well tracer tests
in NC-EWDP-19D1.
LA0207PR831352.001 [162431]
Mineralogy data for alluvium from NC-EWDP-19P and
-19D.
LA0201JS831321.001 [162623]
BET surface areas for alluvium from NC-EWDP-19P
and -19D.
LA0201JS831421.002 [162625]
Cation exchange capacity data for alluvium from NCEWDP-
19P and -19D.
LA0201JS831341.001 [162627]
Cation concentrations from lithium batch sorption
experiments using alluvium from different intervals in
NC-EWDP-19P and -19D.
LA0302JS831341.001 [162628]
Groundwater chemistry data from NC-EWDP-19D1. LA0303PR831232.001 [162781]
Constituent concentrations from column experiments
with highest injection concentrations of LiBr using
alluvium from NC-EWDP-19D.
LA0201JS831361.001 [162629]
Constituent concentrations from column experiments
with intermediate injection concentrations of LiBr using
alluvium from NC-EWDP-19D.
LA0201JS831361.007 [162630]
Constituent concentrations from column experiments
with lowest injection concentrations of LiBr using
alluvium from NC-EWDP-19D.
LA0201JS831361.005 [166205]
NC-EWDP-19D, ATC single-hole hydraulic testing
associated with the July 7, 2000 to April 26, 2001
tracer study.
GS020708312316.001 [162678]
Geophysical log data from borehole NC-EWDP-19D. MO0105GPLOG19D.000 [163480]
Drawdown data for NC-EWDP boreholes. GS020908312316.002 [162679]
ANL-NBS-HS-000039, REV 00 41 December 2003
4.2 CRITERIA
The general requirements to be satisfied by the TSPA are stated in 10 CFR 63.114 
[156605].
Technical requirements to be satisfied by the TSPA are identified in the Yucca Mountain 
Project
Requirements Document (Canori and Leitner 2003 [161770]). The acceptance criteria 
that will
be used by the Nuclear Regulatory Commission (NRC) to determine whether the 
technical
requirements have been met are identified in the Yucca Mountain Review Plan (YMRP) 
(NRC
2003 [163274]). The pertinent requirements and criteria for this report are summarized in
Table 4-2.
Table 4-2. Project Requirements and YMRP Acceptance Criteria
Applicable to This Scientific Analysis Report
Requirement
Numbera Requirement Titlea 10 CFR 63 Link YMRP Acceptance
Criteriab
PRD-002/T-014 Performance Objectives for the Geologic
Repository After Permanent Closure
10 CFR 63.113
(a) 2.2.1.1.3, criteria 2 and 3
PRD -002/T-015 Requirements for Performance Assessment 10 CFR 63.114
(a)-(c) and (e)-(g)
2.2.1.3.8.3, criteria 1 to 4
2.2.1.3.9.3, criteria 1 to 5
PRD -002/T-016 Requirements for Multiple Barriers 10 CFR 63.115
(a)-(c) 2.2.1.1.3, criteria 2 and 3
NOTE: a from Canori and Leitner (2003 [161770])
b from NRC (2003 [163274]).
The acceptance criteria identified in Sections 2.2.1.1.3, 2.2.1.3.8.3, and 2.2.1.3.9.3 of the 
YMRP
(NRC 2003 [163274] are given below, followed by a short description of how this 
scientific
analysis helps to address the criteria or why this scientific analysis does not address the 
criteria.
In cases where subsidiary criteria are listed in the YMRP for a given criterion, only the
subsidiary criteria addressed by this scientific analysis are listed below.
Section 2.2.1.1.3 Acceptance Criteria [for 2.2.1.1 System Description and Demonstration 
of
Multiple Barriers], which are based on meeting the requirements at 10 CFR 63.113 
[156605](a)
and 63.115(a)-(c):
* Acceptance Criterion 1, Identification of Barriers is Adequate:
"Barriers relied on to achieve compliance with 10 CFR 63.113(b), as demonstrated in the
total system performance assessment, are adequately identified, and are clearly linked to
their capability. The barriers identified include at least one from the engineered system
and one from the natural system."
This criterion is not directly addressed in this scientific analysis. The purpose of this
scientific analysis is to document the results and interpretations of field experiments that
have been conducted in the saturated zone (SZ) natural barrier. Other documents serve to
identify barriers in the engineered and natural systems.
ANL-NBS-HS-000039, REV 00 42 December 2003
* Acceptance Criterion 2, Description of Barrier Capability to Isolate Waste is 
Acceptable:
"The capability of the identified barriers to prevent or substantially reduce the rate of
movement of water or radionuclides from the Yucca Mountain repository to the
accessible environment, or prevent the release or substantially reduce the release rate of
radionuclides from the waste is adequately identified and described."
Section 6 of this scientific analysis describes the saturated zone barrier capability to
isolate waste in that it documents the results and interpretations of in-situ testing of this
barrier. Specifically, the in-situ field tests were designed to (1) discriminate between
alternative conceptual models of flow and transport in the saturated zone barrier,
(2) obtain estimates of flow and transport parameters to support the development of
parameter distributions used in downstream SZ flow and transport models, and
(3) identify uncertainties associated with both conceptual models and parameter
estimates.
- Section 6.2 addresses these topics for water flow in the saturated volcanics.
- Section 6.3 addresses these topics for solute and colloid transport in the saturated
volcanics. This section also addresses the ability to predict field-scale sorption
behavior in the saturated volcanics using laboratory estimates of sorption parameters.
- Section 6.4 addresses the above topics for water flow in the saturated alluvium.
- Section 6.5 addresses the above topics for nonsorbing solute transport and colloid
transport in the saturated alluvium.
* Acceptance Criterion 3, Technical Basis for Barrier Capability Is Adequately 
Presented:
"The technical bases are consistent with the technical basis for the performance
assessment. The technical basis for assertions of barrier capability is commensurate with
the importance of each barrier's capability and the associated uncertainties."
Section 6 of this scientific analysis is dedicated to presenting a key part of the technical
basis for the saturated-zone barrier in the natural system. Specifically, it presents the
technical basis related to in-situ testing of the saturated zone barrier.
Section 2.2.1.3.8.3 Acceptance Criteria [for 2.2.1.3.8 Flow Paths in the Saturated Zone], 
which
are based on meeting the requirements of 10 CFR 63.114(a)-(c) and (e)-(g), relating to 
flow
paths in the saturated zone model abstraction:
* Acceptance Criterion 1, System Description and Model Integration are Adequate:
Of the ten subsidiary criteria listed under this primary criterion in the YMRP, this
scientific analysis directly addresses only the following one.
"The description of the aspects of hydrology, geology, geochemistry, design features,
physical phenomena, and couplings, that may affect flow paths in the saturated zone, is
ANL-NBS-HS-000039, REV 00 43 December 2003
adequate. Conditions and assumptions in the abstraction of flow paths in the saturated
zone are readily identified, and consistent with the body of data presented in the
description."
Specifically, Sections 6.2 and 6.4 of this scientific analysis describe aspects of the
hydrology and geology that may affect flow paths in the saturated volcanics and saturated
alluvium, respectively. Other processes or features that may affect flow paths and all
other subsidiary criteria are addressed primarily in other documents.
* Acceptance Criterion 2, Data are Sufficient for Model Justification:
This scientific analysis, by itself, does not completely address this criterion. However,
Sections 6.2 and 6.4 help in addressing all four of the subsidiary criteria listed under this
criterion in the YMRP (for saturated volcanics and saturated alluvium, respectively).
1) "Geological, hydrological, and geochemical values used in the license application to
evaluate flow paths in the saturated zone are adequately justified. Adequate
descriptions of how the data were used, interpreted, and appropriately synthesized
into the parameters are provided."
- The justification of hydrological values used in the license application is
provided, in part, in Sections 6.2 and 6.4 of this scientific analysis.
2) "Sufficient data have been collected on the natural system to establish initial and
boundary conditions for the abstraction of flow paths in the saturated zone."
- The hydrological data collected on the natural system are described in Sections
6.2 and 6.4 of this scientific analysis, although this report does not address
sufficiency of the data for abstraction of flow paths.
3) "Data on the geology, hydrology, and geochemistry of the saturated zone used in the
total system performance assessment abstraction are based on appropriate techniques.
These techniques may include laboratory experiments, site-specific field
measurements, natural analog research, and process-level modeling studies. As
appropriate, sensitivity or uncertainty analyses, used to support the U.S. Department
of Energy total system performance assessment abstraction, are adequate to determine
the possible need for additional data."
- Sections 6.2 and 6.4 of this scientific analysis describe the techniques used to
obtain in-situ hydrological data in the saturated volcanics and alluvium,
respectively. Uncertainties in the data are also discussed in these sections.
4) "Sufficient information is provided to substantiate that the proposed mathematical
groundwater modeling approach and proposed model(s) are calibrated and applicable
to site conditions."
ANL-NBS-HS-000039, REV 00 44 December 2003
- Sections 6.2 and 6.4 of this scientific analysis provide some of the information
needed to substantiate that the groundwater modeling approach is calibrated and
applicable to site conditions.
* Acceptance Criterion 3, Data Uncertainty is Characterized and Propagated Through the
Model Abstraction:
1) "Models use parameter values, assumed ranges, probability distributions, and/or
bounding assumptions that are technically defensible, and reasonably account for
uncertainties and variabilities, and do not result in an under-representation of the risk
estimate."
- Sections 6.2 and 6.4 of this scientific analysis provide some of the technical basis
for the parameter values, assumed ranges, probability distributions and bounding
assumptions used in flow models. They also provide some of the technical basis
for uncertainties and variabilities in hydrologic parameters.
2) Uncertainty is adequately represented in parameter development for conceptual
models, process-level models, and alternative conceptual models considered in
developing the abstraction of flow paths in the saturated zone. This may be done
either through sensitivity analyses or use of conservative limits. For example,
sensitivity analyses and/or similar analyses are sufficient to identify saturated zone
flow parameters that are expected to significantly affect the abstraction model
outcome."
- Sections 6.2 and 6.4 of this scientific analysis provide some of the technical basis
for uncertainties in hydrologic parameters used in flow models.
* Acceptance Criterion 4, Model Uncertainty is Characterized and Propagated Through 
the
Model Abstraction:
This scientific analysis, by itself, does not completely address this criterion. However,
Sections 6.2 and 6.4 help in addressing all four of the subsidiary criteria listed under this
criterion in the YMRP (for saturated volcanics and saturated alluvium, respectively).
1) "Alternative modeling approaches of features, events, and processes are considered
and are consistent with available data and current scientific understanding, and the
results and limitations are appropriately considered in the abstraction."
- Alternative conceptual models of flow in the saturated volcanics and alluvium are
considered in Sections 6.2 and 6.4, respectively, of this scientific analysis when
hydrological data are interpreted.
2) "Conceptual model uncertainties are adequately defined and documented, and effects
on conclusions regarding performance are properly assessed. For example,
uncertainty in data interpretations is considered by analyzing reasonable conceptual
flow models that are supported by site data, or by demonstrating through sensitivity
studies that the uncertainties have little impact on repository performance."
ANL-NBS-HS-000039, REV 00 45 December 2003
- Alternative conceptual models of flow in the saturated volcanics and alluvium are
considered in Sections 6.2 and 6.4, respectively, of this scientific analysis when
hydrological data are interpreted.
3) "Consideration of conceptual model uncertainty is consistent with available site
characterization data, laboratory experiments, field measurements, natural analog
information and process-level modeling studies; and the treatment of conceptual
model uncertainty does not result in an under-representation of the risk estimate."
- Sections 6.2 and 6.4 of this scientific analysis describe the hydrological site
characterization data and field measurements that should be considered for
assessing conceptual model uncertainty in the saturated volcanics and saturated
alluvium, respectively.
4) "Appropriate alternative modeling approaches are consistent with available data and
current scientific knowledge, and appropriately consider their results and limitations,
using tests and analyses that are sensitive to the processes modeled."
- Alternative conceptual models of flow in the saturated volcanics and alluvium are
considered in Sections 6.2 and 6.4, respectively, of this scientific analysis when
hydrological data are interpreted.
* Acceptance Criterion 5, Model Abstraction Output is Supported by Objective
Comparisons:
This criterion is not directly addressed in this scientific analysis. Other documents serve
to address this criterion.
Section 2.2.1.3.9.3 Acceptance Criteria [for 2.2.1.3.9 Radionuclide Transport in the 
Saturated
Zone], which are based on meeting the requirements of 10 CFR 63.114(a)-(c) and (e)-
(g),
relating to the radionuclide transport in the saturated zone model abstraction:
* Acceptance Criterion 1, System Description and Model Integration are Adequate:
This scientific analysis, by itself, does not completely address this criterion. However,
Sections 6.3 and 6.5 help in addressing the following three subsidiary criteria listed under
this criterion in the YMRP (for saturated volcanics and saturated alluvium, respectively).
1) "The description of the aspects of hydrology, geology, geochemistry, design features,
physical phenomena, and couplings, that may affect radionuclide transport in the
saturated zone, is adequate. For example, the description includes changes in
transport properties in the saturated zone, from water-rock interaction. Conditions and
assumptions in the abstraction of radionuclide transport in the saturated zone are
readily identified, and consistent with the body of data presented in the description."
- Sections 6.3 and 6.5 of this scientific analysis describe some of the aspects of the
hydrology, geochemistry, physical phenomena, and couplings that may affect
radionuclide transport in the saturated volcanics and alluvium, respectively.
ANL-NBS-HS-000039, REV 00 46 December 2003
2) "The abstraction of radionuclide transport in the saturated zone uses assumptions,
technical bases, data, and models that are appropriate and consistent with other
related U.S. Department of Energy abstractions. For example, assumptions used for
radionuclide transport in the saturated zone are consistent with the total system
performance assessment abstractions of radionuclide release rates and solubility
limits, and flow paths in the saturated zone (Sections 2.2.1.3.4 and 2.2.1.3.8 of the
Yucca Mountain Review Plan, respectively). The descriptions and technical bases
provide transparent and traceable support for the abstraction of radionuclide transport
in the saturated zone."
- Sections 6.3 and 6.5 of this scientific analysis help address the appropriateness f
assumptions, technical bases, data, and models used in the abstractions of
radionuclide transport in the saturated volcanics and alluvium, respectively.
3) "Sufficient data and technical bases for the inclusion of features, events, and
processes related to radionuclide transport in the saturated zone in the total system
performance assessment abstraction are provided."
- Sections 6.3 and 6.5 of this scientific analysis provide much of the data and
technical bases for inclusion of features, events, and processes related to
radionuclide transport in the saturated volcanics and alluvium, respectively.
* Acceptance Criterion 2, Data are Sufficient for Model Justification:
This scientific analysis, by itself, does not completely address this criterion. However,
Sections 6.3 and 6.5 help in addressing all three of the subsidiary criteria listed under this
criterion in the YMRP (for saturated volcanics and saturated alluvium, respectively).
1) "Geological, hydrological, and geochemical values used in the license application are
adequately justified (e.g., flow path lengths, sorption coefficients, retardation factors,
colloid concentrations, etc.). Adequate descriptions of how the data were used,
interpreted, and appropriately synthesized into the parameters are provided."
- The justification of sorption coefficients and retardation factors are provided, in
part, in Sections 6.3 and 6.5 of this scientific analysis (for the saturated volcanics
and saturated alluvium, respectively).
2) "Sufficient data have been collected on the natural system to establish initial and
boundary conditions for the total system performance assessment abstraction of
radionuclide transport in the saturated zone."
- Some of the data used to establish boundary conditions are described in Sections
6.3 and 6.5 of this scientific analysis (for the saturated volcanics and saturated
alluvium, respectively).
3) "Data on the geology, hydrology, and geochemistry of the saturated zone, including
the influence of structural features, fracture distributions, fracture properties, and
stratigraphy, used in the total system performance assessment abstraction are based
ANL-NBS-HS-000039, REV 00 47 December 2003
on appropriate techniques. These techniques may include laboratory experiments,
site-specific field measurements, natural analog research, and process-level modeling
studies. As appropriate, sensitivity or uncertainty analyses, used to support the U.S.
Department of Energy total system performance assessment abstraction, are adequate
to determine the possible need for additional data."
- Techniques for obtaining data to support conceptual transport models, including
flow porosity and matrix diffusion are described in detail in Sections 6.3 and 6.5
of this scientific analysis (for the saturated volcanics and saturated alluvium,
respectively).
* Acceptance Criterion 3, Data Uncertainty is Characterized and Propagated Through the
Model Abstraction:
This scientific analysis, by itself, does not completely address this criterion. However,
Sections 6.3 and 6.5 help in addressing the following four subsidiary criteria listed under
this criterion in the YMRP (for saturated volcanics and saturated alluvium, respectively).
1) "Models use parameter values, assumed ranges, probability distributions, and
bounding assumptions that are technically defensible, reasonably account for
uncertainties and variabilities, and do not result in an under-representation of the risk
estimate."
- Sections 6.3 and 6.5 of this scientific analysis provide some of the technical basis
for the parameter values, assumed ranges, probability distributions and bounding
assumptions used in radionuclide transport models. They also provide some of
the technical basis for uncertainties and variabilities in transport parameters.
2) "For those radionuclides where the total system performance assessment abstraction
indicates that transport in fractures and matrix in the saturated zone is important to
waste isolation: (i) estimated flow and transport parameters are appropriate and valid,
based on techniques that may include laboratory experiments, field measurements,
natural analog research, and process-level modeling studies conducted under
conditions relevant to the saturated zone at Yucca Mountain; and (ii) models are
demonstrated to adequately predict field transport test results. For example, if a
sorption coefficient approach is used, the assumptions implicit in that approach are
validated."
- Sections 6.3 and 6.5 of this scientific analysis address the appropriateness and
validity of transport parameter estimates, including the sorption coefficient
approach, in the saturated volcanics and saturated alluvium, respectively. These
sections also describe assessments of alternative conceptual transport models for
their adequacy to predict field transport test results.
3) "Parameter values for processes, such as matrix diffusion, dispersion, and groundwater
mixing, are based on reasonable assumptions about climate, aquifer properties,
and ground-water volumetric fluxes (Section 2.2.1.3.8 of the Yucca Mountain Review
Plan)."
ANL-NBS-HS-000039, REV 00 48 December 2003
- Sections 6.3 and 6.5 of this scientific analysis address assumptions about aquifer
properties as they relate to matrix diffusion, dispersion, and other transport
processes (for the saturated volcanics and saturated alluvium, respectively).
4) "Uncertainty is adequately represented in parameter development for conceptual
models, process-level models, and alternative conceptual models considered in
developing the abstraction of radionuclide transport in the saturated zone. This may
be done either through sensitivity analyses or use of conservative limits."
- Sections 6.3 and 6.5 of this scientific analysis provide some of the technical basis
for uncertainties in parameters used in radionuclide transport models in the
saturated zone.
* Acceptance Criterion 4, Model Uncertainty is Characterized and Propagated Through 
the
Model Abstraction:
This scientific analysis, by itself, does not completely address this criterion. However,
Sections 6.3 and 6.5 help in addressing all four of the subsidiary criteria listed under this
criterion in the YMRP (for saturated volcanics and saturated alluvium, respectively):
1) "Alternative modeling approaches of features, events, and processes are considered
and are consistent with available data and current scientific understanding, and the
results and limitations are appropriately considered in the abstraction."
- Alternative conceptual models of transport in the saturated volcanics and alluvium
are considered in Sections 6.3 and 6.5, respectively, of this scientific analysis
when tracer test data are interpreted.
2) "Conceptual model uncertainties are adequately defined and documented, and effects
on conclusions regarding performance are properly assessed."
- Uncertainties associated with alternative conceptual models of transport in the
saturated volcanics and alluvium are considered in Sections 6.3 and 6.5,
respectively, of this scientific analysis.
3) "Consideration of conceptual model uncertainty is consistent with available site-
characterization data, laboratory experiments, field measurements, natural analog
information and process-level modeling studies; and the treatment of conceptual
model uncertainty does not result in an under-representation of the risk estimate."
- Sections 6.3 and 6.5 of this scientific analysis describe the site-characterization
data and field measurements (field tracer test data and supporting laboratory data)
that should be considered for assessing conceptual model uncertainty in the
saturated volcanics and saturated alluvium, respectively.
4) "Appropriate alternative modeling approaches are consistent with available data and
current scientific knowledge, and appropriately consider their results and limitations
using tests and analyses that are sensitive to the processes modeled. For example, for
ANL-NBS-HS-000039, REV 00 49 December 2003
radionuclide transport through fractures, the U.S. Department of Energy adequately
considers alternative modeling approaches to develop its understanding of fracture
distributions and ranges of fracture flow and transport properties in the saturated
zone."
- Alternative conceptual models of transport in the saturated volcanics and alluvium
are considered in Sections 6.3 and 6.5, respectively, of this scientific analysis
when tracer test data are interpreted.
* Acceptance Criterion 5, Model Abstraction Output is Supported by Objective
Comparisons:
This scientific analysis, by itself, does not completely address this criterion. However,
Sections 6.3 and 6.5 help in addressing the following three subsidiary criteria listed under
this criterion in the YMRP (for saturated volcanics and saturated alluvium, respectively).
1) The models implemented in this total system performance assessment abstraction
provide results consistent with output from detailed process-level models and/or
empirical observations (laboratory and field testings and/or natural analogs).
- Sections 6.3 and 6.5 describe both laboratory and field observations that can be
used for consistency checks of abstraction models (for the saturated volcanics and
saturated alluvium, respectively).
2) Outputs of radionuclide transport in the saturated zone abstractions reasonably
produce or bound the results of corresponding process-level models, empirical
observations, or both. The U.S. Department of Energy-abstracted models for
radionuclide transport in the saturated zone are based on the same hydrological,
geological, and geochemical assumptions and approximations shown to be
appropriate for closely analogous natural systems or laboratory experimental systems.
- Sections 6.3 and 6.5 provide both laboratory and field observations that can be
used for comparisons with the outputs of abstraction models (for the saturated
volcanics and saturated alluvium, respectively).
3) Sensitivity analyses or bounding analyses are provided, to support the total system
performance assessment abstraction of radionuclide transport in the saturated zone,
that cover ranges consistent with site data, field or laboratory experiments and tests,
and natural analog research.
- Sections 6.3 and 6.5 provide both laboratory and field data that can be used for
these sensitivity or bounding analyses (for the saturated volcanics and saturated
alluvium, respectively).
4.3 CODES AND STANDARDS
No industrial or technical codes or standards other than those discussed in Section 4.2 
apply
directly to the activities described in this report.
ANL-NBS-HS-000039, REV 00 50 December 2003
INTENTIONALLY LEFT BLANK
ANL-NBS-HS-000039, REV 00 51 December 2003
5. ASSUMPTIONS
A list of the assumptions used in this scientific analysis is provided in Table 5-1. 
Subsections
where assumptions are used are identified. The rationale for each assumption is also 
provided.
Table 5-1. Assumptions
Number Assumption Rationale Location in
Report
1 Flow to a pumping well is derived
from an aquifer of infinite extent.
Analyses of aquifer properties are based
on this assumption but the faults
functioning as boundaries do not support
this. Boundary effects were minimized
but could not be eliminated.
Section 6.2.3
2 Flow to a pumping well from an
aquifer is radial (for hydraulic test
interpretations)
Vertical flow could be ignored in
hydraulic tests of multiple intervals
because the analytical results were
similar to the hydraulic test of one
interval where flow was radial.
Section 6.2.3
3 Flow to a pumping well is from an
infinite, homogeneous, isotropic,
confined aquifer for all hydraulic
tests analyzed using the Theis
(1935 [150327]) method.
Simplification of structural and lithologic
complexities is necessary to analysis by
the Theis method. The consistency of
multiple analyses of varying test
parameters indicates either that errors
are consistent or that calculated values
approximate actual values of hydraulic
properties.
Section 6.2.3
4 Input parameters measured in a
borehole were the same throughout
the thickness of that hydrogeologic
interval.
Simplification of structural and lithologic
complexities is necessary to analysis by
the Theis method. The consistency of
multiple analyses of varying test
parameters indicates either that errors
are consistent or that calculated values
approximate actual values of hydraulic
properties.
Section 6.2.3
5 For water to reach the pumping
well from the intervals that did not
have open sliding sleeves, a
downward component of flow must
have occurred.
The downward flow was assumed by the
investigators to be much less than radial
flow to the pumping well in order to
analyze the drawdown from the nonopen
intervals by the methods outlined in
Section.
Section
6.2.3.1.1
6 Matrix permeability is negligible
compared to fracture permeability
in interpretations of tracer
responses in fractured volcanic
tuffs.
Matrix permeabilities of intact tuff
matrices range from 2 to 6 orders of
magnitude lower than bulk permeabilities
measured in field hydraulic tests.
Sections 6.3.1,
6.3.4, and
6.3.9.2
ANL-NBS-HS-000039, REV 00 52 December 2003
Table 5-1 (Continued). Assumptions
Number Assumption Rationale Location in
Report
7 Matrix diffusion of carboxylatemodified
latex microspheres is
negligible in field tracer tests in
fractured volcanic rocks.
The microspheres are large, which will
tend to physically exclude them from
small pores, and they have diffusion
coefficients 2 to 3 orders of magnitude
lower than solutes.
Section 6.3.4
8 Solute transport in fractured
volcanic rocks can be effectively
modeled using the 1-D advectiondispersion
equation in fractures
with 1-D diffusive transport into the
matrix (perpendicular to the
fractures). Furthermore, fractures
can be assumed to be parallelplate
channels that are either
equally spaced or embedded in a
matrix of infinite extent.
These assumptions capture the general
behavior observed in all the laboratory
and field experiments in fractured
volcanic rocks. Nonidealities such as
rough-walled fractures and multiple flow
pathways in fractures are accommodated
through an adjustable longitudinal
dispersivity.
Sections 6.3.4
and 6.3.9.2
9 Solute concentration gradients
across fracture apertures were
negligible in field and laboratory
tracer experiments in fractured
volcanic rocks.
Given the time scales of the experiments
in fractured rocks (lab and field) and the
small distances associated with fracture
apertures, diffusion should have
effectively eliminated any concentration
gradients across apertures.
Sections 6.3.1,
6.3.4, and
6.3.9.2
10 Solute and microsphere tracers
that are injected simultaneously in
field tracer tests experience the
same mean residence time,
dispersivity, and mass fraction of
tracer participating in the test.
The simultaneous injection ensures that
the tracers should follow the same flow
pathways between the injection and
production wells. Thus, the tracers
should experience the same mean
residence time, dispersivity, and mass
fraction participating in the tracer test.
Section 6.3.4
11 The two tracer peaks in the Bullfrog
Tuff multiple-tracer field test
represent two different sets of flow
pathways between the injection
and production well.
Only one tracer peak was observed in an
earlier test in the same test configuration
when a smaller volume of tracer solution
was injected. The greater injection
volume in the multiple tracer test likely
resulted in a fraction of the tracer mass
entering pathways that were not
accessed in the first tracer test.
Section 6.3.4
12 The tracers following the flow
pathways resulting in the first tracer
peak in the Bullfrog Tuff began
entering these pathways 4 hours
after the injection began in the
injection well.
Flow surveys indicated that the largest
zone of outflow in the injection well was
near the top of the injection interval. If
the tracer solution "sank" in the borehole
due to its greater density than the
ambient ground water, then this flow
zone would have been accessed about
3-4 hours after the start of injection
(when the injection interval became
"filled" with tracer solution).
Section 6.3.4
ANL-NBS-HS-000039, REV 00 53 December 2003
Table 5-1 (Continued). Assumptions
Number Assumption Rationale Location in
Report
13 The matrix diffusion coefficient of
lithium ion is two-thirds that of
bromide.
The free ion diffusion coefficient of Li+ at
infinite dilution should be about 0.5 times
that of Br- (Newman 1973 [148719], p.
230, Table 75-1), but a factor of 0.67 was
used because Li+ and Br- should tend to
diffuse together to maintain local charge
balance.
Sections 6.3.4
and 6.3.9.2
14 Lithium ion experienced equilibrium
sorption conditions (i.e., fast
sorption kinetics) in all field tracer
tests.
The residence times in the field tests
were all quite long relative to times
required for Li+ sorption equilibration in
laboratory experiments.
Sections 6.3.4
15 The microspheres experienced
linear filtration and detachment
processes in all field tracer tests
(i.e., these processes could be
modeled assuming linear first-order
rate constants).
This is a common assumption throughout
the literature, and it is the easiest to
parameterize and implement in process
models and TSPA calculations.
Section 6.3.4
16 All the microspheres following a
given flow pathway in the Bullfrog
Tuff field test had the same
filtration rate constant, but these
microspheres could be split into
fractions that had different
detachment rate constants (a
discrete distribution of detachment
rate constants) to fit the
microsphere responses.
This assumption was necessary to obtain
a good fit to the microsphere responses
in the Bullfrog Tuff test (a single
detachment rate constant offered a poor
fit).
Section 6.3.4
17 The production and recirculation
rates in the Bullfrog Tuff field
reactive tracer test remained
constant throughout the test for the
purposes of interpreting the tracer
tests.
Recirculation was actually stopped after
40 days, but by this time, both tracer
peaks had long past and the tracer
responses were well into their tails. It
was assumed that recirculation
continued because the RELAP V 2.0
(STN: 10551-2.0-00 [159065]) code
cannot simulate transients. Separate
simulations using MULTRAN V 1.0 (STN:
10666-1.0-00 [159068]) indicated that
there was negligible effect of the ceasing
of recirculation on the tracer responses.
Section 6.3.4
18 The test intervals in the C-wells
field tracer tests were reasonably
confined so that flow in the
intervals should have varied
somewhere between radial and
linear (constant velocity) for the
purposes of interpreting tracer
tests.
Hydraulic responses indicated a
reasonable degree of confinement of
intervals.
Section 6.3.4
19 The microspheres in the Bullfrog
Tuff field tracer test did not
experience a 4-hr delay in entering
the flow pathways that resulted in
the first tracer peaks in this test.
The microsphere injection did not begin
until 3.5 hours after the solutes, which
was about the time the solutes were
assumed to start entering the flow
pathways resulting in the first peaks.
Section 6.3.4
ANL-NBS-HS-000039, REV 00 54 December 2003
Table 5-1 (Continued). Assumptions
Number Assumption Rationale Location in
Report
20 75% of the flow in the Bullfrog Tuff
field reactive tracer test occurred
through pathways that resulted in the
first tracer peak, and 25% occurred
through pathways that resulted in the
second tracer peak.
This assumption is consistent with flow
surveys in the injection and production
wells, if it is assumed that the first tracer
peak was the result of flow pathways in the
upper part of the test interval.
Section 6.3.4
21 Bromide and PFBA effectively bound
the sizes of radionuclide solute
species expected in the SZ beneath
Yucca Mountain.
Bromide is a simple halide, while PFBA is a
large aromatic organic molecule. The latter
should be similar in size or larger than
radionuclide complexes with carbonate or
other potential inorganic complexants. This
assumption does not apply to colloidal
radionuclides (including complexes to large
natural organic matter).
Section 6.3.4
22 A confined, homogeneous, isotropic
flow system was assumed for the
purposes of estimating flow porosity in
the field tracer tests.
This assumption is made because it is the
simplest possible assumption that is still
consistent with the data. Assuming
anything else would involve making
implications about the system that, while
reasonable, cannot be supported by direct
evidence.
Sections 6.3.4,
6.5.2, and 6.5.3
23 The interval thicknesses in field tracer
tests are equal to the distances
between the packers that isolate test
zones.
This assumption is made because it is the
simplest possible assumption that is
consistent with the data. Assuming
anything else would involve making
implications about the system that cannot
be supported by direct evidence.
Sections 6.3.1,
6.3.4, and 6.5.3
24 Injection and production intervals
behave as well-mixed regions during
field tracer tests.
Although this assumption may not be
strictly correct, it simulates an exponential
release of tracer from the injection and
production intervals that is thought to be
representative of field behavior in the
boreholes.
Sections 6.3.1,
6.3.4, 6.5.2, and
6.5.3
25 The variance in tracer responses due
to recirculation and the variance due
to true hydrodynamic dispersion are
additive (i.e., these two processes are
independent).
Either process can occur without the other,
and there is no fundamental reason why
recirculation and true hydrodynamic
dispersion should be dependent on one
another.
Section 6.3.4
26 Tracer movement through diffusion
cell wafers follows the 1-D diffusion
equation.
The diffusion cell experiments are designed
for 1-D diffusion measurements, and
advection was eliminated or minimized by
ensuring the same pressure/head on both
sides of diffusion cell wafers.
Section 6.3.8
27 The density of crushed tuff and
alluvium grains is 2.65 g/cm3.
2.65 g/cm3 is the density of most silicate
phases, which dominate the mineralogy of
the tuffs and alluvium.
Sections 6.3.4,
6.3.9, 6.5.3, and
6.5.5
ANL-NBS-HS-000039, REV 00 55 December 2003
Table 5-1 (Continued). Assumptions
Number Assumption Rationale Location in
Report
28 The Peclet number and matrix
diffusion parameters for iodide in
transport experiments conducted at
different flow rates in fractured cores
were the same at each flow rate.
Also, the mean residence times in
these tests were inversely
proportional to the flow rate.
These assumptions are consistent with no
geometrical changes occurring in the
fractured cores. Geometrical changes
were avoided or minimized to the extent
possible.
Section 6.3.9
29 Ion exchange was fast enough in
the fractured core experiments to
satisfy the local equilibrium
approximation (assumed in the
MULTRAN V 1.0 (STN: 10666-1.0-
00 [159068]) model).
The experimental results of Section
6.3.10.1 suggest that this is a reasonable
assumption.
Section 6.3.9
30 Lithium cation exchange capacities
in the fractured cores and packed
porous-media columns were the
same as those measured in batch
experiments on the same tuff or
alluvium samples.
There was no basis for choosing any
other cation exchange capacities other
than what was measured on the same
materials.
Sections 6.3.9 and
6.5.5
31 Lithium sorption occurred in both
fractures and matrix in the second
peak of the Bullfrog Tuff field
reactive tracer test and in the
second test in the Lower Bullfrog
Tuff fractured core.
Better fits to the lithium responses in
these tests were obtained when making
this assumption than when assuming
sorption only in the matrix.
Sections 6.3.4 and
6.3.9
32 Transport through saturated
alluvium may either follow singleporosity
or dual-porosity behavior,
with the latter involving either
diffusion into low-permeability layers
or diffusion into grains (or both).
These are the most plausible possibilities
for transport in saturated alluvium.
Sections 6.5.1,
6.5.2, and 6.5.3
33 For diffusion into low-permeability
layers in saturated alluvium, the
layers are assumed to be of uniform
thickness and uniform spacing.
These assumptions are made for
convenience to simplify modeling. It is
believed that they should effectively
capture the behavior of layered systems.
Sections 6.5.1,
6.5.2, and 6.5.3.
34 Radial flow occurs in single-well
tracer tests in saturated alluvium (for
the purposes of modeling single-well
tests with MULTRAN V 1.0 (STN:
10666-1.0-00 [159068])).
This assumption is made for convenience
to simplify modeling.
Section 6.5.2.
35 Alluvium grains are spherical for the
purposes of modeling diffusion into
and out of grains in the MULTRAN V
1.0 (STN: 10666-1.0-00 [159068])
model.
This assumption is made for convenience
in modeling diffusion into grains. A
distribution of grain sizes can be specified
to effectively simulate odd-shaped grains.
Section 6.5.2
ANL-NBS-HS-000039, REV 00 56 December 2003
Table 5-1 (Continued). Assumptions
Number Assumption Rationale Location in
Report
36 The flow system parameters of Tables
6.5-1 and 6.5-4 are valid for use in
predictive simulations of single-well and
cross-hole tracer tests, respectively, in
saturated alluvium using MULTRAN V
1.0 (STN: 10666-1.0-00 [159068]).
The parameters were chosen for
convenience, although they were
believed to be representative (see text
in Section 6.5.2).
Sections 6.5.2
and 6.5.3
37 "Correction factors" to adjust first, peak,
and mean arrival times for 2-D
(confined) flow to 3-D (unconfined) flow
are the same regardless of the value of
longitudinal dispersivity.
This assumption is made for
convenience, but it seems very
reasonable if dispersion is only
longitudinal (parallel to flow
streamlines). Also, the assumption
seemed to hold in 2WELLS_2D V 1.0
(10665-1.0-00 [159067]) and
2WELLS_3D V 1.0 (10667-1.0-00
[159036]) simulations.
Section 6.5.3
38 "Correction factors" to adjust for the
effects of recirculation are the same for
first and peak arrival times.
This assumption is made for
convenience, but it appeared to be
approximately correct in 2WELLS_2D V
1.0 (10665-1.0-00 [159067]) and
2WELLS_3D V 1.0 (10667-1.0-00
[159036]) simulations.
Section 6.5.3
39 "Correction factors" for various
adjustments in tracer arrival times (to
account for effects of recirculation,
confined vs. unconfined flow,
dispersion) are linearly independent
and commutative.
This assumption is made for
convenience, but it seems reasonable
given that there is no reason to expect
the different processes to be
interdependent.
Section 6.5.3
40 "Drift" with the ambient ground-water
flow caused the differences in the
tracer responses in the three singlewell
tracer tests with different "rest
periods" conducted at NC-EWDP-
19D1.
The responses of tracers with different
diffusion coefficients used in each test
were identical, which rules out the
possibility that the different responses
were caused by diffusion into stagnant
water in the system. This leaves "drift"
as the only plausible explanation for the
different tracer responses as a function
of rest period.
Section 6.5.4
41 The tracer mass corresponding to the
peak in the three single-well tracer tests
at NC-EWDP-19D1 moved directly
upgradient during injection and then
drifted back toward the well during the
rest period.
This assumption is consistent with the
fact that the single-well test with the
longest rest period had the shortest
peak arrival time. Also, the assumption
of moving directly upgradient results in
the lowest possible estimate of ambient
groundwater velocity.
Section 6.5.4
42 Differences in mean- and late- arrival
times of tracers in the three single-well
tracer tests at NC-EWDP-19D1 were
due to tracer mass that had moved
directly downgradient during the tracer
injections.
The mean- and late-arrival times are
both much more strongly influenced by
late arriving tracer mass, which logically
should have moved downgradient
during injection (and taken longer to
recover than mass that moved
upgradient). Also, the assumption of
moving directly downgradient results in
the largest possible estimate of ambient
ground water velocity.
Section 6.5.4
ANL-NBS-HS-000039, REV 00 57 December 2003
Table 5-1 (Continued). Assumptions
Number Assumption Rationale Location in
Report
43 Radial flow in a confined aquifer
occurred in the three single-well tracer
tests at NC-EWDP-19D1 (for the
purposes of estimating ambient ground
water velocity).
This assumption was made for
convenience in estimating ambient
ground water velocity. Although it may
not be strictly correct, it is qualitatively
consistent with flow spreading out from
the injection well during injection and
converging to the well during production.
Section 6.5.4
44 Ambient flow in the saturated alluvium at
NC-EWDP-19D1 was unidirectional in
the three single-well tracer tests.
Flow should have been effectively
unidirectional (with minor variations as a
result of heterogeneities) at the scale of
the tests.
Section 6.5.4
45 The tracer mass associated with the
peak and mean arrival times in the
single-well tracer tests at NC-EWDP-
19D1 corresponded to the midpoints of
the tracer solution injection volume.
The midpoint of the tracer injection
volume should be the most likely volume
associated with the peak and mean
tracer concentrations.
Section 6.5.4
46 The tracer mass associated with high
fractional recoveries in the single well
tracer tests at NC-EWDP-19D1 was at
the leading edge of the tracer injection
volume (i.e., among the first tracer mass
injected).
This assumption is consistent with the
tracer mass being the latest recovered
mass in the single-well tracer tests.
Section 6.5.4
47 Dispersion (longitudinal and transverse)
during the rest periods of the single-well
tracer tests at NC-EWDP-19D1 had
approximately the same effect on tracer
arrival times in each test.
This assumption is made for
convenience. It seems to be reasonable,
although it was not verified.
Section 6.5.4
48 The microsphere response in the singlewell
test at NC-EWDP-19D1 was entirely
due to detachment of microspheres after
90 hours of pumping.
By this time, 72% of the solutes had
been recovered, but only 26% of the
microspheres, so it seemed reasonable
to assume that the microspheres that
were being recovered were detaching
from alluvium surfaces.
Section 6.5.4.6
49 The microspheres remaining on the
alluvium surfaces after 90 hours of
pumping in the single-well tracer test at
NC-EWDP-19D1 were equal to the total
number of spheres injected times the
fraction of spheres not recovered (1 -
fsphere) minus the fraction of solutes not
recovered (1 - fsolute) at any given point in
time.
Subtracting (1 - fsolute) from (1 - fsphere) is
a correction that accounts for the fraction
of spheres that would not have been
recovered at a given time even if they did
not interact with alluvium surfaces.
Section 6.5.4.6
ANL-NBS-HS-000039, REV 00 58 December 2003
INTENTIONALLY LEFT BLANK
ANL-NBS-HS-000039, REV 00 59 December 2003
6. ANALYSIS
6.1 INTRODUCTION
The saturated zone (SZ) near Yucca Mountain, along potential flow paths from the 
repository to
the accessible environment, can be divided into two regimes: (1) fractured tuffs that 
underlie the
repository and that extend for several kilometers to the south of Yucca Mountain (in the 
general
direction of flow), and (2) valley-fill or alluvium deposits that the water table transitions 
into
several kilometers before the current ~18-kilometer (km) performance compliance 
boundary (10
CFR 63 [156605], Subpart 63.302). Radionuclides released from the repository would 
first have
to travel through the saturated fractured tuffs and then through the saturated alluvium to 
reach
the compliance boundary. To support the characterization of the saturated fractured tuffs,
several hydraulic and tracer tests were conducted at a three-well complex (UE-25 c#1, 
UE-25
c#2, and UE-25 c#3, hereafter referred to as c#1, c#2, and c#3, respectively, in this 
report)
known as the C-wells. This complex is located approximately 2 km southeast of the 
repository
footprint. Hydraulic tests conducted at the C-wells are discussed in Section 6.2 of this 
report,
and tracer tests at the C-wells are discussed in Section 6.3. To support the 
characterization of the
saturated alluvium, both hydraulic and tracer testing were conducted at the Alluvial 
Testing
Complex (ATC), well NC-EWDP-19D1 (hereafter referred to as 19D1 in this report), 
which is
located just outside the southwest corner of the Nevada Test Site (NTS), essentially right 
at the
compliance boundary. Hydraulic tests conducted at the ATC are discussed in Section 6.4 
of this
report, and tracer tests at the ATC are discussed in Section 6.5. In addition to presenting 
the
results and interpretations of field tracer testing conducted at the C-wells and the ATC, 
this
report also presents the results and interpretations of laboratory transport tests conducted 
to help
support the interpretation of field tracer tests (Sections 6.3 and 6.5). Transport properties 
of the
alluvium are discussed in Section 6.5.
6.1.1 Hydrogeologic Settings
6.1.1.1 C-Wells
Figure 6.1-1 shows the location and surface layout of the C-wells. The wells were drilled 
on a
two-tiered drill pad in a channel of an ephemeral stream that cuts through Bow Ridge, a 
spur of
Yucca Mountain. The lower tier of the pad, in which borehole c#1 was drilled, is at an 
altitude
of 1,130.5 m above mean sea level. The upper tier, in which boreholes c#2 and c#3 were 
drilled,
is at an altitude of 1,132.3 m. The C-wells are 30.4 to 76.6 m apart at the land surface, but 
they
deviate substantially at depth (Geldon 1993 [101045], p. 6, Figure 2; p. 8, Figure 4) (see 
Figure
6.1-1 and Table 6.1-1 below).
ANL-NBS-HS-000039, REV 00 60 December 2003
Source: Based on Geldon (1998 et al. [129721], p 3, Figure 1).
Figure 6.1-1. Location and Surface Layout of the C-wells Complex
ANL-NBS-HS-000039, REV 00 61 December 2003
Table 6.1-1. Approximate Interborehole Distances at the Midpoints of Hydrogeologic Intervals
as Monitored During Hydraulic Tests at the C-wells Complex, August 1995 to April 1996
Borehole Data Interborehole Distances
c#1 c#2 c#3 c#1 - c#3 c#2 - c#3
Calico Hills
Top depth (m) 418 416 417 78.6 29.0
Bottom depth (m) 547 531 540
Midpoint depth (m) 483 474 478
North coordinate (m) 230,771 230,691 230,703
East coordinate (m) 173,646 173,633 173,607
Distance north/south from c#3 (m) 68.3 12.2 -
Distance east/west from c#3 (m) 39.3 26.2 -
Prow Pass
Top depth (m) 549 533 542 81.1 28.6
Bottom depth (m) 605 606 610
Midpoint depth (m) 577 569 576
North coordinate (m) 230,772 230,691 230,702
East coordinate (m) 173,648 173,634 173,607
Distance north/south from c#3 (m) 70.4 11.0 -
Distance east/west from c#3 (m) 40.2 26.5 -
Upper Bullfrog
Top depth (m) 607 607 612 83.2 28.6
Bottom depth (m) 698 696 695
Midpoint depth (m) 653 652 653
North coordinate (m) 230,773 230,691 230,701
East coordinate (m) 173,648 173,634 173,607
Distance north/south from c#3 (m) 72.2 9.75 -
Distance east/west from c#3 (m) 41.4 26.8 -
Lower Bullfrog
Top depth (m) 700 698 697 85.6 29.3
Bottom depth (m) 797 792 813
Midpoint depth (m) 749 745 755
North coordinate (m) 230,774 230,692 230,700
East coordinate (m) 173,649 173,633 173,606
Distance north/south from c#3 (m) 73.8 8.84 -
Distance east/west from c#3 (m) 43.3 27.7 -
ANL-NBS-HS-000039, REV 00 62 December 2003
Table 6.1-1 (Continued). Approximate Interborehole Distances at the Midpoints of Hydrogeologic
Intervals as Monitored During Hydraulic Tests at the C-wells Complex, August 1995 to April 1996
Borehole Data Interborehole Distances
c#1 c#2 c#3 c#1 - c#3 c#2 - c#3
Upper Tram
Top depth (m) 799 794 814 86.9 29.6
Bottom depth (m) 870 870 878
Midpoint depth (m) 834 832 846
North coordinate (m) 230,774 230,691 230,700
East coordinate (m) 173,648 173,632 173,604
Distance north/south from c#3 (m) 74.7 8.53 -
Distance east/west from c#3 (m) 44.2 28.3 -
Lower Tram
Top depth (m) 872 871 879 87.2 29.9
Bottom depth (m) 898 903 900
Midpoint depth (m) 885 887 890
North coordinate (m) 230,774 230,691 230,700
East coordinate (m) 173,648 173,632 173,603
Distance north/south from c#3 (m) 74.7 8.23 -
Distance east/west from c#3 (m) 44.8 28.6 -
DTN: GS030508312314.003 ([164425], p. 6, Table 1).
NOTE: North and south are referenced to Nevada State Zone 2 coordinates. Depths in c#3 and 
interborehole
distances changed slightly in April 1996 when instrumentation in c#3 was reconfigured.
The C-wells were completed to a depth of 914 m below land surface in Miocene 
tuffaceous
rocks, mainly of the Paintbrush Group, the Calico Hills Formation, and the Crater Flat 
Group
(Table 6.1-2), which are overlain by 0 to 24 m of Quaternary alluvium. The geology 
below the
water table at the C-wells is depicted in Figure 6.1-2, along with fracture densities and 
estimated
average matrix porosities in each unit. The tuffaceous rocks are estimated to be 1,040 to 
1,590 m
thick in the vicinity of the C-wells complex, where they consist of nonwelded to densely 
welded
ash-flow tuff with intervals of ash-fall tuff and volcaniclastic rocks (Geldon 1993 
[101045];
Geldon et al. 1998 [129721]). The tuffaceous rocks have pervasive tectonic and cooling
fractures that strike predominantly north-northeast to north-northwest and dip westward 
at angles
of 50 to 87 (Geldon 1996 [100396], pp. 7 to 9). Several thousand meters of Paleozoic
limestone and dolomite likely underlie the tuffaceous rocks about 460 m below the 
bottom of the
C-wells or ~1370 m below land surface (based on extrapolations from relations in 
borehole UE-
25 p#1, presented by Carr et al. 1986 [102046]. Hereafter, in this report, UE-25 p#1 is 
referred
to as p#1; see Table 1 for a list of abbreviations.).
ANL-NBS-HS-000039, REV 00 63 December 2003
Table 6.1-2. Stratigraphy of Miocene Tuffaceous Rocks in the C-wells Area
Depth Below Land Surface (m)
Geologic Unit USW H-4 c#1 c#2 c#3 UE-25 p#1
Timber Mountain Group
Rainier Mesa Tuff not present not present not present not present 39-55
Paintbrush Group
Tiva Canyon Tuff 0-65 0-96 21-88 24-88 55-81
Topopah Spring Tuff 65-400 96-406 88-401 88-396 81-381
Calico Hills Formation 400-496 406-516 401-510 396-496 381-436
Crater Flat Group
Prow Pass Tuff 496-693 516-656 510-652 496-644 436-558
Bullfrog Tuff 693-812 656-828 652-829 644-814 558-691
Tram Tuff 812-1,164 828-914+ 829-914+ 814-914+ 691-873
Lithic Ridge Tuff 1,164-1,219+ not reached not reached not reached 873-1,068
DTN: GS030508312314.003 ([164425] p. 7, Table 2).
In the vicinity of the C-wells complex, northerly and northwesterly trending, high-angle 
faults,
such as the Paintbrush Canyon, Midway Valley, and Bow Ridge faults, have brecciated, 
offset,
and tilted the tuffaceous rocks (Day et al. 1998 [101557]; Dickerson and Drake 1998 
[102781]).
Figure 6.1-3 shows major faults and structural features in the vicinity of Yucca Mountain. 
The
dip of the tuffaceous rocks increases from 5 to 10 eastward at the crest of Yucca 
Mountain to
about 20 eastward at the C-wells complex (Frizzell and Shulters 1990 [105454], Map I-
2046).
At the C-wells complex, the north-striking Midway Valley fault or Paintbrush Canyon 
fault
dropped Miocene tuffaceous rocks down to the west. Those rocks later were dropped to 
the
northeast by a northwest-striking fault that cuts through Bow Ridge (Figure 6.1-3).
Hydrogeologic data and numerical modeling indicate that groundwater recharge in the 
Yucca
Mountain area discharges mostly to Carson Slough, Ash Meadows, Alkali Flat, the lower
Amargosa River Valley, and Death Valley (D'Agnese et al. 1997 [100131]). Locally,
groundwater flows mainly through Tertiary volcanic rocks and Quaternary and Tertiary 
alluvium
and lacustrine deposits. Controlled largely by faults and related fractures, groundwater 
flows
from basin to basin, mainly through deeper Paleozoic carbonate rocks (Faunt 1997 
[100146]).
Cohen et al. (1996 [156651]) demonstrated by two-dimensional (2-D) numerical 
modeling that
water in Miocene rocks at the C-wells complex could be derived from the Paleozoic 
carbonate
rocks by upward flow along the Paintbrush Canyon, Midway Valley, or Bow Ridge 
faults.
Geldon et al. (1998 [129721], pp. 23 to 25, Figure 2; p. 31) concluded that a northwest-
trending
zone of discontinuous faults between Bow Ridge and Antler Wash also transmits 
groundwater.
ANL-NBS-HS-000039, REV 00 64 December 2003
Source: Information derived from Geldon (1993 [101045], pp. 35 to 37, 68 to 70). Packer locations from DTN:
GS030508312314.003 [164425]; flow survey information from DTN: GS930908312313.008 ([166332],
MOL.19951115.0127 through MOL.19951115.0131).
NOTE: Packer locations indicate intervals in which tracer tests described in this report were conducted (note 
that
the tracer tests were conducted between UE-25 c#2 and c#3). Fracture densities shown are from borehole
UE-25 c#1.
Figure 6.1-2. Stratigraphy, Lithology, Matrix Porosity, Fracture Density, and Inflow
From Open-Hole Flow Surveys at the C-wells
ANL-NBS-HS-000039, REV 00 65 December 2003
DTN: GS980608314221.002 [107024].
NOTE: The geology is based on Day et al. (1998 [100027]).
Figure 6.1-3. Generalized Geologic Map Showing the Location of the
C-wells Complex and Nearby Boreholes
ANL-NBS-HS-000039, REV 00 66 December 2003
The water table in the Miocene tuffaceous rocks at Yucca Mountain in the vicinity of the 
C-wells
complex ranges from about 335 to 520 m below land surface (O'Brien et al. 1995 
[101279], p. 3,
Table 1; pp. 35 to 69) and in the C-wells from 400 to 402 m. These depths all correspond 
to a
water-table elevation of approximately 730 m above mean sea level in the vicinity of the 
Cwells.
Water in the tuffaceous rocks generally flows southeasterly (Ervin et al. 1994 [100633];
Tucci and Burkhardt 1995 [101060]), but flow patterns are disrupted by faults acting as 
conduits
or barriers to flow. Water-level data are sparse in the vicinity of the C-wells complex, but 
the
Paintbrush Canyon, Bow Ridge, and other faults apparently created a groundwater divide
centered on Bow Ridge and Boundary Ridge that directs flow southward to Dune Wash,
northward to Midway Valley, and eastward to Fortymile Wash (Figure 6.1-4). Flow from 
the
west into the area of the C-wells is inhibited by the north-striking Solitario Canyon fault 
(shown
in Figure 6.1-3; Tucci and Burkhardt 1995 [101060]). For the purpose of Figure 6.1-4, 
the
Solitario Canyon fault is assumed to be a constant-head boundary, whereas discharge 
areas
north, east, and south of the C-wells complex are assumed to be head-dependent flux 
boundaries.
The Miocene tuffs near the C-wells complex behave as a single fissure-block aquifer, in 
which
the volume and direction of groundwater flow are controlled mainly by proximity to 
faults,
fracture zones, and partings (Geldon et al. 1998 [129721], p. 4). In a fissure-block 
aquifer, the
permeability of the matrix is essentially negligible compared to the permeability of the 
fractures;
and, hence, the aquifer behaves as a "dual-porosity" system in which the matrix acts as a
reservoir for stagnant groundwater and flow occurs almost exclusively in fractures. 
Fractures in
transmissive intervals have no preferred orientation, and fracture density appears 
unrelated to the
extent of welding and permeability. Matrix permeability of the Calico Hills Formation 
and the
Crater Flat Group within 5 km of the C-wells complex reaches 20 mDarcy. On the basis 
of
barometric efficiency and specific storage, the average effective porosity of the Calico 
Hills
Formation near the water table in the C-wells was determined to be 36 percent (Geldon et 
al.
1997 [156827], p. 11). The Crater Flat Group is much less porous than the Calico Hills
Formation. The average porosity of those geologic units in the C-wells is 21 percent 
(computed
from porosity values reported by Geldon 1993 [101045], pp. 60 to 62). Despite the 
influence of
fractures, rock within about 3 km of the C-wells complex responds to hydraulic tests in a 
manner
that is consistent with the response of a porous medium. In this analysis report, such a 
rock mass
is referred to as an "equivalent porous medium," where the word "equivalent" indicates 
that the
medium is not a true porous medium, but that, at the scale of observation, volume-
averaged
properties normally assigned to porous media can describe the hydraulic behavior of the 
rock
mass.
Borehole flow surveys in combination with geophysical logs and aquifer tests show that 
flow
within the tuffs at the C-wells complex comes primarily from discrete intervals (Figure 
6.1-2).
The total thickness of transmissive intervals identified in individual boreholes ranges 
from 165 to
274 m (Geldon 1996 [100396], pp. 13 to 20). Hydraulic tests conducted in 1984 indicated 
that
those intervals have layered heterogeneity (Geldon 1996 [100396], pp. 9 to 69). Figure 
6.1-5 is a
depiction of the hydrogeologic intervals identified in the C-wells during hydraulic and 
tracer
testing from 1995 to 1997 (Geldon 1996 [100396], pp. 9 to 69).
ANL-NBS-HS-000039, REV 00 67 December 2003
Source: Geldon et al. (2002, [161163], p. 8, Figure 3); Nye County Nuclear Waste Repository Project Office (1995 
[156859],
ONC-1 Drilling log).
Figure 6.1-4. Potentiometric Surface of the Miocene Tuffaceous Rocks in
the Vicinity of the C-wells Complex, May 1995
ANL-NBS-HS-000039, REV 00 68 December 2003
DTN: GS030508312314.003 ([164425], p. 9, Figure 4).
Figure 6.1-5. Hydrogeologic Intervals in the C-wells Identified During
Hydraulic and Tracer Testing from 1995 to 1997
ANL-NBS-HS-000039, REV 00 69 December 2003
6.1.1.2 Alluvial Testing Complex
The SZ flow system to the south of Yucca Mountain transitions from a fractured tuff 
aquifer to a
valley-fill (alluvium) aquifer before reaching the ~18-km performance compliance 
boundary at
the southern boundary of the NTS. Characterization of the valley-fill system was 
conducted just
outside the southwest corner of the NTS at the ATC, which is the site of the Nye County 
Early
Warning Drilling Program (NC-EWDP) wells NC-EWDP-19D1, -19P, -19IM1, and -
19IM2
(these wells will be referred to as 19D1, 19P, 19IM1, and 19IM2 in this report; see Table 
1).
The location of the ATC is shown in Figure 6.1-6 (labeled as "NC-EWDP-19D"). The 
surface
layout of the wells at the ATC is shown in Figure 6.1-7.
Well 19D1 was drilled using a mud/rotary technique in March and April 2000 to a total 
depth of
441.4 m below land surface, with the water table being encountered at ~108.5 m below 
land
surface. The "D1" designation is used because the well was re-drilled after a significant 
vertical
deviation occurred during the original drilling of the "D" well. The "D" well was filled 
with a
bentonite grout below ~213 m (~700 ft), where the deviation occurred, and the well was 
then redrilled
to total depth. Well 19D1 was completed using 18-cm (7.0-in) outer dimension and 15.8-
cm (6.24-in) inner dimension steel pipe to allow pumps, packers, pressure transducers, 
and tracer
injection equipment to be lowered into the hole. This completion also allows for 
installation of
the Westbay monitoring/sampling system that Nye County uses for long-term 
monitoring.
A piezometer well, 19P, was drilled just prior to drilling 19D1 at a location that 
ultimately ended
up being ~25 m northeast of 19D1 at land surface. 19P was drilled using an air/hammer
technique in March 2000 to a total depth of 142 m below land surface, with the water 
table being
encountered at 111 m (366 ft) below land surface. This well was completed with a 7.3-cm 
(2-
7/8-in) outer diameter pipe casing and was screened from 109 to 139.5 m (358 to 458 ft) 
below
land surface. The screened interval was developed by air injection. The well was intended 
to
serve as a piezometer/monitoring well during pumping of 19D/D1.
Wells 19IM1 and 19IM2 were drilled and completed in August and September, 
respectively, of
2001. 19IM1 was completed to a depth of 308.6 m (1,012.5 ft) below land surface, and 
19IM2
was competed to 294.3 m (965.6 ft) below land surface. Figure 6.1-8 shows the 
completions of
19D1, 19P, 19IM1, and 19IM2 along with the site lithology as determined from on-site
geological logging during drilling.
As Figure 6.1-8 shows, 19D1 was screened over seven different depth intervals, with the 
bottom
three intervals completed below the valley-fill deposits. A volcanic tuff was encountered 
at
about 248 m (815 ft) below land surface, and a claystone/siltstone was encountered at 
~375 m
(~1230 ft) below land surface. Although these intervals are potentially significant, they 
were not
the primary focus of the ATC investigations. Thus, 19IM1 and 19IM2 were drilled and
completed only to the depth of the highest screened interval in the volcanic tuff in 19D1. 
It was
desirable to have one interval completed below the valley-fill deposits in each well so 
that
hydraulic communication between the valley fill and the underlying tuff could be 
investigated.
The wells were developed by air injection just below each of the screened intervals and 
also by
pumping for 48 hours (hr) under open-hole conditions. In the case of 19D1, the well was
pumped in an open-hole configuration (no packers or plugs) at ~610 liters per minute 
(L/min)
(~160 gallons per minute) (gpm) with a total drawdown of 4.6 to 6.1 m (15 to 20 ft). The
ANL-NBS-HS-000039, REV 00 70 December 2003
hydrogeologic setting in the vicinity of the ATC, and especially to the north of the ATC 
along
Fortymile Wash, is in the process of being established. Understanding of the 
hydrogeologic
setting near the 18-km compliance boundary is a major goal of the NC-EWDP.
Figure is for illustration purposes only. DTN: MO0107COV01057.000 [157194] is used as reference only.
NOTE: The black circles indicate locations of other wells.
Figure 6.1-6. Map Showing Location of Alluvium Testing Complex (Well NC-EWDP-19D1 - black 
square)
in Relation to the Repository Footprint and the Nevada Test Site
ANL-NBS-HS-000039, REV 00 71 December 2003
For illustration purposes only. Source: BSC (2002 [158198], p. 34, Figure 2).
NOTE: Full well names are preceded by "NC-EWDP-."
Figure 6.1-7. Surface Layout of the Alluvium Testing Complex
ATC SITE LAYOUT
ANL-NBS-HS-000039, REV 00 72 December 2003
DTNs: MO0112DQRWLNYE.018 [157187] (19D1 completion); MO0112DQRWLNYE.014 [157184] (19P completion);
GS011008314211.001 [158690] (19D1 lithologic log); MO0306NYE05259.165 [165876] (19IM1 well completion),
MO0306NYE05260.166 [165877] (19IM2 well completion).
NOTE: The water table is higher in NC-EWDP-19D1 than in -19P because hydraulic head increases with 
depth.
The white spaces between gravel packs below the water table are "grout and bentonite seals." The Nye
County Nuclear Waste Repository Project Office reports all depths in feet.
Figure 6.1-8. Schematic Diagram of NC-EWDP-19D1, -19P, -19IM1, and -19IM2 Completions
___
___
___
___
___
___
___
___
___
___
___
___
___
___
___
___
___
yyy
yyy
yyy
yyy
yyy
yyy
yyy
yyy
yyy
yyy
yyy
yyy
yyy
yyy
yyy
yyy
yyy
___
_ _ _
_ _ _
_ y _yy
y __
__
yy
yy
_ _y y
__ yy
__
__
yy
yy
_ _y y
__
yy
_y
_ _ _
y y y
__
__
__
yy
yy
yy
y
__
__
__
__
yy
yy
yy
yy
___
___
___
___
___
___
yyy
yyy
yyy
yyy
yyy
yyy
_ __ _y y
Valley
Fill
Deposits
Tuff
Claystone/
Siltstone
__
__
- Screen
_ _y y
- Gravel Pack
EWDP-NC-19D1 EWDP-NC-19P
Clay-Rich Layer
2-7/8" Casing
7" Casing
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1450
Depth Below Surface, ft
Water Table
#1
#2
#3
#4
#5
#6
#7
Screen Numbers __
__
__
__
__
__
_y _y
y __ _y y
_ _y y
_y
_ _y y
_ _y y _
y
___
_ _ _
_ y yy
y __
__
yy
yy
_ _y y
__ yy
__
__
yy
yy
_ _y y _
y
EWDP-NC-19IM1 EWDP-NC-19IM2
7" Casing
7" Casing
#1
#2
#3
#4
#5
#1
#2
#3
#4
#5
ANL-NBS-HS-000039, REV 00 73 December 2003
6.1.2 Sequence of Hydraulic and Tracer Tests
Figure 6.1-9 is a graphical timeline showing the sequence of hydraulic and tracer tests 
conducted
at the C-wells since May 1995. Each of the tests is described in detail in Sections 6.2 and 
6.3. In
this report, the C-wells tracer tests are split into two general categories: (1) tests 
involving only
nonsorbing solute tracers and (2) tests involving combinations of nonsorbing and reactive 
solute
tracers and colloid tracers (polystyrene microspheres). The former tests were conducted 
and
interpreted primarily by the U.S. Geological Survey (USGS), and the latter were 
conducted and
interpreted primarily by the Los Alamos National Laboratory (LANL). LANL also 
conducted
two nonsorbing solute-only tracer tests to prepare for a multiple tracer test in the Lower 
Bullfrog
Tuff, but these tests were not quantitatively interpreted because they were conducted 
primarily to
determine which well, c#1 or c#2, would serve as a better injection well for multiple 
tracer
testing when pumping c#3.
The distinction between the nonsorbing (USGS) and the multiple tracer tests (LANL) is
important because the two organizations, while working closely together, took different
approaches to interpreting the tracer tests. These different approaches result in different
transport parameter estimates derived from the tracer responses (see Section 6.3.5 for a
discussion of these differences and how they affect uncertainty). Both approaches are 
presented
so that readers can gain an appreciation for the uncertainties in parameter estimation 
associated
with the different methods and assumptions and can also make informed decisions about 
which
approach they may want to give more weight when determining parameter distributions 
for
performance assessments.
Single-well hydraulic and tracer tests were conducted in 19D1 in 2000 and 2001 (prior to 
the
drilling of 19IM1 and 19IM2), and cross-hole hydraulic testing was conducted in the 
ATC wells
in late 2001 and early 2002 (using 19D1 as the production well and 19IM1 and 19IM2 as
observation wells). These tests are described in Sections 6.4 and 6.5 of this scientific 
analysis
report.
ANL-NBS-HS-000039, REV 00 74 December 2003
For illustration purposes only.
NOTE: The tests listed in the figure are discussed at length in Sections 6.2 and 6.3 and referenced in those
sections.
Figure 6.1-9. Timeline for C-wells Hydraulic and Tracer Tests
00
99
98
97
96
95
Hydraulic Transport
LANL
USGS June 1995 - c#3 Open Hole Pump Test
(Isolated Intervals in c#1 and c#2)
Feb 96 - c#3 Bullfrog-Tram
May 96-Nov 97 - c#3 Lower Bullfrog
June 98 - c#2 Prow Pass Pump Test
Feb 1996 - Iodide into c#2
May 96 - PFBA into c#2
June 96 - Iodide into c#1
Oct 96 - LiBr, PFBA, ?spheres into c#2
Jan 97 - Pyridone into c#1
Jan 97 - 2,6 DFBA into c#2
June 98 - Iodide, 2,4,5 TFBA into c#3
July 98 - 2,3,4,5 TeFBA into c#1
Sept 98 - LiBr, LiCl, PFBA, ?spheres
into c#3
Reinstrument for Prow Pass
April 96 - Install New Pump in c#3
May 1995 - c#3 Open Hole Pump Test
Feb-March 96 - Pumping for Tracer Test
June-Sept 98 - c#3 PP Injection Test
Pumping for Tracer Test through Feb. 99
ANL-NBS-HS-000039, REV 00 75 December 2003
6.1.3 Features, Events, and Processes Supported by This Scientific Analysis
The development of a comprehensive list of features, events, and processes (FEPs) 
potentially
relevant to post-closure performance of the Yucca Mountain repository is an ongoing, 
iterative
process based on site-specific information, design, and regulations. The approach for 
developing
an initial list of FEPs in support of the TSPA-SR (CRWMS M&O 2000 [153246]) was
documented in Freeze et al. (2001 [154365]). To support the TSPA-LA, the FEPs list was 
reevaluated
in accordance with The Enhanced Plan for Features, Events, and Processes (FEPs) at
Yucca Mountain (BSC 2002 [158966], Section 3.2) and the KTI letter report Response to
Additional Information Needs on TSPAI 2.05 and TSPAI 2.06, REG-WIS-PA-000003, 
(Freeze
2003 [165394]). The resulting list of FEPs to be evaluated for the TSPA-LA is 
documented in
DTN: MO0307SEPFEPS4.000 [164527]).
This scientific analysis report does not provide the technical basis for inclusion of any of 
the
FEPs; however, Table 6.1-3 lists the saturated-zone-related FEPs included in the TSPA-
LA that
are supported by the results of the analyses described in this document, and Table 6.1.3 
serves as
a cross-reference to FEPs-relevant sections of this report. Also, Table 6.1-3 lists the 
reports in
which the TSPA dispositions for the included saturated-zone FEPs are located. The 
rationale for
excluding a saturated-zone-related FEP from the TSPA-LA model will be documented in 
the
revision (REV 02) of Features, Events, and Processes in SZ Flow and Transport (BSC 
2003
[163128]), which may cite information from this scientific analysis report.
Table 6.1-3. Saturated Zone Included FEPs Supported by the Results in This Scientific Analysis 
Report
FEP Number
and Name
FEP Description Relevant Section of this
Report
Report in Which
TSPA Disposition is
Located
1.2.02.01.0A
Fractures
Groundwater flow in the Yucca Mountain
region and transport of any released
radionuclides may take place along
fractures. The rate of flow and the extent
of transport in fractures are influenced by
characteristics such as orientation,
aperture, asperity, fracture length,
connectivity, and the nature of any linings
or in-fills.
Flow in fractures is
addressed throughout
Section 6.2. Transport in
fractures is addressed
throughout Section 6.3.
SZ Flow and
Transport Model
Abstraction, MDLNBS-
HS-000021
(BSC 2003 [164870]).
1.2.02.02.0A
Faults
Numerous faults of various sizes have
been noted in the Yucca Mountain region
and, specifically, in the repository area.
Faults may represent an alteration of the
rock permeability and continuity of the
rock mass, alteration or short-circuiting of
the flow paths and flow distributions close
to the repository, and unexpected
pathways through the repository.
The influence of faults on
flow in the saturated
volcanics is addressed in
Section 6.1.1.1 and in
several places in Section 6.2.
SZ Flow and
Transport Model
Abstraction, MDLNBS-
HS-000021
(BSC 2003 [164870]).
ANL-NBS-HS-000039, REV 00 76 December 2003
Table 6.1-3 (Continued). Saturated Zone Included FEPs Supported by the Results
in This Scientific Analysis Report
FEP Number
and Name
FEP Description Relevant Section of this
Report
Report in Which
TSPA Disposition is
Located
2.2.03.02.0A
Rock
Properties of
Host Rock
and Other
Units
Physical properties such as porosity and
permeability of the relevant rock units,
soils, and alluvium are necessary for the
performance assessment. Possible
heterogeneities in these properties should
be considered. Questions concerning
events and processes that may cause
these physical properties to change over
time are considered in other FEPs.
Rock properties as they
relate to flow and transport
are addressed throughout
Sections 6.1 through 6.5.
SZ Flow and
Transport Model
Abstraction, MDLNBS-
HS-000021
(BSC 2003 [164870]).
2.2.07.13.0A
Water-
Conducting
Features in
the SZ
Geologic features in the saturated zone
may affect groundwater flow by providing
preferred pathways for flow.
Geologic features affecting
flow in the volcanics are
addressed in Section 6.1.1.1
and throughout Section 6.2.
Geologic features affecting
flow in the alluvium are
addressed in Section 6.4.
SZ Flow and
Transport Model
Abstraction, MDLNBS-
HS-000021
(BSC 2003 [164870]).
2.2.07.15.0A
Advection and
Dispersion in
the SZ
Advection and dispersion processes affect
contaminant transport in the SZ.
Advection and dispersion
effects on transport are
discussed in many places in
Sections 6.3 (volcanics) and
6.5 (alluvium).
Site-Scale Saturated
Zone Transport, MDLNBS-
HS-000010
(BSC 2003 [162419]).
2.2.07.17.0A
Diffusion in
the SZ
Molecular diffusion processes may affect
radionuclide transport in the SZ.
Molecular diffusion
processes in the volcanics
are addressed in several
places in Section 6.3. In
Section 6.5, molecular
diffusion is discussed for the
alluvium, but it was
concluded that it did not have
a major effect on transport in
ATC single-well tracer tests.
Site-Scale Saturated
Zone Transport, MDLNBS-
HS-000010
(BSC 2003 [162419]).
2.2.08.08.0A
Matrix
Diffusion in
the SZ
Matrix diffusion is the process by which
radionuclides and other species
transported in the SZ by advective flow in
fractures or other pathways move into the
matrix of the porous rock by diffusion.
Matrix diffusion can be a very efficient
retarding mechanism, especially for
strongly sorbed radionuclides, due to the
increase in rock surface accessible to
sorption.
The effects of matrix
diffusion on transport in the
volcanics are discussed in
Sections 6.3.4.2 and 6.3.4.3.
Observations and
parameterizations of matrix
diffusion in the volcanics are
addressed in several places
in Section 6.3. Matrix
diffusion in the alluvium is
discussed in Section 6.5, but
it was concluded that matrix
diffusion did not have a
significant effect on transport
in ATC single-well tracer
tests.
Site-Scale Saturated
Zone Transport, MDLNBS-
HS-000010
(BSC 2003 [162419]).
ANL-NBS-HS-000039, REV 00 77 December 2003
Table 6.1-3 (Continued). Saturated Zone Included FEPs Supported by the Results
in This Scientific Analysis Report
FEP Number
and Name
FEP Description Relevant Section of this
Report
Report in Which
TSPA Disposition is
Located
2.2.08.10.0A
Colloidal
Transport in
the SZ
Radionuclides may be transported in
groundwater in the SZ as colloidal
species. Types of colloids include true
colloids, pseudo colloids, and microbial
colloids.
Colloid transport in the
volcanics is addressed in
Section 6.3.4. Colloid
detachment rates in the
alluvium are addressed in
Section 6.5.4.6. Colloidfacilitated
transport of
radionuclides is not directly
addressed in this report.
SZ Flow and
Transport Model
Abstraction, MDLNBS-
HS-000021
(BSC 2003 [164870]).
2.2.12.00.0B
Undetected
Features in
the SZ
This FEP is related to undetected features
in the SZ portion of the geosphere that
can affect long-term performance of the
disposal system. Undetected but
important features may be present, and
may have significant impacts. These
features include unknown active fracture
zones, inhomogeneities, faults and
features connecting different zones of
rock, and different geometries for fracture
zones.
The potential influence of
undetected features
(primarily faults) on flow in
the volcanics is discussed
throughout Section 6.2. The
potential influence of layered
heterogeneity on flow in the
alluvium is discussed in
Section 6.4.
SZ Flow and
Transport Model
Abstraction, MDLNBS-
HS-000021
(BSC 2003 [164870]).
ANL-NBS-HS-000039, REV 00 78 December 2003
6.2 HYDROLOGIC PROPERTIES OF FRACTURED TUFFS (C-WELLS 
COMPLEX)
The hydrologic properties of the fractured tuffs at Yucca Mountain were obtained as part 
of ongoing
investigations of the hydrologic and geologic suitability of Yucca Mountain as a high-
level
nuclear waste repository by the USGS in cooperation with the DOE. Five cross-hole 
hydraulic
tests, some in conjunction with tracer tests, were conducted by the USGS at the C-wells 
complex
in May and June 1995, February 1996, from May 1996 to November 1997, and between 
April
and June 1998. The first test, conducted in May 1995, is documented in Geldon et al. 
(1998
[129721]). The second through fourth tests (June 1995, February 1996, and May 1996 to
November 1997) are documented in Geldon et al. (2002 [161163]) and reproduced in this 
report.
The fifth test, conducted between April and June 1998, is only described in this report.
This section of the report has three parts: (1) it describes the hydraulic tests conducted, 
the
changes in water levels in monitoring wells as a result of pumping, and analyses 
performed on
the test data; (2) it extrapolates test results to interpret groundwater flow paths in 
Miocene
tuffaceous rocks beyond the immediate vicinity of the C-wells complex; and (3) it 
evaluates the
uncertainties associated with the test data, analyses, and values of hydraulic properties
determined from test analyses.
The analyses performed on the test data to obtain transmissivity, hydraulic conductivity, 
and
storativity are various analytical (as opposed to numerical) solutions of the groundwater 
flow
equation, which assumes a radial flow regime to the pumping well, constant aquifer 
thickness,
and a homogeneous and isotropic medium. In order to calculate anisotropy in the 
horizontal
hydraulic conductivity, analytic solutions of the groundwater flow equation for 
homogeneous,
anisotropic media were employed.
Use of analytic solutions that assume uniform aquifer parameters is commensurate with 
the
spatial distribution of the available geohydrologic and geophysical data. These analytic 
solutions
represent the first-order answer to what the hydraulic parameters at the saturated 
fractured
volcanics are in a manner that does not inflate the knowledge base obtained from actual 
field
data. These methods assume that the tested volume of rock has one average 
transmissivity and
storativity value between the pumping well and the observation well. Only one number is
obtained from the analysis, and one is restricted to a set of simplifying assumptions, but 
the
knowledge base is not inflated. Alternately, the rock mass can be divided into discrete 
blocks
with various parameter values assumed for the different blocks by using a numerical 
model.
Non-conformance of field conditions to the simplifying assumptions required by analytic
solutions is dealt with by defining a three-dimensional (3-D) flow system with 
sophisticated
boundary conditions. However, the flexibility of being able to attribute various parameter 
values
spatially and obviate the restrictions of the simplifying assumptions of analytic solutions 
is
gained at the expense of a high risk of inflating the existing knowledge base. The 
"model"
assumes its own life and can produce just as non-unique a set of parameters as can 
inexperienced
application of analytic solutions. Analytic solutions were selected for this study to obtain 
a basic
overall picture of the hydraulic parameter distribution in the saturated fractured volcanics 
at the
Yucca Mountain site with as little inflation of the knowledge base derived from actual 
field data
as possible.
ANL-NBS-HS-000039, REV 00 79 December 2003
At the C-wells complex, several analytic solutions to the groundwater flow equation were 
used.
Following are the dominant modes of analysis used for each geohydrologic interval or 
aquifer.
Details of these solutions and exceptions to the dominant modes presented here are found 
in
Section 6.2.4. To analyze responses in the Calico Hills aquifer, which is at the water 
table, the
Neuman (1975 [150321]) unconfined-aquifer solution was used to analyze successfully 
five out
of six responses in this aquifer among the various tests. To analyze the Prow Pass aquifer 
and
the Upper Bullfrog and Lower Bullfrog aquifers, which are confined below the largely
unconfined Calico Hills aquifer, either confined single-porosity (Theis 1935 [150327]) or
confined dual-porosity (Streltsova-Adams 1978 [150754]) solutions were mostly used,
depending on whether the test duration was long enough for the fractured-rock aquifers to 
exhibit
their dual-porosity character. To analyze the Upper Tram aquifer, which is intersected by 
the
known faults present at the bottom of the C-wells that provide a source of recharge or 
"leakage,"
the leaky-confined Hantush (1956 [165169]) solution was used successfully for all tests.
6.2.1 Earlier Studies
Before the in-situ testing of the fractured tuffs at Yucca Mountain began in May 1995 
(Geldon et
al. 1998 [129721]), studies were conducted to determine hydrogeologic intervals of the 
rocks,
flow patterns, geologic influences, geologic properties of the rocks, and the hydraulic 
results of
an open-hole test in one of the C-wells. Most of these studies have been published and 
are
referred to in this section. Hydrogeologic intervals discussed in this report were identified 
by
Geldon (1996 [100396], pp. 9 to 69) on the basis of borehole geophysical logs, borehole 
flow
surveys, cross-hole seismic tomography, and aquifer tests. Geophysical logs run in the C-
wells
include caliper, borehole-deviation, temperature, resistivity, gamma-gamma, acoustic, 
epithermal
neutron, acoustic televiewer, and television logs (Geldon 1993 [101045], pp. 14 to 18). 
Flow
surveys run in the C-wells include tracejector, heat-pulse flowmeter, spinner, and 
oxygenactivation
surveys (Geldon 1993 [101045], pp. 14 to 18; Geldon 1996 [100396], pp. 12 to 69).
Tracejector surveys using radioactive iodide were run in the C-wells during hydraulic 
tests
conducted in 1983 and 1984. Heat-pulse flowmeter surveys were run in 1991 without the
boreholes being pumped. Spinner and oxygen-activation surveys were run in borehole 
c#3
during the hydraulic test in June 1995 (described in Section 6.2.3.1). In 1993, a seismic
tomogram was conducted between boreholes c#2 and c#3 by Lawrence Berkeley 
National
Laboratory (LBNL) for the USGS and reported to the USGS by written communication 
from E.
Majer, LBNL (Geldon et al. 2002 [161163], p. 2). That tomogram showed many of the
hydrogeologic details evident from borehole lithologic and geophysical logs and flow 
surveys.
Hydraulic properties of the intervals in the C-wells and the manner in which they transmit 
water
were determined provisionally by Geldon (1996 [100396], pp. 12 to 69) from geophysical 
logs,
laboratory analyses, and aquifer tests. A matrix-porosity profile for the C-wells was 
developed
from a gamma-gamma log and nine values of core porosity obtained from c#1 in 1983 
(Geldon
1993 [101045], p. 62, Table 13). Geldon (1996 [100396], pp. 9 to 69) developed a 
matrixpermeability
profile for the C-wells from permeameter tests on 89 core samples obtained from
the C-wells and four nearby boreholes between 1980 and 1984. Geldon (1996 [100396], 
pp. 9 to
69) developed a hydraulic-conductivity profile for the C-wells by analyzing falling-head 
and
pressure-injection tests done in c#1 in 1983. Transmissivity, hydraulic conductivity, and
storativity of discrete intervals within the Calico Hills Formation and the Crater Flat 
Group were
determined (Geldon 1996 [100396], pp. 9 to 69) from analyses of a constant-flux 
injection test in
ANL-NBS-HS-000039, REV 00 80 December 2003
c#2 and three hydraulic tests in c#2 and c#3 performed in 1984. Simultaneous monitoring 
of
water-level and atmospheric-pressure fluctuations in 1993 established the barometric 
efficiency
of the C-wells (Geldon et al. 1997 [156827], p. 11). The open-hole hydraulic test 
determined the
transmissivity, hydraulic conductivity, and storativity of the composite saturated 
thickness of
Miocene tuffaceous rocks at the C-wells complex; lateral variations in hydraulic 
properties
within a 3.2-km radius of the C-wells complex; and possible hydraulic connection 
between the
tuffaceous rocks and the underlying regional aquifer composed of Paleozoic carbonate 
rocks
(Geldon et al. 1998 [129721], pp. 30, 31).
A hydraulic test conducted at the C-wells complex from May 22 to June 12, 1995 (data 
reside in
DTN: GS960108312313.001 [164801]), indicated that the composite section of 
tuffaceous rocks
in the vicinity of the C-wells has a transmissivity of 2,300 m2/d (square meters per day) 
and a
storativity of 0.003 (Geldon et al. 1998 [129721], p. 41). That test also indicated 
transmissivity
values of 1,600 to 3,200 m2/d and storativity values of 0.001 to 0.003 for the rocks in 
individual
boreholes (c#1, c#2, ONC-1, and USW H-4). Hydraulic tests conducted in 1984 indicated 
that
those intervals have layered heterogeneity (Geldon 1996 [100396], pp. 9 to 69).
6.2.2 Instrumentation Used in C-Wells Hydraulic Testing
Principal components of the equipment installed at the C-wells complex to conduct 
hydraulic
tests from 1995 to 1997 are available commercially, but much of this hardware and 
software has
not been used extensively because of its relatively recent development. Consequently, all 
of the
equipment received extensive performance evaluation during prototype hydraulic tests 
conducted
jointly with LBNL from 1992 to 1994 at a research site near Raymond, California.
Modifications to system components and their assembly were made to address problems
encountered during prototype testing and after the equipment was installed and initially 
used at
the C-wells complex (Umari et al. 1994 [164543], pp. 2413 to 2422). With few 
exceptions
(discussed below), most system components performed to specifications, despite being 
operated
almost continuously for more than two years.
6.2.2.1 Packers
Dual-mandrel packers, manufactured by TAM International, Inc., were installed in c#1 
and c#2
throughout the tests and in c#3 after August 1995. The packers are about 1.83 m long and 
have a
deflated diameter of about 21.6 centimeters (cm) (see Geldon et al. 2002 [161163], 
Figure 5).
Suspended on 7.30-cm-diameter tubing, each packer contains 12 pass-through tubes to 
allow
packer-inflation lines and electrical cable to be installed in the borehole. The packers are 
inflated
individually by injection of argon gas through 0.64-cm, stainless-steel tubing. Inflation
pressures, which are about 1,034 kPa above hydrostatic pressure, range from about 2,758 
to
5,861 kPa at the depths at which packers were set in the C-wells from 1995 to 1997. 
Packer
depths from 1995 to 1997, as measured from the land surface, are listed in Table 6.2-1.
ANL-NBS-HS-000039, REV 00 81 December 2003
Table 6.2-1. Location of Packers Emplaced in the C-wells Complex for Hydraulic Tests, 1995 to 
1997
Packer Depth (m below land surface)
UE-25 c#3 Packer
Number UE-25 c#1 UE-25 c#2
8/95-4/96 4/96-11/97
1 547.4-549.3 531.3-533.1 540.4-542.2 None
2 605.3-607.2 605.6-607.5 609.9-611.7 None
3 698.3-700.1 696.5-698.3 695.0-696.8 694.6-696.5
4 797.1-798.9 791.9-793.7 812.6-814.4 812.9-814.7
5 869.9-871.7 869.6-871.4 877.5-879.4 878.1-880.0
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 12, Table 3).
NOTE: There were no packers in UE-25 c#3 before August 1995.
6.2.2.2 Transducers
Continuous records of pressures and temperatures in packed-off intervals during 
hydraulic tests
were obtained using absolute pressure transducers (manufactured by Paroscientific, Inc), 
which
record water pressure plus atmospheric pressure. The transducers used in the C-wells 
were
strapped into brackets welded onto the 7.30-cm-diameter tubing on which the packers 
were
suspended. Field determinations indicated a precision of 0.30 cm under pumping 
conditions and
0.061 cm under non-pumping conditions.
Although transducers were installed in all hydrogeologic intervals, several of the 
transducers
failed after installation. Transducers that were operative during some or all of the 
hydraulic tests
conducted from 1995 to 1997 and the locations of those transducers, as determined by
subtracting recorded pressure heads from static water-level altitudes, are listed in Table 
6.2-2.
Listed transducer altitudes have an accuracy of 0.3 m.
6.2.2.3 Barometers
A nonsubmersible, temperature-compensated pressure transducer, manufactured by
Paroscientific, Inc., was used as a barometer during the 1995 to 1997 hydraulic tests. The
barometer operated in a temperature-controlled office trailer at the C-wells complex. The
factory-calibrated accuracy of this barometer is 0.005 percent of its full operating range 
(103
kPa). The barometer was checked periodically against another barometer of the same 
type in the
same office trailer.
6.2.2.4 Pumps
A 37-stage, 25.2- liters per second (L/s) capacity, Centrilift submersible pump was used 
during
the hydraulic test in June 1995. The pump was suspended in borehole c#3 on 13.9-cm-
diameter
tubing. The pump intake depth was 450.1 m (48.0 m below the water-level altitude prior 
to
pumping). The pump was powered by a 250-KW generator, and its frequency was 
regulated by
a variable-speed controller. Water discharged by the pump was transported by a 15-cm-
diameter
pipeline to a leachfield in Fortymile Wash, about 8 km from the C-wells complex.
ANL-NBS-HS-000039, REV 00 82 December 2003
Table 6.2-2. Operative Transducers in the C-wells, 1995 to 1997
Transducer
Borehole Interval
Number Depth (m) Altitude (m)
Prow Pass 2 552.09 578.51
Upper Bullfrog 3 610.03 520.57 UE-25 c#1
Lower Bullfrog(a) 4 703.04 427.56
Calico Hills 1 519.83 612.36
Prow Pass 2 536.28 595.91
Upper Bullfrog 3 610.70 521.49
UE-25 c#2
Lower Bullfrog(a) 4 701.58 430.61
Calico Hills(b) 1 533.81 598.62
Upper Bullfrog 3 614.49 517.93
Lower Bullfrog(c) 4 708.93 423.49
UE-25 c#3
Upper Tram(d) 5 817.68 314.75
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], Table 4).
NOTE: (a) Monitored Lower Bullfrog and Upper Tram together, February to March 1996.
(b) Listed transducer locations are for August 1995 to March 1996. Prior to August 1995, a single
transducer was installed in the Calico Hills interval at a depth of 441.12 m (altitude = 691.30 m) to
monitor the composite geologic section in c#3. After April 1996, a new transducer was installed at a
depth of 691.31 m (altitude = 441.11 m) to monitor the Calico Hills, Prow Pass, and Upper Bullfrog
intervals combined.
(c) Operative after April 1996.
(d) Monitored Lower Bullfrog and Upper Tram together in February and March 1996; replaced in April 1996
by a transducer at a depth of 819.32 m (altitude = 313.11 m).
The original pump was replaced in August 1995 by a 43-stage, 12.6 L/s-capacity, 
Centrilift
submersible pump. That pump, enclosed in a protective shroud, was offset from the main 
part of
the 7.30-cm-diameter tubing on which the packers were suspended by a 22.9-m-long "Y-
block"
assembly (see Geldon et al. 2002 [161163], Figure 6 for detailed drawing). The Y-block
assembly was designed to allow wireline tool access past the pump for opening and 
closing
sliding sleeves (screens installed to allow water movement to or from test intervals) and 
for
placing a plug in the tubing to prevent recirculation of water through the pump shroud.
Although the Y-block assembly facilitated operations, its placement in the instrument 
string
created problems that eventually caused pump performance to degrade beyond an 
acceptable
level during hydraulic and tracer tests conducted in February and March 1996. Because 
the
combined diameter of the Y-block assembly and main section of the instrument tubing 
(24.7 cm)
was about the same as the borehole diameter below a depth of 463.4 m, the pump intake 
had to
be set about 247 m above the top of the slotted section of pipe open in the test interval.
Frictional head losses produced by water flowing through small openings (slots) in the 
intake
tubing and through the tubing from the test interval to the pump intake caused the pump 
to
operate at the limit of its designed performance range. Consequently, discharge decreased 
from
8.77 L/s when pumping started on February 8, 1996, to 6.18 L/s when pumping was 
terminated
on March 29, 1996.
ANL-NBS-HS-000039, REV 00 83 December 2003
In April 1996, the pump-performance problem was addressed by (1) discarding the Y-
block; (2)
suspending a 72-stage, 12.6 L/s-capacity Centrilift pump enclosed in a narrower shroud 
directly
on the 7.30-cm-diameter tubing; (3) lowering the pump to within about 47 m of the 
interval to be
tested; and (4) adding 6.1 m of slotted pipe in the test interval. From May 1996 to March 
1997,
the reconfigured pump assembly performed without major problems and sustained a 
relatively
constant discharge of 9.34 to 9.84 L/s. Problems with one of the generators providing 
power to
the pump caused the pump to operate erratically between March 26 and May 8, 1997, but 
the
pump performed adequately again after the generator problem was resolved.
6.2.2.5 Flowmeters
A McCrometer turbine-type flowmeter was used during the hydraulic test in June 1995.
Subsequently, the primary device used for monitoring discharge was a differential 
switched
capacitor, vortex flowmeter, manufactured by Endress and Hauser, measuring vortex 
frequency
past a bluff body, with signal output converted to voltage output across a temperature-
controlled
resistor.
The flowmeter signal was recorded at user-specified intervals by monitoring software 
installed
on a personal computer (PC) in the office trailer at the C-wells complex (see Section 
6.2.2.6).
The software program used a regression equation developed on the basis of the flowmeter
calibration to convert the voltage signal from the flowmeter to a discharge rate.
6.2.2.6 Data Acquisition and Instrument Control
Data acquisition from and control of the transducers, barometer, flowmeter, and an 
automatic
water sampler used for tracer tests was accomplished with a commercially available, 
graphiclanguage
software program called LabView (Johnson 1994 [156837]). Installed on the PC in the
office trailer, LabView made the PC monitor screen look and act like an instrument 
panel.
Two separate programs were written for data acquisition and instrument control. One 
program
communicated with the transducers, barometer, and flowmeter; the other program 
communicated
with the automated water sampler during tracer tests. The two programs ran 
simultaneously.
6.2.3 Results and Interpretations of Hydraulic Tests
The results and interpretations of the hydraulic tests discussed below include the 
conceptual
models considered and tested.
6.2.3.1 Hydraulic Tests Conducted between June 1995 and November 1997
Three hydraulic tests were conducted at the C-wells complex from June 1995 to 
November 1997
(see timeline in Figure 6.1-9). During June 12 to June 22, 1995, well c#3 was pumped, 
without
packers installed, and drawdown and recovery were measured in six hydrogeologic 
intervals
(Figure 6.2-5) that were separated by packers in wells c#1 and c#2 (see Table 6.2-1). 
From
February 8 to February 13, 1996, c#3 was pumped, with packers inflated to isolate the 
Bullfrog-
Tram interval, to establish a steady-state hydraulic gradient for a tracer test in the 
Bullfrog-Tram
interval that continued until March 29, 1996. Drawdown was analyzed in the Bullfrog-
Tram
ANL-NBS-HS-000039, REV 00 84 December 2003
interval and in all other packed-off intervals of c#1 and c#2 that responded to pumping 
during
the hydraulic test.
In the third hydraulic test, with packers inflated to isolate the Lower Bullfrog Tuff 
interval, c#3
was pumped for 553 days, from May 8, 1996 to November 12, 1997, before and during a 
series
of tracer tests in the Lower Bullfrog interval. Drawdown was analyzed in this interval and 
in all
other intervals of c#1 and c#2 that responded to pumping before mechanical problems 
developed
on March 26, 1997. Drawdown was analyzed in UE-25 ONC-1 (ONC-1), USW H-4 (H-
4), UE-
25 WT#14 (WT#14), and UE-25 WT#3 (WT#3) for periods from 7 to 18 months to 
evaluate
heterogeneity and scale effects in the Miocene tuffaceous rocks. Water levels in UE-25 
p#1
(p#1), completed in Paleozoic carbonate rocks, were measured to detect a hydraulic 
connection
between the Miocene tuffaceous rocks and the Paleozoic carbonate rocks in the vicinity 
of the C-
wells.
6.2.3.1.1 Analytical Methods
Although rock at the C-wells complex is fractured pervasively, hydrogeologic intervals 
respond
to pumping as an equivalent porous medium (Geldon 1996 [100396], pp. 12 to 69; 
Geldon et al.
1998 [129721], pp. 29 to 31). Because the water table occurs at or near the top of the 
Calico
Hills interval in the vicinity of the C-wells complex, that interval typically responds to 
pumping
as an anisotropic, unconfined aquifer. With pervasive fracturing that apparently extends 
to the
water table (Geldon et al. 2002 [161163], p. 15]), the Prow Pass and Upper Bullfrog 
intervals
respond to pumping as either an unconfined, fissure-block, or confined aquifer. Isolated 
by
intervals of nonfractured rock, the Lower Bullfrog interval typically responds to pumping 
as a
confined aquifer. Recharged by flow from fractures related to faults (identified on 
lithologic
logs prepared by Richard W. Spengler and included in a report by Geldon (1993 
[101045], pp.
35 to 37, Table 4), the Upper Tram interval typically responds to pumping as a leaky, 
confined
aquifer without confining bed storage.
Analytical methods used for hydraulic tests discussed in this section are those of Theis 
(1935
[150327]) and Cooper and Jacob (1946 [150245]), for infinite, homogeneous, isotropic, 
confined
aquifers; Neuman (1975 [150321]), for infinite, homogeneous, anisotropic, unconfined 
aquifers;
and Streltsova-Adams (1978 [150754]), for fissure-block aquifers. Geldon (1996 
[100396], pp.
21 to 69) discusses assumptions, equations, and application of these analytical methods in
hydraulic tests at the C-wells complex. Analysis of drawdown in this study was restricted 
to
observation wells because drawdown in pumping wells at the C-wells complex typically 
is too
large and rapid to be explained solely by hydraulic properties of the pumped interval 
(Geldon
1996 [100396], pp. 21 to 69). This observation can be illustrated by looking at the 
drawdown in
c#3 at 464,000 minutes (322.22 days) after pumping began on May 8, 1996. That 
drawdown
was 599 cm. With hydraulic properties computed for the Lower Bullfrog interval in c#1 
and c#2
inserted into an approximation of the Theis (1935 [150327]) equation as given by 
Equation 19 of
Lohman (1972 [150250]), the drawdown in c#3 attributable to aquifer characteristics 
should
have been no more than 69 to 72 cm after 322.22 days of pumping, or 12 percent of the 
actual
recorded drawdown. Most of the drawdown in c#3 probably can be attributed to frictional 
head
loss. Therefore, calculation of hydraulic properties from that drawdown is not reliable.
ANL-NBS-HS-000039, REV 00 85 December 2003
All of the analytical methods used in this study, except for the Neuman (1975 [150321]) 
method,
assume radial flow to the pumping well, and, therefore, ignore vertical flow (application 
of the
Neuman fully-penetrating-well solution, as was done in this report, to cases where 
pumping was
in one interval and the analyzed drawdown response was in another, also ignores vertical 
flow).
However, in hydraulic tests of the Bullfrog-Tram interval (February 1996) and the Lower
Bullfrog interval (May 1996 to March 1997), drawdown was observed in the Calico 
Hills, Prow
Pass, and Upper Bullfrog intervals, even though the sliding sleeves allowing direct
communication between those intervals and the flow intake piping were not open. For 
water to
reach the pumping well from the intervals that did not have open sliding sleeves, a 
downward
component of flow must have occurred. The downward flow was assumed by the 
investigators
to be much less than radial flow to the pumping well in order to analyze the drawdown 
from the
non-open intervals by the methods outlined in this section. Hydraulic properties 
calculated under
this assumption have a high level of confidence because they generally are consistent 
with
quantitative results of the hydraulic test conducted in June 1995, which was designed 
such that
flow from hydrogeologic intervals in c#1 and c#2 to c#3 would be largely radial.
6.2.3.1.2 Earth Tides and Barometric Effects
Previous monitoring of water levels in observation wells before, during, and after 
hydraulic tests
conducted in the C-wells indicated that all of those boreholes respond to Earth tides and
atmospheric pressure changes. With frequencies of 0.9 to 2.0 cycles per day (Galloway 
and
Rojstaczer 1988 [156826], p. 107, Table 2), Earth tides caused water levels in the C-wells 
to
fluctuate as much as 12 cm during a 10-day hydraulic test conducted at the C-wells 
complex
from May to June 1995 (Geldon et al. 1998 [129721], Figure 21). Consequently, in the 
hydraulic
testing described here, Earth-tide effects were removed from water levels, and cycles of 
the same
frequency as Earth tides were removed from simultaneously recorded atmospheric 
pressures
before computing the barometric efficiency of most borehole intervals. Earth-tide effects 
also
were removed from the records of observation wells in which drawdown caused by 
pumping was
expected to be obscured by Earth tides (boreholes H-4, WT#14, WT#3, and p#1). The 
boreholes
requiring an Earth-tide correction to water-level records were completed in Miocene 
tuffaceous
rocks more than 1,500 m from c#3 or were completed in a different aquifer than that of 
the Cwells
complex (i.e., in the Paleozoic carbonate rocks). Earth-tide effects were removed from
records of water levels, and cycles of the same frequency as Earth tides were removed 
from
simultaneously recorded atmospheric pressure by applying a low-pass filter with a cutoff
frequency of 0.8 cycles/day to those records. As shown in Figure 6.2-1, this filtering 
removes
semi-diurnal changes in water levels while preserving longer-term trends.
ANL-NBS-HS-000039, REV 00 86 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 16, Figure 7).
Figure 6.2-1. Result of Filtering Out Earth Tides on UE-25 c#2 Lower Bullfrog Interval
Pressure Heads, June 23-29, 1995
Changes in atmospheric pressure in the vicinity of the C-wells complex typically produce
synchronous (but opposite) changes in water levels in boreholes (Figure 6.2-2). The slope 
of a
line fit to a plot of water-level change as a function of atmospheric-pressure change is 
called the
barometric efficiency. Determination of the barometric efficiency of the Lower Bullfrog 
interval
in c#2 is shown in Figure 6.2-3. Barometric efficiency values of borehole intervals for 
which
drawdown was computed during this study ranged from 0.75 to 0.99 (Table 6.2-3). To 
compute
barometrically corrected drawdown, barometric effects were removed from borehole 
records by
subtracting the product of atmospheric-pressure change and barometric efficiency from 
the
change in water level.
ANL-NBS-HS-000039, REV 00 87 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], Figure 8).
Figure 6.2-2. Difference of the Atmospheric Pressure from Its Mean Plotted Against the Opposite 
of the
Difference of Concurrent Pressure Head from Its Mean
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], Figure 9).
Figure 6.2-3. Filtered Pressure-head Change in UE-25 c#2 Lower Bullfrog Interval as a Function
of Filtered Atmospheric-Pressure Change at the C-wells Complex, June 23-29, 1995
ANL-NBS-HS-000039, REV 00 88 December 2003
Table 6.2-3. Barometric Efficiency Values Determined for Borehole Intervals Monitored
at the C-wells Complex, Through May 13, 1996
Borehole Interval Barometer
Location Period of Record Barometric
Efficiency
Regression
Coefficient
Prow Pass C-wells June 23-29, 1995 0.96 0.98
Upper Bullfrog C-wells June 24-29, 1995 0.99 0.97 UE-25 c#1
Lower Bullfrog(a) C-wells June 23-29, 1995 0.97 0.98
Bullfrog-Tram C-wells June 23-29, 1995 0.97 0.98
Calico Hills C-wells June 23-29, 1995 0.93 0.94
Prow Pass C-wells June 23-29, 1995 0.93 0.97
Upper Bullfrog C-wells June 23-29, 1995 0.93 0.97
UE-25 c#2
Lower Bullfrog(a) C-wells June 23-29, 1995 0.91 0.96
Bullfrog-Tram C-wells June 23-29, 1995 0.91 0.96
Calico Hills(b) C-wells February 7-8, 1996 0.83 0.89
Lower Bullfrog C-wells May 9-13, 1996 0.87 0.92 UE-25 c#3
Bullfrog-Tram C-wells Not applicable 0.94(c) Not applicable
UE-25 ONC-1 Prow Pass ONC-1 July 1-Sept. 13,1995 0.99 0.90
USW H-4 Prow Pass to Lithic
Ridge ONC-1 June 8-12, 1995 0.91 0.87
UE-25 WT#14 Calico Hills C-wells June 4-12, 1995 0.89 0.94
UE-25 WT#3 Lower Bullfrog C-wells June 4-12, 1995 0.91 0.82
UE-25 p#1 Paleozoic carbonates C-wells Jan. 1-June 20, 1986 0.75 Not applicable
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 18, Table 5).
NOTE: (a) Barometric efficiency of Lower Bullfrog used, also, for Bullfrog-Tram in hydraulic test February 8-
13,
1996.
(b) Barometric efficiency of Calico Hills used, also, for Calico Hills-Upper Bullfrog in hydraulic test February
8-13, 1996.
(c) Barometric efficiency estimated from values for Bullfrog-Tram in c#1 and c#2.
(d) "Not applicable" means that no record was used to calculate the barometric efficiency for the Bullfrog-
Tram in c#3, per se. The barometric efficiency, in this case, was "estimated" by assuming that it was
the average of the barometric efficiency for the Bullfrog-Tram in c#1 and c#2.
6.2.3.1.3 Flow Distribution in the C-wells
During hydraulic tests conducted in the C-wells in February 1996 and from May 1996 to
November 1997, all hydrogeologic intervals in the C-wells that were being monitored 
responded
to pumping, regardless of the interval being pumped. Leakage around packers could have
occurred, although the packers were seated in non-rugose, sparsely fractured zones, but it 
is
extremely unlikely that all packers failed to seal properly. A more reasonable 
interpretation is
that fractures beyond borehole walls are so interconnected that packers emplaced in the 
C-wells
do not isolate the interval being pumped from other transmissive intervals within the 
volume of
aquifer stressed by the pumping.
Spinner and oxygen-activation flow surveys (Figure 6.2-4) were run in c#3 during the 
hydraulic
test in June 1995 to determine the flow distribution in the C-wells under pumping 
conditions.
ANL-NBS-HS-000039, REV 00 89 December 2003
However, those flow surveys failed to detect flow from the Prow Pass interval that was 
indicated
by heat-pulse flowmeter surveys conducted without pumping in the C-wells in 1991 
(Geldon
1996 [100396], pp. 12 to 20). Oxygen activation logs, employing high-energy "fast" 
neutrons,
can dynamically detect water movement inside and outside of casing. The technique 
consists of
a short neutron-activation period followed by a longer data-acquisition period; flow is 
detected
when the measured count-rate profile does not match the expected profile for a static
environment. Results of the 1991 and 1995 flow surveys were combined algebraically to
estimate a flow distribution during the hydraulic test in June 1995 (Table 6.2-4). That 
flow
distribution was adjusted for the hydraulic tests conducted in February 1996 and May 
1996 to
November 1997 (Table 6.2-4) by inserting discharge and drawdown values recorded at 
the same
elapsed time in the three hydraulic tests into Equation 1c below, which is an algebraic
manipulation of Equations 1a and 1b:
s1 = (P1Q1/4?T)W(u) (Eq. 1a)
s2 = (P2Q2/4?T)W(u) (Eq. 1b)
P2 = Q1P1s2/Q2s1 (Eq. 1c)
where
u = r2S/4Tt is a dimensionless parameter in which:
r[L] = radial distance from pumping well
S[L0] = storativity
T[L/T]= transmissivity of the hydrogeologic interval in question, which is the same in
Equations 1a and 1b
t[T] = elapsed time from beginning of pumping.
W(u) = * u
* ?{(e-u/u) du}; W(u) is the well function, which can be a confined, unconfined, or
leaky well function.
P1[L0] = test in June 1995.
P2[L0] = the proportion of flow determined for a hydrogeologic interval during a
hydraulic test in either February 1996 or May 1996 to November 1997, as
appropriate.
Q1[L3/T] = the average discharge during the hydraulic test in June 1995.
Q2[L3/T] = the average discharge during a hydraulic test in February 1996 or May 1996 
to
November 1997, as appropriate.
s1[L] = the drawdown in a hydrogeologic interval during the hydraulic test in June
1995.
s2[L] = the drawdown in a hydrogeologic interval during a hydraulic test in either
February 1996 or May 1996 to November 1997, as appropriate.
Equations 1a and 1b are based on the Theis equation (Theis (1935 [150327], p. 520, 
Equation 4)
except that s is used for drawdown instead of v, and Q is used for the discharge rate 
instead of F.
ANL-NBS-HS-000039, REV 00 90 December 2003
In the three hydraulic tests discussed in this report, the Lower Bullfrog interval 
consistently
contributed about 70 percent of the flow from observation wells to the pumping well at 
the Cwells
complex; the Upper Tram interval consistently contributed about 20 percent of that flow;
and all other intervals combined contributed about 10 percent of the total flow. To 
analyze the
drawdown in any hydrogeologic interval, the total discharge from c#3 first was 
multiplied by the
percentage of flow contributed by the interval being analyzed to avoid calculating 
erroneously
large values of transmissivity and storativity (both of which are directly proportional to
discharge).
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 19, Figure 10).
Figure 6.2-4. Flow Surveys in UE-25 c#3 During Hydraulic Testing in June 1995
ANL-NBS-HS-000039, REV 00 91 December 2003
Table 6.2-4. Interval Discharges 5,800 Minutes After Pumping Started in Hydraulic
Tests in UE-25 c#3, June 1995 to November 1997
June 1995 February 1996 May 1996 to November 1997
Hydro-
geologic
Unit
Dis-
charge
(L/s)
Draw-
down
(cm)
Flow
%
Dis-
charge
(L/s)
Draw-
down
(cm)
Flow
%
Dis-
charge
(L/s)
Draw-
down
(cm)
Flow
%
UE-25 c#1
Calico Hills 22.5 No data 3.8 8.45 No data 0.5 (est) 9.72 No data 1.1 (est)
Prow Pass 22.5 43.0 2.9 8.45 14.0 2.5 9.72 14.9 2.3
Upper Bullfrog 22.5 52.1 3.9 8.45 21.6 4.3 9.72 19.2 3.3
Lower Bullfrog 22.5 49.7 68.3 8.45 No data No data 9.72 21.0 66.8
Bullfrog-Tram 22.5 No data 89.4 8.45 19.5 92.7 9.72 N/A N/A
Upper Tram 22.5 No data 21.1 8.45 No data No data 9.72 No data 26.5
Lower Tram 22.5 No data trace 8.45 No data trace 9.72 No data trace
UE-25 c#2
Calico Hills 22.5 351.7 3.8 8.45 16.4 0.5 9.72 43.0 1.1
Prow Pass 22.5 75.6 2.9 8.45 14.6 1.5 9.72 22.2 2.0
Upper Bullfrog 22.5 62.2 3.9 8.45 25.0 4.2 9.72 26.5 3.8
Lower Bullfrog 22.5 49.4 68.3 8.45 No data No data 9.72 21.9 70.2
Bullfrog-Tram 22.5 No data 89.4 8.45 21.0 93.8 9.72 N/A N/A
Upper Tram 22.5 283.2 21.1 8.45 No data No data 9.72 No data 22.9
Lower Tram 22.5 239.6 trace 8.45 No data trace 9.72 No data trace
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 20, Table 6).
NOTE: The Bullfrog-Tram refers to the combined Lower Bullfrog and Upper Tram intervals tested together 
as one
unit during the February 1996 test. Flow proportion for the Bullfrog-Tram interval shown in June 1995 is the
sum of values for the Lower Bullfrog and Upper Tram intervals.
est = estimated; N/A = not applicable.
6.2.3.1.4 Monitoring Network
The monitoring network at the C-wells complex was selected after borehole c#3 was 
chosen as
the pumping well for all hydraulic tests conducted from 1995 to 1997 on the basis of its
successful performance during two hydraulic tests conducted in 1984 (Geldon 1996 
[100396],
pp. 48 to 68). Boreholes c#1 and c#2 were used as observation wells for the hydraulic 
tests
conducted in June 1995 and February 1996. Boreholes ONC-1, H-4, WT#14, WT#3, and 
p#1
also were used as observation wells for the longer-term hydraulic test conducted from 
May 1996
to November 1997. Recording barometers were located at the C-wells complex during all
hydraulic tests; a barometer located at borehole ONC-1 also was used during the third 
hydraulic
test. (See Figure 6.1-3 for a map showing the location of the observation wells.)
Borehole c#3 is 900.4 m deep (Geldon 1993 [101045], p. 2). The borehole is cased and 
grouted
to a depth of ~ 417 m, just below the water table (Geldon 1993 [101045], p. 7, Figure 3). 
During
the hydraulic test in June 1995, c#3 did not contain packers and was open from the Calico 
Hills
Formation to the Lower Tram interval. After packers were emplaced in August 1995,
ANL-NBS-HS-000039, REV 00 92 December 2003
manipulation of the packers, sliding sleeves, and slotted casing allowed selective 
hydraulic
communication with only the Lower Bullfrog and Upper Tram intervals during hydraulic 
and
tracer tests in February and March 1996 and with only the Lower Bullfrog interval from 
May
1996 to December 1997.
Borehole c#2 is 30.4 m from c#3 at the land surface (Geldon et al. 1998 [129721], p. 3, 
Figure 1)
and 910.1 m deep (Geldon 1993 [101045], p. 2). It is cased and grouted to a depth of ~ 
416.0 m
(Geldon 1993 [101045], p. 7, Figure 3). Five dual-mandrel packers, suspended on 7.30-
cmdiameter
tubing, were emplaced in the borehole to isolate hydrogeologic intervals throughout the
period of testing discussed in this report. Manipulation of packers and sliding sleeves 
allowed
hydraulic communication with six separate hydrogeologic intervals (Figure 6.1-5 and 
Table 6.2-
1) in June 1995, with the Lower Bullfrog and Upper Tram intervals in February and 
March 1996,
and with the Lower Bullfrog interval from May 1996 to December 1997.
Borehole c#1 is 68.4 m from c#3 at the land surface (Geldon et al. 1998 [129721], p. 3, 
Figure 1)
and is 897.6 m deep (Geldon 1993 [101045], p. 2). It is cased and grouted to a depth of ~ 
417.9
m (Geldon 1993 [101045], p. 7, Figure 3). Five dual-mandrel packers, suspended on 
7.30-cmdiameter
tubing, were emplaced in the borehole to isolate hydrogeologic intervals throughout the
period of testing discussed in this report. Manipulation of packers and sliding sleeves 
allowed
hydraulic communication with the Calico Hills, Prow Pass, Upper Bullfrog, and Lower 
Bullfrog
intervals in June 1995, with the Lower Bullfrog and Upper Tram intervals in February 
and
March 1996 and with the Lower Bullfrog interval from May 1996 to December 1997.
Borehole ONC-1 is 842.8 m from borehole c#3 at the land surface and is 469.4 m deep
(extending about 36.3 m below the water level in the borehole) (Nye County Nuclear 
Waste
Repository Project Office 1995 [156859], ONC-1 Drilling log). The borehole is 
telescoped
downward and has a diameter of about 13 cm in the saturated zone. Seven packers 
inflated
between the bottom of the casing and a depth of 410 m separate the unsaturated and 
saturated
zones; another packer emplaced at a depth of 452 m divides the saturated zone into two 
intervals.
The upper of the saturated-zone intervals is open in the Calico Hills Formation and the 
Prow
Pass Tuff; the lower of those intervals is open in the Prow Pass Tuff. Absolute 
transducers,
installed in all packed-off intervals, transmitted total (atmospheric plus hydraulic) 
pressures to a
data logger every 15 to 20 minutes during the tests reported here. Data from the 
lowermost
transducer, positioned at a depth of 458 m, were converted to pressure heads for analysis.
Borehole H-4, which is 2,245 m from borehole c#3 at the land surface, is 1,219 m deep. 
The
borehole diameter is 37.5 cm to a depth of 564 m and 22.2 cm below 564 m. Casing 
extends to a
depth of 561 m; it is perforated below the water level, which was at an average depth of 
518.3 m
from 1985 to 1995. A packer emplaced at a depth of 1,181 m separates the Prow Pass, 
Bullfrog,
and Tram Tuffs and the upper part of the Lithic Ridge Tuff from the lower part of the 
Lithic
Ridge Tuff in the borehole. A 48-mm-diameter piezometer tube is installed in the upper 
part of
the borehole, and a 62-mm-diameter piezometer tube is installed in the lower part of the
borehole. (Graves et al. 1997 [101046], pp. 4 to 5, Table 1; p. 100). Differential 
transducers
emplaced in the two monitored intervals transmitted hydraulic pressures to a data logger 
every
15 minutes during this study. Only the data from the upper interval were used.
ANL-NBS-HS-000039, REV 00 93 December 2003
Borehole WT#14, which is 2,249 m from borehole c#3 at the land surface, is 399 m deep. 
The
borehole has a diameter of 22.2 cm below the water table, which was at an average depth 
of
346.4 m from 1985 to 1995. The borehole is cased to a depth of 37 m and is open in the
Topopah Spring Tuff and Calico Hills Formation. A 62-mm-diameter piezometer tube is
installed in the borehole. (Graves et al. 1997 [101046], pp. 4 to 5, Table 1; p. 84). A 
differential
transducer emplaced in the piezometer tube transmitted hydraulic pressures to a data 
logger
every 15 minutes during this study.
Borehole WT#3, which is 3,526 m from borehole c#3 at the land surface, is 348 m deep. 
The
borehole has a diameter of 22.2 cm below the water table, which was at an average depth 
of
300.5 m from 1985 to 1995. The borehole is cased to a depth of 12 m and is open in the 
Bullfrog
Tuff. A 62-mm-diameter piezometer tube is installed in the borehole. (Graves et al. 1997
[101046], pp. 4 to 5, Table 1; p. 76). A differential transducer emplaced in the piezometer 
tube
transmitted hydraulic pressures to a data logger every 15 minutes during this study.
Borehole p#1, which is 630 m from borehole c#3 at the land surface, is 1,805 m deep. 
The
borehole diameter decreases from 37.5 to 15.6 cm with depth. Casing and cement 
emplaced to a
depth of 1,297 m isolate the Miocene tuffaceous rocks in the upper part of the borehole 
from
Paleozoic carbonate rocks in the lower part of the borehole. The water level for the 
Paleozoic
carbonate rocks in p#1 was monitored through a 38-mm-diameter piezometer tube. The 
average
depth to water in the piezometer tube was 361.8 m from 1985 to 1995. (Graves et al. 
1997
[101046], pp. 4 to 5, Table 1; p. 90). A differential transducer emplaced in the piezometer 
tube
transmitted hydraulic pressures to a data logger every 60 minutes during this study.
6.2.3.1.5 Description of Tests
A hydraulic test (DTN: GS960108312313.002 [159228]) was conducted in June 1995 to
determine hydraulic properties of six hydrogeologic intervals (Figure 6.2-5) at the C-
wells
complex (Table 6.2-1) (A detailed description of the field tests is contained in Umari 
2002
[162858], Binder 3, Sections D-2 to D-6). The six intervals were isolated by packers in
boreholes c#1 and c#2. Sliding sleeves open in the packed-off intervals of the observation 
wells
allowed hydraulic communication with the pumping well c#3, which was uncased and 
contained
no packers to isolate intervals. Because of malfunctioning transducers, analyzable data 
were
obtained only from the Prow Pass, Upper Bullfrog, and Lower Bullfrog intervals of c#1 
and from
the Calico Hills, Prow Pass, Upper Bullfrog, and Lower Bullfrog intervals of c#2.
The hydraulic test began on June 12 and ended on June 16, after 4.03 days of pumping. 
(Note
that data were collected over thousands of elapsed minutes, the measure of time used by 
dataacquisition
software and needed for hydraulic calculations. For the summarizing discussions
here, those time intervals are expressed in hours and days.) Recovery was monitored until 
June
29, by which date it appeared to be complete in all intervals. At an average discharge rate 
of
22.5 L/s, drawdown in c#3 rapidly increased to a maximum of 10.9 m (Figure 6.2-5). The
pumping in c#3 produced drawdown ranging from 43.0 to 52.1 cm in intervals of c#1 
(Figure
6.2-6) and from 49.4 to 352 cm in intervals of c#2 (Figure 6.2-7).
ANL-NBS-HS-000039, REV 00 94 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 22, Figure 11).
Figure 6.2-5. UE-25 c#3 Discharge and Drawdown, June 12, 1995 (~0 minutes),
to June 16, 1995 (~5,800 minutes)
ANL-NBS-HS-000039, REV 00 95 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 23, Figure 12).
Figure 6.2-6. UE-25 c#1 Drawdown
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 23, Figure 13).
Figure 6.2-7. UE-25 c#2 Drawdown
ANL-NBS-HS-000039, REV 00 96 December 2003
The most permeable interval identified in the hydraulic test conducted in June 1995, the 
Lower
Bullfrog interval, was chosen for subsequent tracer tests at the C-wells complex to 
increase the
chance of successful transport of tracers between the injection and recovery wells. 
Because the
transducer in the Lower Bullfrog interval of c#3 was not working, the packers between 
the
Lower Bullfrog and Upper Tram intervals in all three of the C-wells were deflated, and 
the
combined Lower Bullfrog and Upper Tram intervals (shown in Figure 6.1-5 as the 
Bullfrog-
Tram interval) became the test interval for the following series of tests.
After testing pump performance in January 1996 and allowing water levels in the C-wells 
to
recover, pumping began on February 8, 1996, to establish a steep, quasi-steady-state 
hydraulic
gradient between c#2 (the injection well) and c#3 (the recovery well) for a conservative 
tracer
test. Tracer injection on February 13 disturbed the hydraulic pressure in the injection 
interval for
12.5 hours and effectively terminated the analyzable drawdown record. The 4.85 days of
drawdown recorded between the start of pumping and the injection of tracer on February 
13
(when the hydraulic pressure in the injection interval was disturbed) were analyzed as an
hydraulic test.
During the hydraulic test in February 1996, operation of the pump outside its optimal
performance range caused discharge to decrease steadily, despite an adjustment of the 
pump
speed on February 12, some 5,640 minutes (3.917 days) after pumping started. Prior to 
that
adjustment, discharge decreased from 8.78 to 8.21 L/s. Adjusting the pump speed 
restored the
discharge to 8.75 L/s, but discharge immediately began to decrease and was at 8.57 L/s 
when the
tracer test started on February 13 (Figure 6.2-8). Although average discharge after 
adjusting the
pump speed was 0.10 L/s larger than before that adjustment, deviation from the average
discharge of 8.49 L/s was just 3 percent for the entire period of pumping.
As shown in Figure 6.2-8, the pumping produced as much as 2.86 m of drawdown in the
Bullfrog-Tram interval of c#3 (96 percent of which occurred in the first 10 minutes).
Adjustment of the pump speed caused a step-like increase of 0.19 m in c#3 drawdown, 
but it had
no discernible effect on drawdown in the other C wells. Although oscillatory, drawdown 
in c#1
steadily increased and ranged from 14.3 to 22.1 cm in the Prow Pass, Upper Bullfrog, and
Bullfrog-Tram intervals (Figure 6.2-9). Likewise oscillatory, drawdown in c#2 steadily
increased and ranged from 14.9 to 25.3 cm in the Calico Hills, Prow Pass, Upper 
Bullfrog, and
Bullfrog-Tram intervals (Figure 6.2-10). Steady increases in observation-well drawdown
together with small deviations from the average discharge enabled the observation-well
drawdown for the entire period before tracer injection to be analyzable.
ANL-NBS-HS-000039, REV 00 97 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 24, Figure 14).
Figure 6.2-8. UE-25 c#3 Discharge and Drawdown, February 8, 1996 (~0 minutes),
to February 13, 1996 (~7,000 minutes)
ANL-NBS-HS-000039, REV 00 98 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 ([164425], p. 25, Figure 15).
Figure 6.2-9. UE-25 c#1 Drawdown, February 8, 1996 (~0 minutes),
to February 13, 1996 (~7,000 minutes)
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 25, Figure 16).
Figure 6.2-10. UE-25 c#2 Drawdown, February 8, 1996 (~0 minutes),
to February 13, 1996 (~7,000 minutes)
ANL-NBS-HS-000039, REV 00 99 December 2003
After the tracer test in the Bullfrog-Tram interval ended in March 1996, a new transducer 
was
installed in the Lower Bullfrog interval of c#3, and packers in the borehole were 
reconfigured.
Subsequently, it was possible to conduct hydraulic and tracer tests in the isolated Lower 
Bullfrog
interval. With nearly continuous pumping, a series of tracer tests was conducted in that 
interval
by the USGS and by LANL from May 1996 to November 1997. Pumping in c#3 to 
establish a
steep, quasi-steady-state hydraulic gradient for tracer tests in the Lower Bullfrog interval 
began
May 8, 1996. From May 24, 1996, to March 26, 1997, the pump shut off 11 times 
because of
problems with the generators that provided power to the site. Between March 26 and May 
8,
1997, the pump operated erratically because of continued problems with one of the 
generators.
Problems with the power supply caused the pump to shut off intermittently between May 
30 and
September 29, 1997, and at least once a day between October 15 and November 12, 
1997.
Pumping was terminated on November 12, 1997, 553.24 days after pumping started, and
recovery was monitored until December 31, 1997.
Discharge between May 8, 1996, and March 26, 1997, initially oscillated between 9.6 and 
9.8
L/s, eventually stabilized at about 9.4 L/s, and averaged 9.53 L/s (Figure 6.2-11). After
generator problems were resolved on May 8, 1997, discharge decreased steadily from 9.3 
to 8.9
L/s on November 12, 1997, and averaged 9.01 L/s. The volume of water withdrawn 
between
May 8, 1996, and November 12, 1997, was 440.2 million L, equivalent to an average 
discharge
of 9.21 L/s.
As in previous hydraulic tests, drawdown in the pumped well was large and reached 
steady-state
conditions rapidly (Figure 6.2-11). Drawdown in the Lower Bullfrog interval of c#3 
reached 4.8
m in 60 minutes and remained at 4.85 to 5.0 m until October 16, 1996, 161.11 days 
(232,000
minutes) after pumping started. After March 26, the frequent pump shutoffs kept 
drawdown less
than 5.9 m, except during the process of restarting the pump. Pump shutoffs typically 
caused
rapid and complete or nearly complete recovery in c#3, but those effects were reversed 
just as
rapidly when the pump was restarted. Tracer-test operations affected drawdown in the 
pumped
well minimally. Recovery from pumping on December 12, 1997, approximately 30 days 
(42,965
minutes) after pumping stopped, was 99 percent of antecedent drawdown. The prolonged 
period
of unsteady pump discharge after March 26, 1997, effectively ended the drawdown 
record that
could be analyzed as an hydraulic test for all observation wells except ONC-1. The 
analyzable
drawdown record from May 8, 1996, to March 26, 1997, is 322.32 days in duration. With 
11
down times ranging from 2 to 185 minutes, the pump was off for 10.82 hours (649 
minutes),
about 0.1 percent of the time, during that period.
ANL-NBS-HS-000039, REV 00 100 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 26, Figure 17).
Figure 6.2-11. UE-25 c#3 Discharge and Drawdown, May 8, 1996 (~0 minutes),
to November 12, 1997 (~800,000 minutes)
ANL-NBS-HS-000039, REV 00 101 December 2003
Drawdown in response to pumping the Lower Bullfrog interval of c#3 is known to have 
occurred
in the Prow Pass, Upper Bullfrog, and Lower Bullfrog intervals of c#1 and in the Calico 
Hills,
Prow Pass, Upper Bullfrog, and Lower Bullfrog intervals of c#2. Drawdown in all 
intervals of
these boreholes generally increased steadily but was very oscillatory. Peak drawdown by 
March
26, 1997, ranged from about 36 to 42 cm in intervals of c#1 (Figure 6.2-12) and from 
about 35 to
51 cm in intervals of c#2 (Figure 6.2-13).
Disruptions of drawdown in the Lower Bullfrog and other intervals of c#1 and c#2 
occurred
from pump shutoffs 11 times between May 1996 and March 1997. Pump shutoffs (most 
of the
unlabeled downward spikes in Figures 6.2-12 and 6.2-13) generally resulted in 20 to 50 
percent
recovery of water levels. However, these effects dissipated 50 to 500 minutes after the 
pump
was restarted and did not affect analysis of the drawdown.
Recirculation of water during tracer tests conducted between May and November 1996 
generally
caused small decreases in drawdown in the Lower Bullfrog interval of c#1 or decreases 
followed
by increases in drawdown in the Lower Bullfrog interval of c#2 at the start and end of
recirculation, which generally lasted 70 to 560 minutes. However, recirculation of water 
in c#1
from June 17 to July 3, 1996, to facilitate transport of iodide tracer between the injection 
and
recovery wells, caused drawdown in the Lower Bullfrog interval of c#1 to decrease in 
steps for
23,350 minutes (Figures 6.2-12 and 6.2-14a). Pumping water into c#1 faster than it could 
drain
probably caused the drawdown to decrease. Periodic increases in the injection pump rate 
caused
this decrease to occur in steps.
Tracer injection during four tests that were conducted between May 1996 and November 
1997
caused increased drawdown in the Lower Bullfrog interval of c#1 or c#2 that generally 
lasted
180 to 750 minutes. However, following injection of 2,6 difluorobenzoic acid tracer into 
c#2 on
January 10, 1997, drawdown in the Lower Bullfrog interval of c#2 remained high for 
8,360
minutes (Figures 6.2-13 and 6.2-14b). Changes in hydraulic head associated with the 
dense
tracer injection solution also could have produced the observed water-level changes in 
c#2.
ANL-NBS-HS-000039, REV 00 102 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 27, Figure 18).
Figure 6.2-12. UE-25 c#1 Drawdown, May 8, 1996 (~0 minutes),
to March 26, 1997 (~470,000 minutes)
ANL-NBS-HS-000039, REV 00 103 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 28, Figure 19).
NOTE: PFBA: Pentafluorobenzoic acid; DFBA: 2,6 difluorobenzoic acid.
Figure 6.2-13. UE-25 c#2 Drawdown, May 8, 1996 (~0 minutes),
to March 26, 1997 (~470,000 minutes)
ANL-NBS-HS-000039, REV 00 104 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 29, Figure 20).
NOTE: (a) Iodide tracer test in c#1, June 17, 1996 (~57,000 minutes), to July 5, 1996 (~83,000 minutes).
(b) 2,6 DFBA tracer test in c#2, January 9, 1997 (~354,000 minutes), to January 18, 1997 (~368,000
minutes).
2,6 DFBA: 2,6 Difluorobenzoic acid.
Figure 6.2-14. Disturbance of Drawdown in Lower Bullfrog Interval of UE-25 c#1
and UE-25 c#2 by Tracer Tests in (a) 1996 and (b) 1997
ANL-NBS-HS-000039, REV 00 105 December 2003
Hypotheses regarding disturbances from tracer-test operations cannot be tested and, 
therefore,
are presented only for consideration. It is important to note that (1) tracer-test operations
conducted in one borehole generally did not affect drawdown in other boreholes and (2)
disturbances from tracer-test operations did not affect analyses of drawdown in c#1 and 
c#2.
Events of unknown origin caused hydraulic heads in the Lower Bullfrog interval of c#1 
and c#2
to rise 5 cm to 8 cm from June 1 to June 11, 1996 (a period of 14,800 minutes) and from
November 6, 1996 to November 14, 1996 (a period of 11,900 minutes). Because six 
observation
wells within 3.5 km of c#3 showed similar rises in hydraulic head, the events that 
produced these
disturbances could not have been local in scale.
Shutting off the pump in c#3 on November 12, 1997, caused erratic responses in the 
Lower
Bullfrog intervals of c#2 and c#1 that are not analyzable. Recovery in the Lower Bullfrog
interval of c#1 reached a plateau from 8,000 to 38,500 minutes after pumping stopped, 
after
which it began increasing cyclically. On December 29, 1997, 46.53 days (67,000 
minutes) after
pumping stopped, recovery in the Lower Bullfrog interval of c#1 was about 95 percent of 
the
antecedent drawdown (Figure 6.2-15). The transducer in the Lower Bullfrog interval of 
c#2 was
removed on December 9, 1997, at a time when readings from the transducer were erratic, 
and
recovery was only about 70 percent of the antecedent drawdown.
"Recovery" (as used in the previous paragraph and in Figure 6.2-15) is a calculated value. 
First,
the pattern of water-level decline prior to stopping the pump (antecedent water-level 
decline) is
extrapolated beyond the time of stopping the pump. (This extrapolated antecedent water-
level
decline is presented as the blue antecedent drawdown curve in Figure 6.2-15.) Then, for 
any
point in time after pump stoppage, the "recovery" is calculated as the distance from the
extrapolated antecedent water level to the recovered water level. So, "recovery" is larger 
than
the distance that the water level has rebounded relative to where it was at the point of 
shutting off
the pump.
Pumping in the Lower Bullfrog interval of c#3 from May 1996 to March 1997 caused 
drawdown
in all four of the observation wells beyond the C-wells complex that are completed in 
Miocene
tuffaceous rocks. As in c#1 and c#2, drawdown in the four outlying observation wells 
was very
oscillatory. Drawdown in these wells was not affected by pump shutoffs or tracer test
operations.
Drawdown in ONC-1, the nearest observation well to the C-wells, was detected 200 
minutes
after pumping started and increased steadily thereafter (Figure 6.2-16). Peak drawdown 
by
March 26, 1997, was about 28 to 30 cm. Peak drawdown when pumping ended on 
November
12, 1997, was about 36 to 37 cm. Recovery in ONC-1 followed a pattern similar to the 
Lower
Bullfrog interval in c#1 (Figure 6.2-15). On December 29, 1997, 46.875 days (67,500 
minutes)
after pumping stopped, recovery in ONC-1 was about 76 percent of the antecedent 
drawdown.
Borehole WT#3, the farthest observation well from the C-wells, responded like the C-
wells and
ONC-1 to the pumping in c#3 that began on May 8, 1996. Drawdown in WT#3 was 
detected
6.34 days (9,130 minutes) after pumping started (Figure 6.2-17). Peak drawdown by 
March 26,
1997, was about 14 to 16 cm. Drawdown in WT#3 was more oscillatory than in the other
observation wells after 166.67 days (240,000 minutes) of pumping. This behavior was 
possibly
ANL-NBS-HS-000039, REV 00 106 December 2003
because (1) WT#3 was much farther from the pumping well than the other observation 
wells and
affected by environmental stresses that did not extend to the other wells and (2) pumping-
related
water-level changes in WT#3 were much smaller than in the other observation wells and,
therefore, harder to separate from barometric and Earth-tide effects.
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 30, Figure 21).
NOTE: Pump was turned off 11/12/97 at 15:59:50 PST.
Figure 6.2-15. UE-25 c#1 Lower Bullfrog Recovery, November 12, 1997 (~0 minutes),
to December 31, 1997 (~70,000 minutes)
ANL-NBS-HS-000039, REV 00 107 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 31, Figure 22).
Figure 6.2-16. Drawdown in UE-25 ONC-1, May 8, 1996 (~0 minutes),
to November 12, 1997 (~800,000 minutes)
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 31, Figure 23).
Figure 6.2-17. Drawdown in UE-25 WT#3, May 8, 1996 (~0 minutes),
to March 26, 1997 (~480,000 minutes)
ANL-NBS-HS-000039, REV 00 108 December 2003
Unlike other observation wells monitored during the hydraulic test that began in May 
1996, H-4
and WT#14 exhibited steady-state drawdown as pumping progressed (Figure 6.2-18).
Drawdown in both boreholes was delayed for about 5,000 minutes after pumping started,
although very small, oscillatory water-level changes, possibly caused by borehole-storage
release, occurred during this time. Between 5,000 and 72,000 minutes after pumping 
started,
drawdown increased steadily in response to pumping. Drawdown in H-4 peaked at about 
22 cm;
drawdown in WT#14 peaked at about 15 cm. After about 50 days (72,000 minutes) of 
pumping,
fluxes from recharge boundaries, probably a transmissive fault, prevented further 
drawdown. As
in a hydraulic test of the Tram interval in c#1 conducted in 1984 (Geldon 1996 [100396], 
pp. 67
to 68), recharge boundaries affecting H-4 and WT#14 are inferred to be faults present 
near the
observation wells. Numerous faults are located near H-4 (Day et al. 1998 [101557]), and 
several
segments of the Paintbrush Canyon Fault are located near WT#14 (Dickerson and Drake 
1998
[102781]). Conversely, there are no known changes in stratigraphy or lithology between 
the Cwells
and either H-4 or WT#14 that might be interpreted to create an hydraulic boundary.
6.2.3.2 Hydraulic Tests Conducted in 1998 and 1999 (Prow Pass Interval)
Pumping in c#2 to create a forced hydraulic gradient for tracer tests in the Prow Pass 
interval at
the C-wells complex began June 2, 1998, and continued uninterrupted until September 
22, 1998.
(Detailed description of the field tests is contained in Umari 2002 [162858], Binder 12, 
Sections
M-20 to M-22) The pump in c#2 shut off for 70 minutes on September 22 as one of two 
packers
at the bottom of the Prow Pass interval (number 3) was being deflated. Injection of water 
into
c#3 to expedite tracer transport began June 11 and continued without interruption until
September 2. The injection pump was off briefly on September 2 and 3 while injection 
tubing
was removed from c#3. Tracers were injected into c#3 on June 17 and into c#1 on July 
31.
Responses of c#1, c#3, and ONC-1 to pumping June 2 to June 11, in advance of the tracer 
tests,
were analyzed as a constant-rate withdrawal test. After water injection into c#3 began on 
June
11, the superimposed effects of pumping water from c#2, injecting water into c#3, 
injecting
tracers into c#3 and c#1, operating a mixing pump in c#3 intermittently, and mechanical
problems that affected pumping and injection rates made it difficult to analyze data from 
the
C-wells quantitatively. However, ONC-1 was far enough away from the pumping and 
injection
wells that a water-level rise in ONC-1 resulting from injecting water into c#3 clearly 
could be
separated from relatively minor drawdown in the well caused by pumping c#2. The 
water-level
rise in ONC-1 from June 11 to September 1 was analyzed as a constant-rate injection test.
ANL-NBS-HS-000039, REV 00 109 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 32, Figure 24).
Figure 6.2-18. Drawdown in USW H-4 and UE-25 WT#14, May 8, 1996 (~0 minutes),
to December 4, 1996 (~300,000 minutes)
ANL-NBS-HS-000039, REV 00 110 December 2003
6.2.3.2.1 Performance Tests
Hydraulic and tracer tests in the Prow Pass interval were preceded by pump-performance, 
stepdrawdown,
and 1-day hydraulic tests conducted in c#2 and c#3 from April 21 to May 29, 1998.
These tests were designed primarily to determine whether c#2 could be used as a 
pumping well
for tracer tests and what the optimum pumping rate should be. These tests also were 
analyzed to
determine values of hydraulic properties that would be expected from a longer hydraulic 
test that
was planned to precede tracer tests in the Prow Pass interval. Fluctuations in water and
atmospheric pressures between performance tests indicated barometric efficiency values 
(Table
6.2-5) for the C-wells and ONC-1 that were used to analyze hydraulic tests (DTN:
GS990408312315.002 [140115], DTN: MO0212SPANYESJ.149 [161274]) in the Prow 
Pass
interval.
Table 6.2-5. Barometric Efficiency in the C-wells and UE-25 ONC-1
Interval c#1 c#2 c#3 UE-25 ONC-1
Calico Hills N/A 0.93 0.94 N/A
Prow Pass 0.96 0.93 1.0 0.99
Upper Bullfrog 0.99 0.93 ?1.0 N/A
Lower Bullfrog 0.97 N/A N/A N/A
Output DTN: GS031008312314.004, (from Input DTNs: GS990408312315.002 [140115] and MO0212SPANYESJ.149 
[161274]).
NOTE: N/A: not applicable.
6.2.3.2.2 Analytical Methods
Analytical solutions were used to analyze data from hydraulic tests in the Prow Pass 
interval.
Most of the data were analyzed using the method of Streltsova-Adams (1978 [150754])
(Strelsova-Adams.vi V 1.0, STN: 10971-1.0-00 [162756]) for a fissure-block aquifer. 
Analysis
of data in this study was restricted to observation wells because most water-level changes 
in
pumping wells at the C-wells complex are too large and rapid (Geldon 1996 [100396], 
pp. 12 to
69) to be explained solely by hydraulic properties of the pumped interval.
ANL-NBS-HS-000039, REV 00 111 December 2003
6.2.3.2.3 Constant-Rate Withdrawal Test
A constant-rate withdrawal (CRW) test in the Prow Pass interval started June 2, 1998. 
The
pumping well for this test was c#2, and the observation wells for the test were c#1, c#3, 
and
ONC-1.
Prior to starting the test, the packer in c#2 between the Prow Pass and Calico Hills 
intervals was
deflated, and the two intervals, together, were pumped for 37 minutes at a rate of 0.57 L/s 
to fill
tubing in the pumping well to the level of the flowmeter. After pumping stopped, the 
packer in
c#2 between the Prow Pass and Calico Hills intervals was reinflated. With slight residual 
effects
from the pre-test pumping (which were removed to analyze the test), pumping for the 
CRW test
in the Prow Pass began at 16:00 hours on June 2. Discharge averaged 0.33 L/s between 
June 2
and 11, a period of 12,500 minutes. Pumping water into c#1 on June 5 to attempt a tracer 
test,
injecting argon gas into c#1 on June 9 to blow sediment out of the tracer injection valve, 
and
testing the downhole mixing pump in c#3 on June 10 briefly disturbed discharge from 
c#2 as
well as pressures in c#1 and c#3. The CRW test was terminated on June 11, 1998, at 
08:19 when
operations began for a tracer test between c#3 and c#2.
The pumping in c#2 caused 135 m of drawdown in the Prow Pass interval of c#2 three 
minutes
after pumping started. However, the water level rebounded 22 m in the next nine minutes.
Subsequently, drawdown increased steadily but slowly and was about 128 m after 12,500
minutes of pumping. On the basis of values of transmissivity and storativity determined 
in this
and previous tests in which the drawdown in the Prow Pass in observation wells was 
analyzed,
only 1.04 percent of the 128-m drawdown in the Prow Pass of the pumped well c#2, 
namely 1.34
m, is estimated to have resulted from stressing the aquifer. The remainder of the 
drawdown is
attributed to head losses in the well bore.
The pumping in c#2 caused oscillatory drawdown in the Prow Pass interval of the 
observation
wells. After 12,500 minutes of pumping, this drawdown was 54 cm in c#3 (Figure 6.2-
19), 12
cm in c#1 (Figure 6.2-20), and 0.9 cm in ONC-1. Plotted on log-log scales, drawdown in 
the
Prow Pass interval of c#1 and c#3 indicated delayed yield that is characteristic of a 
fissure-block
aquifer (Streltsova-Adams 1978 [150754]), Figures 6.2-21 and 6.2-22.
ANL-NBS-HS-000039, REV 00 112 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS990408312315.002 [140115]).
Figure 6.2-19. UE-25 c#3 Prow Pass Drawdown, June 2, 1998 (~0 minutes),
to June 11, 1998 (~12,800 minutes)
Output DTN: GS031008312314.004 (from Input DTN: GS990408312315.002 [140115]).
Figure 6.2-20. UE-25 c#1 Prow Pass Drawdown, June 2, 1998 (~0 minutes),
to June 11, 1998 (~12,800 minutes)
ANL-NBS-HS-000039, REV 00 113 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS990408312315.002 [140115]).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.2-21. Drawdown in the Prow Pass Interval of c#1 in Response to Pumping c#2, Starting
June 2, 1998, Exhibiting Delayed Yield, Characteristic of a Fissure-block Aquifer
Output DTN: GS031008312314.004 (from Input DTN: GS990408312315.002 [140115]).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.2-22. Drawdown in the Prow Pass Interval of c#3 in Response to Pumping c#2, Starting
June 2, 1998, Exhibiting Delayed Yield, Characteristic of a Fissure-block Aquifer
0.001
0.01
0.1
1
1 10 100 1000 10000 100000
ELAPSED MINUTES
DRAWDOWN IN FEET
Series1
ANL-NBS-HS-000039, REV 00 114 December 2003
The pumping in c#2 indicated that the Calico Hills and Prow Pass intervals are connected 
by
fractures beyond borehole walls because the Calico Hills responded to pumping in the 
Prow Pass
wherever it was monitored. During the CRW test, the water level in the Calico Hills 
interval was
drawn down as much as 19 cm in c#2 and 12 cm in c#3. In contrast, no drawdown was 
observed
below the Prow Pass interval in c#2 and c#3 and below the Upper Bullfrog interval in c#1 
during
this test. The Upper Bullfrog drawdown in c#1 was 55 cm. The general lack of a response 
to
pumping below the Prow Pass probably indicates that the highly permeable Lower 
Bullfrog and
Upper Tram intervals in the C-wells were isolated from the Prow Pass interval during the 
CRW
test.
The responses of the Calico Hills in the C-wells and the Upper Bullfrog in c#1 during 
pumping
of the Prow Pass interval in c#2 made it necessary to apportion flow among the 
responding
intervals to determine hydraulic properties. Lacking a flow survey for the test conditions,
interval flow was determined by solving analytical equations simultaneously for interval
discharge and transmissivity. To make the number of equations equal to the number of
unknowns, it was assumed that (1) transmissivity values for the Calico Hills and Prow 
Pass
intervals in the C-wells are constant, (2) the transmissivity of the Calico Hills is 5.6 m2/d 
(on the
basis of previous hydraulic tests), and (3) flow laterally and vertically within the Calico 
Hills
interval was the same in each of the C-wells during the test. These assumptions were 
based on
analyses and interpretations of previous hydraulic tests, borehole flow surveys, borehole
geophysical logs, and other information, which are discussed in Section 6.2.4.1 and in 
Geldon
(1996 [100396], pp. 12 to 69).
Calculations indicated that the Prow Pass interval contributed 94 percent of the total flow 
in c#2
and c#3 but only 24 percent of the flow in c#1. The substantially different flow from the 
Prow
Pass in c#1 does not seem reasonable because lithologic changes that might account for 
variable
flow do not occur in the Prow Pass interval at the C-wells complex. It is more likely that 
flow
from the Calico Hills interval, the interconnectivity between the Calico Hills and Prow 
Pass, or
the transmissivity of either or both the Prow Pass and Calico Hills intervals is not 
constant
throughout the C-wells complex. Unquantifiable uncertainty results from failure to 
apportion
flow satisfactorily.
Hydraulic properties of the Prow Pass interval determined from analyses of drawdown 
during the
CRW test are summarized in Table 6.2-6. Input parameters (aquifer thickness, fracture 
halfspacing,
interborehole distance, and discharge rate) needed in the analyses are also presented in
Table 6.2-6.
6.2.3.2.4 Constant-Rate Injection Test
From June 11 to September 1, 1998, a period of 118,159 minutes, 676,973 L of water 
was
pumped into c#3 to conduct tracer tests. The injection rate ranged from 0.032 to 0.16 L/s 
before
tracers were injected into c#3 on June 17, but it subsequently was stabilized by periodic 
valve
adjustments. From June 11 to September 1, the injection rate averaged 0.095 L/s.
As water was being injected into c#3 from June 11 to September 1, 2,311,290 L of water 
were
withdrawn from c#2 at an average rate of 0.33 L/s. Injecting water into c#3 caused the 
discharge
from c#2 to oscillate within a range of 0.05 L/s. The discharge from c#2 ranged from 
0.30 to
ANL-NBS-HS-000039, REV 00 115 December 2003
0.35 L/s after water injection into c#3 started. Lowering the frequency of the pump in c#2 
and
increasing backpressure on it between August 3 and 31 decreased the discharge from c#2 
to a
range of 0.28 to 0.33 L/s after August 31.
Table 6.2-6. Hydraulic Properties of the Prow Pass Interval in the C-wells
and Input Parameters Used in Obtaining Them
Borehole c#1 c#3 ONC-1
Test dates June 2-11, 1998 June 2-11,1998 June 11-Sep. 1, 1998
Period of record (min) 12,500 12,500 ?140,000
Analyzed data Drawdown Drawdown Water-level rise
Transmissivity (m2/d) 30 30 30
Hydraulic conductivity, fractures (m/d) 1 0.8 2
Hydraulic conductivity, matrix (m/d) 0.000003 0.0002 0.00002
Hydraulic conductivity (m/d) No Data No Data No Data
Storativity, fractures 0.00004 0.00004 0.0002
Storativity, matrix 0.0003 0.0004 0.002
Storativity * 0.0004 0.0004 0.002
Distance from pumping well, c#2(m) 82.6 28.7 ?843
Transmissive thickness (m) 18.9 31.7 18.9
Fracture half-spacing (m) 0.34 2.0 0.34
Discharge (L/s) 0.078 0.309
DTN: GS990408312315.002 [140115]. Output DTN: GS031008312314.004.
NOTE: * Combined storativity: sum of fractures and matrix storativities.
Water levels in the Prow Pass interval of c#2 oscillated as much as 10 m between 
readings due to
injection of water into c#3. Although the water injection into c#3 caused drawdown in the 
Prow
Pass interval of c#2 to decrease from 128 to 115 m in the first 11 days after it began, 
pumping in
c#2 eventually predominated over the superimposed effects of the water injection. From 
June 22
to September 1, the range in c#2 drawdown increased from 115-125 m to 130-143 m 
(Figure
6.2-23).
Drawdown in the Prow Pass interval of c#3 decreased from +0.58 m to a range typically 
between
-25 and -30 m between June 11 and September 1 (the period of continuous injection of 
water into
c#3 [Figure 6.2-24]). This pronounced water-level rise was affected slightly by 
periodically
adjusting the injection rate. Drawdown fluctuated markedly from +87 to -32 m while 
tracers
were injected into c#3 on June 17 and 18.
Drawdown in the Prow Pass interval of c#1 was disturbed significantly by tracer-test 
operations
in c#3 and c#1 from June 11 to September 1. Injection of water into c#3 decreased 
drawdown in
c#1 from 13 to 2.8 cm between June 11 and July 27, but drawdown subsequently 
increased and
ranged from 4.0 to 7.9 cm by September 1 (Figure 6.2-25). Injection of tracers into c#3 
on June
17 increased drawdown from 8.9 cm to as much as 13 cm, whereas tracer injection in c#1 
on July
31 decreased drawdown from +5.9 to -174 cm and then increased it to +10 cm. Removal 
of
injection tubing from c#1 on June 26 to replace a cracking valve increased drawdown 
from 10 to
ANL-NBS-HS-000039, REV 00 116 December 2003
217 cm and then decreased it to -16 cm. Reinstallation of the tubing on July 13 increased
drawdown from 5.5 to 10 cm and then decreased it to -1,150 cm.
Drawdown in ONC-1 decreased irregularly from +1.1 to -2.3 cm between June 11 and
September 1 (Figure 6.2-26). Sharply increased drawdown about 9,000 minutes after 
injection
of water into c#3 began may be related to tracer injection into c#3 on June 17, although 
the
timing of this spike does not correlate precisely with the timing of tracer injection in c#3.
DTN: GS990408312315.002 [140115]. Output DTN: GS031008312314.004.
Figure 6.2-23. UE-25 c#2 Prow Pass Drawdown, June 11, 1998 (~0 minutes)
to September 1, 1998 (~120,000 minutes)
Water-level rises in the C-wells from June 11 to September 1, 1998, were very irregular 
and too
disturbed by tracer-test operations to be analyzed quantitatively. However, the water-
level rise
in ONC-1 during this period (with superimposed drawdown from pumping c#2 removed) 
could
be matched to the type curves of Streltsova-Adams (1978 [150754]) (Streltsova-
Adams.vi, V 1.0,
STN: 10971-1.0-00 [162756]) for a fissure-block aquifer. This analysis (presented in 
Table 6.2-
6) indicated a transmissivity of 30 m2/d, a fracture hydraulic conductivity of 2 m/d, 
insignificant
matrix hydraulic conductivity, and a storativity of 0.002 (90 percent of which is in the 
matrix).
The Prow Pass interval in ONC-1 and the C-wells have equally low permeability, but 
storativity
is an order of magnitude larger between ONC-1 and the C-wells than at the C-wells 
complex.
ANL-NBS-HS-000039, REV 00 117 December 2003
DTN: GS990408312315.002 [140115]. Output DTN: GS031008312314.004.
Figure 6.2-24. UE-25 c#3 Prow Pass Drawdown, June 11, 1998 (~0 minutes),
to September 1, 1998 (~120,000 minutes)
DTN: GS990408312315.002 [140115]. Output DTN: GS031008312314.004.
Figure 6.2-25. UE-25 c#1 Prow Pass Drawdown, June 11, 1998 (~0 minutes),
to September 1, 1998 (~120,000 minutes)
ANL-NBS-HS-000039, REV 00 118 December 2003
DTN: GS990408312315.002 [140115]. Output DTN: GS031008312314.004.
Figure 6.2-26. UE-25 ONC-1 Prow Pass Drawdown, June 11, 1998 (~0 minutes),
to September 1, 1998 (~120,000 minutes)
6.2.4 Hydraulic Properties
Hydraulic tests conducted at the C-wells complex from 1995 to 1997 revealed much 
about the
ability of hydrogeologic intervals in the C-wells and the Miocene tuffaceous rocks in the 
vicinity
to store and transmit water. However, it must be emphasized that hydraulic properties 
computed
from these tests pertain only to the structural setting in which the tests were conducted. 
The
Lower Bullfrog interval is the most permeable interval in the C-wells because it is located 
in
these boreholes where two intersecting faults have caused intense fracturing. The Calico 
Hills
interval is the least permeable interval in the C-wells, probably because it is the farthest 
interval
vertically from faults that intersect these boreholes. The combination of its large distance 
from
faults and its low degree of welding (and, thus, high ductility) result in the Calico Hills 
interval
being the least fractured, and, hence, least transmissive, interval at the C-wells. In a 
different
structural setting, the Lower Bullfrog, Calico Hills, and other intervals of the Miocene 
tuffaceous
rocks would be expected to have different hydraulic properties than indicated at the C-
wells
complex. For example, the Bullfrog Tuff yielded very little of the water produced from 
the
Miocene tuffaceous rocks during a tracejector flow survey of p#1 (Craig and Robison 
1984
[101040]), and the Calico Hills Formation yielded 32 percent of the water produced from 
the
Miocene tuffaceous rocks during a tracejector flow survey of b#1 (Lahoud et al. 1984 
[101049]).
Hydraulic properties for the various hydrogeologic intervals at the C-wells are discussed 
in the
following subsections. With the exception of the Prow Pass interval, all of the hydraulic
properties were derived from testing conducted prior to 1998. Properties of the Prow Pass
interval were derived from testing conducted both prior to and during 1998. The 1998 
testing
involved pumping of only the Prow Pass interval.
ANL-NBS-HS-000039, REV 00 119 December 2003
In the analyses described in the following subsections, the interborehole distances were 
as given
in Tables 6.1-1, 6.2-6, and 6.2-7; borehole diameters for all C-wells were assumed to be 
27.94
cm (11 in), and aquifer thicknesses were as given under "transmissive thickness" in 
Tables 6.2-6
and 6.2-7.
6.2.4.1 Calico Hills Interval
The Calico Hills interval responded in most hydraulic tests, including one conducted 
from May
to June 1984 (Geldon 1996 [100396], pp. 12 to 69), as an unconfined aquifer. In four 
tests
conducted from 1984 to 1997, the Calico Hills interval consistently was determined to be 
the
least permeable interval in the C-wells (Table 6.2-7). The hydraulic test in May and June 
1984
indicated that the Calico Hills interval in c#1 has a transmissivity of 9 m2/d, a horizontal
hydraulic conductivity of 0.2 m/d, a vertical hydraulic conductivity of 0.3 m/d, and a 
specific
yield of 0.003 (Geldon 1996 [100396], pp. 12 to 69). The hydraulic test in June 1995 
indicated
that the Calico Hills interval in c#2 has a transmissivity of 6 m2/d, a horizontal hydraulic
conductivity of 0.1 m/d, and a storativity of 0.0002. Hydraulic tests conducted in 
February 1996
and from May 1996 to November 1997 generally supported the previous analyses. The 
specific
yield of 0.4 obtained for the Calico Hills in c#2 from analyzing the May 8, 1996 response 
is
much higher than expected for fractured rock (it can go up to 30 percent for 
unconsolidated
materials (Bouwer 1978 [162675], p. 30). A representative plot indicating a match 
between the
data and one of the type curves of Neuman (1975 [150321]) for an unconfined, 
anisotropic
aquifer is shown in Figure 6.2-27.
6.2.4.2 Prow Pass Interval
The Prow Pass interval generally responded to hydraulic tests conducted from June 1995 
to
November 1997 as a confined aquifer (Table 6.2-7). The hydraulic test in June 1995 
indicated
that the Prow Pass interval in c#1 had a transmissivity of 60 m2/d, a hydraulic 
conductivity of 3
m/d, and a storativity of 0.0003. The same hydraulic test indicated that the Prow Pass 
interval in
c#2 has a transmissivity of 40 m2/d, a hydraulic conductivity of 2 m/d, and a storativity of
0.0004. Analyses of hydraulic tests conducted in February 1996 and from May 1996 to 
March
1997 generally produced parameter values similar to those produced by the previous 
analyses,
even when the February 1996 response was analyzed as an unconfined-aquifer response. 
A
representative plot indicates a match between the data and the type curve of Theis (1935
[150327]) for a confined aquifer (Figure 6.2-28).
Hydraulic testing of the Prow Pass interval conducted in 1998 by pumping c#2 indicated 
a
fissure-block aquifer with transmissivity of 30 m2/d in both c#1 and c#3. Fracture 
hydraulic
conductivities derived from responses in c#1 and c#3 were 1 m/d and 0.8 m/d, 
respectively.
Matrix hydraulic conductivities were negligible, and overall storativity was 0.0004, with 
most of
that being attributed to the matrix. These parameter estimates are in good agreement with 
those
derived from earlier testing in which the Prow Pass interval was not pumped directly 
(above).
This result instills confidence in the ability to estimate hydraulic parameters for intervals 
that are
not pumped directly but that respond to pumping other intervals. Even though 
comparable
parameter values were obtained in c#1 by analyzing some of the test responses in the 
Prow Pass
as either unconfined or fissure-block aquifer responses, the later interpretation is more 
logical
because the Prow Pass interval is not at the water table.
ANL-NBS-HS-000039, REV 00 120 December 2003
Table 6.2-7. Results of Hydraulic Tests in Borehole UE-25 c#3, June 1995 to November 1997
Starting Date 06/12/95 02/08/96 02/08/96
c#1 05/08/96 05/08/96 06/12/95 02/08/96
c#2 05/08/96 05/08/96
Calico Hills
Analyzed data None None N/A None N/A Drawdown Drawdown Drawdown N/A
Period of record (min) N/A N/A N/A N/A N/A 5,800 7,000 464,100 N/A
Aquifer type Unconfined Unconfined N/A Unconfined N/A Unconfined Confined Unconfined N/A
Transmissive thickness (m) 60.4 60.4 N/A 60.4 N/A 45.4 45.4 45.4 N/A
Distance from pumping well (m) 78.3 78.3 N/A 78.3 N/A 29.0 29.0 29.0 N/A
Average discharge (L/s) 0.85 0.042 N/A 0.10 N/A 0.85 0.042 0.10 N/A
Transmissivity (m2/day) 9(est) 9(est) N/A 9(est) N/A 6 10 4 N/A
Horizontal hydraulic conductivity (m/day) 0.2(est) 0.2(est) N/A 0.2(est) N/A 0.1 0.2 0.08 N/A
Vertical hydraulic conductivity (m/day) 0.3(est) 0.3(est) N/A 0.3(est) N/A ND ND 0.01 N/A
Storativity (dimensionless) ND ND N/A ND N/A 0.0002 0.0006 0.0003 N/A
Specific yield (dimensionless) 0.003(est) 0.003(est) N/A 0.003(est) N/A ND ND 0.4 N/A
Prow Pass
Analyzed data Drawdown Drawdown Drawdown Drawdown N/A Drawdown Drawdown Drawdown N/A
Period of record (min) 5,800 7,000 7,000 464,100 N/A 5,800 7,000 464,100 N/A
Aquifer type Confined Unconfined Confined Confined N/A Confined Confined Confined N/A
Transmissive thickness (m) 18.9 18.9 18.9 18.9 N/A 23.8 23.8 23.8 N/A
Distance from pumping well (m) 81.1 81.1 81.1 81.1 N/A 28.6 28.6 28.6 N/A
Average discharge (L/s) 0.65 0.21 0.21 0.22 N/A 0.65 0.13 0.19 N/A
Transmissivity (m2/day) 60 50 60 50 N/A 40 30 30 N/A
Horizontal hydraulic conductivity (m/day) 3 3 3 3 N/A 2 1 1 N/A
Vertical hydraulic conductivity (m/day) ND 0.0001 ND ND N/A ND ND ND N/A
Storativity (dimensionless) 0.0003 0.0003 0.0004 0.0002 N/A 0.0004 0.003 0.0008 N/A
Specific yield (dimensionless) ND ND ND ND N/A ND ND ND N/A
NOTE: *First number is for fractures; second is for matrix. ND: no data; N/A: not applicable; est: estimated to 
be the same as values obtained from an hydraulic
test in May 1984.
ANL-NBS-HS-000039, REV 00 121 December 2003
Table 6.2-7 (Continued). Results of Hydraulic Tests in Borehole UE-25 c#3, June 1995 to 
November 1997
Starting Date 06/12/95 02/08/96 02/08/96
c#1 05/08/96 05/08/96 06/12/95 02/08/96
c#2 05/08/96 05/08/96
Upper Bullfrog
Analyzed data Recovery Drawdown N/A Drawdown N/A Drawdown Drawdown Drawdown N/A
Period of record (min) 5,700 7,000 N/A 464,100 N/A 5,800 7,000 464,100 N/A
Aquifer type Confined Unconfined N/A Fissure-block N/A Confined Confined Confined N/A
Transmissive thickness (m) 46.0 46.0 N/A 46.0 N/A 24.1 24.1 24.1 N/A
Distance from pumping well (m) 83.2 83.2 N/A 82.3 N/A 28.6 28.6 28.6 N/A
Average discharge (L/s) 0.88 0.37 N/A 0.32 N/A 0.88 0.36 0.36 N/A
Transmissivity (m2/day) 90 40 N/A 50 N/A 100 100 80 N/A
Horizontal hydraulic conductivity (m/day) 2 0.8 N/A 1/0.00002* N/A 4 4 3 N/A
Vertical hydraulic conductivity (m/day) ND 0.5 N/A ND N/A ND ND ND N/A
Storativity (dimensionless) 0.00006 0.0009 N/A 0.0001/0.0009* N/A 0.00003 0.00002 0.00002 N/A
Specific yield (dimensionless) ND 0.002 N/A ND N/A ND ND ND N/A
Bullfrog-Tram
Analyzed data N/A Drawdown N/A N/A N/A N/A Drawdown N/A N/A
Period of record (min) N/A 7,000 N/A N/A N/A N/A 7,000 N/A N/A
Aquifer type N/A Confined N/A N/A N/A N/A Confined N/A N/A
Transmissive thickness (m) N/A 112 N/A N/A N/A N/A 51.2 N/A N/A
Distance from pumping well (m) N/A 86.3 N/A N/A N/A N/A 29 N/A N/A
Average discharge (L/s) N/A 7.84 N/A N/A N/A N/A 7.93 N/A N/A
Transmissivity (m2/day) N/A 2,500 N/A N/A N/A N/A 2,500 N/A N/A
Horizontal hydraulic conductivity (m/day) N/A 20 N/A N/A N/A N/A 50 N/A N/A
Vertical hydraulic conductivity (m/day) N/A ND N/A N/A N/A N/A ND N/A N/A
Storativity (dimensionless) N/A 0.0003 N/A N/A N/A N/A 0.002 N/A N/A
Specific yield (dimensionless) N/A ND N/A N/A N/A N/A ND N/A N/A
NOTE: *First number is for fractures; second is for matrix. ND: no data; N/A: not applicable; est: estimated to 
be the same as values obtained from a hydraulic
test in May 1984.
ANL-NBS-HS-000039, REV 00 122 December 2003
Table 6.2-7 (Continued). Results of Hydraulic Tests in Borehole UE-25 c#3, June 1995 to 
November 1997
Starting date 06/12/95 02/08/96 02/08/96
c#1 05/08/96 05/08/96 06/12/95 02/08/96
c#2 05/08/96 05/08/96
Lower Bullfrog
Analyzed data Recovery None N/A Drawdown Drawdown Drawdown None Drawdown Drawdown
Period of record (min) 6,300 N/A N/A 464,100 464,100 5,800 N/A 464,100 464,100
Aquifer type Confined Confined N/A Confined Fissure-block Confined Confined Confined Fissure-block
Transmissive thickness (m) 62.8 62.8 N/A 62.8 62.8 29.9 29.9 29.9 29.9
Distance from pumping well (m) 85.6 85.6 N/A 85.6 85.6 29.3 29.3 29.3 29.3
Average discharge (L/s) 15.3 ND N/A 6.37 6.37 15.3 ND 6.69 6.69
Transmissivity (m2/day) 1,800 ND N/A 1,600 1,300 1,900 ND 1,600 1,300
Horizontal hydraulic conductivity (m/day) 30 ND N/A 30 20/0.0004* 60 ND 50 40/0.001*
Vertical hydraulic conductivity (m/day) ND ND N/A ND ND ND ND ND ND
Storativity (dimensionless) 0.0004 ND N/A 0.0002 0.0002/0.002* 0.003 ND 0.001 0.002/0.02*
Specific yield (dimensionless) ND ND N/A ND ND ND ND ND ND
Upper Tram
Analyzed data None None N/A None N/A None None None N/A
Period of record (min) N/A N/A N/A N/A N/A N/A N/A N/A N/A
Aquifer type Leaky Leaky N/A Leaky N/A Leaky Leaky Leaky N/A
Transmissive thickness (m) 49.7 49.7 N/A 49.7 N/A 21.3 21.3 21.3 N/A
Distance from pumping well (m) 86.9 86.9 N/A 86.9 N/A 29.6 29.6 29.6 N/A
Average discharge (L/s) 4.74 ND N/A 2.52 N/A 4.74 ND 2.18 N/A
Transmissivity (m2/day) ND ND N/A 800 N/A ND ND 900 N/A
Horizontal hydraulic conductivity (m/day) ND ND N/A 20 N/A ND ND 40 N/A
Vertical hydraulic conductivity (m/day) ND ND N/A ND N/A ND ND ND N/A
Storativity (dimensionless) ND ND N/A 0.0001 N/A ND ND 0.001 N/A
Specific yield (dimensionless) ND ND N/A ND N/A ND ND ND N/A
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], pp. 34 to 35, Table 8).
NOTE: *First number is for fractures; second is for matrix. ND: no data; N/A: not applicable; est: estimated to 
be the same as values obtained from a hydraulic
test in May 1984.
ANL-NBS-HS-000039, REV 00 123 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 36, Figure 25).
Figure 6.2-27. Analysis of Drawdown in the Calico Hills Interval of UE-25 c#2, May 8, 1996 (~0 
minutes),
to March 26, 1997 (~470,000 minutes), by the Method of Neuman
ANL-NBS-HS-000039, REV 00 124 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 37, Figure 26).
Figure 6.2-28. Analysis of Drawdown in the Prow Pass Interval of UE-25 c#1,
June 12-16, 1995, by the Method of Theis
6.2.4.3 Upper Bullfrog Interval
The Upper Bullfrog interval in c#2 responded to all hydraulic tests as a confined aquifer
(Table 6.2-7). Those tests consistently indicated a transmissivity of 80 to 100 m2/d, a 
hydraulic
conductivity of 3 to 4 m/d, and a storativity of 0.00002 to 0.00003. A representative plot
indicates a match between the data and the type curve of Theis (1935 [150327]) for a 
confined
aquifer (Figure 6.2-29).
The hydraulic test in June 1995 produced results for the Upper Bullfrog interval in c#1 
that were
consistent with results for that interval in c#2 (Table 6.2-7). During longer tests 
conducted in
February 1996 and May 1996, sufficient time elapsed to reveal the effects of fractures on 
flow
between the Upper Bullfrog interval in c#1 and open intervals in the pumping well. 
Analyses of
drawdown (complicated by downward flow through fractures) indicated smaller values of
transmissivity and hydraulic conductivity and larger values of storativity than analyses of
drawdown in which the effects of fractures were not evident (Table 6.2-7). Hydraulic 
properties
determined from hydraulic tests conducted in 1996 and 1997 using unconfined and 
fissure-block
interpretations are less reliable than properties determined from the hydraulic test in June 
1995
because of the sliding sleeve placement in the observation and pumping wells in the later 
tests.
ANL-NBS-HS-000039, REV 00 125 December 2003
Unconfined and fissure-block responses are similar; however, a fissure-block 
interpretation is
more logical for the Upper Bullfrog aquifer than an unconfined interpretation because 
this
aquifer is not at the water table. Also, the specific yield calculated from the unconfined 
solution,
0.002, seems unrealistically low.
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 38, Figure 27).
Figure 6.2-29. Analysis of Drawdown in UE-25 c#2 Upper Bullfrog Interval,
June 12-16, 1995, by the Method of Theis
6.2.4.4 Lower Bullfrog Interval
Undisturbed drawdown in the Lower Bullfrog interval of c#1 and c#2 during the 
hydraulic test
conducted from May 1996 to November 1997 can be interpreted in several ways that 
were not
evident from previous hydraulic tests of much shorter duration. Although previous tests
indicated a confined-aquifer response, the test beginning in May 1996 progressed long 
enough to
develop a double-humped drawdown curve characteristic of a fissure-block aquifer. From
158,000 minutes (110 days) after pumping started in May 1996 to the end of the analyzed 
record
(464,100 minutes [312 days] after pumping started), drawdown in c#1 and c#2 was 
greater than
anticipated on the basis of extrapolating the earlier drawdown for long periods (using the
equation of Theis (1935 [150327]), to extrapolate drawdown). The oscillatory pattern of
drawdown in the C-wells after 158,000 minutes (110 days) of pumping can be interpreted 
to
indicate that the spreading cone of depression encompassed volumes of the Lower 
Bullfrog
interval that alternately were less transmissive or as transmissive as the Lower Bullfrog in 
the Cwells.
ANL-NBS-HS-000039, REV 00 126 December 2003
Values of transmissivity computed for the Lower Bullfrog interval are significantly 
different
depending on whether the interval is considered a confined aquifer or a fissure-block 
aquifer
(Table 6.2-7). In c#1 and c#2, transmissivity is 1,600 m2/d if the Lower Bullfrog is 
analyzed as a
confined aquifer (Figure 6.2-30) and 1,300 m2/d if analyzed as a fissure-block aquifer 
(Figure
6.2-31). Although the two analytical solutions produced equally plausible results, the 
fissureblock
aquifer solution is consistent with a tracer test conducted from February to March 1996
that indicated dual porosity in the Bullfrog-Tram interval (Fahy 1997 [137456], third
{unnumbered} page). Also, the longer pumping required for the fissure-block aquifer 
response
to develop and the lower transmissivity value determined from that response can be 
interpreted
to confirm that less-transmissive rocks were reached as the cone of depression spread to
increasingly distant areas during the hydraulic test that began in May 1996.
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 39, Figure 28).
Figure 6.2-30. Analysis of Drawdown in UE-25 c#1 Lower Bullfrog Interval,
May 8, 1996, to March 26, 1997, by the Method of Theis
Values of hydraulic conductivity and storativity are considerably larger in the rock mass 
between
c#2 and c#3 than in the rock mass between c#1 and c#3. When analyzed as a confined 
aquifer,
the hydraulic conductivity of the Lower Bullfrog interval is 50 m/d in c#2 and 30 m/d in 
c#1, and
its storativity is 0.001 in c#2 and 0.0002 in c#1. (These hydraulic conductivities and 
storativities
ANL-NBS-HS-000039, REV 00 127 December 2003
of the interval in both boreholes are about the same as those of the fractures in the 
interval in
both boreholes obtained when the Lower Bullfrog is analyzed as a fissure-block aquifer; 
see
Table 6.2-7.)
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 39, Figure 29).
NOTE: For the analysis curve, the parameter ?/B = 0.05.
Figure 6.2-31. Analysis of Drawdown in UE-25 c#1 Lower Bullfrog Interval,
May 8, 1996, to March 26, 1997, by the Method of Streltsova-Adams
6.2.4.5 Upper Tram Interval
The Upper Tram interval was known from earlier hydraulic tests (conducted in 1984) to 
respond
to pumping as a leaky aquifer without confining bed storage because of recharge from 
faults that
intersect the C-wells in that interval (Geldon 1996 [100396], pp. 12 to 69). Although 
hydraulic
properties of the Upper Tram (UT) interval could not be determined directly from 
hydraulic tests
conducted during this study (because of transducer malfunction), they could be estimated 
by
subtracting values of hydraulic properties determined for the Lower Bullfrog (LB) interval 
from
those determined for the Bullfrog-Tram (BT) interval. This is deemed acceptable based on 
the
assumption that flow during the Bullfrog-Tram test and the Lower Bullfrog test was 
radial in an
equivalent porous medium that is homogeneous and isotropic, composed of 
interconnected
fractures. The following equations were used (Geldon 1996 [100396], pp. 21 to 69):
ANL-NBS-HS-000039, REV 00 128 December 2003
TUT = TBT - TLB (Eq. 2)
SUT = SBT - SLB (Eq. 3)
KUT = (KBT X bBT - KLB X bLB)/bUT (Eq. 4)
where
T = transmissivity (L2/T)
S = storativity (dimensionless)
K = hydraulic conductivity (L/T)
b = thickness (L).
Only hydraulic properties of the Lower Bullfrog interval determined by the Theis (1935
[150327]) solution were used in these calculations because hydraulic properties of the 
Bullfrog-
Tram interval (which includes the Lower Bullfrog) were determined by this method. 
These
calculations indicated a transmissivity of 800 m2/day, a hydraulic conductivity of 20 
m/day, and
a storativity of 0.0001 for the Upper Tram interval in c#1 and a transmissivity of 900 
m2/day, a
hydraulic conductivity of 40 m/day, and a storativity of 0.001 for the Upper Tram interval 
in c#2
(Table 6.2-7).
6.2.4.6 Miocene Tuffaceous Rocks: Hydraulic Properties and Large-Scale 
Horizontal
Anisotropy
Indicative of hydraulic connection through a highly developed fracture network, diverse 
intervals
of the Miocene tuffaceous rocks in six observation wells responded to the pumping in c#3 
from
May 1995 to November 1997 (Table 6.2-8). The C-wells, ONC-1, and H-4 appear to be
connected hydraulically through a northwest-trending zone of discontinuous faults that 
extends
from Bow Ridge to Antler Wash (Geldon et al. 1998 [129721], pp. 23 to 25, Figure 2; p. 
31).
The Paintbrush Canyon and related faults that intersect WT#14 and the C-wells probably
enhance hydraulic communication between those boreholes. Hydraulic communication 
between
the C-wells and WT#3 probably is enabled both stratigraphically and structurally because 
those
boreholes were open during hydraulic tests in the same geologic unit (the Bullfrog Tuff) 
and are
cut by the same faults (the Paintbrush Canyon and related faults).
Analyses of the drawdown in individual observation wells (Figures 6.2-32 to 6.2-35) 
provide
hydraulic properties of the rock mass at the scale of the distance between those boreholes 
and
c#3 (Table 6.2-8). Analyses of drawdown in multiple observation wells, either as a 
function of
time (normalized by dividing by the square of the distance between the observation and 
pumping
wells) or as a function of distance at a specified time, allow computation of hydraulic 
properties
of the tuffaceous rock mass in which all of the included observation wells are located.
ANL-NBS-HS-000039, REV 00 129 December 2003
Table 6.2-8. Hydraulic Properties Computed from Observation Well Responses to Pumping in
UE-25 c#3, May 1995 to November 1997
Borehole c#2 c#2 c#1 c#1
Starting date of hydraulic test 05/22/95 05/08/96 05/22/95 05/08/96
Period of record (min) 14,400 464,100 11,400 464,100
Analyzed data Drawdown Drawdown Recovery Drawdown
Geologic units in monitored interval Calico Hills
to Tram
Calico Hills
to Tram
Calico Hills
to Tram
Calico Hills
to Tram
Aquifer type Unconfined Variable Unconfined Variable
Transmissive thickness (m)** 165 144 252 238
Distance from pumping well (m) 29.0 29.0 82.6 82.9
Average discharge (L/s) 17.9 9.53 17.9 9.53
Transmissivity (m2/day) 2,100 2,400-2,600 1,800 2,200-2,600
Horizontal hydraulic conductivity (m/day) 13 16-18 7 9-11
Vertical hydraulic conductivity (m/day) 1.7 Not estimated 0.3 Not estimated
Storativity (dimensionless) 0.003 0.003-0.004 0.001 0.002
Specific yield (dimensionless) 0.2 Not estimated 0.01 Not estimated
Borehole UE-25 ONC-1 USW H-4 UE-25 WT#14 UE-25 WT#3
Starting date of hydraulic test 05/08/96 05/08/96 05/08/96 05/08/96
Period of record (min) 796,663 72,000 72,000 463,500
Analyzed data Drawdown Drawdown Drawdown Drawdown
Geologic units in monitored interval Prow Pass Prow Pass to
Lithic Ridge
Topopah
Spring and
Calico Hills
Bullfrog
Aquifer type Fissure-block Confined Confined Confined
Transmissive thickness (m) 193 (est) 276 Not estimated 47.5 (estimated)
Distance from pumping well (m) 843 2,245 2,249 3,526
Average discharge (L/s) 9.21 9.72 9.72 9.59
Transmissivity (m2/day) 1,000 700 1,300 2,600
Horizontal hydraulic conductivity (m/day) 5/.002* 2 Not estimated 56
Storativity (dimensionless) 0.001/0.01* 0.002 0.002 0.002
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 41, Table 9).
NOTE: *The first number is for fractures; the second is for matrix (values of transmissivity and hydraulic
conductivity listed for UE-25 ONC-1 and USW H-4 differ from those obtained from a hydraulic test
conducted from May 22 to June 1, 1995, but the values determined from the longer test beginning in May
1996 are considered more reliable).
**The sum of transmissive thicknesses of component geologic units is shown in Table 6.2-7 for the
corresponding test.
ANL-NBS-HS-000039, REV 00 130 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 42, Figure 30).
NOTE: For the analysis curve, the parameter ?/B = 0.05.
Figure 6.2-32. Analysis of Drawdown in UE-25 ONC-1, May 8, 1996, to
November 12, 1997, by the Method of Streltsova-Adams
Observation wells showed clear responses to the pumping, allowing computation of 
hydraulic
parameters. Despite being 843 m from c#3, ONC-1 responded to pumping after only 200
minutes because it is in the same structural block as the C-wells (between the Bow Ridge 
and
Paintbrush Canyon faults) and is connected by fractures related to northwest-striking 
faults. That
fracture connection is reflected in a characteristic fissure-block aquifer response. From 
200 to
2,000 minutes (up to 1.4 days), flow from fractures caused drawdown to increase as a 
function of
log time. From 2,000 to 6,000 minutes (1.4 days to 4 days), drawdown remained 
relatively
constant as flow occurred from the rock matrix into fractures. After 6,000 minutes (4 
days),
drawdown increased again as a function of log time as flow from both the fractures and 
matrix
occurred. Drawdown conformed to the type curve of Streltsova-Adams (1978 [150754]; 
see
Figure 6.2-32). Transmissivity computed from the type-curve match equals 1,000 m2/d. If 
the
transmissive thickness between the C-wells complex and ONC-1 is assumed to vary 
linearly
between known thicknesses in c#2 and H-4, then it can be estimated to be about 193 m in
ONC-1. Dividing transmissivity by the estimated transmissive thickness indicates a 
fracture
hydraulic conductivity of 5 m/d. In comparison, the hydraulic conductivity of the matrix 
(Table
6.2-8) is insignificant. Computed storativity for the fractures in ONC-1 is 0.001, which is 
a tenth
of the computed storativity of the matrix.
ANL-NBS-HS-000039, REV 00 131 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 42, Figure 31).
Figure 6.2-33. Analysis of Drawdown in USW H-4, May 8, 1996, to June 27, 1996,
by the Method of Theis
Because of its location 2,245 m from c#3, borehole H-4 took 5,000 minutes (3.5 days) to 
respond
to pumping. Even though an extensive effort had been made to remove the effects of 
Earth tides
and barometric changes on water-level fluctuations, the process is approximate and 
residual
effects are still visible in the H-4 water-level record up to 5,000 minutes. After 5,000 
minutes,
the effect of pumping c#3 at H-4 became discernible above the residual water-level 
fluctuations,
and the drawdown became analyzable (Figure 6.2-33). From 5,000 to 72,000 minutes 
(3.5 to 50
days) after pumping started, drawdown in H-4 conformed to the type curve of Theis 
(1935
[150327]) for a confined aquifer (Figure 6.2-33). After 72,000 minutes (50 days), 
drawdown
became relatively constant, probably in response to flux from a nearby fault boundary. 
The preboundary
drawdown indicated transmissivity of 700 m2/d and storativity of 0.002 (Table 6.2-8).
Dividing transmissivity by the transmissive thickness obtained from a flow survey 
(Whitfield et
al. 1984 [101366]) indicated an hydraulic conductivity of 2 m/d. The location of the 
recharge
boundary could not be ascertained because only H-4 was affected by that boundary, and 
the
analytical solution to determine the location of a boundary (Lohman 1972, pp. 57 to 61
[150250]) requires that at least two wells be affected by the same boundary.
ANL-NBS-HS-000039, REV 00 132 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 ([164425], p. 43, Figure 32).
Figure 6.2-34. Analysis of Drawdown in UE-25 WT#14, May 8, 1996,
to June 27, 1996, by the Method of Theis
Located a nearly identical distance (2,249 m) from c#3, borehole WT#14 took slightly 
longer
(5,250 minutes or 3.7 days) to respond to pumping. From 3.7 days to just over 6 days 
(5,250 to
9,000 minutes), a transition from borehole-storage release to release of water from the 
aquifer
occurred. From 6 to 50 days (9,000 to 72,000 minutes) after pumping started, drawdown 
in
WT#14 conformed to the type curve of Theis (1935 [150327]) for a confined aquifer 
(Figure 6.2-
34). After that time, drawdown became strongly oscillatory, but those broad oscillations 
in the
data deviated about a relatively constant value. Both the period of transition from 
boreholestorage
release (5,250 to 9,000 minutes) and the strongly oscillatory drawdown period (after
72,000 minutes) are not shown in Figure 6.2-34, which is intended to show only the 
portion of
the record that conforms to the confined Theis (1935 [150327]) solution. The late-time 
data are
interpreted to represent less-than-ideal response to a recharge boundary. The pre-
boundary
drawdown indicates transmissivity of 1,300 m2/d and storativity of 0.002 (Table 6.2-8).
Hydraulic conductivity and the location of the boundary could not be determined because 
of
insufficient data.
ANL-NBS-HS-000039, REV 00 133 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 43, Figure 33).
Figure 6.2-35. Analysis of Drawdown in UE-25 WT#3, May 8, 1996,
to March 26, 1997, by the Method of Theis
Borehole WT#3 is located 3,526 m from c#3 and took more than 6 days (9,130 minutes) 
to
respond to pumping. Thereafter, drawdown in WT#3 was oscillatory, but the data could 
be fit to
the type curve of Theis (1935 [150327]) for a confined aquifer (Figure 6.2-35). The 
oscillations,
which are substantially larger than those occurring at the other distant observation wells 
are
likely caused by a combination of factors: (1) a possible low-quality transducer signal, (2)
excessive distance from the pumping well (at 3,526 km, WT#3 is the farthest of the 
distant
observation wells form the C-hole complex), and (3) residual Earth-tide and barometric-
pressure
effects remaining, even after substantial, but approximate, efforts to remove them. The 
solution
indicated a transmissivity of 2,600 m2/d and a storativity of 0.002 (Table 6.2-8). Dividing
transmissivity by the length of the open interval in WT#3 (47.5 m) indicated a hydraulic
conductivity of 56 m/d. Actual hydraulic conductivity probably is smaller than the 
calculated
value because the thickness of transmissive rock between the C-wells complex and WT#3
probably exceeds the length of the open interval.
The transmissivity of the Miocene tuffaceous rocks appears to decrease northwestward in 
the
area containing the observation wells used in the hydraulic test that began in May 1996.
Depending on the analytical solutions used, transmissivity could be interpreted to 
decrease from
2,600 m2/d in the vicinity of WT#3 to about 2,000 m2/d in the vicinity of the C-wells. The
ANL-NBS-HS-000039, REV 00 134 December 2003
transmissivity of the Miocene tuffs is 1,300 m2/d in the vicinity of WT#14, 1,000 m2/d in 
the
vicinity of ONC-1, and 700 m2/d in the vicinity of H-4.
The distribution of hydraulic conductivity in the tuffs in the vicinity of the C-wells 
complex
appears to be structurally controlled. Hydraulic conductivity in c#2 decreases sharply 
from a
range of 20 to 60 m/d in the Upper Tram and Lower Bullfrog intervals to a range of 0.08 
to 0.2
m/d in the Calico Hills interval as the vertical distance from faults that intersect the 
boreholes
increases (Table 6.2-7). Average hydraulic conductivity of the Miocene tuffaceous rocks 
in c#2
is twice that of c#1 (Table 6.2-8), possibly because c#2 is located nearer to the subsurface
intersection of the north-striking Paintbrush Canyon or Midway Valley faults and a 
northweststriking
fault (shown in Figure 6.2-36) that underlies the gap through the northern part of Bow
Ridge. If spatial relations between faults and hydraulic conductivity at the C-wells 
complex are
combined with values of hydraulic conductivity determined from analyses of drawdown 
in
ONC-1, WT#3, and H-4 (Table 6.2-8), then a possible distribution of hydraulic 
conductivity for
the Miocene tuffaceous rocks in the vicinity of the C-wells can be inferred (Figure 6.2-
36).
Clearly, this distribution is not unique: just one possible scenario that attempts to 
extrapolate
areally the correlation between vertical proximity of geohydrologic units at the C-hole 
complex
to faults and the hydraulic conductivities of these units. When that correlation is applied 
areally,
relative to known geologic structures in the area while honoring the hydraulic 
conductivities
obtained at the C-hole complex itself and the distant observation wells, ONC-1, H-4, 
WT#14,
and WT#3, one obtains Figure 6.2-36.
In the 21-km2 area encompassed by observation wells used in hydraulic tests at the C-
wells
complex from 1995 to 1997, the storativity of Miocene tuffaceous rocks in those 
observation
wells uniformly is 0.001 to 0.003 (Table 6.2-8). Analysis of drawdown in observation 
wells not
affected by boundaries as a function of the time divided by the square of the distance 
from the
pumping well (Figure 6.2-37) indicates that the average storativity of the tuffs in the 
observation
area is 0.002. This same analysis indicates that the average transmissivity of the Miocene
tuffaceous rocks in the area is 2,200 m2/d. Derivation of a single analytical solution for 
c#1, c#2,
ONC-1, and WT#3 confirms that the Miocene tuffaceous rocks, at least as far north as 
lower
Midway Valley in the structural block delineated by the Paintbrush Canyon, Bow Ridge, 
and
Dune Wash faults, are a single aquifer in which flow is influenced by the same structural 
and
stratigraphic factors.
Plots of drawdown in observation wells as a function of distance 30,000, 100,000, 
200,000,
305,000, and 463,000 minutes (21, 69, 139, 212, and 322 days) after pumping started in 
May
1996 (drawdown contours at 30,000 and 463,000 minutes shown in Figure 6.2-38) 
confirm an
ovoid pattern of drawdown aligned with faults extending from Bow Ridge to Antler 
Wash that
was detected during the hydraulic test conducted from May 22 to June 1, 1995 (Geldon et 
al.
1998 [129721], pp. 23 to 25, Figure 2; p. 31). Analyzed by the method of Cooper and 
Jacob
(1946 [150245]), plots of drawdown as a function of distance (Figure 6.2-39) indicate 
values of
transmissivity ranging from 2,100 to 2,600 m2/d and values of storativity ranging from 
0.0005 to
0.002 (Table 6.2-9).
ANL-NBS-HS-000039, REV 00 135 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 ([164425], p. 45, Figure 34).
Figure 6.2-36. Inferred Distribution of Hydraulic Conductivity of
Miocene Tuffaceous Rocks in the Vicinity of the C-wells
ANL-NBS-HS-000039, REV 00 136 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 46, Figure 35).
Figure 6.2-37. Analysis of Drawdown in Observation Wells as a Function of Time
Divided by the Square of the Distance from the Pumping Well, UE-25 c#3
Because the higher transmissivity and lower storativity values resulting from the 30,000- 
and
100,000-minute analyses in Table 6.2-9 give way to more stable and consistent lower
transmissivity and higher storativity values from later-time analyses, the later values 
appear to be
more reliable. In comparison, the same type of analysis of drawdown in observation wells 
as a
function of distance 10 days (14,000 minutes) after pumping started in May 1995 had 
indicated a
transmissivity of 2,300 m2/d and storativity of 0.003 (Geldon et al. 1998 [129721], p. 29).
Distance-drawdown and time-drawdown analyses discussed in this section converge on 
similar
solutions.
The ovoid pattern of drawdown aligned with faults extending from Bow Ridge to Antler 
Wash
that was detected during the hydraulic test conducted from May 22 to June 1, 1995 
(Geldon et al.
1998 [129721], pp. 23 to 25, Figure 2; p. 31) and confirmed in this study (Figure 6.2-38)
indicates large-scale anisotropy caused by heterogeneity and structure. Large-scale
transmissivity is higher in the direction of the long axis of the ovoid and lower in the 
direction
perpendicular to it.
ANL-NBS-HS-000039, REV 00 137 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], p. 46, Figure 35).
NOTE: The upper panel shows the drawdown distribution 30,000 minutes (20.8 days) after pumping started; 
the
lower panel shows the distribution 463,000 minutes (321.5 days) after pumping started.
The reason for the question mark in the figure is that the drawdown in the aquifer at the location of the
pumped well, c#3, is unknown; only the apparent drawdown in the well, which contains a lot of friction head,
is known.
Figure 6.2-38. Distribution of Drawdown in Observation Wells at Two Times
After Pumping Started in UE-25 c#3 on May 8, 1996
Table 6.2-9. Hydraulic Properties Determined from Drawdown in Observation Wells as a Function
of Distance From the Pumping Well UE-25 c#3, May 1996 to November 1997
Time Since Pumping Started
(min) Transmissivity (m2/day) Storativity
30,000 2,600 0.0005
100,000 2,500 0.0009
200,000 2,100 0.002
305,000 2,300 0.001
402,000 2,200 0.001
463,000 2,200 0.001
Output DTN: GS031008312314.004 (from DTN: GS030508312314.003 [164425], p. 50, Figure 10).
ANL-NBS-HS-000039, REV 00 138 December 2003
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 [164425], pp. 48 and 49, Figure 37).
NOTE: The panels show the drawdown analyses at 30,000 (upper left), 200,000 (lower left), 305,000 (upper 
right),
and 463,000 (lower right) minutes after pumping started.
Figure 6.2-39. Analyses of Drawdown in Observation Wells as a Function of Distance
from the Pumping Well at Various Times After Pumping Started in UE-25 c#3
6.2.4.7 Paleozoic Carbonate Rocks
Borehole p#1 was monitored during hydraulic tests in 1995 and 1996 to detect hydraulic
connection between the Miocene tuffaceous rocks and Paleozoic carbonate rocks in the 
vicinity
of the C-wells. Hydraulic connection previously had been indicated by hydraulic head
measurements in p#1 and by borehole flow surveys in the C-wells. Measurements made 
as p#1
was being drilled in 1983 detected a 22-m difference in hydraulic heads for the Paleozoic
carbonate rocks and Miocene tuffaceous rocks in p#1 (Craig and Robison 1984 
[101040]), which
indicated a potential for water to flow from the lower to the upper of those hydrogeologic 
units.
Flow surveys conducted in the C-wells in 1991 detected upward flow in the lower parts 
of those
boreholes (Geldon 1996 [100396], pp. 12 to 69) that most likely originated in the 
Paleozoic
carbonate rocks, because the intervening tuffaceous rocks generally behave as a confining 
unit
(Luckey et al. 1996 [100465], p. 18, Figure 7).
ANL-NBS-HS-000039, REV 00 139 December 2003
Although p#1 was monitored for 10 days (14,400 minutes) after pumping started in May 
1995
(Geldon et al. 1998 [129721]) and for about 180 days (256,200 minutes) after pumping 
started in
May 1996, drawdown in the Paleozoic carbonate rocks was not detected (Figure 6.2-40). 
This
lack of drawdown could indicate that the water being pumped was drawn laterally from 
the
Miocene tuffaceous rocks. Alternatively, the water could have been drawn upward from
Paleozoic carbonate rocks without causing drawdown in the underlying aquifer if the 
Paleozoic
rocks have a large storage capacity. Hydraulic connection between the Miocene 
tuffaceous rocks
and Paleozoic carbonate rocks could not be confirmed or refuted by monitoring water 
levels in
p#1 during the study reported here.
Output DTN: GS031008312314.004 (from Input DTN: GS030508312314.003 ([164425], p. 50, Figure 38).
NOTE: Water-level change is relative to the water level in p#1 prior to start of pumping in c#3 on May 8, 
1996.
Figure 6.2-40. Water-level Changes in UE-25 p#1, September 3 to November 2, 1996
6.2.5 Limitations and Uncertainties
All analytical methods used in this study to determine hydraulic properties from 
drawdown or
recovery responses assume that the aquifer is an equivalent porous medium. Although the 
flow
system consists of a fracture network rather than a porous medium, the pressure 
responses
conform quite well to type curves derived for either porous media or uniformly fractured 
media
(Strelsova-Adams 1978 [150754]). Thus, the fracture network at the C-wells is 
apparently
interconnected in such a way that the fractured tuffs respond to pumping as "an 
equivalent
porous medium." Another fundamental assumption is that flow to the pumping well is 
derived
from an aquifer of infinite extent. The many faults near the C-wells complex that 
potentially
ANL-NBS-HS-000039, REV 00 140 December 2003
function as either recharge or barrier boundaries make the concept of an infinite aquifer 
difficult
to support. However, only observation wells that lay between faults bounding the 
structural
block in which the C-wells are located were considered in the analyses, so boundary 
effects,
while not completely eliminated, should have been minimized. Drawdown in H-4 and 
WT#14
obviously was affected by recharge boundaries.
All the analytical methods used in this study assume a constant thickness for the interval 
for
which drawdown is being analyzed, whereas, in reality, the intervals have variable 
thicknesses.
This is a necessary simplification, and extreme care was taken to define transmissive 
intervals in
each well and a meaningful resulting assumed-interval thickness between the pumped 
and
observation well.
In addition, all the analytical methods used in this study, except for the Neuman (1975 
[150321])
method, assume radial flow to the pumping well, and, therefore, ignore vertical flow 
(application
of the Neuman fully-penetrating-well solution, as was done in this report, to cases where
pumping was in one interval and the analyzed drawdown response was in another, also 
ignores
vertical flow). The flow from intervals other than the one being pumped that was detected
during hydraulic tests in February 1996 and May 1996 to November 1997 indicates that 
flow
during those tests actually was three-dimensional or spherical. Ignoring the vertical 
component
of flow seems to have been justified by the generally good agreement between results of 
the
hydraulic test in June 1995 (in which flow between observation and pumping wells was 
radial)
and results for most intervals monitored in subsequent tests. Nevertheless, there is some
inaccuracy involved in analyzing the flow from intervals that did not have open sliding 
sleeves
above or below the pumped interval by techniques developed only for analyzing flow 
from the
pumped interval.
The most commonly applied analytical method in this study, that of Theis (1935 
[150327]),
assumes flow from an infinite, homogeneous, isotropic, confined aquifer. Transected by
numerous faults and variably welded, the Miocene tuffs in the vicinity of the C-wells 
complex
are neither homogeneous nor isotropic. As a result, hydraulic gradients toward the 
pumping well
vary directionally, a situation ignored by the mathematics of the Theis (1935 [150327]) 
solution.
Disregarding a nonuniform hydraulic gradient seemingly would result in inaccurate
computations of hydraulic properties. Consistent calculations, however, of hydraulic 
properties
for individual intervals and the composite section of Miocene tuffaceous rocks (from test 
to test,
from well to well, or from use of multiple observation wells in time-drawdown or 
distancedrawdown
analyses) indicate that errors are at least being made consistently. That consistency
provides confidence that calculated values approximate actual values of hydraulic 
properties,
despite simplification of structural and lithologic complexities.
All the analytical techniques used in this study required input parameters that had to be
determined or approximated for hydrogeologic intervals or boreholes in which drawdown 
was
monitored. Included in those parameters are the distance of the interval or borehole from 
the
pumping well, the transmissive thickness of the interval or borehole, the barometric 
efficiency of
the interval or borehole, the proportion of flow from a given hydrogeologic interval, and 
the
fracture spacing within a hydrogeologic interval. Errors in deriving any of those input
parameters could have changed calculated hydraulic properties considerably.
ANL-NBS-HS-000039, REV 00 141 December 2003
Values of transmissivity and storativity determined in this study are estimated to be 
accurate to
one significant figure, but reported values of hydraulic conductivity are more uncertain.
Hydraulic conductivity can be calculated by dividing the transmissivity by either the 
known
thickness of transmissive intervals within a test interval, the entire thickness of the test 
interval,
or an assumed thickness of transmissive rock between the observation and pumping 
wells.
Because the transmissive thickness was unknown, it was impossible to determine 
hydraulic
conductivity in many analyses. Even where hydraulic conductivity could be determined, 
it was
done with limited confidence. For example, it is impossible to know whether the 
hydraulic
conductivity of the Lower Bullfrog interval in c#1 really is about half that in c#2 or 
whether
these calculated hydraulic conductivity values result from dividing approximately the 
same
transmissivity in each borehole by an assumed transmissive thickness that is twice as 
large in c#1
as in c#2.
6.2.6 Saturated Zone Anisotropy near the C-wells Complex
6.2.6.1 Introduction
Understanding SZ flow and transport near the high-level nuclear waste repository at 
Yucca
Mountain is critical to a successful License Application. Because radionuclides released 
from
the repository at Yucca Mountain must travel through the saturated fractured tuff and the
saturated alluvium before reaching the compliance boundary, it is important to 
characterize the
hydrogeologic properties of the down-gradient media. Since the completion of the 
sitecharacterization
wells in 1983, several single- and cross-hole tracer and pumping tests have been
conducted to gain a better understanding of the hydrogeology of the region. A number of
published studies have assigned transmissivities, storativities, and anisotropy ratios to the
saturated zone in this area (Farrell et al. 1999 [157319]; Ferrill et al. 1999 [118941]; 
Winterle
and La Femina 1999 [129796]). In this scientific analysis report, reviews of the above
mentioned studies are used in conjunction with independent re-analyses of the data to 
suggest a
distribution of anisotropy ratios that are to be used in the finite-element, heat and mass 
transfer
(FEHM) stochastic flow model of the saturated zone (Zyvoloski et al. 1997 [110491]).
6.2.6.1.1 Background
A geologic description of the C-wells complex and the surrounding area can be found in 
several
publications (including Geldon et al. 1998 [129721], Table 1, Figure 3, Figure 5; Farrell 
et al.
1999 [157319]; Ferrill et al. 1999 [118941]; Winterle and La Femina 1999 [129796]).
Nevertheless, one geologic characteristic bears mentioning. Based on in-situ stress-field
analyses, the maximum horizontal geologic stress runs north-northeast (azimuth between 
25 and
30 east of north). Therefore, any fractures oriented in this direction tend to dilate and 
present
potential preferential flow pathways (Farrell et al. 1999 [157319], p. 4-1; Ferrill et al. 
1999
[118941], p. 1). This finding supports some of the calculated principal directions of 
anisotropy
discussed below, but not all.
Although many hydraulic tests have been conducted at the C-wells complex, only the 
long-term
pumping test from May 8, 1996, through November 12, 1997, yielded data suitable for
estimating the hydraulic properties of the medium on a broad scale beyond the immediate
vicinity of the C-wells. These data may help to estimate an overall anisotropy ratio for the 
area.
ANL-NBS-HS-000039, REV 00 142 December 2003
Specifically, changes in local groundwater elevations due to pumping at the C-wells 
complex
were monitored at several distant wells, the locations of which are shown in Figure 6.1-4 
(only
H-4, ONC-1, WT#3, and WT#14 exhibited sufficient drawdown for an anisotropy 
analysis).
Well c#3 has traditionally served as the pumping well because of its record of consistent
production rates.
Although several cross-hole hydraulic tests have been conducted by USGS investigators, 
only
the long-term pumping test yielded data suitable for calculating a nonlocal anisotropy 
ratio. For
this test, well c#3 was packed around the Lower Bullfrog interval, and water levels were
monitored at H-4, ONC-1, WT#3, and WT#14. Data collected during this test were used 
to
calculate transmissivity and storativity at each well-parameters that are necessary to 
estimate
analytically an anisotropy ratio for the area. Although water levels were monitored at 
other
wells, none yielded data suitable for an analytic treatment of anisotropy.
6.2.6.1.2 Technical Approaches
Water-level data for wells H-4, WT#3, and WT#14 were obtained from the DTN:
GS970308312314.002 [161273]. Data from well ONC-1 were collected by Nye County 
under
the Nye County Nuclear Waste Repository Project Office (NWRPO) QA program (QAP)
(NWRPO 2003 [165947], Program Management, Quality Assurance Program). Nye 
County
requires that the NWRPO establish and maintain a documented QAP that meets the 
requirements
of ANSI/ASME NQA-1 and the criteria of 10 CFR 50 (2002 [165855], Appendix B). 
These data
are available under DTN: MO0212SPANYESJ.149 [161274].
Winterle and La Femina (1999 [129796]) reduced and filtered the drawdown data for the 
above
wells to obtain estimates of hydraulic parameters over the affected area. In the analyses
presented here, the filtering of data from wells H-4, WT#3, WT#14, and ONC-1 was
accomplished with Filter.vi (STN: 10970-1-00 [162668]). These filtered drawdown data 
are
identified by Output DTNs: GS030208312314.001 and GS030208312314.002.
The first analytical anisotropy analysis in this report was calculated in Microsoft ExcelTM 
using
the standard formulation offered by Hantush (1966 [161160]); the second uses a 
modification of
the method of Papadopulos (1967 [150265]) combined with the PEST parameter-
estimation
program, Version 5.5 (STN: 10289-5.5-00 [161564]). Winterle and La Femina (1999 
[129796])
used AQTESOLV, Version 2.12, marketed by HydroSOLVE Inc., to analyze pump tests. 
Based
on Geldon et al. (2002 [161163]), the authors of this report used analytical solutions of 
Theis
(1935 [150327]) or Streltsova-Adams (1978 [150754]) for analyses of the responses at 
the four
observation wells to pumping at c#3. These analyses were performed using Theis.vi 
(STN:
10974-1-00 [162758]) and Streltsova-Adams.vi (STN: 10971-1-00 [162756]), 
respectively.
6.2.6.2 Estimating Anisotropy
Interpretation of well test data with analytical solutions consists of inferring the hydraulic
properties of the system from its measured responses based on, among other things, an 
assumed
flow geometry (i.e., radial). The problem becomes more complicated, however, when the 
system
geometry cannot be specified with reasonable certainty. In a layered sedimentary system 
lacking
extreme heterogeneity, flow might reasonably be expected to be radial during an 
hydraulic test.
ANL-NBS-HS-000039, REV 00 143 December 2003
When hydraulic tests are conducted at some arbitrary point within a three-dimensional (3-
D)
fractured rock mass, however, the flow geometry is convoluted. Radial flow would occur 
only if
the test were performed in a single uniform fracture of effectively infinite extent or within 
a
network of fractures confined to a planar body in which the fractures were so densely
interconnected that the network behaves like an equivalent porous medium. More likely, 
flow
would be nonradial and variable, as fracture terminations and additional fracture 
intersections
were reached. The nonradial nature of the cone of depression near Yucca Mountain is 
illustrated
in Figure 6.2-38. Despite all of this, analytic solutions provide important requisite first-
order
answers that are commensurate with the spatial distribution of the available 
hydrogeologic and
geophysical data, and that can only be improved by numerical modeling if that data 
distribution
is enhanced by substantial new data-gathering efforts.
Through the fractured tuff near Yucca Mountain, there are significant heterogeneity and
hydraulic properties that not only vary spatially but also differ depending upon the 
direction in
which they are measured (both horizontally and vertically). In this analysis, 
transmissivity and
storativity are the key parameters defining large-scale anisotropy, and their measured 
values
reflect the heterogeneity of the media. The concept of anisotropy is typically associated 
with a
homogeneous medium-a criterion not met here. Nevertheless, there are clearly spatial 
and
directional variations in transmissivity, and the notion remains that, over a large enough
representative elementary volume, there exists a preferential flow direction that can be 
termed
"anisotropy."
Data from the long-term pumping test conducted from May 8, 1996, to November 12, 
1997, can
be used to evaluate the anisotropy of the C-wells complex and vicinity because 
transmissivity
and storativity can be calculated at four distant wells (H-4, ONC-1, WT#3, and WT#14). 
The
hydraulic properties measured at these wells are used to develop an estimate for the 
anisotropy
ratio. Data from the other C-wells (c#1 and c#2) were not used in the anisotropy analysis
because, according to Farrell et al. (1999 [157319], pp. 4 to 12):
* Over the small scale of observation at the C-wells, pump-test results are likely 
dominated
by discrete fractures (i.e., inhomogeneities).
* Three-dimensional flow effects are likely.
* Recirculation from simultaneous tracer tests obscured results.
Furthermore, because anisotropy is conceptually difficult to define for heterogeneous 
media, it is
more easily described as an average preferential flow over as large a representative 
elementary
volume as possible. Thus, it makes little sense to attempt to define anisotropy over an
heterogeneous area as small as that of the C-wells.
ANL-NBS-HS-000039, REV 00 144 December 2003
6.2.6.2.1 Data Filtering and Reduction
Because drawdown was measured at great distances from the pumping well (up to 3,526 
m
between WT#3 and c#3), natural variations in groundwater levels obscured responses due 
to
pumping and had to be filtered out before the drawdown data could be analyzed. 
Drawdowns
were corrected for Earth-tide effects (head fluctuations of up to 0.12 m) and atmospheric
pressure change (head fluctuation of up to 0.25 m). First, the water levels were processed 
with a
low-pass filter (Filter.vi V 1.0, STN: 10970-1-00 [162668]) to remove oscillations with a
frequency greater than 0.8 cycles per day to eliminate Earth-tide effects and semi-diurnal
barometric-pressure effects, leaving only the effects of long-term weather-related 
barometricpressure
changes. The barometric record from the C-wells complex, which was assumed to
apply to all the wells, was also filtered to remove frequencies greater than 0.8 cycles per 
day to
eliminate semi-diurnal barometric-pressure fluctuations, leaving only long-term weather-
related
barometric pressure changes. Using barometric efficiency values of the wells, the effects 
of
long-term, weather-related, barometric-pressure changes were removed from the filtered 
water
levels, leaving only the effect of c#3 pumping. The filtered and barometrically-corrected 
waterlevel
data for the four observation wells can be found in Output DTNs: GS030208312314.001
and GS030208312314.002. The water-level data for H-4, WT#3, and WT#14 were 
obtained
from DTN: GS970308312314.002 [161273], and the water levels for ONC-1 were 
obtained from
DTN: MO0212SPANYESJ.149 [161274]. The barometric record used for the above 
processing
was from the C-wells complex (DTN: GS981008312314.003) [144464].
Winterle and La Femina (1999 [129796], pp. 3-4 to 3-6) also applied a second stage of 
filtering
to the long-term pumping test to remove barometric effects that reached the aquifer 
through the
unsaturated zone by accounting for the time lag and attenuation that occurs in the 
unsaturated
zone. Second-stage barometric pressure effects were filtered using a 2.6-day running 
average,
multiplied by an attenuation factor of 0.6, and lagged by a period of 0.42 days.
The derivative of the filtered drawdowns with respect to the log of time was calculated 
for H-4,
WT#3, WT#14, and ONC-1 to establish the optimum range of data to fit with the 
straight-line
method of Cooper and Jacob (1946 [150245]). The flattest (zero-slope) portion of the 
resulting
curve is deemed the best location for a linear fit to the drawdown data.
6.2.6.2.2 Transmissivity and Storativity Calculations
In the first analysis of this section, the Cooper-Jacob (1946 [150245]) method applied to 
filtered
and derivative-analyzed data is used to calculate transmissivities and storativities. The 
key to a
reasonable estimate of anisotropy is an accurate assessment of transmissivity and 
storativity at
each monitoring well. Figure 6.2-41 is a plot of the filtered drawdowns fit with the 
Cooper-
Jacob straight-line method to the appropriate portion of the derivative curve. Note the
inconsistent slope of the fit to drawdown in well H-4 resulting in a significantly lower
transmissivity at this well. Transmissivity and storativity values are presented in Table 
6.2-10.
In the second analysis methodology of this report, which uses the modified Papadopulos-
PEST
method, the response of each of observation wells H-4, WT#14, and WT#3 is analyzed 
using the
homogeneous, isotropic method of Theis (1935 [150327]) (Theis.vi V 1.0, STN: 10974-
1-00
[162758]) for confined aquifers, and the response of observation well ONC-1 is analyzed 
using
ANL-NBS-HS-000039, REV 00 145 December 2003
the homogeneous, isotropic method of Streltsova-Adams (1978 [150754]) (Streltsova-
Adams.vi,
V 1.0, STN 10971-1.0-00 [162756]) for fissure-block aquifers-both type-curve-fitting
techniques-to obtain transmissivity and storativity values. Three analyses were made: 
one with
transmissivities constrained to 1,000 m2/day, the other with the transmissivities and 
storativities
as given in Geldon et al. (2002 [161163], p. 50; DTN: GS030508312314.003 [164425]), 
and the
third with transmissivities and storativities obtained from analyzing the filtered and
barometrically-corrected water levels processed for this report and described in the first
paragraph of Section 6.2.6.2.1. The three sets of values are used to produce three sets of
anisotropy magnitudes and directions as discussed below.
DTN: GS970308312314.002 [161273], DTN: MO0212SPANYESJ.149 [161274]. Output DTN: GS031008312314.004.
NOTE: The straight lines were fit to relatively small portions of each drawdown curve that were selected 
because
they had the most constant derivatives (i.e., the least noisy portions of the curves). Fitting a straight line to
larger portions of the curves could result in slopes and, hence, estimated transmissivities, that differ by 
nearly
a factor of two.
Figure 6.2-41. Straight Line Fits to the Filtered and Derivative-Analyzed Data
at the Four Monitoring Wells
ANL-NBS-HS-000039, REV 00 146 December 2003
Table 6.2-10. Transmissivities and Storativities Calculated by the Cooper-Jacob Method
Using the Filtered and Derivative-Analyzed Data
Cooper-Jacob* Analysis
Well
T (m2/day) S (-)
UE-25 ONC-1 446 0.003
UE-25 WT#3 477 0.0005
UE-25 WT#14 318 0.0008
USW H-4 182 0.0007
DTN: GS970308312314.002 [161273], DTN: MO0212SPANYESJ.149 [161274]. Output DTN: GS031008312314.004.
NOTE: *The Cooper-Jacob (1946 [150245]) method was used in the analysis.
6.2.6.2.3 Previously Reported Results
Winterle and La Femina (1999 [129796], Section 4.5) processed the long-term pumping 
data
with AQTESOLV, and their transmissivity and storativity results (obtained with the 
Theis 1935
[150327] method) are shown in Table 6.2-11. Considering the differences in the Cooper-
Jacob
(1946 [150245]) and Theis (1935 [150327]) analysis methods, as well as differences in 
data
reduction methods, the Winterle and La Femina (1999 [129796], p. 4-25) transmissivities 
agree
reasonably well with the results from the analyses shown in Table 6.2-10. The drawdown 
data
from the long-term pumping test in Section 6.2.4.6 and from Winterle and La Femina 
(1999
[129796], p. 4-25) were also analyzed using the Theis method, and these results are 
reproduced
in Table 6.2-11. With the exception of WT#3, the transmissivities are in good agreement 
with
those of Winterle and La Femina (1999 [129796], p. 4-25). The difference of more than a 
factor
of 2 in the transmissivity of WT#3 can probably be attributed to differences in data 
reduction
methods, which lead to greater differences in parameter estimates when the overall 
drawdown is
relatively small (as it is for WT#3).
Table 6.2-11. Transmissivities and Storativities of Distant Wells for the Long-Term Pumping Test
Winterle and La Femina (1999)* Based on Section 6.2.4.6
Well T (m2/day) S (-) T (m2/day) S (-)
UE-25 ONC1 1,340 0.008 1,000 0.001
UE-25 WT#3 1,230 0.005 2,600 0.002
UE-25 WT#14 1,330 0.002 1,300 0.002
USW H-4 670 0.002 700 0.002
Source: *Winterle and La Femina (1999 [129796], p. 4-25).
ANL-NBS-HS-000039, REV 00 147 December 2003
6.2.6.2.4 ONC-1 Data
A discussion is in order regarding the quality of the Nye County water-level data 
collected at
ONC-1. The data were collected under the NWRPO QAP. Nye County policy requires 
that
NWRPO establish and maintain a documented QAP that meets the requirements of 
ANSI/ASME
NQA-1 and the criteria in 10 CFR 50 (2002 [165855]). As shown in Figure 6.2-41, the 
filtered
water levels at ONC-1 are visually consistent with the filtered QA water-level data 
collected at
WT#3, WT#14, and H-4. In addition, the slopes of the Cooper-Jacob (1946 [150245]) fit 
to
drawdown are comparable for ONC-1, WT#3, and WT#14. Although H-4 shows a 
steeper slope,
this corresponds to the hypothesis that the well was drilled in a less transmissive 
formation. The
average slope of the Cooper-Jacob lines in Figure 6.2-41 is 0.49 with a standard deviation 
of 0.2.
At ONC-1, the slope is 0.34, which is less than one standard deviation from the mean 
slope of all
four wells. It should also be noted that in the published literature (Farrell et al. 1999 
[157319], p.
4-11; Ferrill et al. 1999 [118941], p. 6; Winterle and La Femina 1999 [129796], p. 4-25; 
and
Geldon et al. 2002 [161163], p. 23), the transmissivity and storativity calculated near well 
ONC-
1 using Nye County data are consistent with the transmissivities and storativities 
calculated at the
nearby wells (WT#3, WT#14, and H-4) using YMP QA water-level data.
6.2.6.2.5 Anisotropy Ratios
Anisotropy ratio analyses performed for this report employ the analytical solution of 
Hantush
(1966 [161160]) or a modification of the analytic solution of Papadopulos (1967 
[150265])
combined with PEST (STN: 10289-5.5-00 [161564]). The analyses of Winterle and La 
Femina
(1999 [129796], p. 4-24) and Ferrill et al. (1999 [118941], p. 6) used the Papadopulos 
(1967
[150265]) method. Although all techniques assume homogeneous confined aquifers with 
radial
flow to the pumping well, some deviations from these assumptions may still yield 
reasonable
estimates of anisotropy. In particular, these methods require as input: transmissivity, 
storativity,
and the locations of a minimum of three monitoring wells. With this information, 
anisotropy
ratios and principal directions may be calculated. Results from all analyses are presented 
in
Table 6.2-12.
Using transmissivities and storativities from Table 6.2-10 with the Hantush (1966 
[161160])
method yields an anisotropy ratio of 3.3 at principal direction 15 east of north. The data 
from
H-4 were excluded from this analysis (as they were in the Winterle and La Femina (1999
[129796]) and Ferrill et al. (1999 [118941]) analyses) because including the data resulted 
in an
undefined (negative) anisotropy ratio.
In the modified Papadopulos-PEST method, three approaches were considered. In the 
first
approach and in order to satisfy the homogeneous, anisotropic assumption of 
Papadopulos (1967
[150265]), which requires that all the observation-well responses produce the same
transmissivity (to honor the homogeneity assumption), Theis (1935 [150327]) (Theis.vi V 
1.0,
STN: 10974-1-00 [162758]) type-curve fits for H-4, WT#3, WT#14, and a Streltsova-
Adams
(1978 [150754]) (Streltsova-Adams.vi V 1.0, STN 10971-1.0-00 [162756]) type-curve fit 
for
ONC-1 were constrained to produce the intermediate transmissivity value of 1,000 m2/d 
(the
nonconstrained values published in Geldon et al. (2002 [161163], Table 9; DTN:
GS030508312314.003 [164425]) ranged from 700 m2/d for H-4 to 2,600 m2/d for 
WT#3). These
constrained fits produce storativities of 0.0023, 0.0052, 0.0026, and 0.0013 for wells H-4, 
WT#3,
ANL-NBS-HS-000039, REV 00 148 December 2003
WT#14, and ONC-1, respectively. From these constrained fits, ratios of the directional
transmissivity over storativity, Td/S, were obtained after Papadopulos (1967 [150265]). 
The
square roots of these ratios were plotted on a polar plot with the pumping well, c#3, at the 
center.
It is important to note that while the Theis (1935 [150327]) well function was used to 
develop
the anisotropy ratios in this report, there is no reason why the well function cannot be 
replaced
by another appropriate function. For example, if the medium responds as a fissure-block 
system,
the fissure-block well function of Streltsova-Adams (1978 [150754]) may be used. 
Because
anisotropy analyses assume that drawdown, is proportional to the well function, W(u), 
through
the relation s = (Q/4 ?T)W(u), where Q is the pumping rate, substitution of other well 
functions
should not affect the anisotropy-calculation methodology.
The modified Papadopulos-PEST method then fits an ellipse, centered at the pumping 
well,
through the (Td/S)1/2 data. This fitting was done with PEST V 5.5 (STN: 10289-5.5-00
[161564]), in conjunction with a Microsoft Excel spreadsheet, which calculates the 
shortest
distance from each of the (Td/S)1/2 data points to the constructed ellipse. PEST is 
instructed to
vary the long and short axes of the ellipse and the principal direction to minimize the 
distances of
all four (Td/S)1/2 data points from the ellipse. The ellipse in Figure 6.2-42 is the optimal 
PEST
ellipse. For this fit, PEST indicates that the direction of anisotropy is 79 west of north 
(with a
95% confidence interval of 75 to 82) and that the magnitude of anisotropy is 3.5:1 
(with a 95%
confidence interval of 2.7:1 to 4.3:1). This direction of anisotropy is consistent with the 
geologic
evidence of the Antler Wash series of fractures and faults running northwest from the C-
wells to
H-4. Two types of anisotropy are present within the study area: one is the NE-SW 
uniformlydistributed
anisotropy caused by regional stresses, and another is a NW-SE anisotropy related to
the Antler Wash fault zone. The well H-4 is located along Antler Wash, northwest from 
the Cwells.
When the well H-4 is included in the analysis, the results are greatly affected by Antler
Wash and represent the NW-SE anisotropy related to this system. When the well H-4 is 
not
included in the analysis, the results represent the NE-SW uniformly-distributed 
anisotropy
caused by regional stresses.
ANL-NBS-HS-000039, REV 00 149 December 2003
DTN: GS970308312314.002 [161273], DTN: MO0212SPANYESJ.149 [161274]. Output DTN: GS031008312314.004.
Figure 6.2-42. Optimal Papadopulos-PEST Ellipse Fit to the Square Root of the Ratio of 
Directional
Transmissivity to Storativity for USW H-4, UE-25 WT#3, UE-25 WT#14, and UE-25 ONC-1, for 
the
1,000 m2/day Transmissivity Fit for All Wells
ANL-NBS-HS-000039, REV 00 150 December 2003
In the second modified Papadopulos-PEST approach, an optimal PEST ellipse was 
obtained for
the unconstrained transmissivity values from DTN: GS030508312314.003 [164425], 
(published
in Geldon et al. 2002, [161163], p. 41, Table 9), although it violates the homogeneity
requirement inherent in the Papadopulos (1967 [150265]) method. The values for T and S 
are
700 m2/day and 0.002, respectively, for well H-4; 2,600 m2/day and 0.002 for WT#3; 
1,300
m2/day and 0.002 for WT#14; and 1,000 m2/day and 0.001 for ONC-1. From these
nonconstrained fits, ratios of the directional transmissivity over storativity, Td/S, were 
obtained
following the Papadopulos (1967 [150265]) technique. The square roots of these ratios 
were
plotted on a polar plot with the pumping well, c#3, at the center (Figure 6.2-43). For this 
fit,
PEST V 5.5 (STN: 10289-5.5-00 [161564]) indicates that the direction of anisotropy is 
1.1 east
of north (with a 95% confidence interval of 0.5 to 1.7) and that the magnitude of 
anisotropy is
5.5:1 (with a 95% confidence interval of 5.2:1 to 5.8:1).
DTN: GS030508312314.003 [164425]; DTN: MO0212SPANYESJ.149 [161274]. Output DTN: GS031008312314.004.
Figure 6.2-43. Optimal Modified-Papadopulos Ellipse Fit to the Square Root of the Ratio of 
Directional
Transmissivity to Storativity for USW H-4, UE-25 WT#3, UE-25 WT#14, and UE-25 ONC-1, Using 
PEST
for Variable (700-2,600 m2/day, not in order of listed wells) Transmissivities for the Four Wells
ANL-NBS-HS-000039, REV 00 151 December 2003
In the third modified Papadopulos-PEST approach, an optimal PEST ellipse was obtained 
for
unconstrained transmissivity values resulting from Theis (1935 [150327]) (Theis.vi V 
1.0, STN:
10974-1-00 [162758]) type-curve fits for H-4, WT#3, WT#14, and Streltsova-Adams 
(1978
[150754]) (Streltsova-Adams.vi V 1.0, STN: 10971-1.0-00 [162756]) type-curve fits for 
ONC-1,
using the filtered water-level data described in the first paragraph under Section 6.2.6.2.1. 
The
unconstrained values for T and S resulting from analyzing the filtered data are 700 m2/day 
and
0.0024, respectively, for well H-4; 861 m2/day and 0.0045 for WT#3; 743 m2/day and 
0.0029 for
WT#14; and 1,230 m2/day and 0.0012 for ONC-1. From these values, ratios of the 
directional
transmissivity over storativity, Td/S, were obtained after Papadopulos (1967 [150265]). 
The
square roots of these ratios were plotted on a polar plot with the pumping well, c#3, at the 
center
(Figure 6.2-44). For this fit, PEST V 5.5 (STN: 10289-5.5-00 [161564]) indicates that the
direction of anisotropy is 34.7 west of north (with a 95% confidence interval of 31.7 to 
37.7)
and that the magnitude of anisotropy is 11.3:1 (with a 95% confidence interval of 9.3:1 to
13.9:1).
DTN: GS970308312314.002 [161273]; DTN: MO0212SPANYESJ.149 [161274]. Output DTN: GS031008312314.004.
Figure 6.2-44. Optimal Modified-Papadopulos Ellipse Fit to the Square Root of the Ratio of 
Directional
Transmissivity to Storativity for USW H-4, UE-25 WT#3, UE-25 WT#14, and UE-25 ONC-1, using 
PEST,
for Variable (700-1,230 m2/day) Transmissivities Obtained from Filtered Water Levels for the 
Four Wells
ANL-NBS-HS-000039, REV 00 152 December 2003
Using the analytical solution of Papadopulos (1967 [150265]), which assumes an 
homogeneous,
confined aquifer, Ferrill et al. (1999 [118941], p. 7) report an anisotropy ratio of 17:1 
with
principal direction at azimuth 30 (east of north).
The anisotropy ratio of Winterle and La Femina (1999 [129796], p. 4-23) is listed in the 
last row
of Table 6.2-12 as 5 at 33 east of north. It should be noted that the difference in reported
anisotropy between Ferrill et al. (1999 [118941], p. 7) and Winterle and La Femina (1999
[129796], p. 4-23) was solely due to a change in transmissivity for well WT#14, which 
decreased
from 1,370 to 1,330 m2/day due to a difference in technique for correcting barometric 
pressures.
The sensitivity of the analytical solution is demonstrated by the 3% change in 
transmissivity
manifesting itself as a 70% decrease in the anisotropy ratio to 5:1.
Although not listed in Table 6.2-12, the Hantush (1966 [161160]) technique was applied 
to the
transmissivities and storativities of Section 6.2.4.6 of this report, yielding an undefined
anisotropy ratio (i.e., the transmissivities do not define an ellipse). However, when the 
modified
Papadopulos-PEST analysis methodology was applied to these transmissivities and 
storativities,
the anisotropy ratio was estimated as 5.5, as indicated in the third row of Table 6.2-12. 
With the
varied results, it is clear that the anisotropy ratio is highly sensitive to the locations and
transmissivities of the monitoring wells. Three of the principal directions of anisotropy
presented in Table 6.2-12 vary between 15 and 33. These values agree favorably with 
the
geologically interpreted value of between 25 and 30, the principal directional trend of 
faults in
the Yucca Mountain area. In the methods producing these values, H-4 was not included 
in the
analysis, and, hence, the resulting anisotropy values appear to not be affected by the 
Antler Wash
structure; rather, they may be showing the underlying uniformly-distributed anisotropy.
Table 6.2-12. Calculated and Reported Anisotropies and Principal Directions
Data Set Used (Method) Tmax (m2/day) Tmin (m2/day) Anisotropyb Azimuthb
Table 6.2-10 (Hantush 1966)a 748 229 3.3 15E
T = 1,000 m2/day (Papadopulos-PEST)a 1,863 537 3.5 79W
T = 700 - 2,600 m2/day (Papadopulos-PEST)a 3,272 599 5.5 1E
T = 700 - 1,230 m2/day (Papadopulos-PEST)a 3,047 271 11.3 35oW
Ferrill et al. (1999)a 5,400 315 17 30E
Winterle and La Femina (1999)a 2,900 580 5 33E
DTN: GS970308312314.002 [161273]; DTN: MO0212SPANYESJ.149 [161274]. Output DTN: GS031008312314.004.
NOTE: a For a description of the methods used, refer to Hantush (1966 [161160]), Papadopulos (1967 
[150265]),
Ferrill et al. (1999 [118941]), and Winterle and La Femina (1999 [129796]).
b The last two columns list reported values.
ANL-NBS-HS-000039, REV 00 153 December 2003
Winterle and La Femina (1999 [129796], p. 4-25) claim a low degree of confidence in 
their
anisotropy ratio because the problem is poorly constrained (e.g., data from only the 
minimum
number of wells necessary for a solution is used; the medium is not homogeneous; the 
flow is
not radial; and the aquifer may not be confined). Data from well H-4 were only used in 
the
modified Papadopulos-PEST method. When data from H-4 were not used, it was because 
the
transmissivity for this well was consistently about half of the other wells (note that both 
of the
analytical solutions of Hantush (1966 [161160]) and Papadopulos (1967 [150265]) 
require that
all wells have equal or nearly equal transmissivities). The rationale for excluding H-4 
from the
horizontal anisotropy analysis, in some cases, was also based on the Geldon et al. (1998
[129721], p. 31) suggestion that a preferential flow path exists between well H-4 and the 
Cwells.
However, inclusion of the H-4 data in the modified Papadopulos-PEST method and
constraining the transmissivity to 1,000 m2/day (as described above) produced a direction 
of
anisotropy consistent with the alignment of this preferential pathway. It is also noted that 
after
approximately 50 days of pumping, water levels in wells H-4 and WT#14 stopped 
responding to
pumping and actually began to increase, a phenomenon attributed to a recharge or high
transmissivity boundary to the east or northeast of WT#14, which could potentially be a
transmissive fault. This water-level increase was never observed in well ONC-1, even 
after 237
days of monitoring. This result implies that not all of the assumptions used in the 
anisotropy
analysis are justifiable. Overall, this conclusion should serve to underscore the level of
uncertainty in reported anisotropy ratios.
Considering the range of values demonstrated by the various anisotropy calculations, the 
results
in Table 6.2-12 help characterize a parameter that was not targeted explicitly for 
measurement
when the data ultimately used to calculate it were obtained.
6.2.6.3 Interpretation and Assignment of the Anisotropy Distribution
Well-test analysis is the process of estimating hydraulic parameters of interest (in this 
case,
transmissivity and storativity) from measured drawdown data and is known as an inverse 
(or
parameter-estimation) problem. An inherent quality of inverse problems is that the 
parameters
estimated via this process have some degree of uncertainty associated with their values. 
More
importantly, when solving an inverse problem, a family of solutions should be matched to 
the
data. Because there are typically infinitely many solutions that fit the data, reporting only 
a
single value imparts no real information. It is much more important to examine the range 
of
solutions and to evaluate the sensitivity of each parameter to the solution. In other words,
uncertainty must be quantified. To date, there have been no attempts to assign confidence
intervals to the estimated parameters. Comparing the well test results of previous 
researchers
helps to emphasize the dependence of the estimated hydraulic parameters upon the 
solution
technique and input data used. Analytical techniques alone cannot provide a measure of
confidence in their reported solution. Therefore, it is left to scientific judgment to assign a
distribution of anisotropy ratios based upon the available scientific evidence.
Practically speaking, an anisotropy ratio must be selected for each of the 200 stochastic 
model
realizations used as input to the software code FEHM. Because the current version of 
FEHM
(V. 2.20, STN: 10086-2.20-00 [161725]) can only implement anisotropy oriented in a 
northsouth
direction, principal directions discussed above are not applicable in the model. The net
result of being unable to specify a principal direction is that uncertainty in the anisotropy 
ratio
ANL-NBS-HS-000039, REV 00 154 December 2003
can only increase. For example, the analytical result for anisotropy using the Cooper-
Jacob
(1946 [150245]) method is 3.3 at 15 east of north. A projection that orients the principal
direction north-south (0) results in a new anisotropy ratio of 2.5. As illustrated in Figure 
6.2-45,
this value was calculated by dividing the maximum y value on the anisotropy ellipse 
oriented 15
east of north (horizontal blue line at top) by its maximum x value (vertical green line at 
right).
Similarly, the projected north-south anisotropy ratio for an anisotropy ratio of 5 oriented 
33 east
of north is 1.5. Uncertainty in the analytically calculated anisotropy ratio is propagated in 
the
projected anisotropy ratio and magnified as a function of the uncertainty in the principal
direction. In fact, this line of reasoning suggests that it is possible for the projected north-
south
anisotropy ratio to be significantly less than one.
Output DTN: GS031008312314.004.
Figure 6.2-45. Anisotropy Ratio of 3.3 at 15 East of North Projected onto a
North-South Anisotropy Ratio (0) Resulting in a Projected Anisotropy Ratio of 2.5
Based on consultations with USGS staff, the YMP Parameters Team, scientific judgment, 
and
results from the analytical anisotropy analyses, Figure 6.2-46 (a) represents the best 
estimate of
the probability density function (PDF) for the anisotropy ratio in the saturated zone near 
the Cwells
complex. Figure 6.2-46 (b) is the corresponding cumulative distribution function (CDF).
ANL-NBS-HS-000039, REV 00 155 December 2003
Output DTN: SN0302T0502203.001.
Figure 6.2-46. Probability Density Function (a) and Corresponding Cumulative Distribution
Function (b) for the North-South/East-West Anisotropy Ratio Used in FEHM Input Files
There are several noteworthy points based on three distinct regions of the anisotropy ratio
distribution (Output DTN: SN0302T0502203.001).
* Anisotropy ratio between 5 and 20. The maximum anisotropy ratio of 20:1 is physically
based. Although features such as high transmissivity zones and fractures may yield very
large anisotropy ratios locally, globally, their effects are attenuated. That is, over the area
of the saturated-zone model, 45 x 30 km2, an anisotropy ratio of 20 is the expected upper
bound. Additionally, the highest calculated anisotropy ratio reported is 17:1 (Ferrill et al.
1999 [118941], p. 7). The 5.5 anisotropy ratio calculated by the second approach of the
modified Papadopulos-PEST method lies in this range near its highest probability point.
Therefore, between 5 and 20, a triangularly distributed anisotropy ratio is constructed that
decreases to zero probability at 20. A 40% probability is assigned to this portion of the
PDF.
* Anisotropy ratio between 0.05 and 1. Discussions among Sandia National Laboratories
(SNL) and USGS staff established that, although it is likely the saturated zone is
anisotropic with principal direction approximately northeast, it is possible the media
could be isotropic, as well as a small probability that the principal direction could be
significantly different from northeast. Correspondingly, anisotropies less than one are
possible, and the minimum anisotropy ratio is set equal to the inverse of the maximum,
1:20, with a triangularly distributed 10% probability decreasing to zero at a ratio of 0.05.
ANL-NBS-HS-000039, REV 00 156 December 2003
The 3.5 anisotropy ratio calculated by the first approach of the modified Papadopulos-
PEST method, when adjusted according to Figure 6.2-45, falls in this range.
* Anisotropy ratio between 1 and 5. A uniformly distributed 50% probability is assigned 
to
the range of anisotropy ratios between 1 and 5. This interval comprises the most likely
values of anisotropy ratios with no specific value more likely than another.
Figure 6.2-46 (a and b) is the best estimate for the PDF and the CDF, respectively, of 
north-south
anisotropy ratios in the saturated zone to be modeled with FEHM.
6.2.6.4 FEHM Sensitivity Study
One last point worthy of mention is that a sensitivity analysis of FEHM V 2.20 (STN: 
10086-
2.20-00 [161725]) results to the anisotropy ratio demonstrated that the modeled heads are
insensitive to the input anisotropy ratio. However, inferred groundwater travel times and 
flow
pathways, which ultimately are more important for radionuclide transport predictions 
than heads,
are more sensitive to the anisotropy ratio. Figure 6.2-47 illustrates how varying the 
anisotropy
ratio affects the weighted root-mean-square error (RMSE) between measured and FEHM
modeled heads. Note that the RMSE ranges only between 6.9 and 7.6. Although this short 
range
demonstrates relative insensitivity of the modeled heads to the anisotropy ratio, it is 
encouraging
to note that the minimum RMSE corresponds to an anisotropy ratio of 20.
For information purposes only.
Figure 6.2-47. Weighted Root-Mean-Square Error (RMSE) Between Measured Heads and FEHM
Modeled Heads Subject to a Range of Anisotropy Ratios Between 0.01 and 100
ANL-NBS-HS-000039, REV 00 157 December 2003
6.2.6.5 Conclusions
Although analytical and graphical techniques can produce a single, specific anisotropy 
ratio, this
value is sensitive to both the solution technique and the analyst's interpretation of the 
data (e.g.,
what filtering parameters were used or how the slopes of drawdown were calculated). A 
wide
distribution of anisotropy ratios is suggested to account for the significant uncertainty in 
this
hydraulic property. Each run of FEHM V 2.20 (STN: 10086-2.20-00 [161725]) must 
have a
single value of anisotropy assigned to the anisotropy zone of the model area, and though 
this is
unrealistic (no single value of anisotropy truly applies to such a large heterogeneous 
area),
drawing an anisotropy ratio from the specified distribution and running FEHM 
stochastically
should effectively account for the uncertainty in this model parameter. Additionally, 
because the
current version of FEHM cannot specify the principal direction of anisotropy, the range 
of
possible north-south anisotropies is increased to consider this fact.
6.2.7 Summary of Conceptual Models And Parameters
Hydraulic tests conducted by the USGS in Miocene tuffaceous rocks at the C-wells 
complex,
Yucca Mountain, Nevada, between May 1995 and November 1997 determined flow
characteristics in six saturated-zone hydrogeologic intervals. North- and northwest-
striking
faults intersect boreholes of the C-wells complex, defining hydrogeologic intervals by 
spatially
related faults and fracture zones. Flow within those intervals comes from diversely 
oriented
fractures and from the interstices of variably welded ash-flow, ash-fall, and reworked 
tuff. The
tuffs act as a single aquifer. About 70 percent of flow seen in hydraulic tests was 
contributed by
the Lower Bullfrog interval, and another 20 percent came from the Upper Tram interval.
Identified hydrogeologic units, and related hydraulic properties, cannot be extended far 
beyond
the immediate vicinity of the C-wells complex due to control of those intervals by fault 
and
fracture zones.
In several hydraulic tests from 1995 to 1997, borehole c#3 of the C-wells complex was 
used as
the pumping well. Boreholes c#1 and c#2 (tens of meters distant) were used as 
observation
wells. Each of the wells of the complex is about 900 m deep, and all are open below 
surface
casings to the penetrated formations. Additional boreholes were used as observation wells 
in
some of the hydraulic tests, including ONC-1, H-4, WT#14, WT#3, and p#1. The 
observation
wells were completed in various intervals seen also in the holes of the C-wells complex; 
p#1 was
completed in Paleozoic carbonate rocks. Those observation wells were sited 630 to 3,526 
m
from c#3, allowing some extrapolation of hydraulic characteristics from the C-wells 
location.
The hydraulic tests were conducted to determine: (1) properties of the composite 
saturated-zone
section in the C-wells; (2) hydraulic properties of the six intervals in those holes; and (3)
heterogeneity in the tuffs, including the influence of faults. Monitoring in borehole p#1 
was
intended to establish whether the tuffs are connected hydraulically to the Paleozoic 
carbonate
rocks (a regional aquifer), estimated to lie some 455 m below the C-wells.
The series of hydraulic tests began with short-term test episodes. The 10-day test of May 
1995
pumped borehole c#3 at an average rate of 17.9 L/s and produced pumping-well 
drawdown of
7.76 m. Drawdown in observation wells ranged from 0 to 42 cm. The June 1995 test 
lasted four
days and used packers to isolate the six saturated-zone hydrogeologic intervals of the C-
wells
complex. After pumping at a rate of 22.5 L/s, drawdown in the pumping well was 10.9 m, 
and
ANL-NBS-HS-000039, REV 00 158 December 2003
drawdown in monitored intervals of observation wells c#1 and c#2 ranged from 43 to 352 
cm.
The five-day test of February 1996 used packers to isolate and pump the Lower Bullfrog 
and
Upper Tram intervals at a rate of 8.5 L/s. All monitored intervals responded to that 
pumping.
Drawdown in the pumping well was 2.86 m, and drawdown in c#2 and c#1 ranged from 
14 to 25
cm.
A long-term test in which the Lower Bullfrog interval was isolated was conducted over 
more
than 550 days starting in May 1996. All monitored intervals again responded to pumping 
(at a
rate of 9.2 L/s). Drawdown reached nearly 6 m by late March 1997 when some disruption 
due to
pump shutoffs occurred. Drawdown in all observation wells was strongly oscillatory, 
with peak
drawdown in the C-wells complex observation holes of 35 to 51 cm. Drawdown in 
distant
observation wells began after hours to days of pumping and ranged from 15 to 37 cm. No
drawdown had been observed in p#1 (completed in the carbonate aquifer) by December 
1996.
In all of these tests, significant, rapid drawdown and recovery in the pumping well far 
exceeded
amounts that could be predicted from hydraulic properties calculated from observation-
well
drawdown in the same tests. Much of that excess likely can be attributed to frictional 
head loss
("borehole skin") in the pumping well. Because the pumping-well drawdown largely is
independent of aquifer properties, analyses of that drawdown result in misleadingly small 
values
of transmissivity and hydraulic conductivity.
Hydrogeologic intervals in the C-wells exhibit layered heterogeneity. The Calico Hills 
interval
is unconfined; the Prow Pass and Upper Bullfrog intervals are confined; the Lower 
Bullfrog
interval is a fissure-block aquifer; and the Upper Tram interval received flow from cross-
cutting
faults in response to pumping. Transmissivity increases downhole from a range of 4 to 10 
m2/d
in the Calico Hills interval to a range of 1300 to 1600 m2/d in the Lower Bullfrog 
interval. This
trend is reversed near the bottom of the wells: i.e., in the Upper Tram Interval, 
transmissivity is
800 to 900 m2/d. Likewise, hydraulic conductivity increases downhole from about 0.2 
m/d in the
Calico Hills interval to a range of 20 to 50 m/d in the Lower Bullfrog and Upper Tram 
intervals.
Storativity generally increases downhole; for example, in c#2 it increases from a range of 
about
0.0002 to 0.0004 in the Calico Hills and Prow Pass intervals to a range of 0.001 to 0.002 
in the
Lower Bullfrog and Upper Tram intervals. Order-of-magnitude differences, though, are 
evident
between wells of the C-wells complex and nearby observation wells. These vertical 
distributions
of hydraulic properties reflect the greater influence of faults and related fractures toward 
the
bottom of the boreholes.
During hydraulic tests at the C-wells complex, drawdown occurred in all monitored 
intervals of
those holes and in observation wells, regardless of the interval being pumped. That 
hydraulic
connection across lithostratigraphic contacts likely results from interconnected faults, 
fractures,
and intervals with large matrix permeability. The Miocene tuffaceous rocks thereby act as 
a
single aquifer within a portion of the structural block bounded by the Paintbrush Canyon 
and
Dune Wash faults as well as by faults cutting Boundary Ridge (extending at least as far 
north as
lower Midway Valley). This aquifer encompasses a 21-km2 area surrounding the C-wells
complex. These hydraulic results indicate that the formal designation of multiple aquifers 
and
confining units within the tuffaceous sequence at Yucca Mountain may not be justified.
ANL-NBS-HS-000039, REV 00 159 December 2003
Drawdown data from monitored wells during the long-term hydraulic test matched the 
type
curve for a confined aquifer and indicated a transmissivity of 2,200 m2/d and a storativity 
of
0.002 for the tuffs in the region around the C-wells complex. Plots of drawdown in 
observation
wells as a function of distance during the same test showed a transmissivity of 2,100 to 
2,600
m2/d and a storativity of 0.0005 to 0.002. Analyses of drawdown in the C-wells and in 
outlying
observation wells indicated a northwestward decrease in transmissivity from 2,600 m2/d 
in
WT#3 to about 2,000 m2/d at the C-wells and, eventually, to 700 m2/d in H-4. (Hydraulic
conductivity is smallest toward the crest of Yucca Mountain and toward Jackass Flats.)
Distributions of drawdown likewise were influenced strongly by northwest- and north-
striking
faults, as was hydraulic conductivity. Drawdown in observation well ONC-1 showed a 
fissureblock
aquifer response during the long-term test, possibly due to a northwesterly zone of
discontinuous faults that extends beneath Bow Ridge and Antler Wash. Drawdown in 
other
observation wells reached a steady state after some 50 days of pumping, again likely in 
response
to faults and fracture zones. Hydraulic conductivity ranges areally from less than 2 to 
more than
10 m/d and is largest where prominent north-striking faults are closely spaced or 
intersected by
northwest-striking faults. Relatively large hydraulic conductivity occurs beneath Fran 
Ridge,
Bow Ridge, and Boundary Ridge.
Uncertainties in hydraulic parameter estimates, including uncertainties associated with 
the dataanalysis
methods, are discussed in detail in Section 6.2.5. When all the contributing
uncertainties are considered, storativity and transmissivity estimates are considered 
accurate to
within one significant figure. Hydraulic conductivity estimates are considered to be 
somewhat
less accurate because of the inherent uncertainty in the assumed transmissive thickness of 
a given
test interval.
The responses of WT#3, WT#14, ONC-1, and in some cases H-4, to the long-term 
hydraulic test
were analyzed for anisotropy of the hydraulic conductivity. When H-4 was not included 
in the
analysis, the principal directions of anisotropy vary between 15E and 33E. These 
values agree
favorably with the geologically interpreted value of between 25E and 30E, the principal
directional trend of faults in the Yucca Mountain area. Because the methods producing 
these
values do not include H-4 results, the resulting anisotropy values do not appear to be 
affected by
the northwesterly-trending Antler Wash structure; rather, they may be showing the 
underlying
uniformly-distributed anisotropy. When H-4 was included in the analysis of anisotropy, 
the
influence of the northwesterly-trending Antler Wash structure is seen, and the resulting 
principal
directions of anisotropy range from 79oW to 1oE.
Based on these analyses, a probability density function was derived for North-South/East-
West
anisotropy in horizontal hydraulic conductivity in the fractured volcanics (Figure 6.2-46). 
This
probability density function reflects the uncertainty in horizontal anisotropy associated 
with the
analysis of the long-term hydraulic test data. The probability density function assigns a
probability of 0.9 to a North-South orientation of the anisotropy "ellipse," with a 0.5 
probability
of the anisotropy ratio ranging from 1 to 5 and a 0.4 probability of the ratio ranging from 
5 to 20.
Although this is a relatively wide range of possible anisotropy ratios, flow simulations 
indicated
little sensitivity of modeled heads to the full range of ratios. However, flow rates would 
be
expected to be more sensitive to the assumed anisotropy ratio, and the range of specific
discharges used in performance assessments should reflect this uncertainty.
ANL-NBS-HS-000039, REV 00 160 December 2003
6.3 TRANSPORT PROPERTIES OF FRACTURED TUFFS
6.3.1 Nonsorbing Tracer Tests at the C-Wells
Nonsorbing tracer tests conducted at the C-wells complex included: (1) iodide injection 
into the
combined Bullfrog-Tram interval; (2) injection of pentafluorobenzoic acid (PFBA) into 
the
Lower Bullfrog interval, (3) injection of iodide into the Lower Bullfrog interval; (4) 
injection of
2,6 Difluorobenzoic acid (DFBA) into the Lower Bullfrog interval; (5) injection of 3-
carbamoyl-
2-pyridone (Pyridone) into the Lower Bullfrog interval; (6) injection of iodide and 2,4,5
trifluorobenzoic acid (TFBA) into the Prow Pass formation; and (7) injection of 2,3,4,5
tetrafluorobenzoic acid (TeFBA) into the Prow Pass formation. The sequence of testing is
illustrated in Figure 6.1-9.
The purpose of testing with nonsorbing tracers was to obtain estimates of flow porosity 
and
longitudinal dispersivity of the Bullfrog and the Prow Pass Tuffs. The approach to 
developing
parameters was to conduct multiple tests in a cross-hole system and use different 
mathematical
solutions to interpret the results. Consequently, uncertainties and the sensitivity of the 
system
were better understood.
Iodide, benzoic acids (including DFBA, TFBA, TeFBA, and PFBA), and pyridone can be
analyzed by high-performance liquid chromatography (HPLC) with either ultraviolet 
(UV)
absorbance detection or fluorescence detection (pyridone). This method was selected not 
only
because it is precise and sensitive but also because the groundwater samples can be 
injected
directly into the instrument, allowing analyses to be conducted easily in the field for 
immediate
test results.
All nonsorbing tracer tests were analyzed by the Moench (1989 [101146]; 1995 
[148784])
single- and dual-porosity analytical solutions to the advection-dispersion equation or by
superposition of these solutions. Both solutions are implemented using the MOENCH.vi
Function(1) code in conjunction with the rcv2amos.exe routine (STN: 10582-1.0-00 
[162750])
and the MOENCH.vi, Function(2), V 1.0 code (STN: 10583-1.0 [162752]). The first 
software
package implements the published dimensionless solutions. The second allows for curve
matching to actual, dimensional, tracer breakthrough curves. The input parameters 
required by
the Moench single-porosity and dual-porosity solutions are:
* production rate, qo (L/min)
* distance from the production to injection well, rL (m)
* aquifer thickness, h (m)
* radius of production well, rw; and injection well, ri (m)
* thickness where mixing occurs in the production well, hw (m)
* thickness where mixing occurs in the injection well, hi (m)
* mass of tracer injected, M (g)
ANL-NBS-HS-000039, REV 00 161 December 2003
* volume of water in which the mass of tracer is dissolved prior to entering the aquifer, V
(L)
* time for the tracer slug to enter the aquifer, tinj (sec)
* flow porosity, ?f and matrix porosity, ?' (matrix porosity is also referred to,
interchangeably, as "storage porosity" in Section 6.3)
* longitudinal dispersivity, ?L in the form of a Peclet number (Pe = rL/ ?L) (m)
* retardation coefficients representing linear, reversible adsorption R in the fractures and 
R'
in the matrix
* dimensionless diffusion coefficient, Gamma, which is a function of the effective
coefficient of diffusion from the fractures into the matrix, D', and of h, ?f, R, qo, and the
radius, b', of theoretical sphere-shaped matrix blocks of the dual-porosity aquifer
* dimensionless storage parameter, Sigma, which is a function of ?f, ?', R, and R'
* dimensionless skin parameter, SK, which is a function of the mass transfer coefficient, 
ks,
representing the continuity of diffusive flux across the "skin" (such as mineral 
fracturesurface
coatings separating fractures from matrix blocks), and of D' and b'.
In a radially-convergent flow field, the volume of interest is a cylinder centered at the 
production
borehole and extending to the injection borehole. Moench (1989 [101146]) assumes that 
the
injection borehole is well mixed and that the tracer is distributed over a specified fraction 
of the
borehole interval length (i.e., the "mixing length").
Radially-convergent, flow-type curves were generated for a range of Peclet numbers. 
These
single-porosity and dual-porosity type curves are in the form of log-log plots of 
dimensionless
concentration, CD = C/Ci, where Ci = average concentration in injection borehole after 
tracer
injection, versus dimensionless time, tD = t/( ?h ?(rL
2-rw
2)/qo), where the denominator is referred
to as the advective travel time, ta. The observed field tracer breakthrough data are 
presented in
the form of log-log plots of normalized concentration, C/Cmax (where the concentration is
normalized by the maximum observed concentration), versus time since injection. By 
overlaying
the type curve and dimensionless breakthrough curve and matching the rising portions of 
the two
curves, an estimate of the advective travel time, ta, is obtained when the match point (CD 
= 1, tD
= 1) is projected onto the log-time axis of the dimensionless field breakthrough curve 
(e.g.,
Figure 6.3-1, which shows this process for the tracer test described in Section 6.3.1.1.1). 
In
addition, because dimensionless time is defined as the ratio of time since injection to the
advective travel time, the value of ta is equal to the time since injection, indicated on the 
time
axis of the breakthrough curve, corresponding to tD = 1. The Peclet number is also 
estimated
based on the type curve match. In the dual-porosity solution, diffusion is minimal on the 
rising
limb of the breakthrough curve, but it was calculated on the falling limb. The tail of the
observed data was matched to a theoretical dual-porosity breakthrough curve with 
diffusion
processes in which the controlling parameters include the Gamma and Sigma terms. The
ANL-NBS-HS-000039, REV 00 162 December 2003
physical parameters that are estimated are the matrix porosity, ?', and the dimensionless 
diffusion
coefficient, Gamma.
DTN: GS960808312315.001 [159235] (data); Output DTN: GS031008312315.002 (analysis).
NOTE: The Peclet number Pe = 11.
Figure 6.3-1. Type-Curve Match for Iodide Injection into UE-25 c#2
Some of the analyses of nonsorbing tracer tests in this report used the single-porosity 
Moench
solution, some used the dual-porosity solution, and some used a combination of both, 
depending
on the type of test. This was done to explore the effectiveness of a particular solution 
method in
matching a particular set of data. When both the single- and dual-porosity solutions were 
used,
the ta and Peclet number were first obtained from the match of the single-porosity type 
curves to
the rising limb of the data curve; then Moench's dual-porosity solution was used to obtain
estimates of Gamma and Sigma by fitting to the whole data curve.
To constrain the range of parameter values (such as of flow porosity) that can result from 
various
possible interpretations of tracer tests, the fracture characteristics of the formations in 
which
tracer testing was conducted should be considered. Fracture orientations in the Lower 
Bullfrog
were based on televiewer data reported in Geldon (1996 [100396], pp. 14 to 17, Table 6) 
and
obtained in the 1980s when the boreholes were drilled. Two orientations are statistically
significant. The dip and strike of the fracture planes are: 77/167 and 78/191 (first number 
is
degrees from horizontal, and second number is degrees from due north in a clockwise 
direction;
the two orientations are shown in Figure 6.3-2, relative to the sides of the C-wells 
triangle). The
ANL-NBS-HS-000039, REV 00 163 December 2003
fractures at the C-wells complex are moderately to steeply inclined, trend in a northerly
direction, and have a probable nonuniform spacing. If transport is along fractures and 
faults,
then the orientation data represent the possible directions of transport that may be 
occurring at
the small scale in any interpretation.
Source: Geldon (1993 [101045], p. 6 for well locations); Geldon (1996 [100396], pp. 74 to 119 for fracture information).
Figure 6.3-2. Dominant Bullfrog Tuff Fracture Sets in Each of the C-wells
ANL-NBS-HS-000039, REV 00 164 December 2003
6.3.1.1 Results and Interpretations of Nonsorbing Tracer Tests: Bullfrog and Tram
Formations
6.3.1.1.1 Iodide Tracer Test in the Lower Bullfrog/Upper Tram Interval
Following establishment of a quasi-steady-state hydraulic gradient by pumping the 
recovery
borehole (c#3) for about 7,000 minutes, the first convergent tracer test at the C-wells 
complex
was initiated in the Bullfrog-Tram Tuff interval on February 13, 1996, under convergent 
flow
field conditions (Umari 2002 [162858], Binder 4, Section F-12; Binder 5, Sections G-4 to 
G-12,
H-1 to H-7; Binder 6, Sections H-1 to H-7, H-10 to H-11). Tracer solution was injected 
into the
Bullfrog-Tram interval of borehole c#2 for 28 minutes at an average rate of 24.6 (liters 
per
minute (L/m)) (6.5 gallons per minute (gpm)). This test was conducted in the most 
transmissive
interval in the C-wells (the Bullfrog-Tram interval), over the shortest interborehole 
distance
(from borehole c#2 to borehole c#3), and using the simplest flow field (a convergent flow 
field)
to enhance the possibility of successful tracer recovery.
The tracer solution consisted of 5.9 kilograms (kg) of sodium iodide (of which 5 kg were 
iodide)
dissolved in 500 liters (L) (132 gallons) of water from borehole c#3 (Umari 2002 
[162858]).
The tracer solution was chased with 182 L (48 gallons) of water from c#3, which was 
pumped
into borehole c#2 to ensure evacuation of the injection string (Umari 2002 [162858]).
The chemical constituent used as a tracer was iodide with an injection concentration of 
10,200
parts per million (ppm). The iodide injection from c#2 on February 13, 1996, has been 
discussed
by Fahy (1997 [137456], second and third {unnumbered} pages). Iodide concentrations 
in water
sampled during the tracer test were obtained by a reverse-phase, HPLC in conjunction 
with an
ultraviolet (UV)-absorption detector (Stetzenbach and Thompson 1983 [156863], pp. 36 
to 41).
The field-determined detection limit for iodide was 3 ?g/L. The precision of the HPLC
analytical technique, as determined by comparing replicate analyses, was 2.3 percent for 
the
field-determined concentrations and 1.61 percent for laboratory-determined 
concentrations.
Iodide breakthrough occurred 5.07 days after injection. The peak concentration occurred 
17.75
days after injection. The test was terminated 45.1 days after injection. The iodide mass
recovered was estimated as 2.347 kg, 47 percent of the injected mass (Fahy 1997 
[137456],
second and third {unnumbered} pages).
The tracer test was complicated by progressively decreasing discharge from the recovery 
well,
which was caused by a mechanically failing pump. The pump discharge decreased from 
510
L/m (134.7 gpm) on February 13, 1996, to 372 L/m (98.3 gpm) on March 29, 1996. For 
analysis
of the tracer test, the median value of 444 L/m (117.3 gpm) was used as the discharge 
rate (The
decline in discharge rate was approximately linear with time and the discharge 
measurements
were obtained at equal time increments, so the median and mean of all measurements 
were
essentially the same). Despite these problems, a breakthrough curve, with breakthrough 
and
peak arrival times readily discernible, was clearly established by March 29, 1996.
ANL-NBS-HS-000039, REV 00 165 December 2003
Interpretation of Test
Both the single- and dual-porosity Moench (1989 [101146]; 1995 [148784]) solutions 
were used
to interpret the iodide test in the Bullfrog-Tram interval. The rising limb was first 
analyzed
using the single-porosity solution, as presented in Figure 6.3-1, to obtain the flow 
porosity and
Peclet number. The dual porosity solution was then used with these parameter values to 
fit the
whole curve and obtain the matrix porosity. Input parameters and results are the 
following.
* Discharge equal to the median value of 444 L/m (117.3 gpm).
* Aquifer thickness equal to the transmissive thickness of the Bullfrog-Tram interval
between boreholes c#2 and c#3 (168 ft (51.2 m).
* Peclet number of 11 to 12, which corresponds to a longitudinal dispersivity of ~2.5 m.
* Advection travel time of 17.75 days (calculated from peak concentration; Figure 6.3-1).
* The flow porosity, ?f, was estimated as 0.086. This porosity estimate is high if only
fractures are considered as the flow pathways. Typical fracture porosities are of the order
of 0.01 maximum (Freeze and Cherry 1979 [101173], p. 408).
* The complete curve match (Figure 6.3-3) results in an estimate of the matrix porosity of
0.19.
The high flow porosity values above indicate that either (1) a composite flow pathway 
occurred
for the iodide (a combination of both fractures and matrix), or (2) flow heterogeneity 
resulted in
much longer travel times than would be expected under ideal radial convergent flow 
conditions
in a homogeneous, isotropic medium. In the first case, the solute is hypothesized as 
traveling
through a connected-fracture-network segment, then through a segment of matrix until it 
reaches
the next connected-fracture-network segment. In the second case, flow to the production 
well is
seen as being nonuniformly distributed in the flow domain, with a relatively small 
amount of
flow coming from the direction of the injection well. The matrix porosity estimated is
reasonable, based on geophysical logging conducted at the C-wells complex (Geldon 
1996
[100396], pp. 12 to 69).
The software program PEST V 5.5 (STN: 10289-5.5-00 [161564]) was used to 
corroborate tracer
solution results and to obtain optimal parameter values based on the iodide test results. 
The
PEST optimization started with the visual graphical match to the breakthrough curve 
presented
in Figure 6.3-3 for which Pe = 11, Sigma = 2.0, and Gamma = 0.04. Three PEST runs 
were
conducted with each of these parameters changed from the above values while the others 
were
held constant. In the first run, PEST was given Pe = 11, Sigma = 1.0 (intentionally 
"perturbed"
from its good-visual-fit value of 2.0), and Gamma = 0.04; PEST was allowed to change 
only
Sigma. At the end of this run, PEST converged on an optimal value of Sigma = 1.7175 
and an
associated confidence interval for Sigma. In the second run, PEST was given the values 
Pe = 8
(intentionally perturbed from its good-visual-match value of 11), Sigma = 1.7175, and 
Gamma =
0.04; PEST was allowed to change only Pe. At the end of this run, PEST converged on an
optimal value of Pe = 11.478 and an associated confidence interval for Pe. In the third 
run,
PEST was given the values Pe = 11.478, Sigma = 1.7175, and Gamma = 1.0 
(intentionally
ANL-NBS-HS-000039, REV 00 166 December 2003
perturbed from its good-visual-fit value of 0.04); PEST was allowed to change only 
Gamma. At
the end of this run, PEST converged on an optimal value of Gamma = 0.03565 and an 
associated
confidence interval for Gamma. The above optimal values, their associated confidence 
intervals,
and the fit to the actual breakthrough curve that they produce are presented in Figure 6.3-
4.
DTN: GS960808312315.001 [159235] (data); Output DTN: GS031008312315.002 (analysis).
NOTE: Estimated parameters are Peclet number Pe = 11, dispersivity ?L = 2.6 m (8.64 ft), flow porosity ?f = 
0.086,
and matrix porosity ?' = 0.19. The dots on the model fit curve have no significance.
Figure 6.3-3. Preliminary Moench Analytical Model for Iodide Injection in UE-25 c#2
ANL-NBS-HS-000039, REV 00 167 December 2003
DTN: GS960808312315.001 [159235] (data); Output DTN: GS031008312315.002 (analysis).
NOTE: The breakthrough curve was matched by the PEST V 5.5 (STN: 10289-5.5-00 [161564]) program 
with initial
estimates from a manual match. The optimal PEST results, with 95% confidence intervals in parentheses,
are Pe = 11.478 (11.2276-11.7284), R = 1.0, * = 1.71746 (1.4353-1.99962), and * = 0.0356464 (0-
0.12744), and the other estimated parameters are dispersivity ?L = 2.52 m (8.28 ft), flow porosity ?f = 0.087,
and matrix porosity ?' = 0.163. The dots on the model fit curve have no significance.
Figure 6.3-4. Breakthrough Curve for February 13, 1996, Iodide Tracer Test
The visual graphical match and the optimized PEST V 5.5 (STN: 10289-5.5-00 [161564])
parameters are in good agreement. The Peclet number and dispersivity estimates vary by
approximately 4 percent as can be seen by comparing the values listed in the notes under 
Figures
6.3-3 and 6.3-4. The flow porosity estimates vary by less than 1 percent. The visual-
graphicalmatch
matrix-porosity estimate is 0.19, and the PEST estimate is 0.163.
The difference in values is attributed to the different weights assigned to fitting/matching
portions of the breakthrough curve. The rising limb is used exclusively in the visual 
graphical
match to estimate the Peclet number and the advective travel time, and then the advective 
travel
time is used to estimate the flow porosity. The PEST V 5.5 (STN: 10289-5.5-00 
[161564])
approach uses all of the data, both rising- and falling-limb, and optimizes the fit to these 
data.
This results in a slightly different fit than the visual graphical match. Tables 6.3-2 and 
6.3-3 in
Section 6.3.3 (summary section) list the parameter values obtained from all of the 
nonsorbing
tracer testing described in Section 6.3.1.
ANL-NBS-HS-000039, REV 00 168 December 2003
6.3.1.1.2 Difluorobenzoic Acid Tracer Test in the Lower Bullfrog Interval
On January 10, 1997, a purely-convergent conservative tracer test was initiated from c#2 
to c#3
in the Lower Bullfrog interval at an average rate of 568 L/m (Umari 2002 [162858] 
Binder 7,
Sections J-6 to J-12, K-1 to K-9; Binder 8, Sections J-6 to J-12, K-1 to K-9; Binder 9, 
Sections J-
6 to J-12, K-1 to K-9, K-11 to K-12, L-3). Approximately 11.35 kg of 2,6-
difluorobenzoic acid
(2,6 DFBA) mixed with 795 L (210 gallons) of c#3 water were injected into the Lower 
Bullfrog
Tuff in borehole c#2, followed by 238 L (62.9 gallons) of chase water. A total of 1798 L 
(475
gallons) of fluid was injected, the first portion of which was the fluid in the injection 
string
preceding the injectate solution. The average injection rate was 31.2 L/m (8.2 gpm), with 
a
range of 28.8 to 33.0 L/m (7.6 to 8.8 gpm). The average progressive-cavity pump 
(injection
pump) pressure, measured at the surface, was 1.541 megapascals (MPa) (223.6 psi), with 
a range
of 1.5 to 1.6 MPa (215 to 230 psi). The chemical constituent used as a tracer in this test 
was 2,6
DFBA. Chemical analysis indicated that the 2,6 DFBA injectate solution had a 
concentration of
15,560 mg/L. The field-determined detection limit for DFBA was 40 ?g/L. The precision 
of the
HPLC analytical technique, as determined by comparing replicate analyses, was 10 
percent.
Breakthrough occurred at c#3 on January 15, 1997, 5.07 days after injection. The peak
concentration occurred 13.5 days after injection. The mass recovered is estimated as 7.6 
kg,
which is approximately 67 percent of the injected mass (Fahy 1997 [162811]).
Interpretation of Test
Interpretation of the DFBA test using the Moench (1989 [101146]) single-porosity 
analytical
solution for radially convergent flow produced the following results.
* Discharge rate and transmissive thickness used for the analysis were 568 L/m and 51.2 
m,
respectively.
* Peclet number between 12 and 15 (Figures 6.3-5, 6.3-6, and 6.3-7)
* Advection travel time between 12 and 16.5 days
* Flow porosity between 0.072 and 0.099 (Figures 6.3-6 and 6.3-7)
* Matrix porosity between 0.088 and 0.132, and a longitudinal dispersivity value between
1.94 m (6.37 feet) and 2.43 m (7.96 feet) : (Figures 6.3-6 and 6.3-7).
The range of values reflects two approaches for the complete curve match. The Peclet 
number of
12, flow porosity of 0.099, matrix porosity of 0.088, and a dispersivity of 2.43 m (7.96 
feet)
reflect matching the rising limb of the breakthrough curve and honor the initial decline 
closely
(Figure 6.3-6). At longer times, the data and match diverge, possibly indicating secondary
arrivals from longer residence time flow pathways. The alternative is to match the rising 
limb of
the breakthrough curve and reasonably match the complete declining portion of the curve 
(Figure
6.3-7).
ANL-NBS-HS-000039, REV 00 169 December 2003
The program PEST V 5.5 (STN: 10289-5.5-00 [161564]) was applied to the DFBA test 
results
by starting with the visual graphical match to the breakthrough curve presented in Figure 
6.3-7,
for which Pe = 15.0, Sigma = 1.7, and Gamma = 0.12.
DTN: GS010508312315.001 (data) [155860]; Output DTN: GS031008312315.002 (analysis).
NOTE: The Peclet number Pe = 12. Only the rising limb of the observed data was fit because the falling limb 
could
be the result of secondary arrivals.
Figure 6.3-5. Type Curve Fit for 2,6 DFBA Injection in UE-25 c#2
Three PEST V 5.5 (STN: 10289-5.5-00 [161564]) runs were conducted, each with one of 
these
parameters changed from the above values while the other parameters were held constant. 
In the
first run, PEST was given Pe = 15, Sigma = 3.0 (intentionally "perturbed" from its good-
visualfit
value of 1.7), and Gamma = 0.12; PEST was allowed to change only Sigma. At the end 
of
this run, PEST converged on an optimal value of Sigma = 1.8776 and an associated 
confidence
interval for Sigma. In the second run, PEST was given the values Pe = 8 (intentionally
"perturbed" from its good-visual-fit value of 15.0), Sigma = 1.8776, and Gamma = 0.12; 
PEST
was allowed to change only Pe. At the end of this run, PEST converged on an optimal 
value of
Pe = 15.8 and an associated confidence interval for Pe. In the third run, PEST was given 
the
values Pe = 15.8, Sigma = 1.8776, and Gamma = 1.0 (intentionally perturbed from its 
goodvisual-
fit value of 0.12); PEST was allowed to change only Gamma. At the end of this run,
PEST converged on an optimal value of Gamma = 0.11793 and an associated confidence 
interval
ANL-NBS-HS-000039, REV 00 170 December 2003
for Gamma. The above optimal values, their associated confidence intervals, and the fit to 
the
actual breakthrough curve that they produce are presented in Figure 6.3-8.
DTN: GS010508312315.001 (data) [155860]; Output DTN: GS031008312315.002 (analysis).
NOTE: The Fit 1 estimated parameters are Peclet number Pe = 12, dispersivity ?L = 2.4 m (7.96 ft), flow 
porosity
?f = 0.099, and matrix porosity ?' = 0.088. Only the rising limb of the observed data was fit because the
falling limb could be the result of secondary arrivals. The dots on the model fit curve have no significance.
Figure 6.3-6. Fit 1 Preliminary Moench Analytical Model for 2,6 DFBA Injection in UE-25 c#2
The visual-graphical match and the optimized PEST V 5.5 (STN: 10289-5.5-00 
[161564])
parameters are in good agreement. The Peclet number and dispersivity estimates vary by
approximately 5 percent as can be seen by comparing the values listed in the notes under 
Figures
6.3-7 and 6.3-8. The flow porosity estimates are identical. The visual-graphical-match 
matrix
porosity estimate is 0.132, and the PEST estimate is 0.146.
6.3.1.1.3 Pyridone Tracer Test in the Lower Bullfrog Interval from c#1 to c#3
On January 9, 1997, approximately 3.018 kg of 3-carbamoyl-2-pyridone (pyridone), 
mixed with
795 L (210 gallons) of borehole c#3 water, was injected into borehole c#1, followed by 
252 L
ANL-NBS-HS-000039, REV 00 171 December 2003
(66.6 gallons) of chase water to test the Lower Bullfrog interval (Umari 2002 [162858], 
Binder
7, Sections J-6 to J-12, K-1 to K-9; Binder 8, Sections J-6 to J-12, K-1 to K-9; Binder 9, 
Sections
J-6 to J-12, K-1 to K-9, K-11 to K-12, L-3). This injection was made while c#3 was being
pumped at an average rate of 572 L/m (151.1 gpm).
DTN: GS010508312315.001 (data) [155860]; Output DTN: GS031008312315.002 (analysis).
NOTE: The Fit 2 estimated parameters are Peclet number Pe = 15, dispersivity ?L = 1.9 m (6.37 ft), flow 
porosity
?f = 0.072, and matrix porosity ?' = 0.132. The dots on the model fit curve have no significance.
Figure 6.3-7. Fit 2 Preliminary Moench Analytical Model for 2,6 DFBA Injection in UE-25 c#2
A total of 2,082 L (550 gallons) of fluid were injected, the first portion of which was the 
fluid in
the injection string preceding the injectate solution. The average injection rate was 0.38 
L/s (6.1
gpm), with a range of 16.8 to 37.2 L/m (4.4 to 9.8 gpm). The average progressive-cavity 
pump
(injection pump) pressure, measured at the surface, was 1.743 MPa (252.8 psi), with a 
range of
0.3 to 2 MPa (50 to 300 psi). Chemical analysis indicated that the pyridone injectate 
solution
had an average concentration of 2,998 mg/L (or 2,998,000 ?g/L). The field-determined
detection limit for pyridone was 0.1 ?g/L. The precision of the HPLC/fluorometry 
analytical
technique, as determined by comparing replicate analyses, was 10 percent.
ANL-NBS-HS-000039, REV 00 172 December 2003
DTN: GS010508312315.001 (data) [155860]; Output DTN: GS031008312315.002 (analysis).
NOTE: The breakthrough curve was matched by the PEST V 5.5 (STN: 10289-5.5-00 [161564]) program 
with initial
estimates from a manual match. The optimal PEST results, with 95% confidence intervals in parentheses,
are Pe = 15.7954 (15.4998-16.091), R = 1.0, * = 1.87763 (1.65457-2.10068), and * = 0.117934
(0.01741397-0.218454), and the other estimated parameters are dispersivity ?L = 1.83 m (6.01 ft), flow
porosity ?f = 0.072, and matrix porosity ?' = 0.146. The dots on the model fit curve have no significance.
Figure 6.3-8. Breakthrough Curve for January 10, 1997, DFBA Tracer Test
Breakthrough at c#3 occurred on March 27, 1997, 56.3 days after injection. The 
concentration
of pyridone continued to increase but at a gradually-decreasing rate until the end of the 
test (the
test was terminated before a clear peak was observed). The maximum concentration of 
Pyridone
reached was 0.210 ?g/L (parts per billion [ppb]), or 210 parts per trillion (ppt), which 
was
determined by analyses in the laboratory where detection limits were much lower than 
0.1 ?g/L.
The precision of the pyridone concentration values varies. For concentrations less than 
100 ppt,
errors exceeded 10%, based on replicate sample analyses. Concentrations of pyridone 
less than
100 ppt are shown as open-circles on Figure 6.3-9. The filled-circles indicate 
concentrations of
pyridone greater than 100 ppt and those samples with replicate errors less than or equal to 
10%.
ANL-NBS-HS-000039, REV 00 173 December 2003
DTN: GS010508312315.001 (data) [155860]; Output DTN: GS031008312315.002 (analysis).
NOTE: The Peclet number Pe = 11.
Figure 6.3-9. Type Curve for Pyridone Injection in UE-25 c#1
Interpretation of Test
Because the pyridone test was terminated before a peak concentration was reached, only 
the
rising limb part of the test was analyzed. The type curve depicted in Figure 6.3-9 fits the 
rising
limb well. Assuming that the 0.210 ?g/L concentration of pyridone is the maximum for 
the
breakthrough curve, the dual-porosity (Moench 1995 [148784]) analytical solution with a 
Peclet
number of 11 matches the pyridone dimensionless concentration against the 
dimensionless time
curve (Figure 6.3-9). (The single-porosity analytical solution (Moench 1989 [101146]) 
would
have produced a similar result if used to fit the rising limb because the matrix diffusion 
effects
do not manifest themselves until the falling-limb phase of the test.)
ANL-NBS-HS-000039, REV 00 174 December 2003
6.3.1.1.4 PFBA and Iodide Tracer Tests in the Lower Bullfrog Interval
In cooperation with the USGS, LANL conducted two "pilot" tracer tests, each involving 
the
injection of a single nonsorbing tracer in the Lower Bullfrog interval during 1996. These 
tests
were conducted primarily to determine which well, c#1 or c#2, would serve as a better 
injection
well for the planned multiple-tracer test. The primary motivation was the concern that the
responses of both sorbing and colloid tracers might be highly attenuated or excessively 
delayed
relative to nonsorbing tracers, which could make test durations impractically long. Thus, 
it was
desirable to determine which potential injection well yielded the quickest and 
highestconcentration
responses at the production well, c#3. It was not taken for granted that the best
response would be from c#2, the injection well closest to c#3, because c#1 and c#3 are 
more
closely aligned with the predominant fracture strike direction at the C-wells than c#2 and 
c#3.
The first pilot tracer test involved the injection of approximately 10 kg of PFBA into the 
lower
Bullfrog interval in well c#2 on May 15, 1996. This same interval in c#3 was pumped
continuously at about 575 L/min throughout the test (starting on May 8, 1996, prior to 
tracer
injection). The PFBA was dissolved in ~1000 L of groundwater from c#3. The test was
conducted under partial recirculation conditions with about 20 L/min of the water 
produced from
c#3 (~3.5% of production rate) being continuously reinjected into c#2. The recirculation 
was
initiated approximately 24 hr before tracer injection to establish a steady flow field, and it 
was
continued for 23 days after injection. The tracer solution was plumbed into the 
recirculation loop
such that there were no flow interruptions during injection. Information pertaining to the 
PFBA
pilot test is documented in Reimus (2000 [165126]).
The second pilot test involved the injection of about 12.7 kg of iodide (~15 kg of sodium 
iodide
dissolved in ~1000 L of groundwater from c#3) into the Lower Bullfrog interval in c#1. It 
was
conducted in a manner very similar to the PFBA pilot test and was initiated on June 18, 
1996.
The recirculation rate in this test was about 15 L/min (~2.6% of production rate), and
recirculation continued for ~16 days after injection. Production from c#3 was maintained 
at
~575 L/m throughout the test, the same as that of the PFBA pilot test. Information 
pertaining to
the iodide pilot test is documented in Reimus (2000 [165127]).
It was clear a few days after the injection of iodide into c#1 that the PFBA response from 
c#2
was much more conducive to multiple-tracer testing than the iodide response from c#1. 
The
results of the PFBA test are relevant to the interpretation of the multiple-tracer test 
conducted in
the Lower Bullfrog interval, so they are discussed in Section 6.3.4 of this report along 
with the
results of the multiple-tracer test. The iodide response between c#1 and c#3 is shown in 
Figure
6.3-10. This response is complicated by the initially high and gradually declining iodide
background concentrations, which are attributed to the residual iodide in the aquifer from 
the
February 13, 1996, injection of iodide into the Bullfrog-Tram interval in c#2. However, 
there is
clear evidence of a peak occurring about 2 months after injection. The estimated iodide 
recovery
from the c#1 injection by October 1, 1996, (after correcting for the declining background 
by
assuming that it followed an exponential decay) was ~13% of the injected iodide mass 
(Reimus
2003 [165129], Attachment A). In contrast, the PFBA recovery from c#2 was about 72% 
on
October 1, 1996 (Reimus 2003 [165129], Attachment A). Neither the PFBA nor the 
iodide pilot
tracer tests were interpreted quantitatively.
ANL-NBS-HS-000039, REV 00 175 December 2003
DTN: LA0007PR831231.001 [156043] (data).
NOTE: The breakthrough curve is a result of injection of ~12.7 kg of iodide into c#1 on June 18, 1996; the 
declining
background prior to and immediately after injection is due to recovery of iodide from a February 1996 iodide
injection into c#2; and the estimated recovery from c#1 accounting c#2 background was ~13% through June
1, 1997.
Figure 6.3-10. Breakthrough Curve for Iodide Injection in UE-25 c#1
6.3.1.2 Results and Interpretations of Nonsorbing Tracer Tests: Prow Pass 
Formation
6.3.1.2.1 2,4,5 Trifluorobenzoic Acid and Iodide Test from c#3 to c#2
On June 17, 1998, a partial-recirculation nonsorbing tracer test was initiated from c#3 to 
c#2 by
injecting approximately 14.83 kg of 2,4,5 trifluorobenzoic acid (TFBA) and 12.26 kg of 
iodide
(in the form of sodium iodide) into the Prow Pass interval of c#3 while c#2 was pumped 
at the
rate of approximately 5.2 gpm (19.7 L/m). The concentration of 2,4,5 TFBA was 14,239 
ppm in
the injected slug and that of iodide 14,307 ppm. Of the 5.2 gpm (19.7 L/m) pumped from 
c#2,
1.5 gpm (5.7 L/m) was continuously reinjected into the Prow Pass interval of c#3 (Umari 
2002
ANL-NBS-HS-000039, REV 00 176 December 2003
[162858], Binder 13, Sections M-29 to M-36; Binder 14, Sections M-29 to M-36, M-40, 
M-43 to
M-44).
Approximately 40 hours after the injection, breakthrough of both tracers occurred in c#2. 
The
peak for the 2,4,5 TFBA occurred 6.74 days after injection, and the peak for iodide at 7 
days
after injection (Figure 6.3-11).
The iodide and 2,4,5 TFBA breakthrough curves were analyzed using the single- and 
dualporosity
analytical solutions of the advection-dispersion equation as given in Moench (1989
[101146]; 1995 [148784]). These solutions were used, as is, for a hypothetical purely
convergent flow field, and they were also lagged and superposed to obtain the solution 
for the
actual partial-recirculation flow field (see Section 6.3.1.2.1.2). The curves were first 
analyzed
assuming Moench's single-porosity solution for both the convergent and the partially
recirculating flow-field assumptions, using the entire curves for the matches, to obtain the 
flow
porosity and longitudinal dispersivity. In this case, the aquifer is considered to be an 
equivalent
porous medium made up of a network of fractures, some of them continuous, and some
potentially discontinuous with connecting segments of matrix (Fahy 1997 [137456], 
fourth and
fifth {unnumbered} pages). The porosity of this network of fractures and connecting 
segments
of matrix, through which flow of solutes occurs, is referred to herein as "flow porosity" 
(Fahy
1997 [137456], fourth and fifth {unnumbered} pages). The curves were then analyzed 
assuming
a dual-porosity system, also using the entire curves for the match. In addition to the 
above
network of fractures and connecting segments of matrix, the dual-porosity medium is
conceptualized as having a storage component consisting of dead-end fractures and the 
part of
the matrix not contributing to the flow network.
The flow porosity and longitudinal dispersivity are different for each of the solutions 
presented.
The retardation coefficient used for all solutions was 1.0, assuming that iodide and 2,4,5 
TFBA
are considered nonsorbing with respect to the Prow Pass Tuff. All the solutions used the
following input parameters:
* Production rate of 19.7 L/m (5.2 gpm; represents the average rate for the test).
* Aquifer thickness of 61 m (200 ft, packed-off interval, rounded to one significant 
figure)
(Umari 2002 [162858], Binder 10, Section L-11, pp. 70 to 71, Section L-9, pp. 57 to 58).
* Distance between injection and production wells of 29 m (95.15 ft) (see Table 6.2-6).
* Radii of injection and production wells of 13.97 cm (5.5 in.) (assumed for rugose,
variable-diameter open-hole portion of C-wells where all testing was conducted, based on
C-wells caliper logs (Geldon 1993 [101045], p. 10).
* Borehole mixing length of 30.5 m (100.07 ft; assumed, as discussed below).
* Recirculation rate of 5.7 L/m (for the partially-recirculation solution)
ANL-NBS-HS-000039, REV 00 177 December 2003
6.3.1.2.1.1 Single-Porosity, Purely Convergent Interpretation
The single-porosity, purely convergent solution is obtained directly from the Moench 
(1989
[101146]) solution to the advection-dispersion equation. A best visually-matching 
singleporosity
solution corresponding to flow porosity and longitudinal dispersivity values of 0.0007
and 1.45 m, respectively, is presented in Figure 6.3-12, along with the iodide and 2,4,5 
TFBA
breakthrough curves. All breakthrough curves, such as the ones in Figure 6.3-12, were
normalized by dividing the measured concentrations by the maximum concentration, 
Cmax, rather
than by the concentration of the injected mass slug, C0. Longitudinal dispersivity is a 
measure of
the media's ability to disperse a solute along streamlines. Transverse dispersivity, which
represents the media's ability to disperse a solute in a direction perpendicular to 
streamlines, is
not obtainable from this analysis method and flow geometry. The longitudinal 
dispersivity of
1.45 m and the 29-m flow length correspond to a Peclet number of 20.
DTN: GS990208312315.001 [159238] (data).
NOTE: C#2 and C#3 refer to UE-25 c#2 and UE-25 c#3, respectively.
Figure 6.3-11. Breakthrough Curves for 2,4,5 TFBA and Iodide Tracer Test from UE-25 c#3 to 
UE-25 c#2
ANL-NBS-HS-000039, REV 00 178 December 2003
DTN: GS990208312315.001 [159238] (data); Output DTN: GS031008312315.002 (analysis).
NOTE: Flow porosity = 0.0007, storage porosity was not applicable because a single-porosity medium was
assumed, and longitudinal dispersivity = 1.45 m. The dots on the model fit curve have no significance.
Figure 6.3-12. Breakthrough Curve for June 17, 1998, 2,4,5 TFBA and Iodide Tracer Test
Matched by the Single-Porosity, Purely Convergent Moench Solution
The matched values of longitudinal dispersivity and flow porosity may be sensitive to the 
mixing
lengths assumed for the injection and pumped wells. The mixing lengths represent those 
lengths
within the boreholes through which the tracer enters or exits the aquifer. The 30.5-m 
mixing
length assumed for all solutions is based on the thickness of the transmissive interval 
within the
packed-off Prow Pass interval in c#3 (see Table 6.2-6) and is consistent with the 
hydrogeology
of the interval (Geldon 1996 [100396], pp. 9 to 69).
The residence time of the tracer slug within the borehole is directly proportional to the 
mixing
length. Data collected during the tracer injection indicate that the borehole was flushed in 
8.5 hrs
(the concentration in the injected interval was measured in the field and found to rise 
from below
detection limit to 2,721 ppm and then back to below detection limit in 8.5 hrs, 8:00 A.M. 
to 4:30
P.M.) (Umari 2002 [162858], Binder 13, p. 91). When the mixing length is reduced to 0.3 
m and
only the rising limb of the actual breakthrough curve is matched to the theoretical 
breakthrough
curve from the single-porosity solution of Moench (1989 [101146], assuming minimal 
diffusion
during the rising limb), a longitudinal dispersivity value of 4.27 m and a flow porosity 
value of
0.0016 are obtained as fitting parameters. Changing the mixing length from 30.5 m to 0.3 
m
constitutes a two-orders-of-magnitude change in this parameter. Corresponding to this 
change in
the assumed mixing length, the estimates of longitudinal dispersivity and flow porosity 
change
ANL-NBS-HS-000039, REV 00 179 December 2003
from 1.45 m and 0.0007 (for a 30.5-m mixing length) and to 4.3 m and 0.0016 (for a 0.3-
m
mixing length). This is a three-fold change of longitudinal dispersivity and a two-fold 
change of
flow porosity, both less than one order of magnitude. The estimated parameters, 
therefore, are
not very sensitive to the mixing length.
The above porosity value of 0.0007 is in the range of 0.00001 to 0.01 cited in the 
literature to
represent fracture porosity (see, for example, Freeze and Cherry 1979 [101173], p. 408). 
This
implies that the flow network for this test in the Prow Pass Tuff is composed 
predominantly of
fractures.
6.3.1.2.1.2 Single-Porosity, Partially Recirculating Interpretation
When the purely convergent flow field of Figure 6.3-12 is replaced by a partially 
recirculating
flow field, the resulting solution to the advection-dispersion equation changes from the 
curve
labeled "Moench solution" in Figure 6.3-12 to the curve labeled "Modified Moench 
solution"
shown in Figure 6.3-13. The difference between the two solutions reflects the difference 
in flow
field representation and in the fitted values of longitudinal dispersivity and flow porosity 
used (or
implied) for each solution. Two elements of partial recirculation are represented in the 
partialrecirculation
solution, which is obtained using the RECIRC.vi V 1.0 code (STN: 10673-1.0-00
[164432]). Rather than straight converging rays into the production well, the partially
recirculating flow field streamlines that are within the capture zone of the production well
emanate from the injection well and curve towards the production well (Figure 6.3-14a). 
The
streamlines shown in Figure 6.3-14a are lines of equal stream function values, in which 
the
stream function of the partial-recirculation field is calculated as the sum of the stream 
functions
of a 19.8 L/m sink (production rate) and a 5.7 L/m source (recirculation rate) in a 
confined
aquifer of constant thickness (2-D flow). The volume of rock between pairs of these 
curved
streamlines emanating from the injection well and curving towards the production well 
constitute
distinct pathways for the solute (tracer) to take from the injection to the production well. 
Three
such inter-streamline pathways emanating from the injection well and curving towards 
the
production well (Figure 6.3-14a) are assumed for the partial-recirculation analysis in this 
section.
These pathways, labeled Interstreamline pathway 1, 2, and 3 in Figure 6.3-14a, and the 
three
non-labeled pathways, which are mirror images of them around the horizontal line of 
symmetry,
carry all the tracer mass from injection to production well. Symmetry allows that the 
analysis be
restricted to only three of the six interstreamline pathways emanating from the injection 
well and
curving towards the production well, namely Interstreamline pathway 1, 2, and 3, and 
that half of
the mass of the tracer and half the reinjection flow rate be carried by these three 
pathways. The
Moench (1989 [101146]) single-porosity, purely convergent solution is viewed as the 
solution of
the advection-dispersion equation along a single straight pathway (Figure 6.3-14b). This
solution for a particular longitudinal dispersivity value and flow porosity is applied to 
each of the
above three distinct pathways. Because the Moench solution is for a strictly convergent 
flow
field, its application to the first-diverging-then-converging, flow pattern within 
Interstreamline
pathway 1, 2, and 3 in Figure 6.3-14a is an approximation and will introduce some error. 
A
proper delay factor (the advective travel time calculated from the volume of rock of each
pathway, the flow rate within the pathway, and the assumed porosity) is used to account 
for the
differences in lengths, or swept volumes, of these pathways relative to the straight purely
convergent pathway, and the injected mass is distributed among the three pathways in 
proportion
to the flow in each of them.
ANL-NBS-HS-000039, REV 00 180 December 2003
DTN: GS990208312315.001 [159238] (data); Output DTN: GS031008312315.002 (analysis).
NOTE: Three inter-streamline pathways were assumed with delay factors of 2.01 days, 2.99 days, and 3.11 
days.
The flow porosity = 0.00045, storage porosity was not applicable because a single-porosity solution was
assumed, and longitudinal dispersivity = 0.27 m (Pe = 107). Borehole mixing length was 30.5 m.
Figure 6.3-13. Breakthrough Curve for June 17, 1998, 2,4,5 TFBA and Iodide Tracer Test 
Matched by
the Single-Porosity, Partial-Recirculation Solution Derived from Moench
The solutions from Moench (1989 [101146]) for a particular longitudinal dispersivity 
value, flow
porosity, and an instantaneous-slug injection are then superimposed with appropriate 
delay
factors (defined above) to obtain what is considered to be the system's unit response 
function.
The summed curve represents what is seen at the pumped well in response to an 
instantaneous
input function at the injection well in a partial-recirculation flow field.
The second element of partial recirculation is that the reinjected water contains a small 
amount
of tracer; therefore, the tracer is continuously reintroduced into the aquifer. For the 
calculations
presented here, it was assumed that this lag duration is approximately 1 hr, which was the
estimated time for travel of the recirculated fluid in the 2.5-cm (1-in) coil-tubing return 
line
(YMP 1998 [104211], Attachment 5, p. 2) from the production well, c#2, to the injection 
well,
c#3 (536 m [1,760 ft] at 5.7 L/min [1.5 gpm]) (Umari 2002 [162858], Binder 10, p. 57). 
The
input concentration curve at the injection well is, therefore, constructed by starting with 
the
breakthrough curve at the pumped (or extraction) well and then lagging it by the "lag 
duration."
The input concentration curve at the injection well is then convolved (Levenspiel 1972 
[156839],
Chapter 9) with the unit response function to produce the calculated partial-recirculation
ANL-NBS-HS-000039, REV 00 181 December 2003
breakthrough curve at the production well. Different flow porosity and longitudinal 
dispersivity
values are used in a trial and error process to iteratively repeat the process described 
above until
the calculated partial-recirculation breakthrough curve is as visually close as possible to 
the
measured breakthrough curve.
For illustration purposes only
NOTE: English units are shown in the figure because the analysis was conducted in English units.
Figure 6.3-14. Streamlines for a) Partial-Recirculation Flow Field and b) Purely Convergent Flow 
Field
ANL-NBS-HS-000039, REV 00 182 December 2003
Using the iterative parameter-matching process described above, a longitudinal 
dispersivity of
0.27 m (Pe = 107.4) and a flow porosity of 0.00045 were selected as optimal for the 
singleporosity,
partial-recirculation case (as opposed to the 1.45 m and 0.0007 optimal values found
earlier for the single-porosity, purely-convergent solution). These parameters result in the
calculated partial-recirculation breakthrough curve presented in Figure 6.3-13.
The delay factors for the three inter-streamline pathways inherent in the calculation of the
breakthrough curve of Figure 6.3-13 were initially assumed to be 1.83 days for the first 
pathway,
3.5 days for the second, and 7.5 days for the third (these are the advective travel times 
calculated
from the volume of rock of each pathway, the assumed porosity, and the flow rate within 
the
pathway).
However, use of these delay factors (as defined above) produced a calculated 
breakthrough curve
that did not visually match the actual curve. The visual match was substantially improved 
by
changing the delay factors to 2.01 days, 2.99 days, and 3.11 days, which resulted in the
calculated breakthrough curve of Figure 6.3-13. Because these three delay factors are not 
the
ones indicated by the volumes of rock calculated for the three inter-streamline pathways, 
they are
interpreted to represent the uncertainty in either the single-flow porosity value or in the 
assumed
streamline pattern and resulting rock volumes. If the streamline pattern with associated 
rock
volumes is assumed correct, then the delay factors of 2.01, 2.99, and 3.11 days 
correspond to
storage porosities of 0.0005, 0.0004, and 0.0002 for the three inter-streamline pathways,
respectively. However, because different porosities for the three pathways are not 
compatible
with the underlying homogeneity assumption, the three porosities provide a range of 
uncertainty
for the single-porosity estimate of 0.00045 used for all partial recirculation cases.
The results shown in Figures 6.3-12 and 6.3-13 indicate that if the breakthrough curves of 
2,4,5
TFBA and iodide are analyzed as if they result from a purely-convergent flow field, 
ignoring that
the real flow field is partially recirculating, some error in the derived parameters results. 
A
longitudinal dispersivity of 1.45 m is obtained when purely-convergent conditions are 
assumed,
five times the 0.27 m obtained when the partial-recirculation flow field is recognized. 
The flow
porosity of 0.0007 obtained for purely-convergent conditions is 56% higher than the flow
porosity of 0.00045 obtained for partial recirculation.
The partial-recirculation solution shown in Figure 6.3-13, and others in the remainder of 
Section
6.3.1.2 are not as good fits to the actual tracer breakthrough curves as the purely-
convergent
solution of Figure 6.3-12, even though the latter ignores the flow field created by partial
recirculation. This could either mean that the explicit representation of the partial-
recirculation
flow field is not important and that the test can be analyzed successfully as a purely-
convergent
tracer test, or that the homogeneous and isotropic representation of the partial-
recirculation flow
field presented here does not capture the real partial-recirculation flow field. Perhaps 
increasing
the number of the inter-streamline pathways beyond three to, in effect, "discretize" the 
flow field
more finely would improve the fits. This increased discretization was not attempted.
ANL-NBS-HS-000039, REV 00 183 December 2003
6.3.1.2.1.3 Dual-Porosity, Partially Recirculating Interpretation
In the dual-porosity case, the medium is comprised of flow and storage components. The 
flow
component is conceptualized as a flow network of (1) continuous fractures and (2) 
discontinuous
fractures with interconnecting segments of matrix. The porosity of the flow component of 
the
medium is referred to as the "flow porosity." The storage component is assumed to 
consist of
dead-end fractures and the part of the matrix not contributing to the flow network. The 
porosity
of the storage component of the medium is referred to as the "storage porosity" (within 
Section
6.3 of this report, "matrix porosity" means the same thing as "storage porosity"). The 
flow
network is represented by a longitudinal dispersivity and a flow porosity, and the storage
component is represented by a storage porosity and a dimensionless matrix diffusion 
coefficient.
The calculated dual-porosity, partial recirculation solution is predicated upon the single-
porosity,
partial-recirculation solution presented earlier, i.e., a longitudinal dispersivity of 0.27 m 
and a
flow porosity of 0.00045. Two calculated breakthrough curves obtained for a storage 
porosity of
0.001 and two dimensionless matrix diffusion coefficients (Gamma), namely 0.000444 
and
0.001, are presented in Figure 6.3-15 along with the actual breakthrough curves of 2,4,5 
TFBA
and iodide.
The free-water molecular diffusion coefficients of 2,4,5 TFBA and iodide are 8.0 x 10-6 
cm2/s
and 18.0 x 10-6 cm2/s, respectively (Bowman 1984, Table 2 [156645]; Skagius and 
Neretnieks
1986, Tables 2 and 3 [156862]), which corresponds to a ratio of 1:2.25 (TFBA: iodide). 
When a
solution is placed in a porous medium and it diffuses into the matrix, the extent of matrix
diffusion is represented by the dimensionless matrix diffusion parameter, Gamma, 
defined in
Moench (1995, Table 1, p. 1826, [148784]). According to Moench (1995 [148784], Table 
1, p.
1826), the ratio of the dimensionless matrix diffusion parameter, Gamma, for the two 
tracers is
the same as the ratio of their free-water molecular diffusion coefficients. The Gamma 
values of
0.000444 and 0.001 were chosen for Figure 6.3-15 because they have the same ratio as 
the
Gamma values of 2,4,5 TFBA and iodide, namely 1:2.25. Figure 6.3-15 shows the effects 
on
matrix diffusion, as represented by the two calculated breakthrough curves, of changing 
the freewater
diffusion coefficient by a factor of 2.25 for a fixed storage porosity of 0.001 and the fixed
flow rate of the test. The effect of increasing the free-water diffusion coefficient, which
increases Gamma, is a delay of the calculated breakthrough curve for higher Gamma 
relative to
the breakthrough curve for lower Gamma. This "differential matrix diffusion delay" is 
seen as a
horizontal offset between the two calculated breakthrough curves in Figure 6.3-15 and 
later
figures. The larger the difference in Gamma between the two curves, the larger the 
differential
matrix diffusion delay.
ANL-NBS-HS-000039, REV 00 184 December 2003
DTN: GS990208312315.001 [159238] (data); Output DTN: GS031008312315.002 (analysis).
NOTE: The breakthrough curves were matched by the dual-porosity, partial-recirculation solution derived 
from
Moench (1995 [148784]) with storage porosity of 0.001 and dimensionless diffusion coefficients, Gamma, of
0.000444 and 0.001. Three inter-streamline pathways were assumed to have delay factors of 2.01 days, 2.9
days, and 3.11 days. Longitudinal dispersivity = 0.27 m (0.9 ft).
Figure 6.3-15. Breakthrough Curve for June 17, 1998, 2,4,5 TFBA and Iodide Tracer Test
Matched with a Lower Storage Porosity and a Higher Diffusion Coefficient
In addition, it is seen from a comparison of Figures 6.3-15 and 6.3-16 that this differential 
matrix
diffusion delay for a particular pair of free-water diffusion coefficients (or Gamma 
values)
increases with increasing storage porosity. Figure 6.3-16, which uses the same pair of 
Gamma
values used in Figure 6.3-15, shows that when the storage porosity is increased from the 
0.001
value of Figure 6.3-15 to 0.01, the differential matrix diffusion delay is markedly larger 
than
what it is in Figure 6.3-15.
ANL-NBS-HS-000039, REV 00 185 December 2003
DTN: GS990208312315.001 [159238] (data); Output DTN: GS031008312315.002 (analysis).
NOTE: The breakthrough curves were matched by the dual-porosity, partial-recirculation solution derived 
from
Moench (1995 [148784]) with storage porosity of 0.01 and dimensionless diffusion coefficients, Gamma, of
0.000444 and 0.001. Three inter-streamline pathways were assumed with delay factors of 2.01 days, 2.9
days, and 3.11 days. The flow porosity was 0.00045, and the longitudinal dispersivity was 0.27 m.
Figure 6.3-16. Breakthrough Curve for June 17, 1998, 2,4,5 TFBA and Iodide Tracer Test
Matched with a Higher Storage Porosity and a Higher Diffusion Coefficient
The differential matrix diffusion delay between calculated breakthrough curves in Figure 
6.3-16
is similar to that between the actual 2,4,5 TFBA and iodide, suggesting a storage porosity 
value
of approximately 0.01. This result is combined with earlier ones to indicate a dual-
porosity
medium with a flow porosity of 0.00045 (with an uncertainty range of 0.0002 to 0.0005), 
a
storage porosity of 0.01, and a longitudinal dispersivity of 0.27 m. The flow porosity and
longitudinal dispersivity characterize a flow network within this medium comprised of 
(1)
continuous fractures and (2) discontinuous fractures with interconnecting segments of 
matrix.
The storage porosity characterizes a storage component of the conceptualized dual-
porosity
medium consisting of dead-end fractures and the part of the matrix not contributing to the 
flow
network.
ANL-NBS-HS-000039, REV 00 186 December 2003
6.3.1.2.2 2,3,4,5 Tetrafluorobenzoic Acid Test from c#1 to c#2
On July 31, 1998, the nonsorbing tracer 2,3,4,5 tetrafluorobenzoic acid (2,3,4,5 TeFBA) 
was
injected in the Prow Pass interval of c#1 while c#2 continued to be pumped at the rate of
approximately 19.3 L/min (5.1 gpm) (Umari 2002 [162858], Binder 13, Sections M-23 to 
M-25;
Binder 14, Section M-40; Binder 15, Section M-34, pp. 187, 197). Breakthrough of this 
tracer
occurred on August 17, 1998 in the water pumped out of c#2, and the concentration 
eventually
rose to a maximum of around 90 ppb, approximately 65 days after tracer injection (Figure 
6.3-
17). The results of this tracer test were used to qualitatively assess flow heterogeneity at 
the Cwells
(see Table 6.3-1)
DTN: MO0308SPATRCRC.000 [164821].
Figure 6.3-17. Breakthrough Curve for 2,3,4,5 TeFBA Tracer Test in Prow Pass
from UE-25 c#1 to UE-25 c#2
6.3.2 Flow Anisotropy at the Scale of the C-wells from Nonsorbing Tracer Arrival 
Times
The comparisons of tracer responses resulting from injections into well c#1 and into 
either well
c#2 or c#3 (while pumping the other well) provided some insights into flow 
heterogeneity/
anisotropy at the scale of the C-wells. Table 6.3-1 lists the ratios of peak arrival times or 
first
arrival times for nonsorbing tracers between c#1 and the production well (either c#2 or 
c#3) and
between c#2 and c#3 for all tests in which a comparison was possible. For a 
homogeneous,
isotropic medium, the arrival times under radial flow conditions are expected to vary as 
rL
2, the
distance squared between injection and production well (Guimer and Carrera 2000 
[156830],
Equation 6). The ratios of rL
2 values corresponding to each case are also listed in Table 6.3-1. If
ANL-NBS-HS-000039, REV 00 187 December 2003
the ratio of arrival times is less than the ratio of distances squared, then the direction from 
c#1 to
the production well is a preferred flow orientation; on the other hand, if the ratio of 
arrival times
is greater than the ratio of distances squared, then the direction from c#2 to c#3 is a 
preferred
flow orientation. Furthermore, the ratio of arrival times divided by the ratio of distances 
squared
can be taken as a measure of the flow anisotropy ratio for the two different directions 
relative to
the production well (note that these two directions are not strictly orthogonal). The ratios 
of
tracer arrival times and rL
2 values are in reasonably good agreement in all three cases, with
apparent flow anisotropy ratios (c#1 to production well direction divided by c#2-c#3 
direction)
varying from 0.77 to 1.42. These relatively small ratios suggest that flow anisotropy at 
the scale
of the C-wells may be relatively small despite the apparent orientation of the fracture 
network in
the general direction of c#1 to c#2 (Geldon 1993 [101045], pp. 43 to 51). The apparent 
flow
anisotropy ratios deduced from the tracer arrival times should be carefully distinguished 
from the
flow anisotropy ratios derived in Section 6.2.6, which were based on drawdown 
observations
over much larger scales.
Table 6.3-1. Ratios of Observed Tracer Arrival Times and Distances Squared, as Well as 
Apparent Flow
Anisotropy Ratios, for C-wells Nonsorbing Tracer Tests
Tests (Injection Well) Timec#1/
Timec#2-c#3
(a)
rL
2
c#1/
rL
2
c#2-c#3
(a)
Anisotropy Ratio(a)
Bullfrog: PFBA (c#2) and iodide (c#1)(b) 6 8.5 1.42
Bullfrog: 2,6-DFBA (c#2) and pyridone
(c#1)(c) 11 8.5 0.77
Prow Pass: iodide and 2,4,5-TFBA (c#3)
and 2,3,4,5-TeFBA (c#1)(d) 10 8.3 0.83
DTNs: GS010508312315.001 [155860]; GS990208312315.001 [159238]; LA0007PR831231.001 [156043] (data);
GS030508312314.003 [164425], p. 6, Table 1, borehole separations).
NOTE: c#1, c#2, and c#3 are abbreviations for boreholes UE-25 c#1, UE-25 c#2, and UE-25 c#3. rL
2 is the
distance squared between injection and production wells.
(a) Timec#1 and rL
2
c#1 are the time and distance, respectively, between c#1 and the production well (either
c#2 or c#3, depending on the test), and Timec#2-c#3 and rL
2
c#2-c#3 are the time and distance, respectively
between c#2 and c#3. Columns 2 and 3 give the ratios of these times and distances. Ratio is for c#1 to
production well direction divided by c#2 to c#3 direction. For the anisotropy ratio, a value greater than
1.0 indicates that the c#1 to production well direction is the preferred flow orientation.
(b) Both tests conducted with 2.5 to 3.5% recirculation into injection well. Peak tracer arrivals compared.
(c) Both tests conducted with no recirculation. First tracer arrivals compared.
(d) c#3-to-c#2 test conducted with 30% recirculation; c#1-to-c#2 test conducted with no recirculation. Peak
tracer arrivals compared.
6.3.3 Summary of Conceptual Models and Parameters from Nonsorbing Tracer 
Tests at
the C-wells
Uncertainty in the values of longitudinal dispersivity, flow porosity, and matrix (or 
storage)
porosity result from physical processes, such as the scale-dependence of dispersivity 
(when
ANL-NBS-HS-000039, REV 00 188 December 2003
comparing tracer tests conducted from borehole c#1 to those conducted between 
boreholes c#2
and c#3), as well as from variability in the transport characteristics of the tracer materials.
However, there is good agreement in dispersivity values obtained from tracer tests 
conducted
between boreholes c#2 and c#3 in the Bullfrog and Tram intervals. Peclet numbers range 
from
11 to 15; therefore, the longitudinal dispersivities are similar (Table 6.3-2).
The breakthrough times are identical for the iodide and the DFBA tracer tests (Table 6.3-
2), and
the advective travel times are within 10 percent. Therefore, the inferred flow porosities 
are
similar, which implies that similar flow pathways are used by the tracers in those tests. 
These
differences can be explained by the different thicknesses of the zones tested: the iodide 
tracer test
was conducted in the combined Bullfrog-Tram zone, and the DFBA tracer test was 
conducted in
the Lower Bullfrog zone.
The parameter estimates are robust because the visual-graphic match is close to the PEST 
fit
(which is based on the dual-porosity analytical model.) The differences are less than 5% 
for all
parameters except matrix porosity, and these estimates vary by only 0.03.
The estimated flow porosities suggest that the pathways between boreholes c#2 and c#3 
in the
Bullfrog and Tram intervals are not well-connected. This possibility is supported by the
interpretation of the higher-than-expected flow porosities for the Bullfrog and Tram 
Tuffs. The
microsphere responses (Section 6.3.4) are consistent with this interpretation. The arrival 
of the
microspheres at the recovery borehole indicates the existence of a connected pathway,
somewhere, with an aperture at least 0.36 ?m (the diameter of the spheres).
Table 6.3-2. Summary of Results and Transport Properties for the Bullfrog and Tram Tuffs from
Nonsorbing Tracer Tests.
Iodide test from c#2 to
c#3 in Bullfrog-Tram
DFBA test from c#2 to
c#3 in Lower Bullfrog
Pyridone test from c#1 to
c#3 in Lower Bullfrog
Breakthrough (days) 5.07 5.07 56.3
Peak concentration (?g/L) 99.5 251 0.210 (final value)
Peclet number 11 12-15 11
Dispersivity (m) 2.6 2.4-1.9 6.2
Flow porosity, ?f (%) 8.6 9.9-7.2 NA
Matrix (or storage) porosity,
?' (%)
19 8.8-13.2 NA
DTNs: GS960808312315.001 [159235] (Iodide data) and GS010508312315.001 [155860] (DFBA and Pyridone data);
Output DTN: GS031008312315.002 (analysis).
NOTES: NA: the value is not available.
c#1, c#2, and c#3 are abbreviations for boreholes UE-25 c#1, UE-25 c#2, and UE-25 c#3, respectively.
The estimates of flow porosity cannot be separated from the parameter h, which 
represents a
uniform aquifer thickness. In conducting tracer tests in isolated, permeable intervals in 
fractured
rock, it is difficult to identify a meaningful thickness because transport occurs through an
interconnected network of fractures. For this report, we have assumed that the appropriate
ANL-NBS-HS-000039, REV 00 189 December 2003
thickness is the effective thickness as previously reported in Geldon (1996 [100396], pp. 
12 to
20).
This report presents the first unequivocal tracer testing from borehole c#1 to c#3 in the 
Lower
Bullfrog test and from c#1 to c#2 in the Prow Pass test. The preliminary results suggest 
that the
arrival time from c#1 to c#3, 56.3 days, is consistent with the arrival time from c#2 to 
c#3, 5.07
days, because, as implemented in the Moench (1989 [101146]) solution, the arrival time 
is
directly proportional to the square of the distance between injection and production wells 
(see
Section 6.3.2).
Tracer testing in the Prow Pass interval (Table 6.3-3) showed different transport 
characteristics
than those obtained in the Bullfrog and Tram intervals. The flow porosity was found to be
0.00045 in the Prow Pass as opposed to 0.072 to 0.099 in the Bullfrog and Tram Tuffs 
(Table
6.3-2). This result indicates that the flow network in the Prow Pass is dominated by
interconnected fractures (fracture porosity is in the range from 0.00001 to 0.01), whereas 
in the
Bullfrog and Tram, it was dominated by discontinuous fractures with interconnecting 
segments
of matrix. Alternatively, the flow heterogeneity in the Bullfrog and Tram Tuffs may have 
been
such that a vast majority of the water produced from c#3 came from locations that were 
not in
communication with the injection wells (i.e., only a small amount of the production flow 
rate
came from the direction of the injection wells).
Longitudinal dispersivity in the Prow Pass Tuff testing at the scale of the distance 
between c#2
and c#3 was calculated as 0.27 m, whereas it was 1.9 to 2.6 m in the Bullfrog and Tram 
intervals
at the same scale. A relatively small dispersivity is consistent with a flow network 
dominated by
interconnected fractures (Prow Pass), and a relatively large dispersivity is consistent with 
a flow
network dominated by discontinuous fractures with interconnecting segments of matrix 
(Bullfrog
and Tram) because the more the actual microscopic flow pathways are different from the
macroscopic, averaged, flow pathway, the larger is the longitudinal dispersivity. Clearly, 
a flow
network dominated by discontinuous fractures with interconnecting segments of matrix 
(Bullfrog
and Tram) would have more microscopic flow pathways than a flow network dominated 
by
interconnected fractures (Prow Pass).
The storage porosity (or matrix porosity) calculated for the Prow Pass Tuff was 0.01 
(Table 6.3-
3), whereas it was 0.088 to 0.19 for the Bullfrog and Tram (Table 6.3-2). A small storage
porosity is consistent with a dual-porosity medium dominated by interconnected fractures 
(Prow
Pass). In such a medium, the storage component, which is assumed to consist of dead-end
fractures and the part of the matrix not contributing to the flow network, would be 
dominated by
fractures, which have very small porosities. Similarly, a large storage porosity is 
consistent with
a dual-porosity medium dominated by discontinuous fractures with interconnecting 
segments of
matrix (Bullfrog and Tram). In such a medium, the porosity of the storage component 
(dead-end
fractures and the part of the matrix not contributing to the flow network) would be 
dominated by
the large porosity of the matrix component of storage.
ANL-NBS-HS-000039, REV 00 190 December 2003
Table 6.3-3. Summary of Results and Transport Properties in a Partly Recirculating Tracer Test
from Borehole c#3 to c#2 and from Borehole c#1 to c#2, Prow Pass Tuff
Parameter 2,4,5 TFBA & Iodide:
c#3 to c#2
2,3,4,5 TeFBA:
c#1 to c#2
Breakthrough (days) 1.67 17
Peak concentration (ppm) TFBA : 3.7
Iodide : 2.7 0.09
Single-Porosity, Partial
Recirc. Solution
Dual -Porosity, Partial
Recirc. Solution
Longitudinal dispersivity (m) 0.27 0.27
Peclet number 107.4 107.4
Flow porosity, ?f 0.00045 0.00045
Gamma (dimensionless
matrix diffusion coefficient)
N/A 0.000444, 0.001(TFBA
and Iodide, respectively)
Storage porosity, ?' N/A 0.01
DTNs: GS990208312315.001 [159238] and MO0308SPATRCRC.000 [164821] (data); Output DTN: 
GS031008312315.002
(analysis).
NOTE: c#1, c#2, and c#3 are abbreviations for boreholes UE-25 c#1, UE-25 c#2, and UE-25 c#3, 
respectively.
Borehole mixing length was assumed to be 30.5 m.
N/A stands for "Not Applicable."
6.3.4 Multiple Tracer Tests with Sorbing Solutes and Colloid Tracers at the C-wells
6.3.4.1 Introduction and Objectives
This section describes the conduct and interpretation of two cross-hole tracer tests 
between c#2
and c#3 in which multiple solute tracers and colloid tracers (carboxylate-modified latex 
(CML)
microspheres) were simultaneously injected. One test was conducted in the Lower 
Bullfrog Tuff
and the other was conducted in the Prow Pass Tuff (referred to as the Bullfrog test and 
the Prow
Pass test, respectively). The objectives of the multiple-tracer tests in the fractured tuffs at 
the
C-wells included the following:
* Testing/validating the applicability of a dual-porosity conceptual transport model (see
Section 6.3.4.2) in the saturated, fractured volcanic tuffs that underlie Yucca Mountain.
* Obtaining estimates of key transport parameters in the flow system, including 
parameters
for colloid transport.
* Assessing the applicability of laboratory-derived tracer transport parameters to field-
scale
transport predictions.
ANL-NBS-HS-000039, REV 00 191 December 2003
The latter objective is important because radionuclides cannot be tested in the field, so 
favorable
comparisons of laboratory- and field-scale transport of nonradioactive tracers can lend 
credibility
to the practice of using laboratory-derived radionuclide transport parameters in field-scale
predictive simulations.
This section also summarizes laboratory experiments that were conducted to support the 
C-wells
field test interpretations and to provide the comparisons between laboratory-derived 
transport
parameters and field-scale transport parameters. Special emphasis is given to the sorption
behavior of the lithium ion, which was used as a sorbing tracer in the field tracer tests.
6.3.4.2 Dual-Porosity Conceptual Transport Model
A consistent observation in all hydrogeologic units below the water table at the C-wells is 
that
bulk permeabilities (determined from aquifer tests) exceed matrix permeabilities 
(determined
from laboratory core measurements) by 2 to 6 orders of magnitude (Geldon 1993 
[101045], pp.
58 to 64; Geldon 1996 [100396], pp. 69 to 71). This ratio of bulk to matrix permeabilities
suggests that flow in the Miocene tuffs at the C-wells occurs predominantly in fractures.
However, matrix porosities in the C-wells range from about 0.10 to 0.35 (Geldon 1993 
[101045],
pp. 58 to 64), so most of the water in these rocks is stored in the pores of the matrix.
Radionuclide and tracer transport in fractures, therefore, could be attenuated by diffusive 
mass
transfer between the fractures and the rock matrix, a process known as matrix diffusion. 
Matrix
diffusion in fractured systems has been discussed and modeled at length by Neretnieks 
(1980
[101148], pp. 4379 to 4397), Grisak and Pickens (1980 [101132]), Tang et al. (1981 
[101160],
pp. 555 to 564), Maloszewski and Zuber (1984 [156840]; 1985 [148312]), and Moench 
(1995
[148784]). A system exhibiting fracture and matrix flow frequently is called a "dual-
porosity,
dual-permeability" system. When the matrix permeability is small compared to the 
fracture
permeability (e.g., smaller by a factor of 100 or more), the matrix permeability can be 
assumed
to be negligible in transport calculations, and the system is often referred to as simply a 
"dualporosity"
system. It has been suggested elsewhere that the saturated zone in the vicinity of
Yucca Mountain should behave as a dual-porosity system (Robinson 1994 [101154]). 
This
concept has important transport implications, particularly for sorbing radionuclides, 
because it
suggests that solutes moving through fractures will have access to a very large surface 
area for
sorption once they diffuse out of fractures and into adjacent matrix pores.
ANL-NBS-HS-000039, REV 00 192 December 2003
6.3.4.3 Tracer Testing Strategy
To accomplish all of the test objectives mentioned in Section 6.3.4.1 in a reasonable time, 
crosshole,
forced-gradient tracer tests were conducted in which three different solute tracers having
different physical and chemical properties were simultaneously injected into the lower 
Bullfrog
and Prow Pass flow systems. By dissolving the tracers in the same solution and 
simultaneously
introducing them, it was ensured that they all experienced the same flow field and, hence,
initially followed identical flow pathways through the system. This assurance is 
especially
important in field tests where it can be extremely difficult to reproduce exactly flow 
conditions
for different tracer injections because of equipment problems and possible irreversible 
changes in
the system (e.g., well development, biofouling, unsteady drawdown, etc.). The test
interpretations were then based on comparing the responses of the different tracers. The 
tracers
used in each test included two nonsorbing solutes having different diffusion coefficients
(bromide and penta-fluoro-benzoate) and a weakly-sorbing, ion-exchanging solute 
(lithium ion).
The bromide and pentafluorobenzoate were verified to be nonsorbing in a limited set of 
batch
adsorption experiments involving the seven different C-wells tuff lithologies listed in 
Tables 6.3-
16 and 6.3-17 (DTN: LA0302PR831231.001 [162605]). Carboxylate-modified-latex
polystyrene (CML) microspheres were also injected in both tests to serve as colloid 
tracers.
These microspheres have negatively charged hydrophilic surfaces at pH > 5, which tends 
to
minimize their attachment to rock surfaces (Reimus 1995 [101474], p. 35, Table 3.6). 
The
properties of all tracers are summarized in Table 6.3-4 along with the injection masses 
and
concentrations used in the tracer tests.
The rationale for using multiple solute tracers in cross-hole tests is illustrated in Figure 
6.3-18.
The left plot of this figure shows hypothetical solute tracer responses (log normalized
concentration versus log time) for a cross-hole tracer test with a short injection pulse in a 
singleporosity
system. Note that there is no distinction between nonsorbing tracers with different
diffusion coefficients in this plot because there is no secondary porosity for the tracers to 
diffuse
into and, hence, no separation of their responses. The sorbing tracer response is delayed 
in time
and lower in concentration than the nonsorbing tracers. In contrast, the right plot of 
Figure 6.3-
18 shows hypothetical solute tracer responses for a test in a dual-porosity system. In this 
case,
there is a separation between nonsorbing tracers with different diffusion coefficients, with 
the
higher diffusivity tracer exhibiting a lower peak concentration and a longer tail than the 
lower
diffusivity tracer. This separation occurs because the higher-diffusivity tracer diffuses 
more
readily into the matrix than the lower-diffusivity tracer, resulting in a lower recovery at 
early
times but a longer tail due to subsequent diffusion back out of the matrix after the tracer 
pulse
has passed.
ANL-NBS-HS-000039, REV 00 193 December 2003
Table 6.3-4. Tracer Characteristics, Injection Masses, and Injection Concentrations
in the Two Multiple-Tracer Tests
Solute Tracers
Parameters PFBA Bromide Lithium
Free water diffusion coefficient, Df (cm2/sec) (a) 7.2 x 10-6 (b) 2.1 x 10-5 (c) 1.0 x 10-5 (c)
Sorption(d) None(d) None(d) Weak (ion exchange)
Bullfrog test injection mass (kg) 12.1 165.6 14.39
Bullfrog test injection concentration (mg/L) (e) 1000 13800 1200
Prow Pass test injection mass (kg) 12.0 30.6 16.0 (f)
Prow Pass test injection concentration (mg/L) (g) 2000 5100 2670
CML Microsphere Tracers
Tracer (fluorescent dye color) Test Injection Amount(j) Injection
Concentration(k)
0.36-?m CML microspheres (yellow) (h) Bullfrog 3.6 X 1014 spheres 4.6 X 1010 spheres/L
0.64-?m CML microspheres (blue) (i) Prow Pass 3.0 X 1014 spheres 5.1 X 1010 spheres/L
0.28-?m CML microspheres (orange) (i) Prow Pass 2.1 X 1014 spheres 3.5 X 1010 spheres/L
0.28-?m CML microspheres (yellow) Prow Pass 2.1 X 1014 spheres 3.5 X 1010 spheres/L
DTNs: LA0007PR831231.001 [156043] (Bullfrog Test), LAPR831231AQ99.001 [140134] (Prow Pass Test);
LA0302PR831231.001[162605].
Sources: Reimus (2000 [165125]), Reimus (2000 [162855]), Reimus (2000 [162852]), Reimus (2003 [165129], including
Attachment A).
NOTE: (a) Callahan et al. (2000 [156648], Table 7) found that diffusion coefficients in rock matrices had the 
same
ratio as free water diffusion coefficients for PFBA and bromide.
(b) Benson and Bowman (1994, p. 1125 [122788]; 1996 [153427]).
(c) Newman (1973 [148719], p. 230, Table 75-1); based on ionic conductances at infinite dilution.
(d) Based on results of laboratory batch sorption experiments (DTN: LA0302PR831231.001 [162605]).
(e) Tracers were dissolved in ~12,000 L of groundwater from c#3 (Reimus 2000 [162855]).
(f) Lithium was injected as 33.3 kg LiBr and 80.8 kg LiCl (Reimus 2000 [162855]).
(g) Tracers were dissolved in ~6,000 L of groundwater from c#2 (Reimus 2000 [162852]).
(h) The microsphere injection was initiated 3.5 hours after the start of injection of solute tracers in the
Bullfrog test. The microsphere and solute injections ended at the same time. (Reimus 2000
[162855]).
(i) These microspheres were injected 2 days prior to solute tracers in the Prow Pass test (dispersed in
~6,000 L of ground water from c#2) to avoid the possible destabilization of the microspheres in the
high-ionic strength injection solution containing the solute tracers (Reimus 2000 [162852]).
(j) Based on average concentration measured in a dilution of a known volume fraction of the microsphere
stock solution injected. Sources: concentration measurements (Reimus 2000 [165125]); preparation of
dilutions for Bullfrog test (Reimus 2000 [162855]); preparation of dilutions for Prow Pass test (Reimus
2000 [162852]); and summary of calculations (Reimus 2003 [165129], pp. 115 to 116; Attachment A,
pp. A-1 to A-6).
(k) Injection concentrations calculated by dividing number of spheres injected by injection volumes of
12,000 L x (6.5/10) = 7,800 L (Bullfrog test) and 6,000 L (Prow Pass test). The factor of 6.5/10 for the
Bullfrog test accounts for the fact that the microspheres were injected for only 6.5 hours of the total of
10 hrs that the 12,000 L was injected.
Figure 6.3-18 also shows two possible responses for a sorbing tracer: (1) one with 
sorption
occurring in the matrix and (2) one with sorption occurring in the fractures and the matrix 
(if the
ANL-NBS-HS-000039, REV 00 194 December 2003
fractures have sorptive mineral coatings or are filled with sorptive granular material). 
Note that
in the matrix-only case, the sorbing tracer response is attenuated in peak concentration 
but not
significantly in time relative to the nonsorbing tracers, whereas in the latter case both a
concentration and a time attenuation are apparent. The minimal time attenuation of the 
sorbing
tracer relative to the nonsorbing tracers in the matrix-only sorption case is primarily a 
result of
the relatively short duration of a typical cross-hole tracer test relative to characteristic 
times of
diffusion into the matrix; as travel times increase, the time and concentration attenuation 
of a
sorbing tracer relative to nonsorbing tracers should increase.
For illustration purposes only
NOTE: The figure illustrates how multiple tracers can be used to distinguish between single- and dual-
porosity
systems (Reimus 2003 [165129], Attachment A, pp. A-198 to A-208). As cross-hole travel times increase,
the "nonsorbing, high diffusivity" and "sorbing, matrix only" peaks on the right-hand plot will begin to arrive
later than the "nonsorbing, low diffusivity" peak. The curves were generated using the RELAP V 2.0 code
(STN: 10551-2.0-00 [159065]) with arbitrary input parameters intended to qualitatively illustrate the
differences between tracer responses in single- and dual-porosity media. The inputs and outputs of the
simulations were not submitted to the TDMS and do not have a DTN.
Figure 6.3-18. Hypothetical Cross-Hole Responses of Tracers with Different Physical
and Chemical Characteristics in Single- and Dual-Porosity Media
The hypothetical responses in Figure 6.3-18 suggest that a multiple tracer test involving 
the
simultaneous injection of nonsorbing solute tracers with different diffusion coefficients 
and a
sorbing tracer should allow qualitative discrimination between a single-porosity system 
and a
dual-porosity system. That is, if nonsorbing tracers of different diffusion coefficients 
have
different responses and/or if a sorbing tracer has a peak concentration that occurs at about 
the
same time as a nonsorbing tracer but with a lower concentration, then a dual-porosity 
system is
suggested. This approach was taken by Maloszewski et al. (1999 [156841]), although 
they used
only multiple nonsorbing tracers in a fractured sandstone/quartzite/slate system. 
Furthermore, if
a dual-porosity response is observed and one knows the relative diffusion coefficients of 
the two
nonsorbing tracers, it should be possible to determine how much of the apparent 
dispersion in the
responses is due to true hydrodynamic dispersion and how much is due to matrix 
diffusion. Both
Time
Nonsorbing, Low Diffusivity
Nonsorbing, High Diffusivity
Sorbing in Matrix Only
Sorbing in Fractures
and Matrix
Dual-Porosity
Time
Normalized Concentration
Nonsorbing, Any Diffusivity
Sorbing
Single-Porosity
ANL-NBS-HS-000039, REV 00 195 December 2003
of these processes have the effect of broadening the response curves/increasing the tailing 
of the
tracers, but only matrix diffusion can cause a separation of the responses of the two 
tracers. The
magnitude of the separation can be used to distinguish quantitatively between the effects 
of
matrix diffusion and hydrodynamic dispersion, resulting in unambiguous estimates of 
mean
residence times, dispersion coefficients, and matrix diffusion parameters in a tracer test.
Effective sorption parameters associated with the response of a simultaneously injected 
sorbing
tracer can then be estimated by assuming that the sorbing tracer experiences the same 
mean
residence time, longitudinal dispersivity, and matrix diffusion (subject to its diffusion
coefficient) as the nonsorbing tracers. In this case, only the sorption parameter(s) need be
adjusted to obtain a model fit/match to the sorbing tracer response. Likewise, colloid
filtration/attachment and detachment parameters can be obtained by assuming that the 
CML
microspheres experience the same mean residence times and longitudinal dispersivities as 
the
nonsorbing solute tracers. For the microspheres, matrix diffusion is assumed to be 
negligible
because of their large size and small diffusivity relative to the solutes.
6.3.4.4 Conduct of Tracer Tests
The cross-hole tracer tests were conducted between wells c#2 and c#3, which are 
separated by
about 30 m at the surface (Figure 6.3-2). c#2 was used as the tracer injection well and c#3 
as the
production well in the lower Bullfrog Tuff (Reimus 2000 [162855]; Reimus 2000 
[164624]). In
the Prow Pass Tuff, c#3 was the injection well, and c#2 was the production well (Reimus 
2000
[162852]). The natural gradient at the C-wells site, though quite flat, is believed to be 
oriented in
the direction from c#3 to c#2 (Figure 6.3-2), so tracer movement in the Bullfrog test was 
against
the gradient, and in the Prow Pass test, it was with the gradient. Prior to injecting tracers, 
a
weak-dipole flow field was established in each test by reinjecting a fraction of the water 
pumped
from the production well into the injection well. The production and recirculation flow 
rates are
summarized in Table 6.3-5. The weak-dipole flow configuration was chosen over a 
convergent
flow configuration (no recirculation) to ensure that tracers were "flushed" out of the 
injection
wellbore instead of relying on the flow field induced by pumping the production well to 
draw
tracers out of the wellbore. Pressure transducers continuously monitored pressures 
between the
packers, above the upper packer, and below the lower packer in each well during the 
tests.
Because of the drastic differences in transmissivity of the two test intervals, the water 
level
drawdown in the Prow Pass interval (62 m) was over an order of magnitude greater than 
the
drawdown in the Bullfrog interval (5 m) despite the fact that the production rate in the 
Bullfrog
test was ~30 times greater than in the Prow Pass test.
After establishing a reasonably steady weak-dipole flow field, as indicated by stable 
water levels
in the packed-off intervals, the recirculation of produced water into the injection well was
replaced by the injection of a groundwater solution containing the three solute tracers. 
The tracer
solution was injected at the same flow rate as the recirculation and without any 
interruption to
the flow, and when the injection was complete, recirculation was immediately resumed 
without
interruption. Thus, there were no pressure or flow transients introduced to the system as a 
result
of tracer injection. Recirculation of produced water was discontinued after 40 days in the
Bullfrog test, but it was maintained throughout the Prow Pass test. The Bullfrog test was
conducted for 337 days, and the Prow Pass test was conducted for 127 days.
ANL-NBS-HS-000039, REV 00 196 December 2003
Table 6.3-5. Average Production and Recirculation Rates During the Bullfrog and Prow Pass
Tracer Tests and Summary of Flow Interruptions During the Prow Pass Test
Test Production Rate (L/min) Recirculation Rate (L/min) Recirculation Ratio
Bullfrog(a) 568 19 (zero after 40 days) 0.033
Prow Pass(b) 19 5.7 0.3
Prow Pass Test Flow Interruptions: (c)
Interruption Flow Shut Off Flow Turned On Duration (hr)
1 11/14/98, ~9:00 am 11/14/98, ~11:00 pm ~14
2 11/23/98, ~9:00 am 11/30/98, ~4:00 pm ~175
3 12/21/98, ~9:00 am 1/4/99, ~11:00 pm ~337
DTNs: GS981008312314.002 [147068]; GS981008312314.003 [144464] (Bullfrog rates); and DTN: 
GS010799992315.001
[157067] (Prow Pass rates).
NOTE: (a) Injection well was c#2, production well was c#3. Test initiated in October 1996.
(b) Injection well was c#3, production well was c#2. Test initiated in September 1998.
(c) Microsphere tracers were injected on 9/23/98, and solute tracers were injected on 9/25/98.
The Prow Pass test featured three different flow interruptions (two intentional) during the 
tailing
portion of the test. The times and durations of these interruptions are summarized in 
Table 6.3-5.
The first interruption was unplanned and occurred as a result of a diesel generator failure. 
The
latter two interruptions were intentional and coincided with the Thanksgiving and 
Christmas-
New Year's holiday breaks, respectively. In addition to the practical consideration of not
staffing the remote field site over the holidays, these flow interruptions offered the 
opportunity to
obtain independent confirmation of matrix diffusion in the flow system. If a flow 
interruption is
introduced during the tailing portion of a tracer test in a dual-porosity medium when 
tracers are
diffusing back out of the matrix, then an increase in nonsorbing tracer concentrations 
should
result when flow is resumed.
Water samples were collected at the production well throughout both tests using an 
automatic
sampler. The sampling interval was gradually increased as the tests progressed. Sampling 
of the
injection interval was not possible in the Bullfrog test, but a sampling loop that was 
designed to
continuously mix the injection interval in c#3 was implemented in the Prow Pass test.
Unfortunately, the submersible pump used to bring water to the surface generated more 
heat than
could be efficiently removed from the loop, so the use of the loop for mixing had to be
abandoned to prevent overheating of the downhole instrumentation. However, the loop 
was used
40 days into the Prow Pass test to obtain samples over a 10-hr period to assess how well 
the
injection wellbore had been purged of tracers by the reinjection of production water.
Groundwater samples were analyzed for bromide (Br-) by liquid chromatography (with a
conductivity detector) and for lithium (Li+) by inductively-coupled-plasma, atomic-
emissionspectroscopy
(ICP-AES) at LANL. Pentafluorobenzoate (or PFBA) was analyzed by HPLC
(with a UV absorbance detector), also at Los Alamos. The fluorescent CML microspheres 
were
analyzed by flow cytometry.
ANL-NBS-HS-000039, REV 00 197 December 2003
6.3.4.5 Tracer Test Results
Figure 6.3-19 shows the normalized concentrations of the three solute tracers at the 
production
well as a function of time during the Bullfrog test. All concentrations are normalized to 
the
injection masses of tracers (?g/L-kg injected or L-1 x 109). The axes in Figure 6.3-19 
have
logarithmic scales so that the details of the breakthrough curves can be seen throughout 
the entire
test. The fractional recoveries of the tracers over the duration of the test were 0.74 for 
PFBA,
0.69 for bromide, and 0.39 for lithium (Reimus 2003 [165129], Attachment A, pp. A-36 
to A-
86). Figure 6.3-20 shows the response of the 360-nm diameter CML microspheres 
relative to the
PFBA response in the Bullfrog tracer test. It is apparent that while the microspheres 
arrived
slightly earlier than the PFBA, they were significantly attenuated relative to the PFBA
throughout the test. The fractional recovery of microspheres during the test was 0.145 
(Reimus
2003 [165129, Attachment A, pp. A-36 to A-86).
The most striking feature of the tracer breakthrough curves (Figures 6.3-19 and 6.3-20) is 
their
bimodal shape. It is believed that the double-peak responses were the result of at least 
two
distinct fracture-flow pathways between the injection and production wells that were 
located at
different depths within the relatively long (~100 m) test interval. The flow survey 
information in
Figure 6.1-2 suggests that there were probably two principal zones of outflow during 
tracer
injection and recirculation in c#2 (see the triangles indicating percentages of flow during 
openhole
pumping). Because of the lack of mixing in the injection interval, the tracer solutions,
which were injected directly below the top packer and were ~2% more dense than the
groundwater, probably sank rapidly to the bottom of the interval (~200 kg of tracers 
dissolved in
~12,000 L (or kg) of ground water would have resulted in a ~2% increase in water 
density).
Under these conditions, the majority of the tracer mass would be expected to exit c#2 
from the
lower flow zone; and, indeed, the majority of the tracer mass (60%) was associated with 
the
second tracer peak. The first peak was apparently the result of a small percentage (~12%) 
of the
tracer mass exiting c#2 from the upper flow zone. This zone was apparently more 
conductive (as
suggested by the greater percentage of flow during open-hole pumping) and much better
connected hydraulically to c#3 than the lower zone, as the travel time between the wells 
in this
zone was much shorter. Additional evidence to support this hypothesis is obtained by 
comparing
the PFBA response of Figure 6.3-19 with the response of the same tracer injected into 
c#2 six
months prior to the start of the multiple tracer test. Figure 6.3-21 shows that the PFBA
breakthrough curve in the earlier test was a more conventional single-peak response with 
a peak
arrival time that coincided with the arrival time of the second peak in the latter test. The 
earlier
test was conducted in the same interval between c#2 and c#3 and under the same flow 
conditions
as the multiple-tracer test. The only noteworthy difference between the two tests, besides 
the
additional tracers in the second test, was that only ~1000 L of tracer solution was injected 
in the
first test, whereas ~12,000 L was injected in the second. The larger volume in the second 
test
was due to the large mass of LiBr that was dissolved to ensure a quantifiable response of 
lithium
ion. Given that the volume of the injection interval (volume between the two packers) 
was
~4300 L, it seems logical that the ~1000 L of tracer solution injected in the first test 
would have
sunk rapidly and exited the borehole via only the lower flow zone. In contrast, the 
~12,000 L of
tracer solution injected in the second test (approximately 3 interval volumes) would have
eventually "filled up" the interval, and a small fraction of the tracer mass apparently 
accessed the
upper flow zone.
ANL-NBS-HS-000039, REV 00 198 December 2003
DTN: LA0007PR831231.001 [156043].
NOTE: Log-log scales are used for the axes so that the bimodal nature of the tracer responses can be seen 
more
clearly.
Figure 6.3-19. Normalized Tracer Concentrations Versus Time in the Bullfrog Tuff
Tracer Test Conducted from October 1996 to September 1997
PFBA concentrations in the earlier test were monitored for just over 3000 hr with a total
fractional recovery of 0.72; at 3000 hr into the second test, the total PFBA fractional 
recovery
was 0.60 (Reimus 2003 [165129], Attachment A, pp. A-7 to A-14, A-36 to A-86). Thus, 
the
tracer recovery in the former test was actually higher than in the latter test despite the 
early tracer
arrival in the latter test. This observation, plus the fact that the shapes of the common 
peaks of
the two tests are different, suggest that a considerable fraction of the mass injected in the 
latter
test followed additional pathways that were not accessed in the first test. Although the
possibility of additional recovery of PFBA from the first test in the second test cannot be 
ruled
out, it is not plausible that the PFBA from the first test could have caused either the first 
or
second PFBA peak in the second test because all the other tracers used in the second test 
(which
were not injected in the first test) exhibited a bimodal response.
ANL-NBS-HS-000039, REV 00 199 December 2003
DTN: LA0007PR831231.001 [156043].
NOTE: Log-log scales are used for the axes so that the bimodal nature of the tracer responses can be seen 
more
clearly.
Figure 6.3-20. Normalized Concentrations of PFBA and 360-nm-Diameter Carboxylate-Modified
Polystyrene Latex Microspheres in the Bullfrog Tuff Tracer Test
DTN: LA0007PR831231.001 [156043].
NOTE: The test conditions were the same in both tests, but the injection solution volume was ~1000 L in the 
May
test and ~12,000 L in the October test.
Figure 6.3-21. Comparison of Normalized PFBA Responses in the Bullfrog Tuff Resulting
from Tracer Injections in May 1996 and October 1996
ANL-NBS-HS-000039, REV 00 200 December 2003
Figure 6.3-22 shows the normalized concentrations of the three solute tracers at the 
production
well as a function of time during the Prow Pass test. In contrast to the Bullfrog test, the
responses in this test had a more conventional single-peak shape. Figure 6.3-22 also 
shows that
there was indeed an increase in the tracer concentrations upon resumption of flow after 
each of
the three interruptions. The fractional recoveries of the solute tracers over the duration of 
the test
were 0.52 for PFBA, 0.43 for bromide, and 0.19 for lithium ion (Reimus 2003 [165129],
Attachment A, pp. A-87 to A-144). Note that the axes in Figure 6.3-22 have a linear scale 
as
opposed to the logarithmic scale used in Figure 6.3-19 for the Bullfrog test.
It is apparent in both Figures 6.3-19 and 6.3-22 that there is considerable separation 
between the
peak normalized concentrations of bromide and PFBA in the two tracer tests, with PFBA 
always
having a higher normalized concentration in each peak. It is also apparent that the tails of 
the
responses of these two tracers converge, with a suggestion of a crossover at late times. 
However,
the appearance of a second peak in the Bullfrog test precluded a crossover after the first 
peak,
and the Prow Pass test was not conducted long enough to see a definitive crossover. 
Referring to
Figure 6.3-18, these breakthrough-curve features are qualitatively consistent with a dual-
porosity
transport system. The lithium responses in the first peak of the Bullfrog test and in the 
Prow
Pass test are highly attenuated in normalized concentration compared to the nonsorbing 
tracers,
although they are not significantly attenuated in time. Again referring to Figure 6.3-18, 
these
responses are qualitatively consistent with a dual-porosity transport system in which most 
of the
sorption is occurring in the matrix (after diffusive mass transfer from the fractures), with
possibly a small amount of sorption also occurring on fracture surfaces. In the case of the 
second
peak in the Bullfrog test, the lithium response is attenuated both in concentration and in 
time,
which is consistent with sorption occurring in both the matrix and on fracture surfaces.
The responses of the CML microspheres relative to PFBA in the Prow Pass test are 
shown in
Figure 6.3-23, which has a logarithmic normalized concentration axis because of the very 
low
normalized concentrations of the microspheres. The fractional recoveries of microspheres 
in this
test were 0.0033 for the 640-nm-diameter blue microspheres, 0.0012 for the 280-nm-
diameter
orange microspheres, and effectively zero for the 280-nm-diameter yellow microspheres
(Reimus 2003 [165129], Attachment A, pp. A-145 to A-167). The response of the yellow
microspheres is not shown in Figure 6.3-23 because these microspheres effectively never 
arrived
at the production well. The 280-nm-diameter orange and 640-nm-diameter blue 
microspheres
were injected 2 days before the solutes, whereas the 280-nm-diameter yellow 
microspheres were
injected simultaneously with the solutes. It is likely that the high ionic strength of the 
injection
solution (~0.4 M) caused the yellow microspheres to attach to rock surfaces much more 
readily
than the other microspheres, which were injected in untraced groundwater (ionic strength 
=
~0.003 M). It is also interesting to note that the peak concentrations of blue and orange
microspheres occurred at about the same time that solutes began arriving at c#2, and then 
the
microspheres rapidly decreased in concentration as the solute concentrations increased. 
This
behavior may be purely coincidental, or it may hint that the increased ionic strength 
associated
with the solutes caused the remaining microspheres to attach more readily to rock 
surfaces. The
microsphere "spikes" occurring at about 1000 hr into the test (Figure 6.3-23) actually 
correspond
to a few days after the c#3 mixing/sampling loop was run, which suggests that the 
pressure and
flow transients caused by the mixing may have mobilized/detached some microspheres. 
The
timing of this response was consistent with the arrival time of the microspheres after 
injection
into c#3 on September 23, 1998. A second spike in microsphere concentrations occurred 
the day
ANL-NBS-HS-000039, REV 00 201 December 2003
after the unplanned flow interruption on November 14, 1998 (Figure 6.3-23), which 
further
supports the hypothesis that flow and pressure transients may have resulted in 
microsphere
detachment.
DTN: LAPR831231AQ99.001 [140134].
NOTE: "Spheres" in the legend refers to CML microspheres.
Figure 6.3-22. Normalized Tracer Concentrations Versus Time in the Prow Pass Tracer
Test Conducted from September 1998 to January 1999
0
50
100
150
200
250
300
350
400
450
500
0 300 600 900 1200 1500 1800 2100 2400 2700 3000
Time Since Injection, hrs
Normalized Concentration, ?
?g/L per kg injected
Br
Li
PFBA
Unplanned 14-hr
flow interruption
on 11/14/98
Planned 7-day flow
interruption (11/23-30/98)
Planned 14-day flow
interruption (12/21/98
to 1/4/99)
ANL-NBS-HS-000039, REV 00 202 December 2003
DTN: LAPR831231AQ99.001 [140134].
NOTE: "Spheres" in the legend refers to CML microspheres. The 280-nm-diameter spheres are the orange-
dyed
microspheres injected two days prior to the solutes. The 280-nm-diameter yellow-dyed spheres that were
injected with the solutes were not recovered.
Figure 6.3-23. Normalized Concentrations of PFBA and Carboxylate-Modified
Polystyrene Latex Microspheres in the Prow Pass Tracer Test
The sampling loop in c#3 in the Prow Pass test afforded the opportunity to see how well 
tracers
had been "flushed" from the injection borehole after the test had been running for ~40 
days. The
sampling loop was run for ~11 hr, and over 50 samples were collected at the surface 
during this
time. The "responses" from the injection interval are shown in Figure 6.3-24. These 
responses
clearly indicate that there was a "slug" of concentrated tracer solution remaining in the 
interval
and that this slug circulated around the sampling loop/borehole several times during the 
11 hr of
loop operation, dispersing as it circulated (indicated by the lowering and broadening of 
tracer
peaks). Interestingly, the microspheres appear to precede the solutes each time the tracers 
cycle
through the loop, which suggests that there was some as yet unexplained spatial 
separation of
microspheres and solutes in the borehole. The total mass of any given tracer associated 
with the
slugs was less than 0.1% of the mass that was injected, so the injection interval had been
reasonably well purged of all tracers. This result is important because it shows that the
unaccounted-for tracer mass in the overall test is not the result of mass being left behind 
in the
injection borehole, but rather it is mass that is being "lost" by other means (e.g., flow into 
the
0.1
1
10
100
1000
0 300 600 900 1200 1500 1800 2100 2400 2700 3000
Time, hrs
Norm. Conc., ?
?g/L per kg injected
PFBA
640-nm Spheres
280-nm Spheres Mixing of c#3
Flow Interruption
on 11/14/98
ANL-NBS-HS-000039, REV 00 203 December 2003
matrix that never makes it to the production borehole, stagnation points, losses due to 
densitydriven
flow). Given the flow rate through the sampling loop and the volumes of the injection
interval and piping, the timing of the slug(s) suggested that they had been near the bottom 
of the
interval where the pump intake was located. This result is consistent with the expectation 
that
some of the dense tracer solution would have sunk to the bottom of the interval and 
remained
there if there was no flow to push it out.
DTN: LAPR831231AQ99.001 [140134].
NOTE: "Spheres" in the legend refers to CML microspheres. The tracers remaining in the injection interval 
were
apparently highly stratified, probably at the bottom of the interval. Total masses remaining in the injection
interval were less than 0.1% of the total injection mass of each tracer.
Figure 6.3-24. Tracer Concentrations Mixing Loop 40 Days After Tracer Injection
in UE-25 c#3 in the Prow Pass Tracer Test
6.3.4.6 Tracer Test Interpretive Modeling Approach
6.3.4.6.1 Solute Tracers
To obtain estimates of solute transport parameters in the flow system, the semi-analytical 
dualporosity
transport model RELAP (REactive transport LAPlace transform inversion computer
code) V 2.0 (STN: 10551-2.0-00 [159065]) was used to fit simultaneously the solute 
tracer
responses. RELAP, which is described in detail by Reimus and Haga (1999 [154705], 
Appendix
0
5000
10000
15000
20000
25000
0 1 2 3 4 5 6 7 8 9 10 11
Time, hrs
Norm. Conc., ?
?g/L per kg injected
Br
Cl
Li
PFBA
Blue Spheres
Orange Spheres
Yellow Spheres
ANL-NBS-HS-000039, REV 00 204 December 2003
B), essentially combines the Laplace-domain dual-porosity transport equations derived by
Maloszewski and Zuber (1984 [156840], Appendix; 1985 [148312]) (modified to account 
for
linear sorption) with Laplace-domain transfer functions that describe a finite-pulse 
injection,
wellbore mixing, and recirculation. Similar approaches have been used by others 
(Moench 1989
[101146], 1995 [148784]; Becker and Charbeneau 2000 [156633], pp. 299 to 310). 
Maloszewski
and Zuber (1984 [156840], Appendix; 1985 [148312]) assumed that tracer transport in 
fractures
was described by the one-dimensional (1-D) advection-dispersion equation with 1-D 
diffusion
occurring into the surrounding matrix perpendicular to the flow direction in fractures. 
This
simplified flow-system geometry assumed by RELAP is shown in Figure 6.3-25. The 
model
assumes parallel-plate fractures of constant aperture, 2b, and constant spacing, L, no
concentration gradients across the fracture aperture, and a steady flow rate in fractures.
For illustration purposes only.
NOTE: Matrix and fractures extend infinitely in z direction.
Figure 6.3-25. System Geometry Assumed in the RELAP and MULTRAN Codes
ANL-NBS-HS-000039, REV 00 205 December 2003
The equations describing dual-porosity transport under these conditions are the following 
(based
on Maloszewski and Zuber {1984 [156840], Appendix}).
Fracture:
0 = - - +
=
m m
2
f
2
f
f
f
f
f
b y y
C
b
D
x
C
D
x
C
v
t
C
R
* 
* 
?
?
* 
* 
* 
* 
* 
* 
(Eq. 5)
Matrix:
0 = - 2
m
2
m
m
m y
C
D
t
C
R
* 
* 
* 
* 
(Eq. 6)
subject to the following initial and boundary conditions
0 ) 0 , ( f * x C (Eq. 5a)
Input) Pulse (i.e., to 0 from ,0) ( pulse p f t t t C x C * * * (Eq. 5b)
0) , ( f * * ?t C (Eq. 5c)
0) 0 , , ( m * x y C (Eq. 6a)
), ( ) , , ( f m t x C t x b C * (Eq. 6b)
matrix) inifinte - (semi 0 ) , , ( or matrix) (finite 0 m
2
m * * * 
* 
* 
?
t x C
y
C
L
y (Eq. 6c)
where
Cf = tracer concentration in solution in fractures, ?g/cm3
Cm = tracer concentration in solution in matrix, ?g/cm3
Cp = pulse concentration, ?g/cm3
vf = fluid velocity in fractures (in x direction), cm/sec
Df = dispersion coefficient in fractures, cm2/sec
Dm = molecular diffusion coefficient in matrix, cm2/sec
Rf = retardation factor in fractures = A k Asp 1* (or A k
b
2
1* for open parallel-plate
fractures). Alternatively, for fractures that are filled with aquifer material, Rf = d
f 1 K
?
?
?
Rm = retardation factor in matrix = d
B 1 K
?
?
?
Kd = sorption partition coefficient = mass of tracer sorbed per unit mass of aquifer
material divided by solution concentration of tracer at equilibrium, cm3/g
kA = Kd/Asp surface-based sorption partition coefficient , cm3/cm2
Asp = surface area per unit mass of material in fractures or on fracture walls, cm2/g
?f = bulk density in fractures, g/cm3
ANL-NBS-HS-000039, REV 00 206 December 2003
?B = bulk density in matrix, g/cm3
* = porosity within fractures
* = matrix porosity
b = fracture half aperture, cm
L = spacing between centerlines of adjacent fractures, cm.
The transformation of Equations 5 and 6 to the Laplace domain and their subsequent 
solution in
the Laplace domain and inversion of the solution back to the time domain are described 
by
Reimus and Haga (1999 [154705], Appendix B). Note that Equations 5 and 6 reduce to a 
singleporosity
system if the matrix porosity, ?, (or the matrix diffusion coefficient, Dm) is set equal to
zero. RELAP V 2.0 (STN: 10551-2.0-00 [159065]) provides a simultaneous least-squares 
fit to
up to four tracer data sets by automatically adjusting the following model parameters 
(which
arise from the dimensionless forms of the governing equations):
* the mean fluid residence time in fractures ( ?)
* the Peclet number (Pe = rL/ ?, where rL = distance between wells, m, and * = 
dispersivity
in fractures, m)
* the mass fraction of tracers participating in the test (f)
* a matrix diffusion mass-transfer coefficient, m D
b
?
, which is obtained from the Laplace
transformations of Equations 5 and 6.
* the characteristic fracture spacing, L
* the fracture retardation factor, Rf
* the matrix retardation factor, Rm.
The fractional mass participation (f) is used as an adjustable parameter because low mass
recoveries are frequently observed in field tracer tests in fractured rock (e.g., Reimus and 
Haga
1999 [154705], Appendix B), presumably due to (1) dense tracer solutions "sinking" out 
of the
zone of influence of pumping, (2) a significant volumetric flow of tracer solution into the 
matrix
within the injection wellbore (this tracer mass will not make it to the production well 
during the
tracer test because of the very low flow velocities in the matrix), or (3) the loss of tracer 
mass
due to stagnation points induced either by recirculation or by the superposition of the 
induced
flow field on the ambient flow field. Although these phenomena can affect absolute tracer
responses, they should not, in principle, affect the relative responses of different tracers 
that are
injected simultaneously.
The interpretation of the tracer responses in each test involved first fitting the two 
nonsorbing
tracer responses by simultaneously adjusting all of the parameters listed above with the
constraint that the matrix diffusion coefficient, Dm, for bromide was three times that of 
PFBA
ANL-NBS-HS-000039, REV 00 207 December 2003
(and therefore the matrix diffusion mass transfer coefficient, m D
b
?
, was ~1.7 times that of
PFBA). This factor-of-three difference is based on literature data (Newman 1973 
[148719], p.
230, Table 75-1; Benson and Bowman 1994 [122788], p. 1125; 1996 [153427]) and the
experimental diffusion cell results discussed in Section 6.3.8. Rf and Rm were held equal 
to 1 for
the two nonsorbing tracers. This fitting procedure implicitly assumed that both tracers 
had
exactly the same mean residence time, Peclet number, mass fraction participation, and
characteristic fracture spacing during the tracer tests, which is justified because the 
tracers were
injected simultaneously and, thus, should have experienced the same flow system and 
same flow
conditions.
For the Bullfrog test, the two sets of tracer peaks were fitted sequentially with the second 
peak
being fitted after accounting for the contribution of the tail from the first peak. The model
parameters were allowed to vary independently for each peak, as the peaks were assumed 
to
represent different flow pathways with different transport characteristics. Although the 
tracer
injection duration in the Bullfrog test was about 10 hr, it was assumed that for the first 
peak there
was a delay of 4 hr followed by a 6-hr injection of tracer into the pathways that resulted 
in the
first peak. The rationale for this assumption was that there was no early peak in the 
earlier
PFBA test (Figure 6.3-21), which involved an injection of less than one hour, so it 
seemed
logical to assume that the earliest injected tracer solution did not follow the earliest-
arriving
pathways. A 4-hr delay time was chosen because the injected-tracer-solution volume 
exceeded
the injection-interval volume by this time, and it was felt that this was a reasonable 
criterion for
when at least a portion of the tracer solution should have begun moving through the early
arriving pathways.
In contrast to the Bullfrog test, the fitting procedure for the Prow Pass test was very
straightforward, as only one set of tracer peaks was observed. However, because RELAP 
V 2.0
(STN: 10551-2.0-00 [159065]) is based on a semi-analytical Laplace transform inversion
method, it was not capable of simulating the flow transients associated with the flow
interruptions during the latter part of the test. To simulate these transients, the computer 
code
MULTRAN (multicomponent transport) V 1.0 (STN: 10666-1.0-00 [159068]) was used.
MULTRAN is an implicit alternating-direction, two-dimensional (2-D), finite-difference 
code
that accounts for cation exchange (involving up to three exchanging cations), charge 
balance,
and multicomponent diffusion in a dual-porosity transport system (see Section 6.3.9.2.2 
for
details). The best-fitting transport parameters obtained from RELAP fits to the tracer data 
up
until the time of the flow interruptions were used in MULTRAN to extend the 
simulations
throughout the entire test.
Once best simultaneous fits to the nonsorbing tracer responses in both tests were 
obtained, the
lithium responses associated with each distinct tracer peak were fitted with RELAP V 2.0 
(STN:
10551-2.0-00 [159065]) by adjusting Rf and Rm while holding all other parameters equal 
to the
values that provided the best fits to the nonsorbing tracers. However, Dm for lithium was
assumed to be two-thirds that of bromide (and ~2 times that of PFBA), rather than about 
half that
of bromide as indicated in Table 6.3-4, because lithium and bromide would tend to 
diffuse
together to maintain local charge balance. Rate-limited sorption was not considered in the 
field
tests because the response times were all quite long relative to typical rates of ion 
exchange.
ANL-NBS-HS-000039, REV 00 208 December 2003
RELAP V 2.0 (STN: 10551-2.0-00 [159065]) provided a good match to the lithium 
response
associated with the second peak in the Bullfrog test and also to the lithium response in the 
Prow
Pass test. However, in the case of the first peak in the Bullfrog test, RELAP consistently
overestimated the normalized concentrations in the lithium tail when the leading edge of 
the
lithium response was fitted well. The inability to fit the response of an ion-exchanging 
tracer
using a linear equilibrium sorption model (Kd model) had been previously encountered 
when
trying to fit cation responses from both laboratory-scale fracture-transport experiments 
(Section
6.3.9.2) and crushed-rock column experiments (Section 6.3.9.1). In these previous 
studies, it
was observed that cation-exchanging tracers transport with less apparent sorption than Kd 
models
predict when the tracer injection concentration is high relative to the ionic strength of the
groundwater (that is, when the total cation equivalents in the system are dominated by the 
cation
tracer). Under these conditions, some of the cation tracer mass tends to elute with the 
anion
tracers to maintain local charge balance in the system. When tracer concentrations are
sufficiently dilute, local charge balance can be maintained by exchanging cations, and a 
Kd
model tends to approximate more closely the observed transport behavior. In the Bullfrog 
test,
the injection concentration of lithium was ~0.1 M, whereas the ionic strength of the C-
wells
groundwater was ~0.003 M; therefore, the conditions of a very high cation injection
concentration relative to the groundwater ionic strength were met. MULTRAN V1.0 
(STN:
10666-1.0-00 [159068]) provided much better predictions of cation transport data in 
laboratoryscale
dual-porosity systems under these conditions than RELAP because it explicitly accounts
for ion-exchange reactions, multicomponent diffusion, and local charge balance (see 
Section
6.3.9.2.2). For this reason, MULTRAN was employed to match the lithium data in the 
first peak
of the Bullfrog test using the mean residence time, Peclet number, and matrix-diffusion, 
masstransfer
coefficient obtained from the best RELAP fit to the nonsorbing tracer data and allowing
the lithium ion-exchange parameters to be varied to fit the lithium data. Lithium was 
assumed to
exchange with sodium and calcium ions based on the results of cation exchange capacity 
(CEC)
measurements conducted on C-wells tuffs (Section 6.3.7.2).
It should be noted that the relatively low tracer concentrations observed at the production 
well in
the Bullfrog test do not necessarily reflect the concentrations that existed in the fractures 
in
which transport occurred; it is very likely that a significant amount of dilution occurred in 
the
production borehole. Thus, concentrations could have remained quite high in the 
fractures that
conducted tracers, satisfying conditions for weakly-sorbing transport of the lithium ion. 
For the
second lithium peak of the Bullfrog test and for the Prow Pass test, concentrations in the
fractures apparently were dilute enough during the much longer residence times 
associated with
these responses that the lithium transport behavior could be reasonably approximated by 
a Kd
model.
6.3.4.6.2 Colloid Tracers (Microspheres)
As with the solutes, the microsphere responses in the tracer tests were interpreted using 
the
RELAP V 2.0 (STN: 10551-2.0-00 [159065]) code to fit the data. The differential 
equations
used to describe microsphere transport were:
0 = - + - + res filt 2
2
f S k C k
x
C
D
x
C
v
t
C
* 
* 
* 
* 
* 
* ?(Eq. 7)
ANL-NBS-HS-000039, REV 00 209 December 2003
0 = + -
1
res filt S k C k
t
S
b * 
* ?(Eq. 8)
where
C = colloid concentration in solution, no./L
S = colloid concentration on surfaces, no./cm2
vf = flow velocity in fractures, cm/sec
D = dispersion coefficient, cm2/sec
kfilt = filtration rate constant (1/sec) = ?vf, where * = filtration coefficient (1/cm)
kres = resuspension rate constant, 1/cm-sec
x, t = independent variables for distance and time, respectively.
These equations assume that microspheres are confined to fractures because they are too 
large to
diffuse significantly into the porous rock matrix. The RELAP V 2.0 (STN: 10551-2.0-00
[159065]) semi-analytical model is capable of representing Equations 7 and 8 by making 
use of
its rate-limited sorption features and setting the matrix porosity equal to zero (to 
eliminate matrix
diffusion). It was assumed that the mass fractions, mean residence times, and Peclet 
numbers
that provided the best fits to the nonsorbing solute responses also applied to the 
microspheres.
Any size exclusion chromatography effects (Hiemenz 1986 [117358], pp. 42-45) that 
would have
resulted in a shorter mean residence time for the microspheres compared to the solutes 
were
assumed to be accounted for by not allowing the microspheres to diffuse into the matrix. 
Thus,
the only adjustable parameters in the analysis were a forward first-order filtration-rate 
constant
and a first-order reverse-filtration-rate constant (also called a resuspension or 
detachment-rate
constant).
Initially, attempts to fit the microsphere response associated with the first peak in the 
Bullfrog
test were made by assuming only irreversible filtration with no resuspension/detachment.
Although this approach was capable of fitting the timing and normalized concentration of 
the
first microsphere peak, it resulted in a much shorter tail than the data indicated. 
Therefore, to
account for the tail, a small fraction of the filtered microspheres was assumed to detach. 
A fit to
the tail was obtained by adjusting both the fraction of microspheres detaching and the
detachment rate constant (only a single-forward filtration-rate constant was assumed for 
all the
microspheres in the first peak).
A fit to the second microsphere peak in the Bullfrog test was obtained in the same 
manner.
However, in this case, the forward filtration rate constant had to be adjusted large enough 
so that
essentially all of the microspheres were filtered as they moved through the system. This
approach was necessary because any microspheres moving through the system without 
being
filtered were predicted to arrive too early to match the observed response (note that the 
second
microsphere peak occurred after the second nonsorbing solute peaks; see Figure 6.3-20).
Unfiltered microspheres moving through the second set of pathways were predicted to 
arrive at
about the same time as the low point in concentration between the two peaks. Thus, to 
account
for the second microsphere peak, it was necessary to assume that a substantial fraction of 
the
microspheres in the second set of pathways were reversibly filtered. The peak itself was 
fit by
ANL-NBS-HS-000039, REV 00 210 December 2003
assuming a fraction of the microspheres experienced one detachment rate, and the tail 
was fit by
assuming a separate fraction experienced another detachment rate. The remaining 
microspheres
were assumed to not detach at all. This approach implies that there is a distribution of
detachment rate constants, a possibility that has been discussed by Dabros and Ven de 
Ven (1982
[143278], pp. 232 to 244; 1983 [156652], pp. 576 to 579). The forward rate constant 
associated
with each of these mass fractions was set equal to the minimum rate constant necessary to 
ensure
that nearly all of the microspheres were filtered before making it through the system.
In the Prow Pass test, only a single filtration and detachment-rate constant were needed to 
fit the
responses of each microsphere, provided the "spikes" associated with the flow transients 
could
be ignored. No attempt was made to fit these spikes.
6.3.4.7 Tracer Test Interpretations
6.3.4.7.1 Solute Tracers
The best RELAP/MULTRAN fits to the solute tracer breakthrough curves in the Bullfrog 
test are
shown in Figure 6.3-26. As discussed above, RELAP V 2.0 (STN: 10551-2.0-00 
[159065]) was
used to fit the nonsorbing tracer responses and the lithium response in the second peak, 
and
MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) was used to fit the lithium response in 
the first
peak (MULTRAN fits to the bromide and PFBA data are also shown for the first peak in 
Figure
6.3-26). The RELAP fits were obtained assuming a constant production rate of 568 L/min 
and a
constant recirculation rate of 19 L/min (3.3% of production), despite the fact that 
recirculation in
the field test was stopped after 40 days. Both tracer peaks occurred well before 
recirculation was
terminated, so the only portion of the test that was incorrectly modeled was the latter 
tailing
portion of the second peak. Separate simulations comparing the results of MULTRAN 
runs with
and without recirculation after 40 days indicated that the assumption of continued 
recirculation
after 40 days had negligible effect on the fits or the values of the fitted model parameters.
The best-fitting model parameters from RELAP V 2.0 (STN: 10551-2.0-00 [159065]) for 
the
Bullfrog test are listed in Table 6.3-6. Note that separate estimates of * and Pe are 
provided,
depending on whether linear flow (constant flow velocity between injection and 
production well)
or radial flow (flow velocity inversely proportional to distance from production well) is 
assumed
to occur in the test interval. RELAP is capable of providing estimates for these 
parameters under
either assumption (the quality of the fits and the other model parameters are not affected). 
In a
heterogeneous, confined aquifer with fully-penetrating wells (i.e., no flow in the vertical
direction), the flow velocity to a single production well with no recirculation into an 
injection
well is expected to vary between linear and radial (National Research Council 1996 
[139151],
pp. 252 to 261). Thus, if it is assumed that the test interval was reasonably confined, 
presenting
the two values of * and Pe in Table 6.3-6 is a rough way of bounding these model 
parameter
estimates as a result of flow-field uncertainty. Although the Bullfrog flow system was not
perfectly confined, this approach should still yield reasonable bounds for * and Pe, as the 
flow
velocities in pathways carrying tracers from c#2 to c#3 should have started out relatively 
high
due to the recirculation into c#2, gone through a minimum, and then increased again in 
the
vicinity of c#3. Thus, the weak dipole should have resulted in a flow pattern that was
intermediate between linear and radial flow.
ANL-NBS-HS-000039, REV 00 211 December 2003
DTN: LA0007PR831231.001 [156043] (data). Output DTN: LA0303PR831231.003 (model).
Sources: Reimus (2000 [162855]), Reimus (2003 [165129], including Attachment A).
NOTE: The upper plot shows individual fits to first and second tracer peaks (MULTRAN V 1.0 (STN: 10666-
1.0-00
[159068]) and RELAP V 2.0 (STN: 10551-2.0-00 [159065], respectively), and the lower plot shows
composite fits. For clarity, the data points shown are a subset of the actual data. The best-fitting model
parameters are provided in Table 6.3-6.
Figure 6.3-26. RELAP and MULTRAN Fits to the Tracer Response Curves
in the Bullfrog Tuff Tracer Test
0.1
1
10
100
10 100 1000 10000
Time, hrs
Normalized Concentration, 10^9/L
PFBA
Br
Li
0.1
1
10
100
10 100 1000 10000
Time, hrs
Normalized Concentration, 10^9/L
PFBA
Br
Li
ANL-NBS-HS-000039, REV 00 212 December 2003
Table 6.3-6. RELAP Model Parameters Providing the Best Fits to the Bullfrog Tracer Test Data
Parameter Pathway 1 Pathway 2
Mass fraction, f 0.115 0.60
Mean residence time, * , for linear flow (hr) 36 1020
Peclet number, Pe, for linear flow 6.5 1.6
Mean residence time, * , for radial flow (hr) 30 630
Peclet number, Pe, for radial flow 9.3 2.8
?
b
Dm for bromide (sec-1/2) (a) 0.0015 0.000469
Fracture spacing (cm) * ?(2.4) (b) 4.4
Lithium fracture retardation factor, Rf 1 4
Lithium matrix retardation factor, Rm 7.5 (c) 20
Output DTNs: LA0303PR831231.003; LA0303PR831231.005.
NOTE: Pathway 1 and Pathway 2 are associated with the first and second tracer peaks, respectively. The 
fits are
shown in Figure 6.3-26 (MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) was used to fit first lithium peak in
Figure 6.3-26).
(a) The mass transfer coefficient, MTC = m D
b
?
, for PFBA is 0.577 times that for bromide.
(b) The number in parentheses is the minimum fracture spacing that yields the same results as an infinite
fracture spacing.
(c) Lithium response associated with first tracer peak was poorly fitted by RELAP V 2.0 (STN: 10551-2.0-
00 [159065]), so MULTRAN was used to obtain a better fit, which is shown in Figure 6.3-26.
Figure 6.3-27 shows the best RELAP/MULTRAN fits to the Prow Pass solute tracer test 
data,
and Table 6.3-7 gives the best-fitting RELAP V 2.0 (STN: 10551-2.0-00 [159065]) 
model
parameters (obtained by simulating the first 1200 hr of the test, prior to the first flow
interruption). MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) was used after the first 
flow
interruption to model the remainder of the test using the best-fitting parameters from 
RELAP to
extend the simulations. Because the tracer concentrations were significantly higher in this 
test
than in the Bullfrog test, it was possible to determine the responses of the cations (sodium 
and
calcium) that exchanged with lithium during the test. (The background concentrations of 
the
exchanging cations were too high relative to their signals in the Bullfrog test to determine 
their
responses.) Figure 6.3-28 shows the responses of lithium, sodium, and calcium ions in the 
Prow
Pass test, expressed as meq/L versus time. MULTRAN fits to the data are also included 
in
Figure 6.3-28. Although not shown here, it was confirmed that the total cation and anion 
charges
balanced each other, as they must, throughout the test.
ANL-NBS-HS-000039, REV 00 213 December 2003
DTN: LAPR831231AQ99.001 [140134] (data). Output DTN: LA0303PR831231.003 (model).
Sources: Reimus (2000 [162852]), Reimus (2003 [165129], including Attachment A).
NOTE: The best-fitting model parameters are provided in Table 6.3-7.
Figure 6.3-27. RELAP/MULTRAN Fits to the Tracer Response Curves in the Prow Pass Tuff 
Tracer Test
0
100
200
300
400
500
0 500 1000 1500 2000 2500 3000
Time, hrs
Norm. Conc., ?
?g/L per kg injected
PFBA
Br
Li
ANL-NBS-HS-000039, REV 00 214 December 2003
Table 6.3-7. RELAP Model Parameters Providing the Best Fits to the First
1200 Hours of Prow Pass Tracer Test Data
Parameter Parameter Value
Mass fraction, f 0.72
Mean residence time, * , for linear flow (hr) 1210
Peclet number, Pe, for linear flow 1.3 (a)
Mean residence time, * , for radial flow (hr) 610
Peclet number, Pe, for radial flow 2.3 (a)
m D
b
?
for bromide (sec-1/2) (b) 0.00095
Fracture spacing (cm) * ?(6.4) (c)
Lithium fracture retardation factor, Rf 1
Lithium matrix retardation factor, Rm 12
Output DTNs: LA0303PR831231.003; LA0303PR831231.005.
NOTE: The fits (extended by MULTRAN V 1.0 (STN: 10666-1.0-00 [159068) simulations) are shown in 
Figure 6.3-
27.
(a) The Peclet numbers were adjusted to correct for the theoretical dispersion caused by the partial
recirculation flow field (see text). Peclet numbers obtained directly from RELAP V 2.0 (STN: 10551-2.0-
00 [159065]) were 0.9 (linear flow) and 1.9 (radial flow).
(b) The mass transfer coefficient, MTC = m D
b
?
, for PFBA is 0.577 times that for bromide.
(c) The number in parentheses is the minimum fracture spacing that yields the same results as infinite
fracture spacing.
ANL-NBS-HS-000039, REV 00 215 December 2003
DTN: LAPR831231AQ99.001 [140134] (data); Output DTN: LA0303PR831231.003 (model).
Sources: Reimus (2000 [162852]), Reimus (2003 [165129], including Attachment A).
NOTE: Scatter for sodium is due to the background, which has been subtracted, being large relative to the 
signal.
Figure 6.3-28. MULTRAN Fits to Cation Responses in the Prow Pass Tracer Test
6.3.4.7.2 Colloid Tracers (Microspheres)
The fit(s) to the Bullfrog test microsphere data are shown in Figure 6.3-29. The 
"pathways"
labeled 1A and 1B represent the nondetaching (or very slowly detaching) and detaching
fractions, respectively, of the microspheres following the pathway(s) that resulted in the 
first
solute peak. Pathways 2A, 2B, and 2C in Figure 6.3-29 represent the nondetaching (or 
very
slowly detaching) and the two detaching fractions of the microspheres following the 
pathway(s)
that resulted in the second solute peak. The fitted mass fractions and filtration parameters
associated with the "subpathways" in Figure 6.3-29 are given in Table 6.3-8.
0
0.1
0.2
0.3
0.4
0.5
0.6
0 500 1000 1500 2000 2500 3000
Time, hrs
meq/L
Na
Ca
Li
ANL-NBS-HS-000039, REV 00 216 December 2003
Note that the predicted first arrival of microspheres precedes their actual first arrival by 2 
to 3 hr.
This result can be attributed to the fact that a 4-hr delay was not assumed for the injection 
of
microspheres into the pathways that resulted in the first tracer peaks (as it was for the 
solutes).
No delay was assumed for the microspheres because the microsphere injection began 
about 3.5
hr after the solutes were injected. If the solutes did not begin entering the pathways 
resulting in
the first tracer peaks until after the microspheres were injected, then it would be 
reasonable to
assume that the microspheres should have entered those pathways at the same time as the 
solutes.
DTN: LA0007PR831231.001 [156043] (data). Output DTN: LA0303PR831231.003 (model).
Sources: Reimus (2000 [165125]), Reimus (2000 [162855]), Reimus (2003 [165129], including Attachment A).
NOTE: Diamonds are microsphere data points. Numbers followed by letters indicate flow pathways 
discussed in
text and listed in Table 6.3-8. Bold line is the sum of all the pathways.
Figure 6.3-29. RELAP Fits to CML Microsphere
Response in Bullfrog Tuff Tracer Test
0.01
0.1
1
10
10 100 1000 10000
Time, hrs
Norm. Conc., ?
?gL per kg injected
1A
1B
2A
2B
2C
2A
ANL-NBS-HS-000039, REV 00 217 December 2003
Table 6.3-8. Microsphere Filtration and Detachment Parameters
Associated with the Fits Shown in Figure 6.3-29
Parameter Path 1A Path 1B Path 2A Path 2B Path 2C
Mass fraction, f 0.111 0.004 0.42 0.07 0.11
kfilt (1/hr) 0.175 0.175 0.04 0.04 0.04
?
vaw (1/cm) 0.0017 0.0017 0.0084 0.0084 0.0084
bkres
vbw (1/cm-hr) 0.000219vcw 1.08 0.000201cw 0.211 0.00755
Output DTNs: LA0303PR831231.003; LA0303PR831231.005.
NOTE: Other transport parameters used to obtain the fits are given in Table 6.3-6. Note that subpathways 
1A and
1B represent a mass fraction split of Pathway 1 from Table 6.3-6, and subpathways 2A, 2B, and 2C
represent a mass fraction split of Pathway 2 from Table 6.3-6.
(a) * calculated as kfilt/vf, where vf = average linear velocity determined from mean fluid residence time.
(b) b = fracture half aperture in cm. The fitted detachment rate constant is this lumped parameter.
(c) Maximum detachment rate constant; cannot distinguish between this value and zero, so microspheres
could be very slowly detaching or not detaching at all.
However, if the microspheres experienced a delay similar to the solutes, then their 
predicted first
arrival would actually be slightly later than the observed first arrival. In fact, in this case, 
the
first arrival would coincide almost exactly with the first arrival of solutes. Thus, the 
uncertainty
associated with when the microspheres actually began entering the flow system causes
uncertainty in the predicted first arrival of the microspheres.
The fits to the Prow Pass test microsphere data are shown in Figure 6.3-30, and the
corresponding best-fitting filtration and detachment rate constants are listed in Table 6.3-
9. The
fits suggest that the small peaks in this test were the result of a very small fraction of
microspheres that moved through the flow system unfiltered, and the long tails were the 
result of
small detachment rate constants. The filtration-rate constant listed in Table 6.3-9 for the 
280-
nm-diameter yellow microspheres was not obtained from fitting, but rather it was the 
smallest
filtration coefficient that resulted in a peak concentration of microspheres that was at or 
below
detection limits. This number can be considered a lower-bound estimate of the 
yellowmicrosphere
filtration coefficient because any larger value will result in more filtration and an
even lower recovery. Unlike the Bullfrog test, only a single filtration and detachment rate
constant were needed to effectively fit the microsphere responses in the Prow Pass test. 
As
mentioned in Section 6.3.4.6.2, no attempt was made to fit the "spikes" in microsphere
concentration that occurred after flow transients.
It should be pointed out that the interpretations of the microsphere responses presented in 
the
preceding paragraphs, particularly for the Bullfrog test, are by no means unique. First, it 
is quite
likely that there exists a continuous distribution of filtration and detachment rate 
constants rather
than a few discrete ones, as assumed in the above analyses. Such a distribution could 
arise from
a distribution of colloid surface properties and/or physical and chemical heterogeneities 
in
fracture surfaces (Dabros and Van de Ven 1982 [143278], pp. 232 to 244; 1983 [156652], 
pp.
576 to 579). It is also possible that colloid filtration and detachment are not linear first-
order
processes as assumed in Equations 7 and 8. Rather, they might be better described as 
nonlinear
and/or stochastic processes. Finally, as mentioned above, the interpretation of the 
microsphere
ANL-NBS-HS-000039, REV 00 218 December 2003
response relative to the solutes is complicated by the fact that, with the exception of the 
280-nmdiameter
yellow microspheres in the Prow Pass test, the microsphere injections were not started
at exactly the same times as the solute injections. In addition to causing uncertainty as to 
when
the microspheres actually began moving into flow pathways (relative to the solutes), the
differences in injection times may have resulted in the microspheres not being distributed 
into
flow pathways in exactly the same proportion as the solutes (i.e., a different source term). 
If
different assumptions were made about the distribution of microspheres between the two 
major
sets of pathways in the Bullfrog test, different filtration parameters would be obtained.
DTN: LAPR831231AQ99.001 [140134] (data). Output DTN: LA0303PR831231.003 (model).
Sources: Reimus (2000 [165125]), Reimus (2000 [162852]), Reimus (2003 [165129], including Attachment A).
NOTE: The jagged appearance of the fits starting at ~1000 hr is the result of instabilities in the Laplace 
transform
inversion algorithm of RELAP V 2.0 (STN: 10551-2.0-00 [159065]). "Spheres" in the legend refers to CML
microspheres.
Figure 6.3-30. RELAP Fits to the CML Microsphere
Responses in the Prow Pass Tracer Test
0.1
1
10
100
0 300 600 900 1200 1500 1800 2100 2400 2700 3000
Time, hr
Norm. Conc., ?
?g/L per kg injected
640-nm Spheres
640-nm Fit
280-nm Spheres
280-nm Fit
ANL-NBS-HS-000039, REV 00 219 December 2003
Table 6.3-9. Filtration and Detachment Rate Constants for the CML Microspheres
in the Prow Pass Tuff Tracer Test
Microspheres
Parameter 640-nm Blue 280-nm Orange 280-nm Yellow
kfilt (1/hr) 0.043 0.07 0.2(a)
* (1/cm) 0.0087 0.014 0.041
bkres
(b) (1/hr) 0.000154 0.000251 0.0002
Output DTN: LA0303PR831231.003.
NOTE: Mass fractions are assumed to be the same as for solutes (Table 6.3-7).
(a) Minimum value that is consistent with the lack of appearance of these spheres at the production well.
The actual filtration rate constant could be much higher.
(b) Maximum values; cannot distinguish between these values and zero. See also footnote (b) of Table
6.3-8.
6.3.4.8 Discussion of Field Tracer Test Results
Estimates of transport parameters that can be used directly in solute transport models 
were
derived from the best-fitting model parameters in Tables 6.3-6 and 6.3-7. These 
parameter
estimates are presented in Table 6.3-10 as ranges of values that are consistent with the 
tracer test
interpretation(s). Additional discussion of these ranges and how they were derived is 
provided in
the following sections. This parameter estimation exercise has several important 
implications for
radionuclide transport in fractured volcanic tuffs near Yucca Mountain.
Table 6.3-10. Transport Parameter Estimates Deduced from the Bullfrog
and Prow Pass Multiple-Tracer Tests
Prow Pass Bullfrog
Parameter
Lower Bound Upper Bound Lower Bound Upper Bound
Effective flow porosity (from eq. 22) 0.003 0.006 0.003 (a) 0.031 (a)
Longitudinal dispersivity, m (b) 13.0 61.5 3.2 62.5
MTC,
?
b
Dm , for radionuclides (sec-1/2) (c) 0.00054 0.00095 0.00027 0.0015
Fracture aperture (cm) 0.18 1.05 0.081 1.31
Fracture spacing (cm) 6.4 * ?4.4 * 
Ratio of stagnant to flowing water volumes 3.1 * ?2.1 * 
Output DTN: LA0303PR831231.005.
NOTE: These values above are provided as ranges of values; see text for explanations.
(a) These estimates assume that 75% of the production flow was associated with flow pathways that
resulted in the first tracer peak and 25% was associated with the second tracer peak (based on flow
survey information (DTN: GS930908312313.008 [166332]), MOL.19951115.0127 through
MOL.19951115.0131; see Figure 6.1-2).
(b) Lower bounds assume Peclet numbers for radial flow and 30-m travel distance; upper bounds assume
Peclet numbers for linear flow and interval thicknesses as travel distances (see Table 6.1-1 for actual
borehole separations and interval thicknesses; also DTN: GS030508312314.003 [164425]), p. 6,
Table 1).
(c) Assumes that bromide and PFBA effectively bound molecular sizes and diffusion coefficients of
radionuclide solution species.
ANL-NBS-HS-000039, REV 00 220 December 2003
6.3.4.8.1 Conceptual Transport Model
Even without quantitative parameter estimation, it is clear that the tracer responses in 
both the
Bullfrog and Prow Pass tests are consistent with a dual-porosity conceptual transport 
model for
the fractured volcanic tuffs. It is simply not possible to account for the differences in the
bromide and PFBA responses or the relatively small time attenuation but significant
concentration attenuation of the lithium response relative to the nonsorbing tracers (in the 
Prow
Pass test and the first peak of the Bullfrog test) without invoking diffusion between 
flowing
fractures and stagnant matrix water. Some diffusion into stagnant water within fractures 
(e.g.,
dead-end fractures or along rough fracture walls) cannot be ruled out. However, if the 
stagnant
water were primarily in fractures, the surface area for sorption would be limited, and it is
unlikely that there would be as much concentration attenuation of lithium relative to the
nonsorbing solutes as observed in the tracer tests. The large surface-area-to-volume ratio
necessary to result in the large observed concentration attenuation of lithium seems 
plausible
only if a significant fraction of the stagnant water is in matrix pores.
The quantitative estimates of the lumped mass transfer parameter m D
b
?
for bromide in Tables
6.3-6 and 6.3-7 are based on the assumption that bromide has a diffusion coefficient that 
is a
factor of three greater than PFBA. This assumption is based on matrix diffusion 
coefficients
measured in laboratory diffusion cell tests, which are discussed in Section 6.3.8. It is 
worth
noting that RELAP V 2.0 (STN: 10551-2.0-00 [159065]) simulations in which a finite 
matrix
was assumed (i.e., a finite spacing between fractures) offered a slightly better fit to the 
tracer
responses associated with the second peak of the Bullfrog test than simulations assuming 
an
infinite matrix. This result suggests that tracer molecules may have diffused far enough 
into the
matrix to begin encountering molecules from neighboring fractures, which implies a 
relatively
small fracture spacing. Alternatively, the tracers may have encountered diffusion 
boundaries
(no-flux boundaries) within the matrix, which implies a significant increase in tortuosity 
or a
decrease in interconnected porosity at some distance into the matrix from fracture 
surfaces. For
the first peak in the Bullfrog test and for the Prow Pass test, a finite matrix offered no 
better fits
to the tracer data than an infinite matrix. In these cases, it can only be stated that the 
fracture
spacing must have exceeded some threshold value below which the tracer responses 
would have
been significantly different than observed. The applicable threshold values for the first 
Bullfrog
test peak and for the Prow Pass test were estimated by adjusting the fracture spacing in 
RELAP
until the simulated tracer responses began to differ significantly from the simulated 
responses
assuming an infinite matrix. The results are presented in Table 6.3-10 as lower bounds for
fracture spacing.
The tracer responses and the qualitative and quantitative conclusions about matrix 
diffusion that
can be drawn from them illustrate very clearly the advantages of using multiple 
nonsorbing
tracers with different diffusion coefficients in tracer tests to distinguish between 
alternative
conceptual transport models. The individual responses of either bromide or PFBA could 
have
been fit reasonably well assuming no matrix diffusion at all. Only when the responses of 
these
tracers are considered together is it obvious that diffusive mass transfer must be invoked 
to
explain the test results. Even long tails that plot linearly on log-log plots of tracer 
responses
(power-law behavior), which are often said to infer matrix diffusion when single tracer 
responses
are analyzed (Haggerty et al. 2000 [156832], pp. 3467 to 3469), do not unequivocally
ANL-NBS-HS-000039, REV 00 221 December 2003
substantiate diffusive mass transfer. Such responses can also be attributed to 
hydrodynamic
dispersion that scales with residence time (due to the recirculating flow field or effects of
density-driven flow), stagnation points, and/or source-term effects (e.g., the slow release 
of
tracers from the injection borehole). Furthermore, the fact that the lithium responses were
significantly attenuated in concentration but not in time supports the concept that a 
significant
amount of diffusion occurred into the matrix pores and not simply into stagnant water 
within the
fracture network. This conclusion is very important for Yucca Mountain performance
assessment because mass transfer between flowing fractures and the true matrix implies 
that a
large amount of surface area will be available for sorption of radionuclides in the 
saturated,
fractured tuffs.
6.3.4.8.2 Fracture Apertures
An estimate of the average fracture aperture (2b) experienced by the tracers in the 
Bullfrog and
Prow Pass tests can be obtained from the estimate of the lumped, diffusive, mass-transfer
parameter, m D
b
?
, provided independent estimates of matrix porosity, ?, and matrix diffusion
coefficients, Dm, are available. Using estimates of * determined from laboratory 
measurements
and Dm for bromide and PFBA from diffusion cell tests (Section 6.3.8), estimates of 2b 
range
from 0.081 to 1.31 cm in the Bullfrog Tuff and from 0.18 to 1.05 cm in the Prow Pass 
Tuff, as
listed in Table 6.3-10. Because the long tracer test intervals in each test both included 
more than
one major lithology (Figure 6.1-2), it was necessary to estimate 2b for each major 
lithologic unit
in each interval. The fact that there is a positive correlation between matrix porosity and 
matrix
diffusion coefficient results in a relatively large range of aperture estimates. If it is 
assumed that
the flow pathways associated with the first tracer peak in the Bullfrog test were in the 
central
Bullfrog unit and the pathways associated with the second tracer peak were in the lower 
Bullfrog
unit, then the aperture estimates in these two units correspond to the two extremes listed 
in Table
6.3-10. These aperture estimates based on tracer responses should be distinguished from 
friction
loss or cubic-law aperture estimates that are obtained from hydraulic responses (Tsang 
1992
[113901], pp. 1451 to 1455), although they should be the most appropriate aperture 
estimates to
use for transport calculations.
6.3.4.8.3 Ratios of Stagnant Water to Flowing Water Volumes
Estimates of the ratio of stagnant water volume to flowing water volume in the flow 
system(s)
can be calculated from estimates of fracture spacings obtained from RELAP V 2.0 (STN: 
10551-
2.0-00 [159065]) simulations and the matrix porosities and fracture apertures used in the 
RELAP
simulations (ratio = * L/2b - 1)). Ranges of these estimates are listed in Table 6.3-10. The
upper-bound ratios for both tracer tests are listed as infinite because all tracer responses 
could be
fitted reasonably well, assuming infinite fracture spacing. The lower bounds in Table 6.3-
10
were obtained using fracture spacings that yielded slightly better fits to the tracer 
responses than
the fits obtained assuming an infinite fracture spacing. These ratios plus one can be 
considered
physical retardation factors for nonsorbing species in the flow system when flow rates are 
low
enough that there is ample time for solutes to diffuse throughout the stagnant water in the 
system
(Robinson 1994 [101154]).
ANL-NBS-HS-000039, REV 00 222 December 2003
6.3.4.8.4 Lithium Sorption Behavior
Tables 6.3-6 and 6.3-7 list the best-fitting values of the lithium fracture and matrix 
retardation
factors (Rf and Rm, respectively) for the Bullfrog and Prow Pass tests. Note that the Rf 
values are
1 for both the Prow Pass test and for the first peak in the Bullfrog test, implying 
negligible
retardation within the fractures and sorption only in the matrix. Note that a fracture 
retardation
factor of 1 does not necessarily imply that sorption did not occur on fracture surfaces; it 
merely
suggests that the majority of the lithium sorption occurred after a diffusive mass-transfer 
step to
sorptive surfaces in the matrix. For the second peak in the Bullfrog test, the lithium 
response
was best fitted with Rf = 4 and Rm = 20, implying some sorption in fractures and a large 
amount
of sorption in the matrix.
Matrix Kd values were deduced from the fitted matrix retardation factors by simple
rearrangement of the expression defining the retardation factor:
* ?1 - m
B
d R K
?
* * (Eq. 9)
Because the Kd values depend on the matrix porosity, values are listed in Table 6.3-11 for 
each
lithologic unit that transport may have occurred in for each test (matrix porosities from 
Section
6.3.8 were used in Equation 9). For a given retardation factor, the corresponding Kd value 
is
always higher in a unit with higher matrix porosity. The Rm value associated with the first
lithium peak in the Bullfrog test (Table 6.3-6) was obtained by fitting the rising limb of 
the
lithium response using RELAP V 2.0 (STN: 10551-2.0-00 [159065]). However, because 
it was
necessary to use MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) to achieve a 
reasonable fit to
the tail of the response (see above), the Kd value for this peak was estimated from the 
ionexchange
parameters that yielded the best fit to the lithium data (see Section 6.3.9.1.3) rather
than from the Rm value obtained from RELAP. The best-fitting, ion-exchange parameters
suggested a nonlinear sorption isotherm for lithium in the matrix; hence, Kd values are 
reported
in Table 6.3-11 for lithium concentrations of both ~600 mg/L (low Kd value) and ~0.5 
mg/L
(high Kd value). This range of concentrations should reasonably bound the concentrations
experienced in the field test.
Laboratory batch measurements of lithium sorption onto crushed tuff from C-wells cores
indicated a dependence of Kd values on both lithium concentrations and the mineralogy
associated with the different lithologies (see Section 6.3.7). The concentration 
dependence in
each case could be represented by a classic nonlinear isotherm in which Kd values 
decreased as
lithium solution concentrations increased. There was also a strong dependence of lithium 
Kd
values on the smectite and zeolite content of the tuffs (Anghel et al. 2002 [164635], pp. 
822-824,
Section 3.2). The range of laboratory-derived Kd values associated with each unit that 
could
have participated in the Bullfrog and Prow Pass tests is listed in Table 6.3-11 next to each
corresponding field-derived Kd value.
ANL-NBS-HS-000039, REV 00 223 December 2003
Table 6.3-11. Lithium Partition Coefficients Derived from Field Tracer Tests and Laboratory
Measurements
Parameter Field Kd (ml/g) Laboratory Kd
(a) (ml/g)
Prow Pass matrix Kd assuming Central Prow Pass Tuff 0.66 0.13
(0.26 at infinite dilution)
Prow Pass matrix Kd assuming Lower Prow Pass Tuff 1.68 0.084
(0.44 at infinite dilution)
Bullfrog matrix Kd in Pathway 1 assuming Central Bullfrog
Tuff (b) 0.58-4.1 (nonlinear) (c) 0.19
(0.44 at infinite dilution)
Bullfrog matrix Kd in Pathway 1 assuming Lower Bullfrog
Tuff (b) 0.58-4.1 (nonlinear) (c) 0.32
(1.64 at infinite dilution)
Bullfrog matrix Kd in Pathway 2 assuming Central Bullfrog
Tuff (b) 0.74 0.19
(0.44 at infinite dilution)
Bullfrog matrix Kd in Pathway 2 assuming Lower Bullfrog
Tuff (b)
3.04 0.32
(1.64 at infinite dilution)
Output DTN: LA0303PR831231.005.
NOTE: These lithium partition coefficients (Kd values) were derived from field tracer tests assuming transport 
in
different lithologies within the test intervals.
(a) Values at "infinite dilution" obtained from Langmuir isotherm fits to the data (asymptotic slope at very
low concentrations (i.e., KLSmax - see Section 6.3.7.2 for definitions). Other values obtained from a
simple linear fit to the entire range of data.
(b) "Pathway 1" refers to pathways that resulted in the first tracer peak in the Bullfrog reactive tracer test,
and "Pathway 2" refers to pathways that resulted in the second peak in this test. Kd values were
calculated from the smallest matrix retardation factors obtained from alternative interpretations of the
test.
(c) The first number corresponds to a Kd value calculated at ~600 mg/L Li+ using the three-component
cation exchange model parameters yielding the best fit to the first lithium peak (see Section 6.3.9.1.3 for
description of three-component model); the second number corresponds to a Kd value calculated at 0.5
mg/L Li+ concentration using the same model parameters. In obtaining the field parameters, a matrix
porosity of 0.10 was assumed in the MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) simulations
(approximately equal to that of the Central Bullfrog Tuff). The Kd values for pathway 1 would increase if
a greater matrix porosity was assumed, and they would decrease if a smaller matrix porosity was
assumed.
ANL-NBS-HS-000039, REV 00 224 December 2003
The lithium Kd values deduced from the field tracer tests (assuming any given lithologic 
unit) are
consistently higher than the corresponding Kd values measured at the lowest lithium
concentrations in the laboratory. These results suggest that the use of laboratory-derived 
Kd
values to predict sorbing species transport in the saturated fractured tuffs near the C-wells
location would tend to underpredict the amount of sorption experienced by the species in 
the
field. The fact that the field Kd values tended to be greater than the laboratory Kd values 
suggests
that lithium may have come into contact with alteration minerals in the field that were not
present or were depleted in the lab rock samples. Any loosely adhering alteration 
minerals (e.g.,
clays) that may have been present in the core samples would very likely have been lost 
during
crushing and wet sieving of the material when it was prepared for the batch sorption
experiments.
6.3.4.8.5 Effective Flow Porosity
Contaminant transport predictions are generally very sensitive to assumed flow porosities
because transport rates are directly proportional to the specific discharge divided by flow
porosity. The effective flow porosity in a cross-hole tracer test without recirculation can 
be
estimated from the following equation, which assumes a steady-state, 2-D (confined with 
fullypenetrating
well), homogeneous and isotropic flow system (Guimera and Carrera 2000 [156830],
Equation 6):
T r
Q
2
L
?
* * ?(Eq. 10)
where
* = effective flow porosity
Q = production flow rate, m3/hr
* = mean residence or travel time, hr
rL = distance between wells, m
T = formation thickness (assumed to be interval length).
With recirculation, the situation is complicated by the fact that there is a hypothetical 
stagnation
point; hence, the mean tracer residence time theoretically approaches infinity. However, 
the
interpretive method described in this report allows for incomplete tracer mass recoveries 
that
could result from stagnation, so a finite estimate of the mean tracer residence time can 
always be
obtained. Guimera and Carrera (2000 [156830]) discuss an alternative method of 
estimating
effective flow porosity from peak, rather than mean, tracer arrival times in tests with 
partial
recirculation. However, their method was derived for system Peclet numbers (rL/ ?) 
ranging
from 10 to 100, which are considerably larger than the Peclet numbers obtained in the C-
wells
multiple-tracer tests (1.3 to 9.3); therefore, their method was not applied here.
For the mean tracer arrival times and flow conditions in the C-wells tracer tests, Table 
6.3-10
gives the effective flow porosities calculated using Equation 10 for the Bullfrog and Prow 
Pass
tests. The upper and lower bounds given in Table 6.3-10 were calculated using the mean 
tracer
residence times calculated assuming linear and radial flow, respectively (values in Tables 
6.3-6
and 6.3-7). Also, in the Bullfrog test, it was assumed that 75% of the total production 
flow rate
ANL-NBS-HS-000039, REV 00 225 December 2003
was associated with the first tracer peak and 25% was associated with the second tracer 
peak
(based on flow survey information suggesting that a large amount of flow occurred in the 
upper
part of the injection interval in c#2 (DTN: GS030508312314.003 [164425], p. 6, Table 1; 
see
Figure 6.1-2).
The relatively large effective porosity estimates obtained from Equation 10 could be due 
to
heterogeneities in the flow field. Flow is undoubtedly not radial, as assumed in the above
equations, but rather it very likely follows tortuous pathways between the injection and
production wells. Furthermore, it is conceivable that a single high-conductivity feature 
such as a
large, open fracture or fault could transmit the vast majority of the flow to the production 
well.
If this feature does not pass near the injection well, the effective flow rate drawing tracers 
to the
production well will be greatly reduced relative to what would occur in a radial flow 
field.
6.3.4.8.6 Longitudinal Dispersivity
Longitudinal dispersivity estimates from cross-hole tracer tests generally have 
considerable
uncertainty due to (1) uncertainty in the actual tracer transport distance (the actual flow 
pathways
followed by tracers are unknown), (2) whether the flow field is radial, linear, or some
combination, (3) the amount of apparent dispersion caused by nonidealities such as a 
poorly
mixed injection wellbore or density/buoyancy effects, and (4) the amount of apparent 
dispersion
caused by recirculation or the ambient flow field. It is beyond the scope of this report to 
address
in detail the possible effects of each of these uncertainties on the longitudinal dispersivity
estimates provided in Table 6.3-10. These estimates can be considered "upper and lower
bounds" that were obtained as follows.
1. The maximum transport distance, rL, was assumed to be the distance from the top of
one packed-off interval in the production well to the bottom of the packed-off interval
in the injection well (80 to 100 m) while the minimum transport distance was
assumed to be the linear distance between the wells (~30 m).
2. The radial and linear Peclet numbers were used to obtain estimates of the dispersivity
for the two cases above ( * = rL/Pe), and the most extreme values were used for the
upper and lower bounds.
3. The RELAP V 2.0 code (STN: 10551-2.0-00 [159065]) simulated a gradual release of
tracer from the borehole to the formation by assuming a well-mixed interval, resulting
in an exponential decay in tracer concentration in the wellbore. The decay time
constant was determined from the volume of the packed-off interval divided by the
injection/recirculation rate. Thus, the slow release of tracers from the injection well
did not bias the dispersivity (or mean residence time) estimates.
4. An attempt to "subtract out" the apparent dispersion caused by recirculation in the
Prow Pass test was made by the following (Reimus 2003 [165129], pp. 123 to 129).
a. Obtaining a simulated tracer response for a cross-hole test with the
appropriate amount of recirculation in a homogeneous, isotropic medium
using the 2WELLS_2D V 1.0 computer code (STN: 10665-1.0-00 [159067]).
ANL-NBS-HS-000039, REV 00 226 December 2003
b. Calculating the variance of the particle residence times in (a).
c. Calculating the variance of tracer response in the actual field test from
Pe
2
2 2
* * * where * ?is the variance.
d. Subtracting the variance in (b) from the variance in (c) to obtain the variance
due to "true hydrodynamic dispersion", ?T, in the flow system (this assumes
that the variance due to recirculation and the variance due to true dispersion
are additive, which assumes that the two processes giving rise to the total
variance are independent).
e. Rearranging the above expression to obtain the Peclet number and, hence,
dispersivity, that represents true hydrodynamic dispersion; i.e., ?
?
?
T
Pe
?
* 2 .
Corrections for dispersion caused by recirculation in the Bullfrog test were assumed to be
negligible because 2WELLS_2D V 1.0 (STN: 10665-1.0-00 [159067]) simulations 
indicated that
the variance in tracer travel times for 3.5% recirculation was very small (Reimus 2003 
[165129],
Attachment A). No attempt was made to account for density/buoyancy effects or the 
effects of
the ambient flow field on the longitudinal dispersivity estimates.
6.3.4.8.7 Colloid Transport
The microsphere filtration and detachment rate constants deduced from the Bullfrog and 
Prow
Pass tracer tests can potentially be used as estimates of filtration and detachment rate 
constants
for natural colloids that could facilitate the transport of radionuclides that are strongly 
adsorbed
to colloids. However, it must be kept in mind that the CML microspheres do not have the 
same
physical and chemical properties as natural inorganic colloids (see the revision of the SZ 
colloid
transport report, BSC 2003 [162729], Section 6.8). The revision to the SZ colloid 
transport
report summarizes laboratory experiments (BSC 2002 [162729], Section 6.8), in which it 
was
shown that 330-nm-diameter CML microspheres transported with the same attenuation or 
less
attenuation through saturated fractures than 100-nm-diameter silica spheres, suggesting 
that
microsphere filtration and detachment rate constants may be conservative if used to 
predict silica
colloid transport in fractured media.
Perhaps of greater importance than the microsphere filtration and detachment rate 
constants
derived from the field tests is the fact that the microsphere responses qualitatively 
indicate that
(1) colloid detachment from fracture surfaces is a process that clearly occurs in fractured 
tuffs,
and (2) colloid detachment is apparently enhanced by flow transients. These qualitative 
results
suggest that it is not sufficient to consider only colloid filtration when assessing 
colloidfacilitated
radionuclide transport, but that colloid detachment and its dependence on other
variables must also be considered and could actually dominate the transport behavior of 
colloids.
ANL-NBS-HS-000039, REV 00 227 December 2003
6.3.5 Limitations and Uncertainties Associated with Transport Parameter Estimates
6.3.5.1 Limitations and Uncertainties Inherent in Tracer Testing
Several factors contributed to the uncertainty in transport parameters derived from tracer 
test
interpretations. First, there are data uncertainties, which are related to the accuracy and 
precision
of the tracer chemical analyses, including both random and systematic errors. Random 
errors
were estimated to be small because the breakthrough-curve data are not widely scattered 
and
show well-defined trends. The most significant sources of systematic errors would have 
been
day-to-day differences in analytical instrument operation and in analytical standard 
preparation
over extended periods of time. However, repeat measurements on separate days indicate 
that
these errors were also minimal.
During the iodide tracer test in the Bullfrog-Tram interval (February to April 1996), the 
pump
gradually failed, resulting in a decreasing flow rate during the test, which changed from 
526
L/min (139 gpm) at the beginning to 371 L/min (98 gpm) at the end (Umari 2002 
[162858],
Binder 5, Section G-10, pp. 65 to 77). This violated the assumption of a steady-state flow 
field
in the Moench (1989 [101146]) semi-analytic method employed to analyze the tracer test 
results.
This source of uncertainty was eliminated for subsequent tests by replacing the pump.
There was uncertainty regarding the extent to which the tracers were evacuated from the
injection intervals to the aquifer in each test. The very long injection intervals (ranging 
from
75 m to almost 200 m) and the lack of down-hole mixing contributed to this uncertainty. 
Slow
release of tracers from the injection intervals could have contributed to tailing in the 
solute tracer
responses that would have been interpreted as dispersion or matrix diffusion when only 
one
nonsorbing tracer was used. Attempts to reduce this uncertainty in the Prow Pass tests 
were
made by deploying a down-hole system capable of mixing the tracer solution after its 
injection
into the borehole. Although the down-hole mixing system worked only marginally, it is 
believed
that stratification of tracer concentrations in the borehole was minimized. Also, 
recirculation of
30% of the water produced from c#2 during the Prow Pass test should have served to help
"flush" tracers out of the injection interval.
The influence of the natural gradient that exists at the C-wells on tracer recovery at the 
pumped
well is a source of uncertainty. Determinations of the capture zone of the pumped well, 
and how
it is altered by the existence of a natural gradient, depend on the assumptions made 
regarding
flow heterogeneity and anisotropy. Mass that is not recovered by the pumped well is 
potentially
the result of path ways other than the postulated radially convergent or partially 
recirculating
streamlines toward the pumped well. However, it could also be a result of some of the 
tracer
mass moving through the matrix rather than fractures; transport through the matrix would 
be so
slow that the mass would not be expected appear in the production well during the time 
of the
tracer tests.
A limitation of all tracer tests conducted at the C-wells is that they produce estimates 
only of
longitudinal dispersivity, not transverse dispersivity (because sampling occurs only at the
production well and is not spatially distributed). In addition, the estimate of flow porosity 
has
the uncertainty of an unknown travel distance between the tracer injection and production 
points
in the boreholes (i.e., the source and the sink locations). This travel distance was bounded 
by
ANL-NBS-HS-000039, REV 00 228 December 2003
assuming a minimum of the straight-line distance between the injection and production 
wells and
a maximum of the formation thickness, defined by the distance between packers in the 
injection
and the pumped intervals.
6.3.5.2 Uncertainties Associated with Test Interpretation Methods
When estimating transport parameters using a semi-analytical solution to the 
advectiondispersion
equation, such as the Moench (1989 [101146]) solution or the RELAP V 2.0 computer
code (STN: 10551-2.0-00 [159065]) employed in this study, several assumptions are 
made. The
medium is assumed to be homogeneous and isotropic, and the flow regime is assumed to 
be
either radial or linear (i.e., having a velocity that varies as 1/r or having a constant 
velocity
between injection and production well). Also, the aquifer is assumed to be two-
dimensional
(flow only in the two horizontal dimensions without a vertical component). To the extent 
that
these assumptions do not reflect the true nature of the media, the transport parameter 
estimates
will be erroneous. However, the information necessary to implement more sophisticated 
models
that explicitly account for flow and transport heterogeneity does not exist. Even data to 
support
stochastically-generated hydraulic conductivity distributions in numerical models are 
scarce to
nonexistent. Thus, the interpretive models used in this report, while relatively 
unsophisticated,
reflect the level of knowledge of flow and transport heterogeneity at the scale of the 
tracer tests.
Uncertainty associated with assuming either radial or linear flow (when the actual nature 
of the
flow field could be somewhere in between) is addressed in the multiple tracer-test 
interpretations
by reporting mean residence times and Peclet numbers for both radial and linear flow
assumptions.
The Moench (1989 [101146]; 1995 [148784]) and RELAP V 2.0 (STN: 10551-2.0-00 
[159065])
semi-analytical models are mathematically very similar. However, differences in the
methodologies and assumptions used in the implementation of the models to interpret 
tracer
responses result in differences in the resulting transport parameter estimates. Highlights 
of the
differences in the two approaches are the following.
(1) The first approach (Moench model, Section 6.3.1) involves normalizing tracer
concentrations to the maximum (peak) tracer concentration, whereas the second approach
(RELAP model, Section 6.3.4.6) involves normalizing tracer concentrations to the
injection mass. The first method results in matching the shapes of breakthrough curves
(or differences in shapes when there are multiple tracers), while the second is aimed at
matching not only shapes, but also peak normalized concentrations and total recoveries.
Thus, the second method has some additional fitting constraints that result in different
transport parameter estimates compared to the first method.
(2) Both methods use essentially the same mathematical model to account for the tracer
residence time in the injection borehole (i.e., a well-mixed interval with an exponential
decay in tracer concentration). However, the mean residence time in the borehole was
allowed to be much larger when running simulations using the first method (Section
6.3.1) compared to the second method (Section 6.3.4.6). A larger residence time in the
injection borehole effectively adds dispersion to the simulated response curves, which
results in a smaller flow-system dispersivity when the tracer data are fitted. Thus, the
ANL-NBS-HS-000039, REV 00 229 December 2003
longitudinal dispersivity estimates from the first method tend to be lower than from the
second method.
To assess the different results obtained from the two approaches qualitatively, the 
RELAP V 2.0
(STN: 10551-2.0-00 [159065]) computer code was used to interpret the iodide and 2,4,5-
TFBA
tracer test in the Prow Pass Tuff. The Moench model (Moench 1995 [148784]) 
interpretation of
this test is presented in Section 6.3.1.2.1. First, the parameters obtained from the Moench 
model
analysis were used in RELAP to see how well the two models agree when using the same 
inputs.
It can be shown through algebraic manipulations that the mass transfer coefficient m b
D
* in
RELAP is equivalent to
?
* * ' '
b' 6 in the Moench model (Moench 1995 [148784]), where b' =
radius of spheres that represent matrix blocks (into which diffusion occurs), ' * = 
dimensionless
storage parameter =
f ?
* , and ' * = 2
m
) (b' f
D
?
?
. f
* is the fracture porosity in this case, and ?is
defined as
Q
) r r ( h 2
w
2
L f * * * , where h is the aquifer thickness, rL is the distance between the
injection and production wells, rw is the radius of the production well, and Q is the 
volumetric
flow rate from the production well. Additionally, an injection borehole "mixing length" 
of 30.5
m was used in the Moench model analysis of Section 6.3.1.2.1. This mixing length can be
shown to translate to an injection borehole time constant of ~0.0023 hr-1 in the RELAP 
model
(time constant * ?
?
?
* * 
?
?
i
2
i L
i
h r
1
r 2
r Q 4
* ?
, where ri = injection well radius and hi = mixing length;
Moench 1989 [101146]). Using these input parameters, along with a Peclet number of 
100 (i.e.,
a longitudinal dispersivity of 0.29 m), the RELAP model yields the fits shown in Figure 
6.3-31
(the mean residence time and mass fraction were adjusted to obtain these fits). The 
longitudinal
dispersivity reported in Section 6.3.1.2.1 was 0.27 m. The tracer responses and fits in 
Figure
6.3-31 are adjusted so that they all have the same maximum concentration, which is 
consistent
with the analysis used in Section 6.3.1.2.1. A comparison of Figure 6.3-31 and Figure 
6.3-16
shows that the two models yield almost indistinguishable results when the same input 
parameters
are used.
The injection borehole time constant of 0.0023 hr-1 used in the above analysis translates 
to a
mean tracer residence time in the borehole of 1/0.0023, or ~435 hr. This residence time is 
at
odds with the tracer concentration measurements in the injection borehole described in 
Section
6.3.1.2.1.1, where it is stated that the borehole was effectively flushed of tracer in ~8.5 
hr. The
fact that the tracer was flushed from the borehole in such a short time is not surprising 
given that
there was a continuous injection of ~1.5 gpm (~5.7 L/min) of groundwater into the 
injection zone
following the injection of tracers. A mean residence time of ~9 hrs is calculated by 
dividing the
volume of the injection interval (~3,000 L) by the 5.7 L/min flow rate. For these reasons, 
a
second RELAP simulation was conducted in which it was assumed that the injection 
borehole
ANL-NBS-HS-000039, REV 00 230 December 2003
Output DTN: LA0304PR831231.001.
NOTE: Data points represent a subset of the actual data. Data and curves are adjusted so that they all have 
the
same maximum normalized concentration (see Figure 6.3-16 for comparison). The same parameters
obtained from the Moench model in Section 6.3.1.2.1 were used.
Figure 6.3-31. RELAP Fits to the Iodide and 2,4,5-TFBA Responses in the Prow Pass Tuff Tracer 
Test
Assuming an Injection Zone Time Constant of 0.0023 hr-1
time constant was 0.11 hr-1 ((5.7)(60)/3000). This is the same time constant value that 
was used
in the analysis of the PFBA and bromide tracer test conducted in the Prow Pass Tuff 
described in
Section 6.3.4.7.1. The resulting RELAP fits to the tracer data are shown in Figure 6.3-32, 
where
in this case the tracer concentrations are normalized to tracer injection mass, as in Section 
6.3.4.
The RELAP transport parameters for the simulations of Figures 6.3-31 and 6.3-32 are 
listed in
Table 6.3-12. Also listed in this table are the parameters obtained from RELAP fits to the 
PFBA
and bromide data in the Prow Pass Tuff, discussed in Section 6.3.4.7. This test was 
conducted in
the same configuration and with the same flow rates as the iodide and 2,4,5-TFBA test, 
although
the volume of the tracer solution injected was considerably larger. Clearly, there is a very 
large
difference in the mean residence times and Peclet numbers of the simulations with 
significantly
different borehole time constants, although the iodide mass transfer coefficients, m D
b
* , are in
reasonably good agreement in all simulations.
0
50
100
150
200
250
300
0 200 400 600 800 1000 1200 1400 1600 1800 2000
Time, hr
Norm. Conc., ?
?g/L-kg injected
Iodide
2,4,5-TFBA
Iodide Model
2,4,5-TFBA Model
ANL-NBS-HS-000039, REV 00 231 December 2003
Output DTN: LA0304PR831231.001.
NOTE: Data points represent a subset of the actual data.
Figure 6.3-32. RELAP Fits to the Iodide and 2,4,5-TFBA Responses in the Prow Pass Tuff Tracer 
Test
Assuming an Injection Borehole Time Constant of 0.11 hr-1
The reason for the large differences in mean residence times and Peclet numbers in Table 
6.3-12,
particularly between the two interpretations of the iodide and 2,4,5-TFBA test, becomes 
clear
when one considers the implications of the different borehole mixing assumptions. Figure 
6.3-
33 shows tracer responses calculated by RELAP V 2.0 (STN: 10551-2.0-00 [159065]) in 
a
hypothetical system with a mean residence time in the aquifer (not the injection borehole) 
of 1
hr, a Peclet number of 100, and no matrix diffusion. With this choice of parameters, the
responses are due almost entirely to tracer residence time in the injection borehole. The 
tails of
the responses are linear on a semi-log plot because tracer concentrations in a well-mixed 
region
decay exponentially. The curve with the largest time constant corresponds to the tracer 
residence
time distribution in the borehole for the RELAP fits of Figure 6.3-32, and the curve with 
the
smallest time constant shows the residence time distribution associated with the fits of 
Figure
6.3-31. The iodide response in the Prow Pass tracer test is also shown in Figure 6.3-33. It 
is
apparent that the curve with the smallest time constant has a tail that matches the tracer 
data
quite well. Thus, to match the entire breakthrough curve, it is only necessary to impose a 
lag on
the borehole response (accounted for by a finite residence time in the flow system), with 
only a
very small amount of additional dispersion or matrix diffusion in the flow system 
necessary to
optimize the fit. However, as the borehole time constants get larger, it becomes necessary 
to
impose a greater lag and account for more dispersion or matrix diffusion in the flow 
system to
achieve a match to the data.
0
50
100
150
200
250
300
0 200 400 600 800 1000 1200 1400 1600 1800 2000
Time, hr
Norm. Conc., ?
?g/L per kg injected
Iodide
2,4,5-TFBA
Iodide Model
2,4,5-TFBA Model
ANL-NBS-HS-000039, REV 00 232 December 2003
Table 6.3-12. Transport Parameters Estimates from RELAP Fits of Figures 6.3-31, 6.3-32, and 
from the
Fits to the PFBA and Bromide Responses in the Prow Pass Tuff
Parameter I, TFBA
Figure 6.3-31
I, TFBA
Figure 6.3-32 Br, PFBA Test
Borehole Time Constant, ?, hr-1 0.0023 0.11 0.11
Mean Res. Time, ?, hr (linear flow) 55 520 1210
Peclet number, Pe (linear flow) 100 1.6 0.9
MTC, m D
b
?
, sec-1/2 0.00161 0.001 0.000949
Output DTN: LA0304PR831231.001.
Output DTN: LA0304PR831231.001.
NOTE: Data points represent a subset of the actual data. Iodide data from the Prow Pass Tuff tracer test 
(Figures
6.3-31 and 6.3-32) are shown for comparison. See Section 6.3.4.7 for discussion.
Figure 6.3-33. Tracer Responses as a Function of Injection Borehole Time Constant in a
Hypothetical Flow System with a Mean Residence Time of 1 hr in the Aquifer,
a Peclet Number of 100, and No Matrix Diffusion
10
100
1000
10000
0 100 200 300 400 500 600
Time, hr
Norm. Conc., ?
* g/L per kg injected
T Const = 0.11 hr-1 (Model)
T Const = 0.02 hr-1 (Model)
T Const = 0.008 hr-1 (Model)
T Const = 0.0024 hr-1 (Model)
ANL-NBS-HS-000039, REV 00 233 December 2003
Figure 6.3-34 shows the mean residence times (in the aquifer), Peclet numbers, and mass 
transfer
coefficients, m b
D
* or MTC, that provided best fits to the combined iodide and 2,4,5-TFBA
tracer data sets as a function of borehole time constant. The fits were equally good until 
the time
constant became less than about 0.0025 hr-1, which roughly corresponds to the time 
constant
used in Figure 6.3-31. Note that there is a sharp transition at a time constant of ~0.007 hr-
1,
where residence times increase and Peclet numbers decrease dramatically. This transition
corresponds to the point where the tracer residence time in the borehole can no longer 
account
for the majority of the dispersion in the tracer curves. Figure 6.3-34 shows that the MTC 
does
not vary nearly as much as the mean residence time and Peclet number, although it goes 
through
a maximum at the transition point because of an attempt to account for tracer dispersion 
with
increased matrix diffusion. This result is important because it indicates that despite the 
dramatic
differences in mean residence time and Peclet number as a function of borehole time 
constant,
matrix diffusion is always necessary to explain the tracer responses (at least until 
borehole
residence times become so low that all fits are poor). Furthermore, the estimates of matrix
diffusion parameters do not vary all that much. Thus, the various interpretations, while
significantly different in mean residence time and Peclet number, are all consistent with a 
dualporosity
conceptualization of the fractured volcanics.
Output DTN: LA0304PR831231.001.
NOTE: Units on y axis depend on the curve.
Figure 6.3-34. Mean Residence Time (?), Peclet Number, and MTC (x 1000) as a Function of 
Borehole
Time Constant from RELAP Fits to the Iodide and 2,4,5-TFBA Data of Figure 6.3-32
0.1
1
10
100
1000
0.001 0.01 0.1 1
Borehole Time Constant, hr-1
Tau, hrs
Peclet Number
MTC x 1000, sec^-1/2
Poor fits Good fits
ANL-NBS-HS-000039, REV 00 234 December 2003
6.3.5.3 Uncertainties Associated with Nonuniqueness of Test Interpretations
Nonuniqueness of tracer test interpretations must be considered before uncertainties in 
transport
parameters derived from tracer tests can be fully addressed. A prime example of 
nonuniqueness
is that long tails in tracer responses can be interpreted as either being the result of large
longitudinal dispersion or significant matrix diffusion. In the nonsorbing tracer tests,
nonuniqueness was addressed by using PEST V 5.5 (STN: 10289-5.5-00 [161564]) to 
obtain
optimal transport parameter estimates and to estimate confidence intervals associated 
with the
parameters. In the multiple tracer tests, nonuniqueness of interpretations was minimized 
by
simultaneously fitting the tracer responses using known ratios of diffusion coefficients as
constraints on the relative matrix diffusion of different tracers. However, even after 
taking these
measures, there is considerable nonuniqueness associated with tracer test interpretations.
Output DTN: LA0304PR831231.001.
NOTE: Data points represent a subset of the actual data. Model parameters associated with the fits are 
listed in
Table 6.3-13. Note that Fits 1 and 3 essentially fall on top of each other.
Figure 6.3-35. RELAP Fits to Iodide Data from Prow Pass Tracer Test
0
50
100
150
200
250
0 200 400 600 800 1000 1200 1400 1600 1800 2000
Time, hr
Norm. Conc., ?
?g/L per kg injected
Iodide Data
Fit 1
Fit 2
Fit 3
ANL-NBS-HS-000039, REV 00 235 December 2003
Table 6.3-13. Transport Parameters Obtained from RELAP Fits to Iodide Data shown in Figure 
6.3-35
Parameter Fit 1 Fit 2 Fit 3
Mass Fraction 0.23 0.11 0.24
Borehole Time Constant, hr-1 0.11 0.11 0.11
Mean Res. Time, ?, hr (linear flow) 50 700 9000
Peclet number, Pe (linear flow) 17 1.3 0.1
Iodide MTC, m D
b
?
, sec-1/2 0.01 0.0 0.0001
Output DTN: LA0304PR831231.001.
First, nonuniqueness associated with the interpretation of responses of single tracers is 
addressed.
Figure 6.3-35 shows three RELAP V 2.0 (STN: 10551-2.0-00 [159065]) fits to the iodide
response in the Prow Pass tracer test shown in Figure 6.3-32. These fits, which were 
obtained by
arbitrarily fixing the Peclet number and then allowing the mean residence time, mass 
fraction,
and MTC to be adjusted to achieve a fit, are arguably equally good. However, the best-
fitting
parameters, listed in Table 6.3-13, vary by 2 to 4 orders of magnitude, and it is not even 
possible
to distinguish between a single-porosity and a dual-porosity system (MTC can be zero). 
Clearly,
nonuniqueness associated with interpreting single tracer responses is excessive and 
probably
unacceptable for the purpose of transport parameter estimation.
A similar exercise in determining nonuniqueness of test interpretations was conducted for 
each
of the multiple tracer responses; i.e., two in the Prow Pass Tuff and two in the Bullfrog 
Tuff (two
peaks in this case). Although the absolute best-fitting parameters in each case, as 
determined by
minimizing the sum of squares of differences between model and data, are reported in 
Sections
6.3.1 and 6.3.4, there is still considerable nonuniqueness of the fits. If we arbitrarily 
establish a
criterion that any sum of squares of differences less than 1.5 times the minimum is an 
equally
good fit to the data, then the ranges of parameter values that provide equally good fits to 
the data
sets are listed in Table 6.3-14. Fits having sum-of-squares differences of less than a factor 
of 1.5
times the minimum are essentially equally good in appearance; and when one considers 
that the
best fits are dependent on data scatter and on variability in data point density in the 
breakthrough
curves (e.g., more data in tails as opposed to peaks), then a good case can be made that 
the fits
are equally plausible. The parameter ranges were determined by varying each parameter 
in
Table 6.3-14 manually over a wide range of values while letting all other parameters in 
Table
6.3-14 be adjusted to achieve fits to the data sets. Figure 6.3-36 shows the fits to the 
iodide and
2,4,5-TFBA data from the Prow Pass tracer test (Figure 6.3-32) that had the lowest and 
highest
optimized sum-of-squares differences (with the highest still being within a factor of 1.5 
of the
lowest). Another "parameter" that was varied in the exercise was the ratio of the diffusion
coefficients of halides (bromide and iodide) and FBAs (PFBA and TFBA) in the multiple 
tracer
tests. This ratio is somewhat uncertain, especially in rock matrices, because most 
literature
values are based on free water measurements. However, the values of the other transport
parameters were found to be quite insensitive to this ratio when it was varied over a 
reasonable
range.
ANL-NBS-HS-000039, REV 00 236 December 2003
Table 6.3-14. Transport Parameter Ranges from Multiple-Tracer Tests at the C-wells
Parameter BF, Peak 1 BF, Peak 2 PP, I-TFBA PP, Br-PFBA
Mass Fraction 0.11 - 0.13 0.56 - 0.7 0.17 - 0.3 0.56 - 0.82
Mean Res. Time, ?, hr (linear flow) 320 - 420 700 - 1800 340 - 1340 600 - 1900
Peclet number, Pe (linear flow) 5 - 8 0.9 - 2.4 0.6 - 2.6 0.6 - 1.9
Halide MTC, m D
b
?
, sec-1/2
0.000837 -
0.00224
0.000245 -
0.000775
0.000775 -
0.00122
0.000632 -
0.00122
Output DTN: LA0304PR831231.001.
NOTE: BF refers to Bullfrog
PP refers to Prow Pass.
It is important to note that the ranges of parameter values in Table 6.3-14 are not 
completely
independent of each other. That is, when one parameter value is taken from the high end 
of its
range, another may have to be taken from near the low end of its range to achieve a good 
fit.
This is especially true of the mean residence time and Peclet number, which have a very 
strong
inverse correlation. Figure 6.3-37 shows the relationship between best-fitting values of 
Peclet
number and mean residence time for the four multiple-tracer tests at the C-wells. All of 
the
points plotted in this figure are associated with equally good fits to the data according to 
the
criterion stated in the previous paragraph. Note that the range of mean residence times is
significantly lower for the data set with the largest Peclet numbers compared to the three 
data
sets with smaller Peclet numbers. This result was found to be true in general; i.e., the 
range of
mean residence times was smaller for hypothetical tracer responses with less longitudinal
dispersion.
Figure 6.3-38 shows that the best-fitting mass fractions are positively correlated with the 
bestfitting
mean residence times for the iodide and 2,4,5-TFBA responses in the Prow Pass Tuff.
This result and Figure 6.3-37 imply a negative correlation of mass fraction with Peclet 
number.
These same trends were obtained for all other multiple-tracer tests. Interestingly, the 
MTC,
m b
D
* , was poorly correlated with any of the other transport parameters. In fact, the extremes
of MTC values were generally associated with values of other parameters that were not 
near the
ends of their respective ranges. Also, the range of MTC values never included zero, 
which
indicates that a dual-porosity system is always implied from the fits.
The parameter ranges in Table 6.3-14 reflect considerable uncertainty associated with the
nonuniqueness of interpretive model fits for multiple tracer tests. These ranges, in 
general, are
comparable in magnitude to the ranges of derived parameter values provided in Table 
6.3-10,
which were based on uncertainties in tracer travel distances and radionuclide diffusion
coefficients, as well as the range of parameter values obtained from different tests in the 
same
interval. The ranges in Table 6.3-10 would have to be expanded somewhat to account for 
the
additional uncertainty associated with the nonuniqueness of model fits. Expanding these 
ranges
by multiplying the lower value of any parameter in Table 6.3-10 by 0.5 and the upper 
value by 2
would effectively capture this additional uncertainty.
ANL-NBS-HS-000039, REV 00 237 December 2003
Output DTN: LA0304PR831231.001.
NOTE: Data points represent a subset of the actual data. Bold curves represent the best fits to data. The 
sum of
squares differences between data and models are within a factor of 1.5 of each other.
Figure 6.3-36. RELAP Fits to the Iodide and 2,4,5-TFBA Data from the Prow Pass Tracer Test
0
50
100
150
200
250
300
0 200 400 600 800 1000 1200 1400 1600 1800 2000
Time, hr
Norm. Conc., ?
?g/L per kg injected
Iodide
2,4,5-TFBA
Iodide Model 1
Iodide Model 2
TFBA Model 1
TFBA Model 2
ANL-NBS-HS-000039, REV 00 238 December 2003
Output DTN: LA0304PR831231.001.
NOTE: PP refers to Prow Pass; BF refers to Bullfrog. Note that the residence times (but not Peclet numbers) 
are
multiplied by 10 for peak 1 of the Bullfrog Tuff tracer test.
Figure 6.3-37. Correlation Between Best-fitting Peclet Numbers and Mean Residence Times
for the Multiple-Tracer Tests at the C-wells
Output DTN: LA0304PR831231.001.
Figure 6.3-38. Correlation Between Best-fitting Mass Fractions and Mean Residence Times for 
the
Multiple-Tracer Tests at the C-wells
0
1
2
3
4
5
6
7
8
9
100 1000 10000
Mean Residence Time, hrs
Peclet Number
PP - I, TFBA
PP - Br, PFBA
BF Pk 1 (Time X 10)
BF Pk 2
0.1
0.15
0.2
0.25
0.3
0.35
0 200 400 600 800 1000 1200 1400 1600
Mean Residence Time, hrs
Mass Fraction
ANL-NBS-HS-000039, REV 00 239 December 2003
A few points are worthy of mention regarding uncertainty associated with nonuniqueness 
of
model fits to obtain transport parameter estimates:
1. Although there is considerable uncertainty associated with model fits to multiple-tracer 
data
sets, the uncertainty is far less than the uncertainty associated with fits to single-tracer 
data
sets (compare Tables 6.3-13 and 6.3-14). Also, all the fits to multiple-tracer data sets
indicated a dual-porosity system, while fits to single-tracer data sets cannot effectively
distinguish between a single- and dual-porosity transport system.
2. This uncertainty analysis and discussion is by no means complete. Other factors must 
be
considered when doing a rigorous uncertainty analysis. A couple of additional
considerations that go beyond the scope of this analysis report are:
- When fitting multiple data sets, one must be careful to not inadvertently give one set
more weight than the others in the fitting procedure. Inappropriate weighting can occur,
for instance, when one data set has significantly more data points than the other(s) or
when one set has much larger numerical values than the other(s). Approaches to dealing
with this problem include (1) various weighting schemes, (2) making the number of data
points the same for all data sets (by dropping some data from the larger data sets), or (3)
normalizing the sum-of-squares errors for each data set by dividing by the number of
points fitted for each set. Each of these approaches introduces some arbitrary bias into
the fitting procedure, which introduces bias into the errors associated with the parameter
estimates. In this analysis report, we use approach (3).
- The fitting criteria (or objective function) are very important and can have a significant
influence on both parameter estimates and error estimates. For instance, one will obtain
different answers if the sum-of-squares differences between model and data are
minimized vs. minimizing the sum-of-squares differences between the log of the data and
the model. In this analysis report, it was chosen to minimize the straight sums-of-squares
differences rather than the differences in any transformations of the data and model
values.
6.3.6 Concluding Remarks About Field Tracer Tests
It is recognized that the tracer-test interpretations using primarily semi-analytical solution
methods that assume an idealized geometry and steady flow rates are a considerable
simplification of reality. Numerical models could certainly be used to account for greater 
system
heterogeneity. Also, more sophisticated semi-analytical representations of dual-porosity
systems, such as the multirate-diffusion model of Haggerty and Gorelick (1995 [156831], 
pp.
2383 to 2400), could be applied. However, the information available to support these 
more
sophisticated representations of the flow and transport system is sparse to nonexistent.
Furthermore, the agreement between the relatively simple semi-analytical models (either 
the
Moench 1989 [101146]; 1995 [148784]) model or RELAP (LANL 2002 [159065]) and 
the tracer
responses are considered to be very good. The only additional model complexity needed 
to
explain any portion of the tracer-test data sets was the multicomponent transport and ion
exchange capabilities of the MULTRAN V 1.0 (STN: 1066-1.0-00 [159068]) model 
needed to
match the lithium response in the first peak of the Bullfrog tracer test. Although the 
introduction
ANL-NBS-HS-000039, REV 00 240 December 2003
of additional model complexity could improve the agreement between model and data, it 
appears
that all of the critical features of the tracer responses are effectively captured, and the
introduction of additional complexity, especially in light of the minimal information to 
support
it, is not justified.
One must also keep in mind that the tracer-test results are intended to support predictive
calculations that span much larger time and distance scales than represented by the test. 
With
this in mind, it is desirable to capture the important transport processes with as concise a 
model
as possible so that others can incorporate a relatively simple model on a local scale into a 
more
sophisticated flow model that captures the important hydraulic features of the larger-scale 
flow
system. It is believed that the C-wells tracer tests and their interpretations presented in 
this
report accomplish this objective.
6.3.7 Batch Testing of Lithium Sorption to C-wells Tuffs
6.3.7.1 Materials and Methods
The batch lithium sorption experiments were conducted as follows (full details of the 
sorption
measurements are provided in Reimus 2000 [164625]).
* C-wells core from a stratigraphic unit of interest was crushed, pulverized, and passed
through a 500-m sieve but retained on a 75-m sieve.
* A specified amount of crushed tuff was added to polycarbonate (polyallomer) Oak 
Ridge
centrifuge tubes. In some experiments, the tuff and centrifuge tubes were autoclaved
prior to contacting the tuff with the lithium solution.
* The tuff was preconditioned with filter-sterilized (0.2-m filter) J-13 water.
* A specified amount of lithium-bearing water (either from well J-13 or well c#3) was
added to the preconditioned tuff, and the mixture was continuously shaken for 24 to 72 hr
at either 25C or 38C. Previous studies had indicated that lithium sorption equilibrium
onto C-wells tuffs was reached in ~1 hour (Newman et al. 1991 [156849], so 24 hours
should have been sufficient to achieve equilibration between solid and solution.
* After equilibration, the tubes were centrifuged and a portion of the supernate was 
filtered
(0.2- or 0.4-m filter) for tracer analysis to determine the tracer concentration remaining
in solution. Lithium was analyzed by inductively-coupled plasma-atomic emission
spectrometry (ICP-AES).
ANL-NBS-HS-000039, REV 00 241 December 2003
* The mass of tracer sorbed to the tuff was determined by mass balance, with corrections, 
if
necessary, to account for sorption to the container walls, which was measured in control
experiments in which tuff was omitted.
* All measurements were made in duplicate or triplicate.
Sorption isotherms were determined under several different experimental conditions:
* 1:1 solution:solid ratio in J-13 water at 25C
* 1:1 solution:solid ratio in J-13 water at 38C
* 2:1 solution:solid ratio in J-13 water at 25C
* 4:1 solution:solid ratio in C-3 water at 38C
* 4:1 solution:solid ratio in J-13 water at 25C
* 4:1 solution:solid ratio in J-13 water at 38C.
The two temperatures were intended to approximate the range of conditions under which
sorption would occur in either the laboratory or the field (the groundwater temperature in 
the
Bullfrog Tuff at the C-wells ranges from about 38C to 45C {Geldon 1993 [101045], pp. 
68 to
70, Figures 31 to 33}).
At the time of these studies, groundwater from the C-wells complex was not consistently
available, so groundwater from well J-13, located 4 km southeast of the C-wells complex, 
was
used as a surrogate in most tests. J-13 water is well-characterized and has become a de 
facto
standard groundwater for use in Yucca Mountain sorption studies (Harrar et al. 1990 
[100814],
pp. 6.6 to 6.7; Triay et al. 1997 [100422], pp. 11, 16, 45). A comparison of J-13 and C-
wells
groundwater chemistry shows that the two waters are both sodium bicarbonate dominated 
and, in
all regards, quite similar (Table 6.3-15). Lithium solutions for sorption tests were 
prepared by
dissolving reagent-grade lithium bromide in either c#3 or J-13 water. All solutions were 
filtersterilized
before use.
ANL-NBS-HS-000039, REV 00 242 December 2003
Table 6.3-15. Comparison of Major Ion Chemistry of J-13 and c#3
DTNs: MO0007MAJIONPH.013 [151530] (J-13); MO0007MAJIONPH.011 [151524] (c#3).
A few tests were conducted in a sodium bicarbonate solution having the same ionic 
strength as
J-13 water but without the calcium and other cations present in J-13 water. Lithium 
sorption in
this solution was noticeably greater than in J-13 water, presumably because of the 
absence of
cations that compete with lithium for sorption sites (primarily calcium). The results of 
these
experiments are not reported here (Callahan 2001 [165123]).
Ion-exchange theory suggests that the actual ion-exchange process is rapid and will reach
equilibrium quickly; in natural systems, apparent equilibration rates are limited by 
diffusion of
ions through the solution to the mineral surface (Bolt et al. 1978 [113856], pp. 54 to 90). 
In a
well-mixed system, such as a shaken centrifuge tube, diffusion is not limiting, and 
equilibration
should be achieved quickly. A previous study of lithium sorption to the Prow Pass 
member of
the Crater Flat Tuff found that sorption equilibrium was reached within 1 hr, confirming 
this
hypothesis (Newman et al. 1991 [156849]). For consistency with other sorption studies 
and for
scheduling convenience, a minimum equilibration period of 24 hr was adopted for these 
studies.
Tuffs from seven different lithologies were tested, including two samples of the same unit 
(the
central Bullfrog Tuff) from two different holes (c#1 and c#2) to allow an assessment of 
spatial
heterogeneity in lithium-sorption parameters. The experimental matrix of tuffs, 
groundwaters,
temperatures, and solid-solution ratios is summarized in Table 6.3-16. Figure 6.3-39 
shows the
sampling locations of the C-wells core used in the experiments. This figure is essentially
identical to Figure 6.1-2 except that the triangles indicating flow zones in the wells have 
been
replaced with triangles identifying locations of core samples used in the batch 
experiments.
Batch-sorption experiments were also conducted on each of the tuffs to determine 
whether PFBA
and bromide sorbed to them. The bromide experiments were actually conducted 
simultaneously
with the lithium experiments, as lithium was added to the solutions as lithium bromide. 
The
starting bromide concentrations ranged from ~10 ppm to ~1000 ppm. The PFBA 
experiments
were conducted at a single concentration (1 ppm). These experiments were conducted on 
each
rock type at 25C. There was no measurable sorption of PFBA or bromide on any of the 
tuffs
(DTN: LA0302PR831231.001 [162605]).
Concentration (?g/mL)
Species
J-13 C-wells
Ca 12 11
Cl 7.1 7.2
K 5 1.9
Mg 2.1 0.4
Na 42 55
SiO2 47 53
SO4 17 22
HCO3 124 137
pH 7.2 7.7
ANL-NBS-HS-000039, REV 00 243 December 2003
Table 6.3-16. Summary of C-wells Experimental Batch Lithium Sorption Test Matrix
Tuff* (Lithology, Borehole, Depth (m)) Water (Well ID) Solution: Solid (mL:g) Temperature (C)
Central Bullfrog, c#1, 715 m (1)
J-13
J-13
2:1
2:1
25
38
Central Bullfrog, c#2, 734 m (2)
J-13
J-13
c#3
1:1
1:1
4:1
25
38
38
Lower Bullfrog, c#1, 795 m (3)
J-13
J-13
J-13
4:1
4:1
2:1
25
38
25
Upper Prow Pass, c#2, 533 m (4)
J-13
J-13
J-13
4:1
4:1
2:1
25
38
25
Central Prow Pass, c#2, 553 m (5)
J-13
J-13
J-13
4:1
4:1
2:1
25
38
25
Lower Prow Pass, c#1, 573 m (6)
J-13
J-13
J-13
4:1
4:1
2:1
25
38
25
Bedded Prow Pass, c#2, 643 m (7)
J-13
J-13
J-13
4:1
4:1
2:1
25
38
25
Upper Tram, c#2, 839 m (8)
J-13
J-13
J-13
4:1
4:1
2:1
25
38
25
Source: This table shows the test matrix.
NOTE: *The numbers in parentheses correspond to the numbers in Figure 6.3-39 (the locations where core 
was
collected from the C-wells).
ANL-NBS-HS-000039, REV 00 244 December 2003
Source: Geldon (1993 [101045], pp. 35 to 37, 43 to 51, 58 to 64) for lithology, stratigraphy, porosity, and fracture density
information. DTN: GS990408312315.002 [140115] for packer locations. Reimus (2000 [165124], pp. E1 to E10, M1 to
M14, Q1 to Q20, W1 to W15, X1 to X14, AB1 to AB11, AC1 to AC17) for locations of core samples.
NOTE: The numbers in the figure correspond to the numbers in Table 6.3-16. Also shown are approximate
locations of packers for the tracer tests in the Prow Pass Tuff.
Figure 6.3-39. C-wells Hydrogeology Showing Sampling Locations of All Core Used in the
Laboratory Experiments Described in Sections 6.3.7, 6.3.8, and 6.3.9
ANL-NBS-HS-000039, REV 00 245 December 2003
The mineralogy of the tuffs used in the batch-sorption experiments is listed in Table 6.3-
17. The
mineralogy was determined from quantitative X-ray diffraction (XRD) analyses. The 
tuffs differ
primarily in their smectite and zeolite (clinoptilolite and mordenite) content, both of 
which have
high cation-exchange capacities and would be expected to sorb lithium quite strongly 
compared
to other minerals present in the rocks (Anghel et al. 2002 [164635], pp. 822-824, Section 
3.2).
Table 6.3-17. X-Ray Diffraction Results for Tuffs from Prow Pass, Bullfrog, and Tram Units
Concentration (wt %)
Tuff Depth
(m) Smectite Clinoptilolite Mordenite Analcime Calcite
Central Bullfrog, c#1 715 2 + 1 - - - 2 + 1
Central Bullfrog, c#2 734 5 + 2 - - - -
Lower Bullfrog, c#1 795 9 + 3 4 + 1 3 + 1 12 + 1 4 + 1
Upper Prow Pass, c#2 533 - - - - Trace
Central Prow Pass, c#2 553 2 + 1 - - - 2 + 1
Lower Prow Pass, c#1 573 2 + 1 - - - -
Bedded Prow Pass, c#2 643 - - 20 + 4 39 + 2 -
Upper Tram, c#2 839 1 + 1 - - - -
DTN: MO0012MINLCHOL.000 [153370]; LA9909PR831231.004 ([129623] for Central Bullfrog c#2 only (non-Q data).
NOTE: c#1, c#2, and c#3 are abbreviations for boreholes UE-25 c#1, UE-25 c#2, and UE-25 c#3, 
respectively.
Trace: trace abundance of < 0.5 wt%.
Only the main sorptive mineral fractions are listed; the balance of the tuffs was mostly quartz and feldspar
with small amounts of hematite, mica/illite, and/or kaolinite.
Dashes indicate "not measured."
A Li-specific CEC method was developed to quantify the Li affinity for the selected 
tuffs. The
method involved two steps: saturation of the exchange sites with Li, followed by 
displacement of
the Li and other cations with Cs. The mineralogical composition of the samples was 
preserved
as close as possible to the field conditions; therefore, no pretreatment was applied to 
remove
carbonate or organic matter. The method involved the following steps (Anghel et al. 2002
[164635], pp. 822 to 824, Section 3.2).
* The tuff samples were crushed and wet-sieved with J-13 water to a particle-size range
between 75 to 500 m. Then ~5 g of each tuff was weighed into a 50-mL centrifuge
Teflon tube. Each tuff sample was tested in triplicate.
* The samples were saturated three times with 30 mL of 0.8 N LiBr-0.2 N LiOAc 
solution
to ensure replacement of cations present on mineral surface sites with Li. The pH of the
solution was maintained at ~8.2 to prevent dissolution of calcite. After each LiBr
addition, the tubes were sonicated to disperse the centrifuged sediment, and then the
samples were shaken for 30 min.
* The samples were centrifuged at 10,000 rpm for 15 minutes to achieve a good 
separation
of solids and solution. The supernatant from each Li-sorption step was combined and
analyzed for Na, K, Ca, and Mg.
ANL-NBS-HS-000039, REV 00 246 December 2003
* After the Li-sorption steps, the tuff present in each centrifuge tube was washed three
times with 30 mL of 1 N CsCl to remove the sorbed Li. The combined supernate from
centrifuging was analyzed for Li, Na, Ca, K, and Mg. Residual Li saturating solution
remaining in the centrifuge tubes was accounted for by analyzing for Br and making the
appropriate correction. Cs has more affinity for zeolites, and it should, therefore,
displace more cations than Li. In many cases, Cs sorption gives a measure of the total
CEC (Li measurements of the aliquots give the CEC for Li-Cs exchange).
The method described yields two different CEC results: (1) CEC-LiT, the total CEC 
available to
Li, estimated from the total cations displaced by Li in the saturation step, and (2) CEC-
CsT, the
total CEC available to Cs, estimated from the total cations displaced by Cs in the 
displacement
step. CEC-CsT can be further subdivided into CEC-CsLi, based on the Li displaced by Cs, 
and
CEC-CsNat, based on the native cations (Na, K, Ca, Mg) displaced by Cs. Each of these 
results is
expressed in milliequivalents per 100 g of dry tuff.
6.3.7.2 Results and Discussion
During the course of the experiments, it became apparent that lithium sorption was 
essentially
independent of solution:solid ratio, temperature, and water composition (J-13 or c#3) 
over the
range of conditions studied. Therefore, the data sets for a given tuff lithology were 
combined to
estimate sorption parameters. Three common isotherm models, defined as follows, were 
fitted to
the data for each tuff.
(1) Linear Isotherm:
S = KdC (Eq. 11)
where
S = equilibrium sorbed concentration (g/g)
C = equilibrium solution concentration (g/mL)
Kd = linear distribution coefficient (mL/g).
(2) Freundlich Isotherm:
S = KFCn (Eq. 12)
where
KF = Freundlich coefficient (mL/g)n(g/g)
n = Freundlich exponent (dimensionless).
(3) Langmuir Isotherm:
C K
C S K
S
L
max L
1?
* (Eq. 13)
where
KL = Langmuir coefficient (mL/g)
Smax = maximum attainable solid sorption capacity (g/g).
ANL-NBS-HS-000039, REV 00 247 December 2003
Figures 6.3-40 to 6.3-46 show the experimental data for each tuff plotted as log-
equilibriumsorbed
concentration, S (g/g) versus log-solution concentration, C (g/mL). A Langmuir
isotherm consistently yielded better visual fits to the data than the other isotherms, so a 
fitted
Langmuir isotherm is also shown in each figure. The Langmuir isotherm is the only 
isotherm
that captures the curvature of the data when graphed on log-log axes. Furthermore, only 
the
Langmuir isotherm recognizes the finite sorptive capacity of the solid matrix; the other 
models
imply potential infinite sorption. A previous study of lithium sorption to the Prow Pass 
member
of the Crater Flat Tuff also revealed Langmuir behavior (Newman et al. 1991 [156849]). 
The
Langmuir, Freundlich, and linear isotherm parameters associated with the data in Figures 
6.3-40
to 6.3-46 are given in Table 6.3-18. It is concluded that a Langmuir isotherm provides the 
best
representation of lithium sorption onto C-wells tuffs. However, a detailed statistical 
analysis to
quantify how much better this representation is relative to the other isotherms (or whether 
it is
statistically better) was not conducted. Statistical analyses were not conducted to 
determine
whether there were significant isotherm differences as a function of temperature, solid-
solution
ratio, or core taken from different locations in the same lithological unit (i.e., the Central
Bullfrog Tuff from c#1 or c#2). However, it appears from Figures 6.3-40 to 6.3-46 that 
any of
these differences should have been minimal.
The error bounds shown in Figures 6.3-40 to 6.3-46 reflect the propagation of analytical 
errors
associated with lithium concentration measurements in the solutions before and after 
contact
with the sorbing tuffs (Reimus 2003 [165129], p. 126). These bounds are shown relative 
to the
fitted Langmuir isotherms, not relative to individual data points. The bounds were 
calculated
assuming a 10% relative standard deviation in the lithium concentration measurements, 
which is
high for ICP-AES measurements but it also serves to account for other experimental 
errors, such
as imperfect separations of solid and solution phases during centrifugation. Errors 
increase as
concentrations increase because there is a lower percentage of lithium sorbing at higher
concentrations and, hence, a smaller relative difference between measured initial and 
final
solution concentrations. It is apparent that the scatter in the data sets often exceeds the 
analytical
error bounds, suggesting greater than 10% error in some of the measurements.
In Figures 6.3-40 to 6.3-44, the lithium isotherm associated with the ion-exchange 
parameters
used in MULTRAN V 1.0 (STN: 1066-1.0-00 [159068]) to obtain a good match to either 
the first
lithium peak in the Bullfrog Tuff tracer test (Figure 6.3-26) or the lithium response in the 
Prow
Pass Tuff tracer test (Figure 6.3-27) are plotted along with the laboratory data and the 
Langmuir
isotherm fits to the laboratory data. In all cases, the isotherms derived from the 
simulations of
the field data indicate greater lithium sorption in the field than in the laboratory 
experiments.
"Field" isotherms are not shown in Figures 6.3-45 and 6.3-46 because the Bedded Prow 
Pass and
Upper Tram Tuff lithologies were not part of the packed-off intervals in the reactive 
tracer tests.
The fitted Langmuir isotherms corresponding to all seven C-wells tuff lithologies are 
plotted
together in Figure 6.3-47. By comparing Figure 6.3-47 to the XRD results of Table 6.3-
17, it is
apparent that the two tuffs demonstrating the greatest affinity for lithium (Bedded Prow 
Pass and
Lower Bullfrog) are also the tuffs that have the greatest smectite and/or zeolite contents. 
A
quantitative relationship between lithium sorption and tuff mineralogy is discussed 
further
below.
ANL-NBS-HS-000039, REV 00 248 December 2003
DTN: MO0012SORBCHOL.000 [153375] (data). Output DTN: LA0303PR831341.003 (model).
NOTE: C-1 and C-2 refer to UE-25 c#1 and c#2, respectively. The legend indicates the borehole (c#1 or 
c#2) from
which the tuff came, the solution:solid ratio (mL:g), and the temperature of the experiments. The dashed
line is an upper error bar associated with a 10% experimental error (this error bar is plotted relative to the
Langmuir isotherm line - lower error bound is off-scale over the entire range of data). The method for
calculating the error bars is described in Reimus (2003 [165129], p. 126). J-13 water was used in all
experiments except for "C-2, 4:1, 38C." Water from c#3 was used for "C-2, 4:1, 38C." The lithium
concentration range in the Bullfrog Tuff field test spanned from less than 0.1 g/mL up to 1200 g/mL. The
line labeled "Field Fit" is the isotherm corresponding to the MULTRAN V 1.0 (STN: 1066-1.0-00 [159068])
"fit" to the first lithium peak in the Bullfrog Tuff field tracer test (see Figure 6.3-26).
Figure 6.3-40. Lithium Sorption Data and Fitted Langmuir Isotherm for the Central Bullfrog Tuff
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
3
-1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5
Log C, g/ml
Log S, g/g
C-2, 1:1, 25C
C-2, 1:1, 38C
C-2, 4:1, 38C
C-1, 2:1, 25C
C-1, 2:1, 38C
Langmuir Fit
upper bound
Field Fit
ANL-NBS-HS-000039, REV 00 249 December 2003
DTN: MO0012SORBCHOL.000 [153375] (data). Output DTN: LA0303PR831341.003 (model).
NOTE: The legend indicates the solution:solid ratio (mL:g) and the temperature of the experiments. The 
dashed
lines are error bars associated with a 10% experimental error (these error bars are plotted relative to the
Langmuir isotherm line). The method for calculating the error bars is in Reimus (2003 [165129], p. 126).
J-13 water was used in all experiments. The lithium concentration range in the Bullfrog Tuff field test
spanned from less than 0.1 g/mL up to 1200 g/mL. The line labeled "Field Fit" is the isotherm
corresponding to the MULTRAN V 1.0 (STN: 1066-1.0-00 [159068]) "fit" to the first lithium peak in the
Bullfrog Tuff field tracer test (see Figure 6.3-26).
Figure 6.3-41. Lithium Sorption Data and Fitted Langmuir Isotherm for the Lower Bullfrog Tuff 
(c#1,
795 m below land surface).
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
3
3.5
-1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5
Log C, g/ml
Log S, g/g
4:1, 25C
4:1, 38C
2:1, 25C
Langmuir Fit
lower bound
upper bound
Field Fit
ANL-NBS-HS-000039, REV 00 250 December 2003
DTN: MO0012SORBCHOL.000 [153375] (data). Output DTN: LA0303PR831341.003 (model).
NOTE: The legend indicates the solution:solid ratio (mL:g) and the temperature of the experiments. The 
dashed
line is an upper error bar associated with a 10% experimental error (this error bar is plotted relative to the
Langmuir isotherm line - lower error bound is off-scale over entire range of data). The method for
calculating the error bars is in Reimus (2003 [165129], p. 126). J-13 water was used in all experiments.
The lithium concentration in the Prow Pass Tuff field test ranged from less than 0.1 g/mL up to 2700
g/mL. The line labeled "Field Fit" is the isotherm corresponding to the MULTRAN V 1.0 (STN: 1066-1.0-00
[159068]) "fit" to the lithium data in the Prow Pass Tuff field tracer test (see Figure 6.3-27).
Figure 6.3-42. Lithium Sorption Data and Fitted Langmuir Isotherm for the Upper Prow Pass Tuff
(c#2, 533 m below land surface)
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
3
-1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5
Log C, g/ml
Log S, g/g
4:1, J-13, 25C
4:1, J-13, 38C
2:1, J-13, 25C
Langmuir Fit
upper bound
Field Fit
ANL-NBS-HS-000039, REV 00 251 December 2003
DTN: MO0012SORBCHOL.000 [153375] (data). Output DTN: LA0303PR831341.003 (model).
NOTE: The legend indicates the solution:solid ratio (mL:g) and the temperature of the experiments. The 
dashed
line is an upper error bar associated with a 10% experimental error (this error bar is plotted relative to the
Langmuir isotherm line - lower error bound is off-scale over entire range of data). The method for
calculating the error bars is in Reimus (2003 [165129], p. 126). J-13 water was used in all experiments.
The lithium concentration in the Prow Pass Tuff field test ranged from less than 0.1 g/mL up to 2700
g/mL. The line labeled "Field Fit" is the isotherm corresponding to the MULTRAN V 1.0 (STN: 1066-1.0-00
[159068]) "fit" to the lithium data in the Prow Pass Tuff field tracer test (see Figure 6.3-27).
Figure 6.3-43. Lithium Sorption Data and Fitted Langmuir Isotherm for the Central Prow Pass Tuff
(c#2, 553 m below land surface)
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
3
-1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5
Log C, g/ml
Log S, g/g
4:1, 25C
4:1, 38C
2:1, 25C
Langmuir Fit
upper bound
Field Fit
ANL-NBS-HS-000039, REV 00 252 December 2003
DTN: MO0012SORBCHOL.000 [153375] (data). Output DTN: LA0303PR831341.003 (model).
NOTE: The legend indicates the solution:solid ratio (mL:g) and the temperature of the experiments. The 
dashed
line is an upper error bars associated with a 10% experimental error (this error bar is plotted relative to the
Langmuir isotherm line - lower error bound is off-scale over entire range of data). The method for
calculating the error bars is in Reimus (2003 [165129], p. 126). J-13 water was used in all experiments.
The lithium concentration in the Prow Pass Tuff field test ranged from less than 0.1 g/mL up to 2700
g/mL. The line labeled "Field Fit" is the isotherm corresponding to the MULTRAN V 1.0 (STN: 1066-1.0-00
[159068]) "fit" to the lithium data in the Prow Pass Tuff field tracer test (see Figure 6.3-27).
Figure 6.3-44. Lithium Sorption Data and Fitted Langmuir Isotherm for the Lower Prow Pass Tuff
(c#1, 573 m below land surface)
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
3
-1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5
Log C, g/ml
Log S, g/g
4:1, 25C
4:1, 38C
2:1, 25C
Langmuir Fit
upper bound
Field Fit
ANL-NBS-HS-000039, REV 00 253 December 2003
DTN: MO00012SORBCHOL.000 [153375] (data). Output DTN: LA0303PR831341.003 (model).
NOTE: The legend indicates the solution:solid ratio (mL:g) and the temperature of the experiments. The 
dashed
lines are error bars associated with a 10% experimental error (these error bars are plotted relative to the
Langmuir isotherm line). The method for calculating the error bars is in Reimus (2003 [165129], p. 126).
J-13 water was used in all experiments.
Figure 6.3-45. Lithium Sorption Data and Fitted Langmuir Isotherm for the Bedded Prow Pass 
Tuff
(c#1, 643 m below land surface)
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
3
3.5
-1 0 1 2 3 4
Log C, g/ml
Log S, g/g
4:1, 25C
4:1, 38C
2:1, 25C
Langmuir Fit
lower bound
upper bound
ANL-NBS-HS-000039, REV 00 254 December 2003
DTN: MO0012SORBCHOL.000 [153375] (data). Output DTN: LA0303PR831341.003 (model).
NOTE: The legend indicates the solution:solid ratio (mL:g) and the temperature of the experiments. The 
dashed
line is an upper error bar associated with a 10% experimental error (these error bars are plotted relative to
the Langmuir isotherm line - lower error bound is off-scale over entire range of data). The method for
calculating the error bars is described in Reimus (2003 [165129], p. 126). J-13 water was used in all
experiments.
Figure 6.3-46. Lithium Sorption Data and Fitted Langmuir Isotherm for the Upper Tram Tuff
(c#2, 839 m below land surface)
ANL-NBS-HS-000039, REV 00 255 December 2003
Output DTN: LA0303PR831341.003.
NOTE: The lithium concentration range in the field test in the central and lower Bullfrog Tuff spanned from 
less than
0.1 g/mL up to 1200 g/mL. The concentration range in the Prow Pass Tuff field test ranged from less than
0.1 g/mL up to 2700 g/mL.
Figure 6.3-47. Fitted Langmuir Isotherms for the Seven C-wells Tuffs
ANL-NBS-HS-000039, REV 00 256 December 2003
Table 6.3-18. Lithium Sorption Isotherm Parameters Associated with the Different C-wells Tuffs
Langmuir Freundlich Linear
Unit
KL (L/mg) Smax (g/g) KF n Kd (mL/g)
Central Bullfrog, c#1 + c#2 (a) 0.014 31.4 0.70 0.79 0.186
Lower Bullfrog, c#1 0.0070 233.9 2.26 0.75 0.321
Upper Prow Pass, c#2 0.00094 53.1 0.075 1.03 0.068
Central Prow Pass, c#2 0.0031 83.3 0.48 0.80 0.131
Lower Prow Pass, c#1 0.011 39.8 0.48 0.78 0.084
Bedded Prow Pass, c#2 0.012 254.9 4.17 0.69 0.383
Upper Tram, c#2 0.0026 59.8 0.27 0.78 0.072
Output DTN: LA0303PR831341.003 (also from Anghel et al. 2002 [164635], Section 3.2, pp. 822 to 824).
NOTE: c#1 and c#2 are abbreviations for boreholes UE-25 c#1 and UE-25 c#2, respectively.
(a) Sorption data from c#1 and c#2 tuffs are lumped together to obtain parameter estimates. KL and Smax
were 0.0053 L/mg and 110 ?g/g, respectively, for the Central Bullfrog Tuff from c#2 alone (used in
crushed tuff column experiments of Section 6.3.9).
Results of the four CEC measurements on the seven tuff samples are presented in Figure 
6.3-48
and Table 6.3-19. In all cases, the total CEC available to Cs (CEC-CsT) exceeds that 
available to
Li (CEC-LiT). This result is not surprising; the hydrated ionic radius of Cs (0.33 nm) is 
smaller
than that of Li (0.38 nm) (Israelachvili 2000 [156835], p. 55), which permits Cs access to
internal exchange sites in zeolites that are not available to Li. More surprising is the 
consistent
observation that Cs displaces more Li during the displacement step than Li displaced 
other
cations during initial saturation (i.e., CEC-CsLi > CEC-LiT). This phenomenon, a "lithium
excess" during the displacement step, was also reported by Eckstein et al. (1970 
[156653], pp.
341-342). They attributed this Li excess to a separate process that occurs in addition to 
normal
cation exchange: selective and specific adsorption of Li, particularly to amorphous 
silicates and
to edges and broken bonds of non-expanding clay minerals. They state that "it [is] 
difficult or
even doubtful that a 'true' value for the exchange capacity can be given for any specific 
clay."
They further conclude that "the sum of cations replaced by Li will usually give a better 
value for
the exchange capacity than the amount of Li retained and replaced by Ca(OAc)2."
Inspection of the mineralogy of the samples, presented in Table 6.3-17, indicates that the 
primary
minerals likely to participate in cation exchange include smectite and the zeolite minerals
clinoptilolite and mordenite. (Although analcime has a high theoretical CEC (Ming and
Mumpton 1995 [156843], pp. 873 to 911), kinetic factors prevent significant cation 
exchange at
normal environmental temperatures, (Vaughan 1978 [156867], pp. 353 to 371)). To test 
whether
a simple two-mineral model could explain the observed measurements, a multivariable 
linear
regression was conducted on the CEC results, using measured smectite and (clinoptilolite 
+
mordenite) fractions (fsmec, fclin/mord) as independent variables, and three CEC estimates as 
the
dependent variables. In all cases, the model yielded the following results:
ANL-NBS-HS-000039, REV 00 257 December 2003
CEC-LiT = 1068 meq/100g.fsmec + 993 meq/100g.fclin/mord + 1.50.3 meq/100g, R2 = 
0.997.
CEC-CsLi = 10313 meq/100g.fsmec + 955 meq/100g.fclin/mord + 6.10.5 meq/100g, R2 = 
0.990.
CEC-CsT = 9013 meq/100g.fsmec + 1995 meq/100g.fclin/mord + 7.70.5 meq/100g, R2 = 
0.997.
where R2 = coefficient of regression (sum of squares regression divided by sum of 
squares total).
0
10
20
30
40
50
1 2 3 4 5 6 7
Interval Number
CEC-LiT
CEC-CsNat
CEC-CsLi
"Lithium Excess"
1 - Upper Prow Pass
2 - Central Prow Pass
3 - Lower Prow Pass
4 - Bedded Prow Pass
5 - Central Bullfrog
6 - Lower Bullfrog
7 - Upper Tram
DTNs: MO0012CATECHOL.000 [153371] (CEC-Li data); LA0302PR831341.001 [162604] (CEC-Cs data); Output DTN: 
LA0303PR831341.001.
NOTE: Interval numbers in legend do not correspond to numbers in Table 6.3-16 or Figure 6.3-39.
Figure 6.3-48. Cation Exchange Capacity Results for the Seven Different C-wells Tuff Intervals
meq/100 g
ANL-NBS-HS-000039, REV 00 258 December 2003
Table 6.3-19. Cation Exchange Capacity Measurements for C-wells Tuffs
Cation Exchange Capacity (meq/100g)
Sample(a)
CEC-LiT CEC-CsNat CEC-CsLi CEC-CsT Li Excess
Upper Prow Pass (1) 2.0  0.5 1.5  0.1 6.1  0.8 7.5 4.1
Central Prow Pass (2) 4.3  0.1 2.1  0.0 7.4  0.4 9.5 3.1
Lower Prow Pass (3) 3.2  0.4 1.0  0.9 9.8  1.9 10.8 6.6
Bedded Prow Pass (4) 21.3  0.1 22.5  0.4 25.0  1.4 47.5 3.8
Central Bullfrog (5) (b) 3.7  0.1 2.0  0.5 7.7  0.6 9.7 4.1
Lower Bullfrog (6) 18.0  0.2 7.5  0.4 21.9  0.2 29.5 4.0
Upper Tram (7) 1.9  0.1 0.5  0.2 6.6  0.5 7.1 4.7
DTNs: MO0012CATECHOL.000 [153371] (CEC-Li data); LA0302PR831341.001 [162604] (CEC-Cs data). Output DTN:
LA0303PR831341.001.
NOTE: Range shown is  one standard deviation. Refer to text for definitions.
(a) Numbers correspond to numbers in Figure 6.3-48.
(b) Only the Central Bullfrog Tuff from c#1 was analyzed for CEC.
The exchange factors for the individual minerals can be compared to literature values of 
110 
23 meq/100 g for smectite (Borchardt 1995 [156639], Chapter 14) and 220 meq/100 g for 
both
clinoptilolite and mordenite (Ming and Mumpton 1995 [156843]). Starting with the 
model for
CEC-LiT, we see that the specific exchange capacity for smectite matches reported value 
from
Borchardt (1995 [156639], Chapter 14), whereas the modeled capacity for the zeolite 
minerals is
less than half that reported by Ming and Mumpton (1995 [156843]). This discrepancy is
consistent with the inaccessibility of some of the internal zeolite exchange sites to the 
relatively
large Li ion. The CEC-LiT model includes a relatively small constant term, indicating that
almost all of the observed behavior can be explained by smectite and 
clinoptilolite/mordenite
cation exchange. Comparing this model to the CEC-CsLi model, we see that the major 
difference
lies in the constant term; the larger constant term in the second model reflects the 
observed Li
excess. The similarity of the other two terms demonstrates that the Li-excess effect is not 
a
result of exchange onto either smectite or clinoptilolite/mordenite; additional correlation 
analysis
shows that the Li excess is not proportional to any of the mineral phases identified by
quantitative x-ray diffraction (QXRD). These observations, combined with the overall
uniformity of the Li excess among these widely varying tuff samples, lead one to agree 
with
Eckstein et al. (1970 [156653], pp. 341, 342) and attribute the Li excess to a noncation 
exchange
sorption process.
The final model for CEC-CsT reveals a similar specific CEC for smectite as found in the
literature and the previous models but shows a much higher specific CEC for the zeolite
minerals, which is more in line with published values (Ming and Mumpton 1995 
[156843]).
This demonstrates the accessibility to the smaller Cs ion of internal exchange sites that 
were
apparently unavailable to Li.
To a first approximation, it can be seen that the two samples that sorb Li most strongly 
have the
highest isotherms in Figure 6.3-47 and the largest Kd and KF values in Table 6.3-18. These 
two
rocks also showed the highest CEC values. To quantify the sorption relationships more
rigorously, the linearization of the nonlinear Freundlich isotherm was undertaken, and 
Klin was
ANL-NBS-HS-000039, REV 00 259 December 2003
calculated. Klin is an effective distribution coefficient with uniform units, identical to 
those of
Kd. For this purpose, the equal-area linearization of van Genuchten et al. (1977 [156868], 
pp.
278 to 285) was used:
1 n
C 2K
K
1 n
?
?
?
max F
lin (Eq. 14)
where Cmax is the maximum solution concentration of interest; in this case, 1000 mg/L, 
and KF
and n are taken from Table 6.3-18. Using the same multivariate linear regression methods
described above, Klin can be modeled as a function of smectite and 
clinoptilolite/mordenite
content:
Klin = 2.280.45 L/kg.fsmec + 2.460.18 L/kg.fclin/mord + 0.090.02 L/kg, r2 = 0.981.
This model does not fit the data quite as well as the CEC models described above but,
nevertheless, demonstrates that Li sorption can be estimated fairly accurately for these 
tuffs,
given smectite, clinoptilolite, and mordenite concentrations. The small constant term in 
the
model indicates that the contribution of other minerals to Li sorption is quite low.
6.3.7.3 Conclusions from Batch Lithium Sorption Studies
Lithium ion sorption onto devitrified tuffs from the saturated zone near Yucca Mountain 
follows
nonlinear isotherm behavior. Both the lithium sorption parameters and the lithium-
specific
cation exchange capacities of the tuffs are highly correlated with the clay (smectite) 
content and
the zeolite (clinoptilolite + mordenite) content of the tuffs. Multiple linear regression 
analyses
shows that these two classes of minerals account for the majority of the observed lithium
exchange. Regression of cesium cation-exchange data yields results that are consistent 
with the
accessibility of the smaller cesium ion to internal zeolite exchange sites that lithium 
cannot
access. The cesium CEC data also suggest that some of the lithium sorption to the tuffs 
can be
attributed to a noncation exchange process. The results of this study support the 
development
and use of mineralogy-based models for predicting cation sorption in the saturated zone 
near
Yucca Mountain.
6.3.8 Diffusion Cell Experiments
6.3.8.1 Materials and Methods
Six diffusion cell experiments were conducted to determine diffusion coefficients of 
PFBA and
bromide ion in five different C-wells tuff matrices (details are in Reimus 2000 [165121]).
Estimates of matrix diffusion coefficients are important because they can greatly reduce
uncertainty in interpreting and predicting both field-scale and laboratory-scale tracer
experiments. One of the tests was a repeat experiment using a different core from the 
same
interval as another test (the lower Prow Pass Tuff). This test was conducted to determine 
the
reproducibility and variability of the experiments. The five different intervals tested in 
the
diffusion cell experiments represented all of the major lithologies in either the Bullfrog 
field
tracer test or the Prow Pass field tracer test (see Table 6.3-20 for specific intervals tested).
ANL-NBS-HS-000039, REV 00 260 December 2003
A schematic drawing of the experimental diffusion cell apparatus is illustrated in Figure 
6.3-49.
The apparatus consists of two Plexiglas reservoirs, one large and one small, separated by 
a
"pellet" of tuff, which is cut/cored from C-wells core and incorporated into either a flat 
epoxy
cast or a room-temperature vulcanizing (RTV) silicone cast of the same thickness as the 
pellet.
After saturating the tuff, experiments were initiated by carefully pouring a solution 
containing
PFBA and LiBr into the large reservoir and tracer-free solution into the small reservoir. 
The
pressures in the two reservoirs were kept approximately equal to minimize advective flow
through the tuff, thus ensuring that tracer movement through the tuff was by diffusion 
only. The
small reservoir was kept well mixed with a magnetic stir bar and flushed continuously at 
a
relatively low flow rate. The flush water was collected in an automatic fraction collector, 
and
fractions were analyzed for tracers to establish breakthrough curves through the tuff from 
which
diffusion coefficients could be estimated. As in the other laboratory experiments, PFBA 
and
bromide were analyzed by liquid chromatography, and lithium was analyzed by ICP-
AES.
Filtered J-13 water or synthetic J-13 water (a sodium/calcium bicarbonate solution having 
the
same ionic strength as J-13 water - see Reimus 2000 [165121] for details) were used in 
all
experiments.
The porosities of the tuffs were measured by subtracting dry weights from saturated 
weights of
intact tuff samples and dividing by the volumes of the samples (measured by water
displacement). Porosity measurements were used to obtain unambiguous estimates of 
diffusion
coefficients in the tuff matrices (see equations below). Hydraulic 
conductivities/permeabilities
of the tuffs were also measured by imposing a known head difference across the tuff 
pellets,
either before or after a diffusion experiment was conducted. The flow through the pellets 
at the
imposed head difference was measured by weighing the water that flowed through the 
pellet over
a specified amount of time.
Hydraulic conductivities were then calculated from the following equation:
H A
L Q
K
?
- = (Eq. 15)
where
K = hydraulic conductivity, cm/sec
?H = water height (head) difference across pellet, cm
A = surface area of pellet, cm2
Q = volumetric flow rate through pellet, ml/sec
L = thickness of pellet, cm.
Permeabilities were calculated from hydraulic conductivities using the following well-
known
formula (Freeze and Cherry 1979 [101173], pp. 26 to 30):
ANL-NBS-HS-000039, REV 00 261 December 2003
* ?g
K
k
10 x 1.013 = 11
?
?
(Eq. 16)
where
k = permeability, millidarcys (mD)
* = water viscosity, g/cm-sec (1.00 centipoise or 0.01 g/cm-sec at 20oC (Weast and Astle
1981 [100833], p. F-42))
* = water density, g/cm3 (0.998 g/cm3 at 20oC (Weast and Astle 1981 [100833], p. F-11))
g = acceleration due to gravity, cm/sec2 (980 cm/sec2 on Earth (Weast and Astle 1981
[100833], p. F-144))
and the constant 1.013 x 1011 has units of mD/cm2.
For illustration purposes only
Figure 6.3-49. Diffusion Cell Experimental Apparatus
ANL-NBS-HS-000039, REV 00 262 December 2003
To estimate diffusion coefficients, it was assumed that the tracers moved according to 1-
D
diffusive transport through the tuff pellets. The 1-D diffusion equation is:
2
2
=
x
c
R
D
t
c
* 
* 
* 
* 
(Eq. 17)
where
c = tracer concentration in tuff pellet, g/mL
D = diffusion coefficient, cm2/sec
R = retardation factor (1 for nonsorbing solutes),
x = position within tuff pellet (x = 0 at inlet reservoir), cm
t = time, sec.
Although analytical solutions to this simple partial differential equation exist for simple
boundary conditions (Jenson and Jeffreys 1977 [156836], pp. 291 to 295), the time-
dependent
concentration boundary conditions at the inlet and outlet reservoirs in the diffusion cell
experiments demand a numerical solution. Thus, Equation 17 was solved using an 
implicit
finite-difference technique. The equations describing the tracer concentrations in the inlet 
and
the outlet reservoirs (the first and last finite difference nodes), respectively, were:
0 i
2
i =
* x x
c
V
D r
t
c
* 
* * ?
* 
* 
(Eq. 18)
o
o o
2
o - - = c
V
q
x
c
V
D r
t
c
L x* * 
* * ?
* 
* 
(Eq. 19)
where
ci = tracer concentration in inlet reservoir, g/mL
co = tracer concentration in outlet reservoir, g/mL
Vi = volume of inlet reservoir, mL
Vo = volume of outlet reservoir, mL
q = flush rate of outlet reservoir, mL/sec
* = porosity of tuff
r = radius of tuff "pellet", cm
L = thickness of tuff "pellet", cm.
The numerical solution of Equations 17, 18, and 19 was obtained using computer code
DIFFCELL 2.0 (STN: 10557-2.0-00 [159063]). This code allows the user to specify 
changes in
the flush rate, q, with time, which was necessary to simulate the manner in which the
experiments were conducted.
ANL-NBS-HS-000039, REV 00 263 December 2003
6.3.8.2 Results and Discussion
Figures 6.3-50 through 6.3-55 show the breakthrough curves of the bromide and PFBA in 
each
of the six diffusion cells along with "fits" to the data obtained using DIFFCELL 2.0 
(STN:
10557-2.0-00 [159063]). The "fits" are not actual least-squares fits; rather, they were 
obtained
by manual adjustment of the diffusion coefficients until a reasonable match to the data 
was
obtained. The apparent discontinuities in some of the data sets and the corresponding 
model
predictions are a consequence of changes in the flush rate through the outlet reservoirs. A
decrease in concentration occurs when the flush rate is increased and vice-versa.
The resulting estimates of tracer diffusion coefficients in each diffusion cell are given in 
Table
6.3-20 (measured tuff porosities, pellet thicknesses, and tuff permeabilities are also listed 
in this
table). It is apparent that there is about an order of magnitude range of diffusion 
coefficients in
the various tuff lithologies. Figures 6.3-56 and 6.3-57 show the bromide diffusion 
coefficients in
the tuff matrices as a function of porosity and permeability, respectively, for the five 
different Cwells
tuffs. Although the diffusion coefficients are not well correlated with porosity, they are
quite well correlated with permeability (on a log-log scale). This result suggests that
permeability may be a good predictor of matrix diffusion coefficients. Such correlations 
could
prove useful for estimating matrix diffusion coefficients, as diffusion coefficients are 
typically
more difficult to measure than matrix properties such as permeabilities.
Table 6.3-20 shows that excellent agreement was obtained between the two diffusion cell
experiments conducted for the same lithology (the lower Prow Pass Tuff). This result 
suggests
that the experiments have reasonably good reproducibility, although certainly more 
experiments
should be conducted in the same lithologies before measurement uncertainty and tuff 
variability
can be properly assessed.
It is interesting to note that although the PFBA and bromide diffusion coefficients are
significantly different in the different tuffs, the ratios of the diffusion coefficients are
approximately the same in each tuff. This result suggests that advection through the tuff 
pellets
was successfully eliminated, as any advection would result in different ratios in different 
tests.
The factor of ~3 difference in the diffusion coefficients of the PFBA and bromide is the 
basis for
assuming a factor of 3 difference in all of the field and laboratory tracer-test 
interpretations in
this report.
ANL-NBS-HS-000039, REV 00 264 December 2003
DTN: MO0012DIFFCHOL.000 [159243] (data). Output DTN: LA0303PR831362.001 (model).
NOTE: Diffusion coefficients are given in Table 6.3-20.
Figure 6.3-50. Diffusion Cell Data (Tracer Concentrations in Outlet Reservoir
Normalized to Starting Concentrations in Inlet Reservoir, Co) and
DIFFCELL Model Fits for Bromide and PFBA in the Central Bullfrog Tuff
0.000
0.002
0.004
0.006
0.008
0.010
0.012
0 100 200 300 400 500 600 700
Time, hr
Concentration (C/Co)
Br Data
Br Model
PFBA Data
PFBA Model
ANL-NBS-HS-000039, REV 00 265 December 2003
DTN: MO0012DIFFCHOL.000 [159243] (data). Output DTN: LA0303PR831362.001 (model).
NOTE: Diffusion coefficients are given in Table 6.3-20.
Figure 6.3-51. Diffusion Cell Data (Tracer Concentrations in Outlet Reservoir Normalized to 
Starting
Concentrations in Inlet Reservoir, Co) and DIFFCELL Model Fits for Bromide and PFBA
in the Lower Bullfrog Tuff
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0 100 200 300 400 500 600 700
Time, hr
Concentration (C/Co)
Br Data
Br Model
PFBA Data
PFBA Model
ANL-NBS-HS-000039, REV 00 266 December 2003
DTN: MO0012DIFFCHOL.000 [159243] (data); Output DTN: LA0303PR831362.001 (model).
NOTE: Diffusion coefficients are given in Table 6.3-20.
Figure 6.3-52. Diffusion Cell Data (Tracer Concentrations in Outlet Reservoir Normalized to 
Starting
Concentrations in Inlet Reservoir, Co) and DIFFCELL Model Fits for Bromide and PFBA
in the Upper Prow Pass Tuff
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0 100 200 300 400 500 600 700
Time, hr
Concentration (C/Co)
Br Data
Br Model
PFBA Data
PFBA Model
ANL-NBS-HS-000039, REV 00 267 December 2003
DTN: MO0012DIFFCHOL.000 [159243] (data). Output DTN: LA0303PR831362.001 (model).
NOTE: Diffusion coefficients are given in Table 6.3-20.
Figure 6.3-53. Diffusion Cell Data (Tracer Concentrations in Outlet Reservoir Normalized to 
Starting
Concentrations in Inlet Reservoir, Co) and DIFFCELL Model Fits for Bromide
and PFBA in the Central Prow Pass Tuff
0.000
0.002
0.004
0.006
0.008
0.010
0.012
0.014
0 100 200 300 400 500 600 700 800
Time, hr
Concentration (C/Co)
Br Data
Br Model
PFBA Data
PFBA Model
ANL-NBS-HS-000039, REV 00 268 December 2003
DTN: MO0012DIFFCHOL.000 [159243] (data). Output DTN: LA0303PR831362.001 (model).
NOTE: Diffusion coefficients are given in Table 6.3-20.
Figure 6.3-54. First Diffusion Cell Data (Tracer Concentrations in Outlet Reservoir Normalized to
Starting Concentrations in Inlet Reservoir, Co) and DIFFCELL Model Fits for Bromide
and PFBA in the Lower Prow Pass Tuff
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0 100 200 300 400 500 600 700 800
Time, hr
Concentration (C/Co)
Br Data
Br Model
PFBA Data
PFBA Model
ANL-NBS-HS-000039, REV 00 269 December 2003
DTN: MO0012DIFFCHOL.000 [159243] (data). Output DTN: LA0303PR831362.001 (model).
NOTE: Diffusion coefficients are given in Table 6.3-20.
Figure 6.3-55. Second Diffusion Cell Data (Tracer Concentrations in Outlet Reservoir Normalized 
to
Starting Concentrations in Inlet Reservoir, Co) and DIFFCELL Model Fits for Bromide
and PFBA in the Lower Prow Pass Tuff
0.000
0.005
0.010
0.015
0.020
0.025
0 100 200 300 400 500 600 700 800
Time, hr
Concentration (C/Co)
Br Data
Br Model
PFBA Data
PFBA Model
ANL-NBS-HS-000039, REV 00 270 December 2003
Table 6.3-20. Measured Porosities, Permeabilities, and Matrix Diffusion
Coefficients of Bromide and PFBA in C-wells Tuffs
Diffusion Coefficient (cm2/s x 106)
Tuff (a) Porosity Permeability
(mDarcy)
Thickness (b)
(cm) Br PFBA Br/PFBA
Central Bullfrog (1) 0.094 0.00107 1.12 0.42 0.12 3.5
Lower Bullfrog (3) 0.298 0.0949 0.79 1.0 0.35 2.86
Upper Prow Pass (4) 0.272 4.72 0.98 6.2 2.0 3.1
Central Prow Pass (5) 0.138 0.000786 1.23 0.38 0.13 2.92
Lower Prow-1 (6) (c) 0.288 0.455 2.27 3.0 1.1 2.73
Lower Prow-2 (6) (c) 0.288 0.455 1.82 2.8 1.0 2.8
DTNs: MO0012POROCHOL.000 [153376] (porosity); MO0012PERMCHOL.000 [153368] (permeability); 
MO0012DIFFCHOL.000
[159243] (diffusion cells). Output DTN: LA0303PR831362.001 (model results - diffusion coefficients).
NOTE: Synthetic J-13 water was used for the experiments involving the first three tuffs. Filtered J-13 water 
was
used in the other three experiments.
(a) Numbers in parentheses correspond to numbers in Figure 6.3-39 (locations where core was collected
from the C-wells) and in Table 6.3-16 (where actual depths associated with the cores are listed).
(b) Thickness, L, of tuff pellet.
(c) Experiments were conducted using two separate tuff pellets from the Lower Prow Pass Tuff.
DTN: MO0012POROCHOL.000 [153376] (porosity data). Output DTN: LA0303PR831362.001 (diffusion coefficients).
NOTE: Porosity and diffusion coefficient for bromide are listed in Table 6.3-20.
Figure 6.3-56. Bromide Diffusion Coefficients Versus Tuff Porosity
for all C-wells Diffusion Cell Experiments
0
1
2
3
4
5
6
7
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
Matrix Porosity
Diffusion Coef., cm 2/s X 10 6
ANL-NBS-HS-000039, REV 00 271 December 2003
DTN: MO0012PERMCHOL.000 [153368] (permeability data). Output DTN: LA0303PR831362.001 (diffusion coefficients).
NOTE: Permeability and diffusion coefficient are listed in Table 6.3-20.
Figure 6.3-57. Bromide Diffusion Coefficients Versus Tuff Permeability
for all C-wells Diffusion Cell Experiments
6.3.9 Laboratory Studies of Lithium Transport in Crushed Tuff Columns and 
Fractured
Cores
Several laboratory transport experiments were conducted to study lithium transport under
flowing conditions in both columns packed with crushed C-wells tuff and fractured C-
wells
cores (Reimus 2003 [163760], Attachments A, B1, and B2). The crushed-tuff column
experiments were conducted to compare lithium sorption parameters under flowing 
conditions to
batch-sorption measurements. The fractured-core experiments were conducted to study 
lithium
transport under more realistic fracture flow conditions where matrix diffusion and 
sorption in the
matrix should also influence transport. The crushed-tuff experiments are described in 
Section
6.3.9.1, and the fractured-core experiments are described in Section 6.3.9.2.
6.3.9.1 Crushed-Tuff Column Experiments
6.3.9.1.1 Experimental Methods
A series of transport experiments was conducted in plexiglass columns 91.44 cm in 
length and
0.62 cm in diameter (Reimus 2003 [163760], Attachment A). The columns were packed 
with
crushed central Bullfrog Tuff (from location number 2 in Figure 6.3-39) that had been 
wetsieved
to a size range between 75 and 500 ?m. A wet slurry technique was used to pack the
0
1
2
3
4
5
6
7
0.0001 0.001 0.01 0.1 1 10
Matrix Permeability, mDarcy
Diffusion Coef., cm 2/s X 10 6
ANL-NBS-HS-000039, REV 00 272 December 2003
columns. Column porosity was measured at ~57% (average of two columns), and dry 
bulk
density was calculated at 1.14 g/mL by assuming a mineral density of 2.65 g/mL, which 
are
typical values for columns prepared in this fashion (e.g., Treher and Raybold 1982 
[125967], pp.
8 to 9; Thompson 1989 [100830], pp.353 to 364). Two columns were prepared 
identically. The
column apparatus included a constant-rate pump, a valve to switch between a reservoir
containing J-13 "background" water and a solution of lithium bromide in J-13 water, and 
an
automatic fraction collector at the downstream end of the column. Each experiment 
began by
pumping approximately 180 mL (roughly 12 pore volumes) of J-13 water through the 
column at
a specified flow rate to equilibrate the tuff with the groundwater. The input was then 
switched to
a lithium bromide solution, which was maintained for approximately three pore volumes 
before
being switched back to tracer-free groundwater. Effluent samples were analyzed for 
lithium and
bromide using liquid chromatography (detection limits were 0.10 mg L-1 for Li+ and 
0.005 mg
L-1 for Br-). Bromide was used as a nonsorbing tracer to determine mean residence times 
and
dispersivities in the columns as well as to serve as a nonsorbing tracer against which 
lithium
retardation could be gauged.
A total of five experiments were conducted in the two columns, with the tracer 
concentrations
and flow rate both being varied. In three of the five column experiments, the responses of 
Li+
and Br- were monitored until concentrations returned to background levels; in the other 
two
experiments, concentrations were monitored only until they leveled off at the inlet
concentrations. The experimental conditions are summarized in Table 6.3-21. The 
different
tracer concentrations were intended to investigate potential effects of lithium sorption
nonlinearity, and the different flow rates were intended to reveal rate-limited effects such 
as
sorption nonequilibrium or diffusion-controlled sorption rates. All tests were conducted 
at 25C.
Table 6.3-21. Results of RELAP Fits to Rising Limbs of Lithium and Bromide
Breakthrough Curves in Crushed Tuff Columns
Column Figure Flow Rate
(mL/hr)
Li Conc.
(mg/L)
?
(hr)
Pe RF kf
(1/hr) Da
1* 6.3-58 2.2 23.5 7.6 250 2.0 (2.0) 3.1 24
1 6.3-59 1.6 23.5 10.3 260 2.0 (2.0) 3.7 38
1* 6.3-60 9.7 20.1 1.8 580 1.8 (1.7) 8.8 16
2* 6.3-61 2.2 5.9 7.7 870 2.3 (2.3) 22 169
2 6.3-62 1.6 5.9 10.4 750 2.3 (2.25) 4.6 48
DTN: LA0301PR831231.001 [162603] (for flow rates and concentrations). Output DTN: LA0303PR831361.003 (model 
results).
NOTE: *Denotes experiments in which tracer concentrations were monitored until background levels were 
reached.
In this table, * is residence time; Pe is the Peclet number; Rf is the retardation factor; kf is the rate constant
for sorption onto the column material; and Da is the Damkohler number (= kf ?), which represents the ratio of
reaction rate to advection rate in the columns. Rf values in parentheses indicate the best-fitting retardation
factors when equilibrium sorption was assumed (i.e., very fast sorption kinetics).
ANL-NBS-HS-000039, REV 00 273 December 2003
6.3.9.1.2 Interpretive Methods
The bromide responses in the experiments were interpreted using the RELAP V 2.0 
computer
code (STN: 10551-2.0-00 [159065]) to obtain estimates of mean residence times and
dispersivities/Peclet numbers in the columns. RELAP was also used to fit the rising limbs 
of the
lithium responses in each experiment to obtain an estimate of the lithium retardation 
factor in the
columns. The rate-limited sorption features of RELAP were also used to obtain an 
estimate of
the rate constant (kf) describing lithium sorption onto the column packing material. The 
rate
constants were obtained by relaxing the equilibrium sorption assumption and adjusting 
the rate
constants for each data set until the RELAP fits were optimized. Damkohler numbers (kf 
?),
which represent the ratio of reaction rate to advection rate in the columns, were 
calculated for
each experiment. Damkohler numbers significantly greater than one indicate a system 
that can
be treated as being at equilibrium locally (Valocchi 1985 [144579], pp. 808 to 820).
It was apparent that while RELAP V 2.0 (STN: 10551-2.0-00 [159065]) could fit the 
arrival of
lithium, it could not fit the tails of the lithium responses when concentrations were 
monitored
until they returned to background levels. The tails exhibited a behavior suggesting that a 
portion
of the lithium eluted with the bromide as if it were a nonsorbing tracer. This behavior can 
occur
when an ion-exchanging cation such as lithium comprises the majority of the cation 
equivalents
in the tracer solution, which was certainly the case in the higher-concentration LiBr 
experiments.
Essentially, if the CEC of the tuff and the exchange equilibria are not sufficient to 
exchange all
of the lithium injected into a column, then some of the lithium must elute with the 
bromide to
maintain charge balance in the solution exiting the column. Thus, for the tests in which 
the
lithium was fully eluted from the columns, the MULTRAN V 1.0 computer code ([STN: 
10666-
1.0-00 [159068]), which is capable of explicitly modeling cation exchange and 
maintaining
solution charge balance, was used to interpret the lithium responses (see Section 6.3.9.2.2 
for
description of the code).
6.3.9.1.3 Results and Interpretations
The rising limbs of the breakthrough curves for the five experiments along with the 
RELAP V
2.0 (STN: 10551-2.0-00 [159065]) fits to the data are shown in Figures 6.3-58 through 
6.3-62.
The best-fitting model parameters are listed in Table 6.3-21. Although significant 
improvements
to the RELAP fits of the lithium breakthrough curves were obtained by assuming finite 
sorption
rates, the relatively large Damkohler numbers listed in Table 6.3-21 suggest that the local
equilibrium assumption is reasonably valid in the columns. Furthermore, this assumption 
should
be even more valid in field experiments where tracer residence times are much longer 
than in the
columns. Figure 6.3-58 shows the results of fitting the lithium response curve from one of 
the
experiments assuming a nonlinear (Langmuir) sorption isotherm with parameters 
obtained from
batch sorption testing (KL = 0.0058 mL/?g and Smax = 106 ?g/g for the Bullfrog Tuff 
from c#2
used in these columns). It is apparent that the model fits are not improved by assuming a
nonlinear isotherm. The RETRAN V 2.0 computer code (STN: 10552-2.0-00 [159066]) 
was
used for the nonlinear simulations.
ANL-NBS-HS-000039, REV 00 274 December 2003
DTN: LA0301PR831231.001 [162603] (data). Output DTN: LA0303PR831361.003 (models).
NOTE: The curves above are numbered as follows:
(i) fit to bromide data with a Peclet number of 250
(ii) fit to lithium data assuming linear isotherm (RF = 2.0) with equilibrium sorption
(iii) fit to lithium data assuming linear isotherm with a forward rate constant of 3.1 1/hr (and RF = 2.0)
(iv) fit to lithium data assuming a Langmuir isotherm with equilibrium sorption
(v) fit to lithium data assuming a Langmuir isotherm with a forward rate constant of 3.2 1/hr.
Langmuir isotherm parameters: KL = 0.0058 mL/g and Smax = 105.8 g/g (batch isotherm values
obtained for lithium on central Bullfrog Tuff from UE-25 c#2).
Figure 6.3-58. Bromide and Lithium Breakthrough Curves in Column 1 at a Flow Rate
of 2.2 mL/hr and Corresponding RELAP and RETRAN Fits to Data
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0 5 10 15 20 25
Time, hr
Concentration (C/Co)
i
ii
iii
iv
v
Bromide
Lithium
ANL-NBS-HS-000039, REV 00 275 December 2003
DTN: LA0301PR831231.001 [162603] (data). Output DTN: LA0303PR831361.003 (models).
NOTE: The curves above are numbered as follows:
(i) fit to bromide data with a Peclet number of 260
(ii) fit to lithium data assuming linear isotherm (RF = 2.0) with equilibrium sorption
(iii) fit to lithium data assuming linear isotherm with a forward rate constant of 3.7 1/hr (and RF = 2.0).
Figure 6.3-59. Bromide and Lithium Breakthrough Curves in Column 1 at a Flow Rate
of 1.6 mL/hr and Corresponding RELAP Fits to Data
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0 5 10 15 20 25 30
Time, hr
Concentration (C/Co)
i
ii
iii
Bromide
Lithium
ANL-NBS-HS-000039, REV 00 276 December 2003
DTN: LA0301PR831231.001 [162603] (data). Output DTN: LA0303PR831361.003 (models).
NOTE: The curves above are numbered as follows:
(i) fit to bromide data with a Peclet number of 580
(ii) fit to lithium data assuming linear isotherm (RF = 1.7) with equilibrium sorption
(iii) fit to lithium data assuming linear isotherm with a forward rate constant of 8.8 1/hr (and RF = 1.8).
Figure 6.3-60. Bromide and Lithium Breakthrough Curves in Column 1 at a Flow Rate
of 9.7 mL/hr and Corresponding RELAP Fits to Data
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0 1 2 3 4 5 6
Time, hr
Concentration (C/Co)
i
ii
iii
Bromide
Lithium
ANL-NBS-HS-000039, REV 00 277 December 2003
DTN: LA0301PR831231.001 [162603] (data). Output DTN: LA0303PR831361.003 (models).
NOTE: The curves above are numbered as follows:
(i) fit to bromide data with a Peclet number of 870
(ii) fit to lithium data assuming linear isotherm (RF = 2.3) with equilibrium sorption
(iii) fit to lithium data assuming linear isotherm with a forward rate constant of 22 1/hr (and RF = 2.3).
Figure 6.3-61. Bromide and Lithium Breakthrough Curves in Column 2 at a Flow Rate
of 2.2 mL/hr and Corresponding RELAP Fits to Data
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0 5 10 15 20 25
Time, hr
Concentration (C/Co)
i
ii
iii
Bromide
Lithium
ANL-NBS-HS-000039, REV 00 278 December 2003
DTN: LA0301PR831231.001 [162603] (data). Output DTN: LA0303PR831361.003 (models).
NOTE: The curves above are numbered as follows:
(i) fit to bromide data with a Peclet number of 750
(ii) fit to lithium data assuming linear isotherm (RF = 2.3) with equilibrium sorption
(iii) fit to lithium data assuming linear isotherm with a forward rate constant of 4.6 1/hr (and RF = 2.25).
Figure 6.3-62. Bromide and Lithium Breakthrough Curves in Column 2 at a Flow Rate
of 1.6 mL/hr and Corresponding RELAP Fits to Data
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0 5 10 15 20 25 30
Time, hr
Concentration (C/Co)
i
ii
iii
Bromide
Lithium
ANL-NBS-HS-000039, REV 00 279 December 2003
Table 6.3-21 shows that lithium retardation factors (RFs) for the tests with lower tracer
concentrations ranged from 2.2 to 2.3, with a mean of 2.25; whereas RFs for the higher
concentration tests ranged from 1.7 to 2.0, with a mean of 1.87. The observed decreased 
RF at
higher concentrations is consistent with a nonlinear sorption isotherm. For the Langmuir
isotherm, the RF can be shown to be (Fetter 1993 [102009], pp. 122 to 123):
* * * 
?
?
* * 
?
?
* * 2
L
max L B
F 1
1
C K
S K
R
?
* (Eq. 20)
where
?B is the dry bulk density of the medium (g/mL)
* is the volumetric moisture content, or porosity for a saturated medium.
By solving Equation 20 with the batch Langmuir parameters obtained for the Central 
Bullfrog
Tuff used in the column experiments (KL = 0.0053 mL/?g and Smax = 110 ?g/g - see 
Table 6.3-
18 footnote) and column values for ?B and ?, retardation factor predictions of 2.11 are 
obtained
for the lower concentration tests and 1.95 for the higher concentration tests. Overall these
predictions match the RF values of Table 6.3-21 very well, differing by 7% or less for 
both
concentration levels. The MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) fits to the 
full data
sets for the three experiments in which tracer concentrations were monitored until they 
returned
to background levels are shown in Figures 6.3-63 to 6.3-65. The Q1 and Q2 values listed 
in
these figures correspond to the "selectivity coefficients" for the following cation 
exchange
reactions:
] Li ][ Na [
] Na ][ Li [
Na Li Na Li 1 ?
?
* * * * * ?
X
X
Q X X (Eq. 21)
2
2
2 2
2
2
2 ] ][Li [Ca
] [Ca ] [Li
Ca Li 2 Ca Li 2 ?
?
* * * * * ?
X
X
Q X X (Eq. 22)
where X = a negatively charged surface site.
In addition to these reactions, MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) also 
accounts
for the exchange between sodium and calcium ions, and it solves the surface cation-
exchange
balance equation for a three-component system:
2
2
2 2
2
1
2 2
2 ] Na ][ Ca [
] Ca [ ] Na [
Ca Na 2 Ca Na 2 ?
?
* * * * * ?
X
X
Q
Q
X X , (Eq. 23)
]) Ca [ 2 ] Na [ ] Li [ ( 2 X X X CEC B * * ?
?
?
(Eq. 24)
The measured CEC for the Bullfrog Tuff (Section 6.3.7.2) was used as the CEC value in 
the
model simulations, and the selectivity coefficients Q1 and Q2 were adjusted to fit the 
lithium
ANL-NBS-HS-000039, REV 00 280 December 2003
data. However, without sodium and calcium concentration data, it was not possible to 
obtain a
unique fit to the lithium responses. In fact, the lithium responses could be fit equally well
assuming lithium exchange with only sodium or only calcium. Thus, the Q1 and Q2 values
presented in Figures 6.3-63 through 6.3-65 should be considered as only one of many 
possible
combinations that could fit the lithium data equally well. However, it is not the values of 
these
parameters that are important but rather the recognition that cation-exchange equilibria 
must be
explicitly accounted for to explain the observed transport behavior of the lithium. For
comparison, a RELAP V 2.0 (STN: 10551-2.0-00 [159065]) "fit" to the data from Figure 
6.3-63
is shown in Figure 6.3-66. It is clear that the single-component equilibrium Kd-model fit 
cannot
capture the tailing behavior of the lithium. These results could have important 
implications for
field tracer tests conducted in porous media that have a small sorption capacity for 
cationexchanging
tracers.
DTN: LA0301PR831231.001 [162603] (data). Output DTN: LA0303PR831361.003 (model).
NOTE: "MULTRAN Params" refers to the parameter values used in MULTRAN V 1.0 (STN: 10666-1.0-00 
[159068])
to obtain the simulated curves.
Figure 6.3-63. MULTRAN Fits to Complete Bromide and Lithium Breakthrough Curves
from High-Concentration Experiment Conducted at 9.7 mL/hr in Column 1 (Figure 6.3-60)
0
0.0005
0.001
0.0015
0.002
0.0025
0.003
0 10 20 30 40 50 60 70 80 90 100 110 120
Volume, ml
mol/L
Br Data
Li Data
Br MULTRAN
Li MULTRAN
MULTRAN Params:
Q1 = 0.04
Q2 = 0.06
CEC = 0.037 eq/kg
ANL-NBS-HS-000039, REV 00 281 December 2003
DTN: LA0301PR831231.001 [162603] (data). Output DTN: LA0303PR831361.003 (model).
NOTE: "MULTRAN Params" refers to the parameter values used in MULTRAN V 1.0 (STN: 10666-1.0-00 
[159068])
to obtain the simulated curves.
Figure 6.3-64. MULTRAN Fits to Complete Bromide and Lithium Breakthrough Curves
from High-Concentration Experiment Conducted at 2.2 mL/hr in Column 1 (Figure 6.3-58)
0
0.0005
0.001
0.0015
0.002
0.0025
0.003
0.0035
0.004
0 10 20 30 40 50 60 70 80 90 100 110
Volume, ml
mol/L
Br Data
Li Data
Br MULTRAN
Li MULTRAN
MULTRAN Params:
Q1 = 0.045
Q2 = 0.05
CEC = 0.037 eq/kg
ANL-NBS-HS-000039, REV 00 282 December 2003
DTN: LA0301PR831231.001 [162603] (data). Output DTN: LA0303PR831361.003 (model).
NOTE: "MULTRAN Params" refers to the parameter values used in MULTRAN V 1.0 (STN: 10666-1.0-00 
[159068])
to obtain the simulated curves.
Figure 6.3-65. MULTRAN Fits to Complete Bromide and Lithium Breakthrough Curves
from Low-Concentration Experiment Conducted at 2.2 mL/hr in Column 2 (Figure 6.3-61)
0
0.0002
0.0004
0.0006
0.0008
0.001
0 10 20 30 40 50 60 70 80 90 100 110 120
Volume, ml
mol/L
Br Data
Li Data
Br MULTRAN
Li MULTRAN
MULTRAN Params:
Q1 = 0.05
Q2 = 0.072
CEC = 0.037 eq/kg
ANL-NBS-HS-000039, REV 00 283 December 2003
DTN: LA0301PR831231.001 [162603] (data). Output DTN: LA0303PR831361.003 (model).
Figure 6.3-66. RELAP Fits to Complete Bromide and Lithium Breakthrough Curves from 
Experiment
Conducted at 9.7 mL/hr in Column 1 (Figure 6.3-63 shows the MULTRAN fits)
6.3.9.2 Fractured-Core Experiments
6.3.9.2.1 Experimental Methods
Fractured-core transport experiments were conducted on four separate cores obtained 
from the
C-wells following the procedure of Callahan et al. (2000 [156648], pp. 3547 to 3558). 
The
experiments are documented in detail in Reimus (2003 [163760], Attachments B1 and 
B2). The
cores were obtained from locations 3, 4, 5, and 6 in Figure 6.3-39. In the following 
discussion,
the cores from the upper, central, and lower flow zones of the Prow Pass Tuff (locations 
4, 5, and
6, respectively) will be referred to as cores 1, 2, and 3, respectively. The core from the 
lower
flow zone of the Bullfrog Tuff will be referred to as core 4. The mineralogy of the cores 
is given
in Table 6.3-17. Core 4 (lower flow zone of the Bullfrog Tuff) contained the highest 
percentage
of clay and zeolite minerals, 9 * 3 wt. % smectite, 4 * 1 wt % clinoptilolite, and 13 * 1 
wt. %
analcime. A single fracture was mechanically induced in each of the four cores. The cores 
were
laid on a cement floor and a four-pound hammer and chisel were used to induce an axial 
fracture
running the length of the core. The cores were then encased in an epoxy and Plexiglas 
column
apparatus following the procedure of Callahan et al. (2000 [156648]). Figure 6.3-67 
shows a
schematic illustration of a column experimental system.
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0 2 4 6 8 10 12 14
Time, hr
Concentration (C/Co)
Bromide
Lithium
Bromide RELAP
Lithium RELAP
ANL-NBS-HS-000039, REV 00 284 December 2003
Cross-section Top view
Flow ports
Induced
fracture
Epoxy
fill
Lucite
sleeve
12 cm
16-17 cm
Rock
core
For illustration purposes only
NOTE: Three flow ports on each end of the core allowed access to the inlet and outlet regions; the central 
flow ports
were used to connect the cores to a syringe pump and fraction collector via a 0.8-mm diameter tubing. The
lengths of the cores varied, but the diameters of all cores were 9.5 cm.
Figure 6.3-67. Schematic Illustration of a Fractured Rock Core Experimental System
The tracer experiments conducted in each core are summarized in Tables 6.3-22 through 
6.3-27.
As described by Callahan et al. (2000 [156648]), cores 1 and 2 each featured three 
experiments
in which iodide was used as a nonsorbing tracer at three different flow rates. The 
objective of
these experiments was to obtain estimates of matrix-diffusion, mass-transfer parameters 
in the
cores by using RELAP to fit simultaneously the iodide responses at each flow rate. All 
four
cores also featured at least two multiple-tracer experiments that were conducted and 
interpreted
very similarly to the C-wells field tracer tests. Each experiment involved the injection of 
a pulse
containing PFBA, lithium bromide (LiBr), and, in some cases, sodium iodide (NaI). Five
multiple-tracer experiments were conducted in core 1. Two of these experiments were 
intended
to be replicates, and they yielded very similar results, indicating good experimental
reproducibility. Only two multiple-tracer tests were conducted in each of the other three 
cores.
The flow rate in at least one of the multiple-tracer experiment in each core was 
approximately an
order of magnitude lower than the flow rate(s) in the other multiple-tracer experiment(s). 
Flow
rates were varied over this large range so that the effect of experiment time scale on 
matrix
diffusion processes could be assessed in fracture systems of constant geometry. The 
fractures
were thoroughly flushed after each experiment so that residual tracer concentrations were
minimized in subsequent experiments.
A steady-state flow field was established in each core by continuously injecting degassed,
filtered groundwater obtained from well J-13. A pulse of tracer solution (tracers dissolved 
in J-
13 water) was then injected. After injection of the tracer pulse, continuous injection of 
tracerfree
J-13 well water was resumed. The effluent was monitored for the tracer ions as well as 
for
Na+ and Ca2+ using ion chromatography for Br- and PFBA and ICP-AES for analysis of 
Li+, Na+,
and Ca2+. Iodide was analyzed either using an ion-selective electrode or ion 
chromatography.
The quantitative detection limits were 0.05 mg/L for Li+, Na+, and Ca2+, 0.04 mg/L for 
Br-, 0.02
mg/L for I-, and 0.02 mg L-1 for PFBA. Na+ and Ca2+ were analyzed so that cation 
exchange
ANL-NBS-HS-000039, REV 00 285 December 2003
equilibria could be more rigorously quantified than in the crushed-tuff column 
experiments
described in Section 6.3.9.1. Cu-EDTA (copper complexed with ethylenediamine 
tetraacetic
acid) was used as a tracer in some of the experiments to determine its potential to serve as 
a
weakly sorbing tracer in field tests. In some of the tests (Tables 6.3-23 through 6.3-27), 
flow
was interrupted for a time after the tracer concentrations had been tailing to verify 
diffusive mass
transfer in the cores (Brusseau et al. 1997 [156647], pp. 205 to 219; Callahan et al. 2000
[156648]). This strategy was similar to that used in the Prow Pass multiple-tracer field 
test
(Section 6.3.4.4).
Table 6.3-22. Experimental Conditions for the Iodide Fracture Transport Tests,
Upper Prow Pass Tuff Core (Core 1)
Experimental Parameters
Core length, L (m) 0.161
Core width, w (m) 0.095
Matrix porosity, nm 0.272
Hydraulic aperture, Bh (m) (a) 0.14 x 10-3
Iodide tests: Test 1 Test 2 Test 3
Volumetric flow rate, Q (mL/hr) 2.2 19.6 8.7
Injection duration, tp (hr) 28.02 3.08 7.23
Injection concentration, Co (mg/L) 1000 1000 1000
Flow interruption period, time since start of injection (hr) N/A (b) N/A(b) N/A (b)
Flow rate after restart, Q (mL/hr) N/A (b) N/A(b) N/A (b)
Mass recovery (%) 86 96 94
Source: Reimus (2003 [163760], Attachment B1).
NOTE: (a) Determined from a constant head permeameter method.
(b) N/A: Not applicable; flow was not interrupted during these tests.
ANL-NBS-HS-000039, REV 00 286 December 2003
Table 6.3-23. Experimental Conditions for the Multiple-Tracer Fracture Transport Tests,
Upper Prow Pass Tuff Core (Core 1)
Experimental Parameters Test 1 Test 2
Volumetric flow rate, Q (mL/hr) 3.8 3.9
Injection duration, tp (hr) 14.97 15.22
Injection concentration, Co (mg/L)
192 (Li+)
0 (Na+)
0 (Ca2+)
1728 (Br-)
300 (I-)
635 (PFBA)
192 (Li+)
0 (Na+)
0 (Ca2+)
1728 (Br-)
300 (I-)
635 (PFBA)
Background groundwater concentration, Ci (mg/L)
0.64 (Li+)
46.7 (Na+)
12.8 (Ca2+)
3.63 (Br-)
1.8 (I-)
1.11 (PFBA)
1.79 (Li+)
45.4 (Na+)
12.8 (Ca2+)
10.7 (Br-)
0.55 (I-)
3.86 (PFBA)
Flow interruption period,
time since start of injection (hr) 87.3-137.3 87.1-137.2
Flow rate after restart, Q (mL/hr) 3.96 3.99
Mass recovery (%)
89 (Li+)
89 (Br-)
92 (I-)
95 (PFBA)
89 (Li+)
89 (Br-)
86 (I-)
95 (PFBA)
Experimental Parameters Test 3 Test 4 Test 5
Volumetric flow rate, Q (mL hr-1) 0.51 7.9 6.3
Injection duration, tp (hr) 156.85 19.0 10.5
Injection concentration, Co (mg/L)
159 (Li+)
394 (Na+)
0 (Ca2+)
1870 (Br-)
296 (I-)
641 (PFBA)
145 (Cu2+)
699 (EDTA (b))
1010 (Li+)
59.1 (Na+)
0 (Ca2+)
11400 (Br-)
N/A (a) (I-)
766 (PFBA)
216 (Li+)
250 (Na+)
0 (Ca2+)
2528 (Br-)
N/A (a) (I-)
766 (PFBA)
192 (Cu2+)
1131 (EDTA (b))
Background groundwater concentration, Ci (mg/L)
0.08 (Li+)
51.8 (Na+)
13.2 (Ca2+)
10.87 (Br-)
< 0.4 (I-)
2.07 (PFBA)
0.08 (Li+)
45 (Na+)
13.3 (Ca2+)
< 0.02 (Br-)
< 0.4 (I-)
< 0.005 (PFBA)
0.53 (Li+)
45 (Na+)
13.3 (Ca2+)
0.98 (Br-)
< 0.4 (I-)
< 0.005 (PFBA)
Flow interruption period,
time since start of injection (hr) 689-904 19.8-21.2,
49.9-64.2 44.0-64.0
Flow rate after restart, Q (mL/hr) 0.51
8.05,
8.04
6.46
Mass recovery (%)
83 (Li+)
94 (Br-)
82 (I-)
94 (PFBA)
89 (Li+)
89 (Br-)
N/A (a) (I-)
95 (PFBA)
89 (Li+)
89 (Br-)
N/A (a) (I-)
95 (PFBA)
Source: Reimus (2003 [163760], Attachment B1).
NOTE: (a) N/A: not applicable; iodide was not injected in these tests.
(b) EDTA: ethylenediamine tetraacetic acid.
ANL-NBS-HS-000039, REV 00 287 December 2003
Table 6.3-24. Experimental Conditions for the Iodide Fracture Transport Tests,
Central Prow Pass Tuff Core (Core 2)
Experimental Parameters
Core length, L (m) 0.173
Core width, w (m) 0.095
Matrix porosity, nm 0.138
Hydraulic aperture, Bh (m) (a) 0.13 x 10-3
Test 1 Test 2 Test 3
Volumetric flow rate, Q (mL/hr) 19.7 49.3 11.3
Injection duration, tp (hr) 4.0 1.47 6.05
Injection concentration, Co (mg/L) 1000 1000 1000
Flow interruption period,
time since start of injection (hr) N/A (b) N/A (b) N/A (b)
Flow rate after restart, Q (mL/hr) N/A (b) N/A (b) N/A (b)
Mass recovery (%) 89 98 84
Source: Reimus (2003 [163760], Attachment B2).
NOTE: (a) Determined from a constant head permeameter method.
(b) N/A: not applicable; flow was not interrupted during these tests.
ANL-NBS-HS-000039, REV 00 288 December 2003
Table 6.3-25. Experimental Conditions for the Multiple-Tracer Fracture Transport Tests,
Central Prow Pass Tuff Core (Core 2)
Experimental Parameters Test 1 Test 2
Volumetric flow rate, Q (mL/hr) 5.9 0.44
Injection duration, tp (hr) 12.3 170
Injection concentration, Co (mg/L)
216 (Li+)
205 (Na+)
0 (Ca2+)
2528 (Br-)
N/A (a) (I-)
766 (PFBA)
192 (Cu2+)
1131 (EDTA (b))
159 (Li+)
301 (Na+)
0 (Ca2+)
1870 (Br-)
296 (I-)
641 (PFBA)
145 (Cu2+)
699 (EDTA (b))
Background groundwater concentration, Ci (mg/L)
0.08 (Li+)
45 (Na+)
13.3 (Ca2+)
< 0.02 (Br-)
< 0.4 (I-)
< 0.005 (PFBA)
0.55 (Li+)
75.1 (Na+)
10.0 (Ca2+)
1.97 (Br-)
0.9 (I-)
0.98 (PFBA)
Flow interruption period, time since start of injection (hr) 42.9-62.9 799-999
Flow rate after restart, Q (mL/hr) 5.95 0.44
Mass recovery (%)
84 (Li+)
90 (Br-)
N/A (a) (I-)
95 (PFBA)
68 (Li+)
97 (Br-)
97 (I-)
102 (PFBA)
Source: Reimus (2003 [163760], Attachment B2).
NOTE: (a) N/A: not applicable; iodide was not injected in these tests.
(b) EDTA: ethylenediamine tetraacetic acid.
ANL-NBS-HS-000039, REV 00 289 December 2003
Table 6.3-26. Experimental Conditions for the Multiple-Tracer Fracture Transport Tests,
Lower Prow Pass Tuff Core (Core 3)
Experimental Parameters
Core length, L (m) 0.116
Core width, w (m) 0.095
Matrix porosity, nm 0.288
Hydraulic aperture, Bh (m) (a) 0.16 x 10-3
Test 1 Test 2
Volumetric flow rate, Q (mL/hr) 11.4 0.46
Injection duration, tp (hr) 14.5 340
Injection concentration, Co (mg/L)
159 (Li+)
331 (Na+)
1.2 (Ca2+)
1870 (Br-)
296 (I-)
641 (PFBA)
145 (Cu2+)
699 (EDTA (b))
165 (Li+)
310 (Na+)
0 (Ca2+)
1930 (Br-)
299 (I-)
681 (PFBA)
150 (Cu2+)
699 (EDTA (b))
Background groundwater concentration, Ci (mg/L)
0.08 (Li+)
44.6 (Na+)
13.3 (Ca2+)
< 0.02 (Br-)
< 0.35 (I-)
< 0.005 (PFBA)
4.41 (Li+)
67.2 (Na+)
16.4 (Ca2+)
60.1 (Br-)
9.49 (I-)
16.2 (PFBA)
Flow interruption period, time since start of injection (hr) 43.6-68.6 792-992
Flow rate after restart, Q (mL/hr) 11.4 0.47
Mass recovery (%)
97.2 (Li+)
95.7 (Br-)
98.4 (I-)
99.3 (PFBA)
72.4 (Li+)
87.3 (Br-)
84.2 (I-)
80.1 (PFBA)
Source: Reimus (2003 [163760], Attachment B1).
NOTES: (a) Determined from a constant head permeameter method.
(b) EDTA: ethylenediamine tetraacetic acid.
ANL-NBS-HS-000039, REV 00 290 December 2003
Table 6.3-27. Experimental Conditions for the Multiple-Tracer Fracture Transport Tests,
Lower Bullfrog Tuff Core (Core 4)
Experimental Parameters Test 1 Test 2
Volumetric flow rate, Q (mL/hr) 5.0 0.47
Injection duration, tp (hr) 34.0 335.0
Injection concentration, Co (mg/L)
165 (Li+)
342 (Na+)
0 (Ca2+)
1930 (Br-)
299 (I-)
681 (PFBA)
150 (Cu2+)
699 (EDTA*)
192 (Li+)
0 (Na+)
0 (Ca2+)
1728 (Br-)
300 (I-)
635 (PFBA)
Background groundwater concentration,
Ci (mg/L)
0.04 (Li+)
51.1 (Na+)
11.0 (Ca2+)
0.14 (Br-)
0.07 (I-)
0.14 (PFBA)
4.41 (Li+)
67.2 (Na+)
16.4 (Ca2+)
60.1 (Br-)
9.49 (I-)
16.2 (PFBA)
Flow interruption period,
time since start of injection (hr) 67.2-87.2 79-992
Flow rate after restart, Q (mL/hr) 5.05 0.47
Mass recovery (%)
57 (Li+)
96 (Br-)
86 (I-)
99 (PFBA)
85 (Li+)
103 (Br-)
86 (I-)
91 (PFBA)
Source: Reimus (2003 [163760], Attachment B2).
NOTE: *EDTA: ethylenediamine tetraacetic acid.
ANL-NBS-HS-000039, REV 00 291 December 2003
6.3.9.2.2 Interpretive Methods
The RELAP V 2.0 (STN: 10551-2.0-00 [159065]) code was used to interpret the 
nonsorbing
iodide, bromide, and PFBA tracer responses. For the iodide-only experiments conducted 
in
cores 1 and 2, the responses at the three different flow rates were simultaneously fitted, 
assuming
the same Peclet number and matrix diffusion mass transfer coefficient (MTC = m D
b
?
) in each
test, and a mean residence time ( ?) that was inversely proportional to flow rate. This 
procedure
assumes that the MTC and Peclet number have no flow rate or time scale dependence.
For the multiple-tracer tests, the bromide and PFBA responses were simultaneously 
fitted,
assuming that bromide had a matrix diffusion coefficient a factor of three greater than 
PFBA
(this same assumption was used in the field tracer-test interpretations). However, because 
of the
difficulties encountered in fitting the lithium responses in the crushed-tuff column 
experiments,
and the fact that Na+ and Ca2+ were analyzed in addition to Li+ in the fractured-core 
experiments,
it was decided to use the MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) model 
(described
below) rather than RELAP V 2.0 (STN: 10551-2.0-00 [159065]) to interpret the lithium
responses. The values of ?, Pe, and MTC that provided the best RELAP fits to the 
bromide and
PFBA responses were used as inputs to MULTRAN (note that for tests conducted at 
different
flow rates in the same core, * was adjusted such that it was inversely proportional to 
flow rate
and Pe was held constant for all tests). The parameters Q1 and Q2 were then adjusted to fit 
the
Li+, Na+, and Ca2+ data while holding the CEC values equal to the measured CEC values.
MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) is a 2-D numerical model that employs 
an
implicit-in-time, alternating-direction, finite-difference method to solve the equations 
describing
multicomponent transport of sorbing and nonsorbing solutes in a single- or dual-porosity
medium. Figure 6.3-68 illustrates the assumed model domain and shows an example 
spatial
discretization. Advective transport, simulated by solving the advection-dispersion 
equation, is
assumed to occur only in the x-direction in Region I. The first and last nodes in the x-
direction in
this region are modeled as well-mixed regions that simulate either boreholes in field 
experiments
or flow manifolds in laboratory experiments. Reinjection of part or all of the solution 
entering
the last node back into the first node can be specified to simulate recirculating conditions 
in
tracer experiments. Only diffusive transport is assumed to occur in the y-direction in both
regions I and II, with the model having the capability to simulate different diffusion 
coefficients
in the different regions. Finally, within each region, additional diffusive transport can be
simulated into "grains," which are assumed to be spherical. These grains can be assigned 
a
lognormal distribution of diameters with specified mean and variance. The user can 
control the
spatial discretization within each region and within the grains.
The user also can eliminate certain portions of the model domain shown in Figure 6.3-68 
simply
by specifying that they have zero porosity. For instance, if one wishes to simulate a 
singleporosity
medium, it is only necessary to specify a zero porosity for region II and zero porosity
for the grains in region I. This approach was taken to simulate the crushed-tuff column 
transport
experiments described in Section 6.3.9.1 because the columns were packed with a 
relatively
uniform material that had no apparent secondary porosity. Reducing the model 
effectively to a
1-D system (region I) greatly simplifies numerical computations.
ANL-NBS-HS-000039, REV 00 292 December 2003
For illustration purposes only.
NOTE: Blocks are finite-difference cells that are solved at their midpoints. Region I is the high-permeability 
layer
(advective transport in x-direction, diffusive in y-direction); region II is the low-permeability layer (diffusive
transport in y-direction only).
Figure 6.3-68. Schematic Illustration of MULTRAN Model Domain
Each time-step of a MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) simulation is 
broken into
four computational segments that are conducted sequentially, as follows.
(1) Solution of the advection-dispersion equation in the x-direction in region I
- 2
2
x x
c
D
x
c
v
t
c
* 
* * 
* 
* * 
* 
* ?(Eq. 25)
Half-width
Half-width
1-D Diffusion
in Radial Direction
(Spherical Coordinates)
Zero Solute Flux Boundary
Zero Solute Flux Boundary
Well-Mixed Region
(Injection Wellbore)
Well-Mixed Region
(Production Wellbore)
Recirculation Loop (Optional)
Tracer Injection
x
y
Grains
Region II
Region I Flow Direction
ANL-NBS-HS-000039, REV 00 293 December 2003
where
c = molar concentration, moles/L
vx = velocity in x direction, cm/sec
D = dispersion coefficient, cm2/sec (D = * vx, * = dispersivity, cm).
(2) Solution of the multicomponent diffusion equation(s) and the local electroneutrality
equation in the y-direction in regions I and II (coupled)
a. Multicomponent diffusion equation for all species except species n (Newman 1973
[148719], p. 228):
* * ) ( - 2
i i n j
j i
j
i i
i c t D D
z
z
c D
t
c * * * * * * * 
* 
* * * (Eq. 26)
where
ci = molar concentration of species i, moles/L
Di = diffusion coefficient of species i, cm2/sec
* = del operator
2 * ?= Laplacian operator
ti = * 
j
j j j
i i i
c u z
c u z
2
2
= transference number of species i
zi = charge of species i
ui =
RT
Di = mobility of species i, where R = gas constant and T = temperature (K)
n = species being determined using electroneutrality equation,
b. Electroneutrality equation for species n:
* * 
?
n j
j j n n c z c z - (Eq. 27)
(3) Solution of the multicomponent diffusion equation(s) and the local electroneutrality
equation in the radial direction in the grains of both regions I and II (same as step 2, but
using spherical coordinates).
(4) Chemical re-equilibration of the entire system with respect to cation exchange. This 
step is
accomplished by solving Equations 21 through 24 at each node in the model domain to
ensure that the equilibrium expressions and the surface cation balance are locally 
satisfied.
The system is assumed to always be at chemical equilibrium (i.e., reaction kinetics 
assumed
to be fast relative to transport rates).
ANL-NBS-HS-000039, REV 00 294 December 2003
6.3.9.2.3 Results and Interpretations
The experimental data and modeling fits for the iodide-only tests conducted in cores 1 
and 2
(three in each core) are shown in Figures 6.3-69 and 6.3-70, respectively. Tables 6.3-28 
and 6.3-
29 list the model parameters associated with the fits shown in these figures. It is apparent 
that
RELAP offered good simultaneous fits to the three data sets.
The experimental data and associated MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) 
fits for
Tests 1 and 3 in the Upper Prow Pass Tuff core (Core 1) are shown in Figure 6.3-71.
MULTRAN fits to the multiple-tracer tests in Cores 2, 3, and 4 (two tests in each core) 
are
shown in Figures 6.3-72, 6.3-73, and, 6.3-74, respectively. Table 6.3-30 lists the model
parameters associated with the fits to the tracer responses in Cores 1 and 2, and Table 
6.3-31 lists
the parameters associated with the fits to the responses in Cores 3 and 4. The Br- and 
PFBA
responses in the two tests in each core were first fitted simultaneously using RELAP V 
2.0
(STN: 10551-2.0-00 [159065]) (i.e., a total of four responses were fitted simultaneously, 
two
from each test). The RELAP fits were executed only up to the time of a flow interruption 
(which
was introduced in several of the tests). For these fits, the Peclet numbers and tracer 
matrixdiffusion
parameters were constrained to be the same for both tests, and the mean residence
times were constrained to be inversely proportional to the flow rates in the tests. The 
fracture
spacing was also manually varied to improve the simultaneous fits to the tracer 
responses; this
was justified because the residence times in the low-flow-rate tests were long enough for 
tracers
to potentially diffuse to the epoxy sealing the periphery of the fractured cores, which 
should
serve as a diffusion boundary. The parameters resulting from the RELAP fits were then 
used in
MULTRAN with only the ion-exchange parameters, Q1 and Q2, being varied to achieve a 
match
to the Li+, Na+, and Ca2+ responses.
Figures 6.3-71 through 6.3-74 indicate that MULTRAN V 1.0 (STN: 10666-1.0-00 
[159068])
was able to simulate very effectively the responses of all tracers in each multiple-tracer 
test in
each core. The finite fracture spacing used in both the RELAP V 2.0 (STN: 10551-2.0-00
[159065]) and MULTRAN simulations was found to be essential for obtaining a 
reasonable
simultaneous fit to the tracer responses at the two significantly different flow rates in 
each core,
suggesting that diffusion boundaries played an important role at the lower flow rates.
The matrix-diffusion, MTCs for Br- in the first two cores were surprisingly much smaller 
than
the MTCs obtained for iodide in these two cores. In theory, these two halides should have 
very
similar diffusion properties. However, the apparent dispersivities and deduced fracture 
apertures
in the two cores were both larger in the multiple-tracer tests than in the iodide-only tests. 
Larger
apertures directly decrease MTCs, and larger dispersivities indirectly decrease MTCs 
because
greater dispersion results in longer-tailed and lower-peaked tracer responses, both of 
which
matrix diffusion also produces. The greater apparent dispersion and lower apparent 
matrix
diffusion in the multiple-tracer tests relative to the iodide-only tests cannot be explained.
However, it is speculated that microbial growth or small geometry changes in the flow 
systems
could have played a role because the iodide-only tests were conducted well before the 
multipletracer
tests in both cores. An inherent fundamental difference in the transport behavior of Br-
and iodide can be ruled out because these two tracers behaved almost identically in the 
multiple-
tracer tests in which both were injected simultaneously (8 of the 11 multiple tracer tests - 
see
Tables 6.3-23 and 6.3-25 to 6.3-27). Another more subtle explanation could be that the 
iodide
ANL-NBS-HS-000039, REV 00 295 December 2003
tests were conducted only at what would be considered the higher flow rates in the 
multipletracer
tests, raising the possibility that tests conducted at higher flow rates could be biased
toward greater apparent matrix diffusion because of a greater influence of diffusion into 
stagnant
free water in the fractures or other time-scale effects (see next section).
DTN: LA0212PR831231.001 [162607] (data). Output DTN: LA0303PR831361.004 (models).
NOTE: All three data sets were used to simultaneously fit ?, Pe, and MTC. Concentrations are normalized 
to
injection concentration. Lower plot is same as upper plot except with log scales for the x- and y-axes. The -
3/2 slope on the log-log plot is the expected slope for a system experiencing single-rate matrix diffusion.
Figure 6.3-69. Experimental and Modeling Results from the Three Iodide-Only Transport Tests in 
Core 1
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0 20 40 60 80 100 120 140 160 180 200
Time, hr
Concentration (C/Co)
2.2 ml/h
19.6 ml/h
8.7 ml/h
2.2 ml/h Model
19.6 ml/h Model
8.7 ml/h Model
0.001
0.010
0.100
1.000
1 10 100 1000
Time, hr
Concentration (C/Co)
2.2 ml/h
19.6 ml/h
8.7 ml/h
2.2 ml/h Model
19.6 ml/h Model
8.7 ml/h Model
-3/2 slope
ANL-NBS-HS-000039, REV 00 296 December 2003
DTN: LA0212PR831231.001 [162607] (data). Output DTN: LA0303PR831361.004 (models).
NOTE: All three data sets were used to simultaneously fit ?, Pe, and MTC. Concentrations are normalized 
to
injection concentration. Lower plot is same as upper plot except with log scales for the x- and y-axes. The -
3/2 slope on the log-log plot is the expected slope for a system experiencing single-rate matrix diffusion.
Figure 6.3-70. Experimental and Modeling Results from the Three Iodide-Only Transport Tests in 
Core 2
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
0 20 40 60 80 100 120 140 160
Time, hr
Concentration (C/Co)
19.7 ml/h
49.3 ml/h
11.3 ml/h
19.7 ml/h Model
49.3 ml/h Model
11.3 ml/h Model
0.0001
0.0010
0.0100
0.1000
1.0000
1 10 100 1000
Time, hr
Concentration (C/Co)
19.7 ml/h
49.3 ml/h
11.3 ml/h
19.7 ml/h Model
49.3 ml/h Model
11.3 ml/h Model
-3/2 slope
ANL-NBS-HS-000039, REV 00 297 December 2003
Table 6.3-28. Modeling Results for the Three Iodide Tracer Tests in Upper Prow Pass Tuff Core
(Core 1)
Modeling Parameters (a) Test 1 Test 2 Test 3
Solute mean residence time, * (hr) 3.0 0.34 0.76
Peclet number, Pe 18
Mass transfer coefficient, m D
b
MTC
* * (hr-0.5) 1.56 (I-)
Fracture aperture, 2b (cm) (b) 0.043
Dispersivity in fracture,
Pe
L * * (cm) 0.89
Matrix diffusion coefficient, Dm (x 10-10 m2/s) (c) 4.3 (I-)
Output DTNs: LA0303PR831361.004; LA0303PR831231.005.
NOTES: (a) The three I- data sets were fit simultaneously assuming Pe was the same for the three tests and 
* was
inversely proportional to the volumetric flow rate.
(b) Based on the relationship
Lw
Q
b
* * , where * is the solute mean residence time.
(c) Determined from the MTC using the measured * and the calculated b.
Table 6.3-29. Modeling Results for the Three Iodide Tracer Tests in Central Prow Pass Tuff Core
(Core 2)
Modeling Parameters (a) Test 1 Test 2 Test 3
Solute mean residence time, * (hr) 0.48 0.19 0.84
Peclet number, Pe 24
Mass transfer coefficient, m D
b
MTC
* * (hr-0.5) 0.518 (I-)
Fracture aperture, 2b (cm) (b) 0.058
Dispersivity in fracture,
Pe
L * * (cm) 0.72
Matrix diffusion coefficient, Dm (x 10-10 m2/s) (c) 3.2 (I-)
Output DTNs: LA0303PR831361.004; LA0303PR831231.005.
NOTE: (a) The three I- data sets were fit simultaneously assuming Pe was the same for the three tests and 
* was
inversely proportional to the volumetric flow rate.
(b) Based on the relationship
Lw
Q
b
* * , where * is the solute mean residence time.
(c) Determined from the MTC using the measured * and the calculated b.
ANL-NBS-HS-000039, REV 00 298 December 2003
DTNs: LA0212PR831231.003 [162609] (Li, Br, PFBA data); LA0212PR831231.005 [166215] (Na, Ca data); Output DTN: 
LA0303PR831361.004 (models).
NOTE: The jumps in the concentrations and in the model curves correspond to flow interruptions in the 
tests. The flow rate in Test 1 (left) was 3.9 ml/h, and the
flow rate in Test 3 (right) was 0.51 ml/h. The Br- and PFBA data were fit simultaneously by constraining the 
Dm ratio for Br:PFBA to 3:1.
Figure 6.3-71. Experimental Data and MULTRAN Modeling Results for Multiple Tracer Tests 1 
and 3 in the Upper Prow Pass Tuff Core (Core 1)
Test 1 Test 3
0
0.002
0.004
0.006
0.008
0.01
0.012
0 100 200 300 400 500 600
Volume, ml
Moles/Liter Br
PFBA
Li
Na
Ca
Na Model
Ca Model
Li Model
Br Model
PFBA Model
0.000001
0.00001
0.0001
0.001
0.01
0.1
10 100 1000
Volume, ml
Moles/Liter
Br
PFBA
Li
Na
Ca
Na Model
Ca Model
Li Model
Br Model
PFBA Model
0
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
0 100 200 300 400 500 600
Volume, ml
Moles/Liter
Br
PFBA
Li
Na
Ca
Na Model
Ca Model
Li Model
Br Model
PFBA Model
0.00001
0.0001
0.001
0.01
10 100 1000
Volume, ml
Moles/Liter
Br
PFBA
Li
Na
Ca
Na Model
Ca Model
Li Model
Br Model
PFBA Model
ANL-NBS-HS-000039, REV 00 299 December 2003
DTNs: LA0212PR831231.002 [162608] (Na, Ca data); LA0212PR831231.005 [166215] (Li, Br, PFBA data); Output DTN: 
LA0303PR831361.004 (models).
NOTE: The jumps in the concentrations and in the model curves correspond to flow interruptions in the 
tests. The flow rate in Test 1 (left) was 5.9 ml/h, and the
flow rate in Test 2 (right) was 0.44 ml/h. The Br- and PFBA data were fit simultaneously by constraining the 
Dm ratio for Br:PFBA to 3:1.
Figure 6.3-72. Experimental Data and MULTRAN Modeling Results for Multiple Tracer Tests 1 
and 2 in the Central Prow Pass Tuff Core (Core 2)
Test 1 Test 2
0
0.005
0.01
0.015
0.02
0.025
0.03
0.035
0 50 100 150 200 250 300
Volume, ml
Moles/Liter Br
PFBA
Li
Na
Ca
Na Model
Ca Model
Li Model
Br Model
PFBA Model
0.000001
0.00001
0.0001
0.001
0.01
0.1
1 10 100 1000 10000
Volume, ml
Moles/Liter
Br
PFBA
Li
Na
Ca
Na Model
Ca Model
Li Model
Br Model
PFBA Model
0
0.005
0.01
0.015
0.02
0.025
0 100 200 300 400 500 600
Volume, ml
Moles/Liter
Br
PFBA
Li
Na
Ca
Na Model
Ca Model
Li Model
Br Model
PFBA Model
0.000001
0.00001
0.0001
0.001
0.01
0.1
1 10 100 1000
Volume, ml
Moles/Liter
Br
PFBA
Li
Na
Ca
Na Model
Ca Model
Li Model
Br Model
PFBA Model
ANL-NBS-HS-000039, REV 00 300 December 2003
DTNs: LA0212PR831231.002 [162608] (Na, Ca data); LA0212PR831231.003 [162609] (Li, Br, PFBA data); Output DTN: 
LA0303PR831361.004 (models).
NOTE: The jumps in the concentrations and in the model curves correspond to flow interruptions in the 
tests. The flow rate in Test 1 (left) was 11.4 ml/h, and the
flow rate in Test 2 (right) was 0.46 ml/h. The Br- and PFBA data were fit simultaneously by constraining the 
Dm ratio for Br:PFBA to 3:1.
Figure 6.3-73. Experimental Data and MULTRAN Modeling Results for Multiple Tracer Tests 1 
and 2 in the Lower Prow Pass Tuff Core (Core 3)
Test 1 Test 2
0
0.005
0.01
0.015
0.02
0.025
0 100 200 300 400 500 600
Volume, ml
Moles/Liter Br
PFBA
Li
Na
Ca
Na Model
Ca Model
Li Model
Br Model
PFBA Model
0.000001
0.00001
0.0001
0.001
0.01
0.1
10 100 1000
Volume, ml
Moles/Liter
Br
PFBA
Li
Na
Ca
Na Model
Ca Model
Li Model
Br Model
PFBA Model
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014
0.016
0 100 200 300 400 500 600
Volume, ml
Moles/Liter
Br
PFBA
Li
Na
Ca
Na Model
Ca Model
Li Model
Br Model
PFBA Model
0.00001
0.0001
0.001
0.01
0.1
10 100 1000
Volume, ml
Moles/Liter
Br
PFBA
Li
Na
Ca
Na Model
Ca Model
Li Model
Br Model
PFBA Model
ANL-NBS-HS-000039, REV 00 301 December 2003
Table 6.3-30. Best-Fit Model Parameters for the Multiple-Tracer Tests Conducted in Cores 1 and 
2
Modeling Parameters Core 1,
Test 1
Core 1,
Test 3
Core 2,
Test 1
Core 2,
Test 1
Porosity of matrix 0.27 0.27 0.14 0.14
Solute mean residence time, * (hr) (a) 5.4 40.2 1.95 26.1
Peclet number, Pe(a) 4.0 4.0 3.5 3.5
Dispersivity in fracture,
Pe
L * * (cm) 4.0 4.0 5.0 5.0
Li+ Retardation factor, R (a) 2.25 1.1 4.2 5.9
Li+ Partition coefficient, Kd (L/kg) 0.17 0.014 0.19 0.30
Mass transfer coefficient(a),
m D
b
MTC
* * (hr-0.5)
0.80 (Br-)
0.46 (PFBA)
0.80 (Br-)
0.46 (PFBA)
0.21 (Br-)
0.12 (PFBA)
0.21 (Br-)
0.12 (PFBA)
Fracture aperture, 2b (cm) (b) 0.134 0.134 0.07 0.07
Distance to diffusion boundary (fracture half
spacing), (cm) 1.9 1.9 0.9 0.9
Matrix diffusion coefficient(c), Dm (x 10-10
m2/s)
11.0 (Br-)
3.7 (PFBA)
11.0 (Br-)
3.7 (PFBA)
0.8 (Br-)
0.27 (PFBA)
0.8 (Br-)
0.27 (PFBA)
CEC (meq/kg), Measured 19.9 19.9 43.2 43.2
Q1
(d) 0.05 0.025 10.2 6.0
Q2
(d) 0.079 0.04 3.0 0.45
DTN: MO00012POROCHOL.000 [153376] (for porosity); Output DTNs: LA0303PR831361.004 (model results);
LA0303PR831231.005.
NOTE: Cores 1 and 2 are shown in Figures 6.3-69 through 6.3-72.
(a) Parameters obtained using RELAP to fit simultaneously the Br- and PFBA data from the two tests for a
given core with the constraint that the Dm ratio for Br-:PFBA was 3:1. The matrix diffusion coefficient for
Li+ was assumed to be two-thirds the value for Br-.
(b) Based on the relationship
Lw
Q
b
* * , where * is the solute mean residence time.
(c) Determined from the MTC using the measured * and the calculated b.
(d) Equilibrium ion-exchange coefficients, obtained using MULTRAN to manually "fit" the Li+, Na+, and Ca2+
data for each test.
ANL-NBS-HS-000039, REV 00 302 December 2003
DTNs: LA0212PR831231.002 [162608] (Na, Ca data - Test 1); LA0212PR831231.005 [166215] (Na, Ca data - Test 2); 
LA0212PR831231.003 [162609] (Li, Br,
PFBA data). Output DTN: LA0303PR831361.004 (models).
NOTE: The jumps in the concentrations and in the model curves correspond to flow interruptions in the 
tests. The flow rate in Test 1 (left) was 4.85 ml/h, and the
flow rate in Test 2 (right) was 0.47 ml/h. The Br- and PFBA data were fit simultaneously by constraining the 
Dm ratio for Br:PFBA to 3:1.
Figure 6.3-74. Experimental Data and MULTRAN Modeling Results for Multiple Tracer Tests 1 
and 2 in the Lower Bullfrog Tuff Core (Core 4).
Test 1 Test 2
0
0.005
0.01
0.015
0.02
0.025
0 100 200 300 400 500 600
Volume, ml
Moles/Liter Br
PFBA
Li
Na
Ca
Na Model
Ca Model
Li Model
Br Model
PFBA Model
0.000001
0.00001
0.0001
0.001
0.01
0.1
10 100 1000 10000
Volume, ml
Moles/Liter
Br
PFBA
Li
Na
Ca
Na Model
Ca Model
Li Model
Br Model
PFBA Model
0
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
0.009
0 200 400 600 800
Volume, ml
Moles/Liter
Br
PFBA
Li
Na
Ca
Na Model
Ca Model
Li Model
Br Model
PFBA Model
0.00001
0.0001
0.001
0.01
10 100 1000
Volume, ml Moles/Liter
Br
PFBA
Li
Na
Ca
Na Model
Ca Model
Li Model
Br Model
PFBA Model
ANL-NBS-HS-000039, REV 00 303 December 2003
The ion exchange parameters, Q1 and Q2, exhibited a curious decreasing trend from the 
first to
the second multiple-tracer test in each core, suggesting that some Li+ may have become
irreversibly sorbed in the first test and reduced the sorption capacity for Li+ in subsequent 
tests.
This speculation is consistent with the incomplete recovery of Li+ in each test. In any 
case, the
Li+ sorption isotherms calculated from the ion-exchange parameters deduced from 
MULTRAN
V 1.0 (STN: 10666-1.0-00 [159068]) fits were generally higher than or comparable to the
sorption isotherms derived from batch Li+ sorption experiments (Figure 6.3-75).
It is important to point out that the best-fitting values of the ion-exchange parameters Q1 
and Q2
in the MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) simulations were somewhat 
sensitive to
the background concentrations specified for all three cations in the system. These 
background
concentrations were chosen to match the concentrations measured in the first one or two 
samples
collected in each experiment (prior to the arrival of the tracers), which generally differed 
slightly
from one experiment to the next in a given core. There were also significant differences 
in the
relative amounts of cations and the overall ionic strengths of the tracer solutions used in 
different
experiments, which could have affected the experimental and modeling results. One 
notable
difference in the cation mix occurred as a result of using either NaOH or LiOH to 
neutralize the
PFBA in the tracer solutions (if a stoichiometric amount of OH- was not added, the pH of 
the
tracer solutions was <2). These differences in cation mix and ionic strength were 
accounted for
in the MULTRAN inputs, but any "memory" effects resulting from the use of 
significantly
different tracer solutions in consecutive experiments, which could affect the pre-
experiment mix
of cations sorbed to mineral surfaces, were not accounted for. It is possible that if these 
factors
had been accounted for, the Q1 and Q2 values from consecutive experiments may have 
been in
better agreement.
It was also found that reasonable matches to the cation responses in the cores could be 
obtained
using almost any value of the CEC greater than some threshold, provided that Q1 and Q2 
were
both adjustable. This nonuniqueness problem was avoided by setting the CEC values in 
all
MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) simulations equal to the laboratory
measurements for each tuff. However, if the effective CEC value had been reduced for 
each
subsequent experiment in each core (because of some irreversible sorption of Li+), then 
the Q1
and Q2 values would have been higher in the later experiments, which would have 
brought them
into better agreement with the values in earlier experiments.
Although not all of the experimental and modeling results can be completely explained, 
Figure
6.3-76 shows that the use of the multicomponent ion-exchange MULTRAN V 1.0 (STN: 
10666-
1.0-00 [159068]) model offers a significant improvement over the single-component 
RELAP V
2.0 (STN: 10551-1.0-00 [159065]) model in simulating the responses of ion-exchanging 
tracers
in dual-porosity systems. This improvement is especially pronounced when there is a 
large
amount of sorption in the matrix, as there is for the Lower Bullfrog Tuff core (Figure 6.3-
76).
ANL-NBS-HS-000039, REV 00 304 December 2003
DTN: MO0012SORBCHOL.000 [153375] (data). Output DTN: LA0303PR831341.003 (models) .
Figure 6.3-75. Comparison of Li+ Isotherms Calculated from Best-Fitting MULTRAN Parameters
(Designated by XXX_Y, where Y is the Fractured Core Test Number) and Obtained in Batch
Sorption Experiments for the Four Different C-wells Tuffs Used in the Fracture Experiments
Upper Prow Pass
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
-1 0 1 2 3 4
Log C, g/ml
Log S, g/g
4:1, J-13, 25C
4:1, J-13, 38C
2:1, J-13, 25C
Langmuir Fit
UPP_1
UPP_3
Lower Prow Pass
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
-1 0 1 2 3 4
Log C, g/ml
Log S, g/g
4:1, 25C
4:1, 38C
2:1, 25C
Langmuir Fit
LPP_1
LPP_2
Central Prow Pass
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
3
-1 0 1 2 3 4
Log C, g/ml
Log S, g/g
4:1, 25C
4:1, 38C
2:1, 25C
Langmuir Fit
CPP_1
CPP_2
Lower Bullfrog
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
3
3.5
-1 0 1 2 3 4
Log C, g/ml
Log S, g/g
4:1, 25C
4:1, 38C
2:1, 25C
Langmuir Fit
LBF_1
LBF_2
ANL-NBS-HS-000039, REV 00 305 December 2003
Table 6.3-31. Best-Fit Model Parameters for the Multiple-Tracer Tests Conducted in Cores 3 and 
4
Modeling Parameters
Core 3,
Test 1
Core 3,
Test 2
Core 4,
Test 1
Core 4,
Test 2
Porosity of matrix 0.29 0.29 0.30 0.30
Solute mean residence time, * (hr) (a) 0.55 13.6 2.0 21.3
Peclet number, Pe(a) 4.5 4.5 130 130
Dispersivity in fracture,
Pe
L * * (cm) 2.6 2.6 0.09 0.09
Li+ Retardation factor, R (a) 1.3 1.6 9.2 8.2
Li+ Partition coefficient, Kd (L/kg) 0.046 0.092 1.33 1.16
Mass transfer coefficient(a),
m D
b
MTC
* * (hr-0.5)
1.32 (Br-)
0.76 (PFBA)
1.32 (Br-)
0.76 (PFBA)
1.45 (Br-)
0.84 (PFBA)
1.45 (Br-)
0.84 (PFBA)
Fracture aperture, 2b (cm) (b) 0.057 0.057 0.049 0.049
Distance to diffusion boundary (fracture half
spacing), (cm) 4.4 4.4 4.6 4.6
Matrix diffusion coefficient(c), Dm (x 10-10
m2/s)
4.6 (Br-)
1.5 (PFBA)
4.6 (Br-)
1.5 (PFBA)
3.8 (Br-)
1.3 (PFBA)
3.8 (Br-)
1.3 (PFBA)
CEC (meq/kg), Measured 31.9 31.9 179.7 179.7
Q1
(d) 0.1 0.085 6.0 0.2(d)
Q2
(d) 0.08 0.035 0.3 0.12(d)
DTN: MO00012POROCHOL.000 [153376] (for porosity). Output DTNs: LA0303PR831361.004 (model results),
LA0303PR831231.005.
NOTE: Cores 3 and 4 are shown in Figures 6.3-73 and 6.3-74.
(a) Parameters obtained using RELAP V 2.0 (STN: 10551-2.0-00 [159065]) to simultaneously fit the Br-
and PFBA data from the two tests for a given core with the constraint that the Dm ratio for Br-:PFBA was
3:1. The matrix diffusion coefficient for Li+ was assumed to be 2/3 the value for Br-.
(b) Based on the relationship
Lw
Q
b
* * , where * is the solute mean residence time.
(c) Determined from the MTC using the measured * and the calculated b.
(d) Equilibrium ion exchange coefficients, obtained using MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) to
manually "fit" the Li+, Na+, and Ca2+ data for each test.
(e) The MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) "fit" shown for Core 4, Test 2 in Figure 6.3-74 was
actually obtained assuming sorption in both the fracture and the matrix. The fracture was assumed to
have a porosity of 0.9, a CEC of 200 meq/kg, K1 = 5.0, and K2 = 50.0. The matrix had a CEC of 179.7
meq/kg, and K1 = K2 = 0.0223. The resulting fit was somewhat better than the fit assuming sorption
only in the matrix.
ANL-NBS-HS-000039, REV 00 306 December 2003
DTN: LA0212PR831231.003 [162609] (Li data). Output DTN: LA0303PR831361.003 (models).
Figure 6.3-76. Comparison of the Fits of the MULTRAN Multicomponent Ion-Exchange Model and 
the
Single-Component RELAP Model to the Lithium Transport Data in the First Multiple-Tracer Test 
in Core 4
6.3.10 Scale-Dependence of Transport Parameters in Fractured Tuffs
6.3.10.1 Scale-Dependence of Longitudinal Dispersivity
A plot of the longitudinal dispersivity values as a function of test scale for several NTS
fractured-rock, tracer-test programs is shown in Figure 6.3-77. The plot indicates that the
longitudinal dispersivity increases with test scale that ranges from less than one meter to 
over
100 meters. Figure 6.3-78 shows the range of longitudinal dispersivities as a function of 
scale
derived from the C-wells multiple-tracer tests (darkened area) superimposed on a plot of
dispersivity versus scale prepared by Neuman (1990 [101464], Figure 1). Note that the 
lower
end of the range of length scales associated with the darkened area corresponds to the 
interwell
separation in the tracer tests, and the upper end corresponds to the test interval thickness 
(used as
an upper bound for the transport distance).
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014
0 50 100 150 200 250 300 350 400
Volume, ml
Moles/Liter
Li
Li MULTRAN
Li RELAP
ANL-NBS-HS-000039, REV 00 307 December 2003
Source: LeCain et al. (2000 [144612], Figure 19).
Figure 6.3-77. Longitudinal Dispersivity as a Function of Test Scale in Several Tracer Tests
Conducted in the Vicinity of Yucca Mountain
ANL-NBS-HS-000039, REV 00 308 December 2003
Source: Plot taken from Neuman (1990 [101464], Figure 1). Output DTN: LA0303PR831231.003 (dispersivities from C-
wells).
NOTE: The darkened box shows the range of values derived from the multiple-tracer field tests at the C-
wells in
which lithium ion was used as a sorbing tracer. The right edge of the box corresponds to the interwell
separation distance, and the left edge of the box corresponds to the test interval thickness (taken to be the
upper limit of transport distance).
Figure 6.3-78. Plot of Longitudinal Dispersivity Versus Length Scale Showing the Range of C-
wells
Values Derived from Interpretations of the Prow Pass and Bullfrog Multiple Tracer Tests in which
Lithium Ion was Used as a Sorbing Tracer
ANL-NBS-HS-000039, REV 00 309 December 2003
6.3.10.2 Scale-Dependence of Matrix Diffusion
There is some question about whether matrix diffusion parameters measured in 
laboratory-scale
experiments can be used reliably in field-scale transport predictions. To address this 
issue, it is
first of interest to compare the matrix diffusion coefficients measured in the diffusion cell 
tests of
Section 6.3.8 with the diffusion coefficients calculated from the fractured-core tests of 
Section
6.3.9.2. Table 6.3-32 shows that the Br- matrix diffusion coefficients deduced from the
fractured-core experiments (from simultaneous RELAP V 2.0 (STN: 10551-2.0-00 
[159065]) fits
to the Br- and PFBA responses at two different flow rates in each fracture) were 
consistently
greater than the Br- diffusion coefficients obtained from the diffusion cell experiments. 
This
result could be explained by the fact that matrix diffusion in the fractured cores was 
really a
combination of diffusion into stagnant free water in the fractures (e.g., into voids along 
the rough
walls of the fracture surfaces or into stagnant regions between flowing channels) and true
diffusion into the matrix, whereas diffusion in the diffusion cell experiments, by design, 
occurred
only in the matrix. The RELAP computer code interprets both free-water and matrix 
diffusion as
matrix diffusion, so any free-water diffusion will tend to increase estimates of matrix 
diffusion
coefficients (Callahan 2001 [156649], Chapter 5). The time scales of the diffusion cell
measurements also tended to be longer than in the fractured cores, which would have 
resulted in
greater tracer penetration of the matrices and, hence, a more representative measurement 
of true
matrix diffusion.
It is also of interest to compare matrix-diffusion MTCs derived from the fractured-core
experiments (Section 6.3.9.2) with MTCs derived from the C-wells field tracer tests 
(Section
6.3.4.7). Such a comparison is provided in Figure 6.3-79, which shows the laboratory and 
field
MTCs plotted as a function of time scale in the tests. The MTCs derived from the 
laboratory
experiments are plotted as lines that span the range of tracer residence times in the cores. 
It is
apparent that the residence times in the iodide-only core experiments were shorter than in 
the
multiple-tracer experiments, and there is a corresponding increase in the deduced MTC 
values in
the iodide experiments. The MTCs from the field experiments are also plotted as lines 
that span
the range of tracer residence times obtained assuming either linear or radial flow fields. 
Separate
lines are plotted for the two pathways that resulted in the two tracer peaks in the Bullfrog 
Tuff
field test.
It is clear that the MTCs collectively exhibit a decreasing trend with tracer residence 
times in
Figure 6.3-79. This trend is consistent with the notion that as time scales increase, more 
of the
apparent diffusion will be true matrix diffusion and less will be diffusion into stagnant 
free
water. However, it is also likely that effective fracture apertures over the 30-meter scales 
of the
field tests were much larger than in the ~0.2-meter-scale laboratory tests. Intuitively, one 
would
expect that, as distance scales increase, there will be a higher probability of encountering 
largeraperture
fractures in which flow can occur. Larger apertures would have contributed to the
decreasing trend of Figure 6.3-79 because fracture apertures appear in the denominator of 
the
MTC. Alternatively, matrix diffusion coefficients, which appear as a square-root term in 
the
numerator of the MTC, would have to be nearly two orders of magnitude smaller in the 
field than
in the lab to explain the trend of Figure 6.3-79 if fracture apertures were held constant, 
which
seems implausible. Similarly, matrix porosities, which appear in the numerator of the 
MTC,
would have to be smaller by about a factor of 10 in the field to explain the observed trend 
if
ANL-NBS-HS-000039, REV 00 310 December 2003
fracture apertures were held constant and matrix diffusion coefficients were assumed to 
be the
same as in the lab experiments - also seemingly implausible.
One would expect an asymptotic lower limit to be reached eventually for the MTC in 
saturated
fractured systems, given a long enough travel time or distance. However, for the C-wells 
field
system, the transport data suggest that this asymptotic value, if it exists, was not reached 
for
characteristic travel times of up to ~1200 hrs or travel distances of ~30 m (Figure 6.3-79).
All of the test results discussed here are consistent with diffusive mass transfer having a 
strong
influence on the migration of solutes in fractured volcanic tuffs. However, at short time 
and
distance scales, there may be a significant influence of diffusion into stagnant free water 
within
fractures in addition to "true" matrix diffusion. Thus, matrix diffusion parameters 
obtained from
laboratory tracer experiments should be used cautiously when predicting contaminant 
migration
at larger scales in fractured media.
Table 6.3-32. Comparison of Matrix Diffusion Coefficients Calculated from Fractured-Core
Tracer Tests and from Diffusion-Cell Experiments
Core
Fractured Core
Dm (Br-) (m2/s) (a)
Diffusion Cell
Dm
* (Br-) (m2/s)
Upper Prow Pass (1) 11.0 x 10-10 6.2 x 10-10
Central Prow Pass (2) 0.8 x 10-10 0.38 x 10-10
Lower Prow Pass (3) 4.6 x 10-10 2.9 x 10-10 (b)
Lower Bullfrog (4) 3.8 x 10-10 1.0 x 10-10
Output DTNs: LA0303PR831362.001 (diffusion cells); LA0303PR831361.004 (fractured cores).
NOTE: (a) Determined from MTC using the measured matrix porosity and b determined from b = Q * (see 
Tables
6.3-30 and 6.3-31).
(b) Average of two measurements.
ANL-NBS-HS-000039, REV 00 311 December 2003
Output DTNs: LA0303PR831231.003 (field data); LA0303PR831361.004 (lab data); LA0303PR831231.005.
NOTE: The lines represent the field tests; endpoints of the lines reflect the uncertainty in the mean 
residence time
depending on whether radial or linear flow is assumed.
The matrix diffusion mass transfer coefficient, MTC, is defined as m D
b
?
.
The experimental time scale here is the mean residence time.
Figure 6.3-79. Matrix Diffusion Mass Transfer Coefficient as a Function of Experimental Time 
Scale
in All of the C-wells Laboratory and Field Multiple Tracer Tests
0.01
0.1
1
10
0.1 1 10 100 1000 10000
Mean Residence Time, hrs
MTC, hr -0.5
Iodide Lab Tests
Multiple-Tracer Lab Tests
Field Tests
core 1
core 2
core 1
core 2
core 3
core 4
Bullfrog Peak 1
Bullfrog Peak 2
Prow Pass
ANL-NBS-HS-000039, REV 00 312 December 2003
6.4 HYDRAULIC PROPERTIES OF THE ALLUVIUM (ATC)
6.4.1 ATC Single-Well Hydraulic Tests
Single-well hydraulic testing of the saturated alluvium in well NC-EWDP-19D1 was 
conducted
between July 2000 and November 2000. This section presents the results and 
interpretations of
those tests. Detailed documentation of the tests is contained in Umari (2003 [164573]).
6.4.1.1 Hydraulic Test of the Four Combined Alluvium Intervals in NC-EWDP-
19D1
On July 7, 2000, a single-well hydraulic test of the alluvium aquifer to a depth of 247.5 m 
(812
ft) below land surface was initiated in NC-EWDP-19D1 (referred to as 19D1 in the 
remainder of
this document) to determine the transmissivity and hydraulic conductivity of the entire 
alluvium
system at the 19D1 location. The construction of this well, including the location of all 
the
screens discussed in this section, is summarized in Figure 6.1-8. The well was pumped 
for seven
days, with production coming from the upper four screened intervals in 19D1, for all of 
the
intervals completed in the alluvium (a packer was inflated below the fourth screen to 
isolate the
alluvium from the underlying tuffs). Prior to the completion of 19D1, Nye County and
USGS/LANL representatives agreed to install screens 5, 6, and 7 in the tuffaceous units
encountered by the well bore to allow for possible testing of these intervals in the future. 
Depth
to water just before the test was ~106 m (~349 ft) below land surface, and the effective 
alluvium
thickness tested was ~136 m (446 ft), which is the distance from the water table to the 
bottom of
the fourth screened interval; the total saturated alluvium thickness is 141 m (463 ft). 
Recovery
data were collected for 14 days after pumping stopped. The test was used, along with the
isolated-interval tests that followed, to obtain preliminary estimates of transmissivity and
horizontal hydraulic conductivity that were then improved with cross-hole testing. Also, 
during
this test, distant wells (NC-EWDP-15P, NC-EWDP-4PA, NC-EWDP-4PB, and 
Washburn-1x)
were monitored. The nearby piezometer NC-EWDP-19P was also monitored. No 
responses
were detected at these wells. (Note that the wells discussed in this report will be referred 
to by
their abbreviated forms).
During the combined-interval test, 19D1 was pumped at the rate of approximately 564 
L/min
(149 gpm); after seven days of pumping, the drawdown was approximately 33.5 m (110 
ft).
Comparable pumping rates in the Nye County 48-hour (hr) well-development aquifer test 
in
which all seven screened intervals in 19D1 were allowed to produce water caused an 
order of
magnitude less drawdown. This result indicates that the Tertiary volcanics and tuff below 
the
alluvium had contributed significantly to that test.
Figure 6.4-1 presents the drawdown data for the entire combined-interval test, including 
both the
pumping and recovery periods. Pumping was started at 12:00 P.M. on July 7, 2000, and 
ended at
12:00 P.M. on July 14, 2000. The open alluvium interval was allowed to recover until 
1:00 P.M.
on July 28, 2000. The average pumping rate during the test was 564 L/min (149.11 gpm). 
The
day markers in Figure 6.4-1 are at 12:00 P.M., so the day-1 marker indicates 12:00 P.M. 
on July
8, 2000; the day-2 marker indicates 12:00 P.M. on July 9, 2000, and so forth. There were 
no
changes in the pumping rate or any other configuration changes to cause the jump in 
drawdown
seen at the 6-day marker. All drawdown values were calculated relative to the starting 
pressure
head at 12:00 P.M. on July 7, 2000, registered by one of the two pressure transducers 
placed
ANL-NBS-HS-000039, REV 00 313 December 2003
above the packer isolating the alluvium from the underlying tuffs (there were two 
transducers for
redundancy; only one was used for drawdown measurements). Negative drawdown 
values
during recovery indicate pressure heads higher than the starting pressure head. These 
negative
drawdowns indicate that when the test was started on July 7, 2000, there was some 
residual
drawdown relative to background water levels due to pumping associated with 
preparations for
the test, including a step-drawdown test on July 6, 2000.
DTN: GS020708312316.001 [162678] (data).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-1. Drawdown and Recovery Data Associated with the Pump Test
of the Four Combined Alluvium Intervals in NC-EWDP-19D1, July 2000
Figure 6.4-2 presents a fit of the Neuman (1975 [150321]) (Neuman.vi V 1.0, STN: 
10972-1.0-
00 [162754]) fully-penetrating unconfined aquifer analytic solution to the combined-
interval test
data. The Neuman solution gives a transmissivity value of 20.7 m2/day (223 ft2/day). If 
the
thickness of the saturated alluvium from the water table to the bottom of the fourth 
screened
interval 136 m (446 ft) is used, a hydraulic conductivity of approximately 0.5 ft/day is 
calculated.
The type-curve matching procedure for the Neuman unconfined aquifer solution involves
matching both the early and late portions of the drawdown data. In Figure 6.4-2, these 
two
portions of the matching type curve are graphically spliced together (the late portion of 
the type
curve match is horizontally shifted to the left) to give the appearance of a single type 
curve. The
latter portion of the early curve match and the early portion of the late curve match are 
not shown
in Figure 6.4-2. Both portions of this match are consistent with the transmissivity and 
hydraulic
conductivity reported above. The slope of 1 for the early-time data (less than 2 minutes) 
in
ANL-NBS-HS-000039, REV 00 314 December 2003
Figure 6.4-2 (log-log scale) is indicative of borehole storage (Papadopulos and Cooper 
1967
[150323]), so these very early time data were not considered in the curve-matching 
procedure.
6.4.1.2 Hydraulic Tests of Isolated Alluvium Intervals in NC-EWDP-19D1
After the combined interval test, each of the four intervals in the alluvium in NC-EWDP-
19D1
were isolated and hydraulically tested to obtain transmissivity and associated hydraulic
conductivity. This interval testing program was initiated in an effort to evaluate 
heterogeneity in
hydraulic properties over the thickness of the alluvium at the NC-EWDP-19D1 location 
to help
determine the conceptual model of flow in the saturated alluvium south of Yucca 
Mountain.
The following description of the isolated-interval hydraulic tests is presented in order of 
screen
depth, starting with screen #1, the top screen, and ending with screen #4, the bottom 
screen. The
chronological order in which the tests were conducted was screens #4, #3, #1, and #2.
DTN: GS020708312316.001 [162678] (data); Output DTN: GS031008312316.002 (analysis).
NOTE: The blue line is a composite curve showing both early- and late-time fits of July 7, 2000, open-hole
drawdown data to Neuman's (1975 [150321]) beta = 0.001 type curve (latter portion of early-time type curve
and beginning portion of late-time type curve are truncated so that the two curves are joined into one
continuous type curve). A value of beta = 0.001 in the Neuman (1975 [150321]) solution translates to a
transmissivity of 20.7 m2/day (223 ft2/day). The early-time data (less than 2 minutes) were not considered in
the type-curve analysis because this early-time response was attributed to borehole storage, not aquifer
response. English units are shown in the figure because the analysis was conducted in English units.
However, parameter estimates are reported in metric units to downstream users.
Figure 6.4-2. Drawdown as a Function of Elapsed Time for the Combined Interval Hydraulic
Test in NC-EWDP-19D1 Overlaid with the Neuman Unconfined Aquifer Type Curve Solution
ANL-NBS-HS-000039, REV 00 315 December 2003
On October 24, 2000, a hydraulic test in the top interval in the alluvium, screen #1, was 
started in
19D1. Pumping continued at a nominal rate of 61 L/min (16 gpm), with an average of 
61.7
L/min (16.3 gpm), until October 27, 2000. Recovery was monitored until October 30, 
2000.
Figure 6.4-3 presents the drawdown data from the test. Figure 6.4-4 presents a fit of the 
Neuman
(1975 [150321]) (Neuman.vi V 1.0, STN: 10972-1.0-00 [162754]) fully-penetrating 
unconfined
aquifer analytic solution to the data, which was obtained following the same procedure of
matching the early- and late-time drawdown responses as in the combined-interval test, 
but with
no horizontal shift required. The fully-penetrating Neuman solution gives a transmissivity 
value
of 6.1 m2/day (66 ft2/day) (see Section 6.4.1.3 for correction needed because screen #1 
only
partially penetrates the total saturated alluvium section).
DTN: GS020708312316.001 [162678].(data).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-3. Drawdown as a Function of Time for the Hydraulic Test
in Screen #1 of NC-EWDP-19D1, October 24 to October 27, 2000
15
16
17
18
19
20
21
22
23
24
25
0 1 2 3 4
Elapsed days since pump on at 9 AM on 10/24/00
ANL-NBS-HS-000039, REV 00 316 December 2003
DTN: GS020708312316.001 [162678] (data); Output DTN: GS031008312316.002 (analysis).
NOTE: The chosen type curve fits early- and late-time data simultaneously. Lw is defined in Section 6.4.1.3.
English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-4. Drawdown Versus Elapsed Time for the Hydraulic Test in Screen #1
of NC-EWDP-19D1 Overlaid with the Neuman Unconfined Aquifer Type Curves
On October 31, 2000, a hydraulic test in the second interval from the top in the alluvium, 
screen
#2, was started in 19D1. Pumping continued at a nominal rate of 17 L/min (19 gpm) until
November 6, 2000. Recovery was monitored until November 9, 2000. Figure 6.4-5 
presents the
drawdown data from the test. It is apparent that, unlike the other isolated interval 
hydraulic tests
in 19D1, the drawdown in screen #2 increased at a relatively constant rate. This interval 
was
completed just below a clay-rich layer in the alluvium, and there is a possibility 
(unconfirmed)
that the screen and gravel pack may have been gradually clogging with fines during the 
test.
Figure 6.4-6 presents a fit of the Neuman (1975 [150321]) (Neuman.vi V 1.0, STN: 
10972-1.0-
00 [162754]) fully-penetrating unconfined aquifer analytic solution to the drawdown data 
from
screen #2, which was obtained following the same procedure of matching the early- and 
latetime
drawdown responses as in the combined-interval test, but with no horizontal shift 
required.
The fully-penetrating Neuman solution gives a transmissivity value of 0.70 m2/day (7.5 
ft2/day)
(Output DTN: GS031008312316.002) (see Section 6.4.1.3 for correction needed because 
screen
#2 only partially penetrates the total saturated alluvium section).
ANL-NBS-HS-000039, REV 00 317 December 2003
DTN: GS020708312316.001 [162678] (data); Output DTN: GS031008312316.002 (analysis)
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-5. Drawdown as a Function of Time for the Hydraulic
Test in Screen #2, NC-EWDP-19D1, October 31 to November 6, 2000
0
20
40
60
80
100
120
0 1 2 3 4 5 6
Elapsed days since pump on at 10:30 AM, 10/31/00
ANL-NBS-HS-000039, REV 00 318 December 2003
DTN: GS020708312316.001 [162678] (data); Output DTN: GS031008312316.002 (analysis).
NOTE: The chosen type curve fits early- and late-time data simultaneously. Lw is defined in Section 6.4.1.3. 
English
units are shown in the figure because the analysis was conducted in English units. However, parameter
estimates are reported in metric units to downstream users.
Figure 6.4-6. Drawdown as a Function of Time During the Hydraulic Test in Screen #2,
NC-EWDP-19D1, Overlaid with the Neuman Unconfined Aquifer Type Curves
On September 9, 2000, a hydraulic test in the second interval from the bottom in the 
alluvium,
screen #3, was started in 19D1. Pumping continued at a nominal rate of 314 L/min (83 
gpm),
with an average of 309.3 L/min (81.7 gpm), until September 16, 2000. Recovery was 
monitored
until September 21, 2000. Figure 6.4-7 presents the drawdown data from this test. The 
stair-step
shape of the drawdown versus time curve suggests that the gravel pack was compacting 
at
discrete times during this test, thus causing nearly instantaneous jumps in the drawdown. 
Figure
6.4-8 presents a fit of the Neuman (1975 [150321]) (Neuman.vi V 1.0, STN: 10972-1.0-
00
[162754]) fully-penetrating unconfined aquifer analytic solution to the drawdown data 
from
screen #3, which was obtained following the same procedure of matching the early- and 
latetime
drawdown responses as in the combined-interval test, but with no horizontal shift 
required.
The fully-penetrating Neuman (1975 [150321]) solution gives a transmissivity value of 
20.7
m2/day (223 ft2/day) (see Section 6.4.1.3 for correction needed because screen #3 only 
partially
penetrates the total saturated alluvium section).
ANL-NBS-HS-000039, REV 00 319 December 2003
DTN: GS020708312316.001 [162678] (data); Output DTN: GS031008312316.002 (analysis).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-7. Drawdown as a Function of Elapsed Time for the Hydraulic Test
in Screen #3 of NC-EWDP-19D1, September 9 to September 16, 2000
20
25
30
35
40
45
50
55
0 1 2 3 4 5 6 7 8
Elapsed days since pump on at 11 AM on 9/9/00
ANL-NBS-HS-000039, REV 00 320 December 2003
DTN: GS020708312316.001 [162678] (data); Output DTN: GS031008312316.002 (analysis).
NOTE: The chosen type curve fits early- and late-time data simultaneously. Lw is defined in Section 6.4.1.3.
English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-8. Drawdown as a Function of Time During the Hydraulic Test in Screen #3,
NC-EWDP-19D1, Overlaid with the Neuman Unconfined Aquifer Type Curves
On August 24, 2000, a hydraulic test in the lower-most screen in the alluvium section of 
19D1,
screen #4, was started. Pumping continued at the nominal rate of 299 L/min (79 gpm) 
until
August 31, 2000, with an average of 299.8 L/min (79.2 gpm). Recovery was monitored 
from
August 31, 2000, to September 7, 2000. Figure 6.4-9 presents the drawdown data from 
this test,
including both the pumping and recovery periods. Figure 6.4-10 presents a fit of the 
Neuman
(1975 [150321]) (Neuman.vi V 1.0, STN: 10972-1.0-00 [162754]) fully-penetrating 
unconfined
aquifer analytic solution to the drawdown data from screen #4, which was obtained 
following the
same procedure of matching the early- and late-time drawdown responses as in the 
combinedinterval
test. The fully-penetrating Neuman solution gives a transmissivity value of 28 m2/day
(300 ft2/day) (Output DTN: GS031008312316.002) (see Section 6.4.1.3 for correction 
needed
because screen #4 only partially penetrates the total saturated alluvium section).
ANL-NBS-HS-000039, REV 00 321 December 2003
The drawdown in the combined screens #5, #6, and #7 interval as a function of elapsed 
time
during the above test in screen #4 beginning on August 24, 2000, is presented in Figure 
6.4-19 in
Section 6.4.1.5, where it is used to calculate the rate of leakage from below the alluvium 
into the
screen #4 interval.
DTN: GS020708312316.001 [162678] (data).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-9. Drawdown as a Function of Time for the Hydraulic Test
in NC-EWDP-19D1, Screen #4, August 24 to August 31, 2000
0
10
20
30
40
50
60
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Elapsed days since 12 PM on 8/24/00
ANL-NBS-HS-000039, REV 00 322 December 2003
DTN: GS020708312316.001 [162678] (data); Output DTN: GS031008312316.002 (analysis)
NOTE: The matching type curve has been shifted horizontally to emphasize the match to the late-time data. 
The
early time data were also matched by this type curve, although, unlike in Figure 6.4-2, the early-time and
late-time type curve (Neuman 1975 [150321]) matches are not "spliced " together to show a single
composite fit. Lw is defined in Section 6.4.1.3. English units are shown in the figure because the analysis
was conducted in English units. However, parameter estimates are reported in metric units to downstream
users.
Figure 6.4-10. Drawdown as a Function of Time During the Hydraulic Test in Screen #4,
NC-EWDP-19D1, Overlaid with the Neuman Unconfined Aquifer Type Curves
6.4.1.3 Summary of Single-Well Hydraulic Tests in Alluvium in NC-EWDP-19D1
The hydraulic tests in 19D1, screens 1 through 4, were analyzed using the fully-
penetrating
Neuman (1975 [150321]) (Neuman.vi V 1.0, STN: 10972-1.0-00 [162754]) unconfined 
aquifer
solution because all 4 individual screens, as well as the combined intervals, exhibited
characteristic unconfined aquifer responses. Because each of the screens did not fully 
penetrate
the unconfined alluvial aquifer, they should be analyzed by the partially-penetrating 
Neuman
solution. However, there is no YMP-qualified software to perform this analysis, so the
transmissivity, T, values resulting from the Neuman fully-penetrating solution should be
corrected to account for the length of the screen, Le, and the depth from the water table to 
the
bottom of the screen being tested, Lw (see, for example, Bouwer 1978 [162675], pp. 79 to 
82,
114 to 117). An empirical relationship was sought between T and each of Le and Lw by 
plotting
ANL-NBS-HS-000039, REV 00 323 December 2003
T versus Le (Figure 6.4-11) and T versus Lw/b in Figure 6.4-12, where b is the total 
unconfined
alluvial aquifer thickness (136 m or 446 ft). The results from screen #2 are not included 
in
Figures 6.4-11 and 6.4-12 because they don't follow the trend of the results from the 
other
screens, probably because the screen #2 interval is highly affected by a clay layer at the 
same
horizon. Figure 6.4-13 is a plot of T versus Lw/b showing results from all four screens.
DTN: GS020708312316.001 [162678] (data); Output DTN: GS031008312316.002 (analysis).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-11. Transmissivity of Screens #1, #3, and #4 of NC-EWDP-19D1
as a Function of Screen Thickness
DTN: GS020708312316.001 [162678] (data); Output DTN: GS031008312316.002 (analysis).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-12. Transmissivity of Screens #1, #3, and #4 of NC-EWDP-19D1 as a Function of 
Distance
from Water Table to Bottom of Screen Divided by Distance from Water Table to Bottom of Screen 
#4
R2 = 0.9982
0
50
100
150
200
250
300
350
0 0.2 0.4 0.6 0.8 1 1.2
Lw/b
Transmissivity (ft^2/d)
R2 = 0.4812
0
50
100
150
200
250
300
350
0 20 40 60 80 100 120 140
Screen thickness, Le, in feet
Transmissivity (ft^2/d)
ANL-NBS-HS-000039, REV 00 324 December 2003
DTN: GS020708312316.001 [162678] (data); Output DTN: GS031008312316.002 (analysis).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-13. Transmissivity of Screens #1, #2, #3, and #4 of NC-EWDP-19D1 as a
Function of Distance from Water Table to Bottom of Screen Divided by Distance from
Water Table to Bottom of Screen #4
It can be seen from Figures 6.4-11 and 6.4-12 that the hydraulic test results from screens 
#1, #3,
and #4 indicate that T calculated with the fully-penetrating solution is a very weak 
function of Le
(R2 = 0.4812) but is very strongly correlated (R2 = 0.9982) with Lw/b, and, therefore, with 
Lw. In
fact, Figure 6.4-12, and even Figure 6.4-13, can be viewed as an empirical relationship 
derived
from ATC single-well hydraulic testing for correction of the partially-penetrating T 
values that
give a value for T of 28 m2/day (300 ft2/day) as their upper limit when the aquifer is fully
penetrated, i.e. at Lw/b = 1. Thus, the transmissivity values obtained in the hydraulic tests 
of
screens #1, #3, and #4 are all consistent with an overall transmissivity of 28 m2/day (300 
ft2/day)
for the saturated alluvium at 19D1 (Output DTN: GS031008312316.002). The T value of 
28
m2/day (300 ft2/day) from the 8/24/00 screen #4 test is essentially the same as the 
transmissivity
from the fully-penetrating open-hole test started on July 7, 2000 (20.7 m2/day or 223 
ft2/day),
considering that the borehole was slugged to increase its capacity between the two tests. 
Using
an aquifer thickness equal to the distance from the water table to the bottom of screen #4 
(136 m
or 446 ft), an overall transmissivity value of 28 m2/day (300 ft2/day) represents a 
hydraulic
conductivity of 0.20 m/day (0.67 ft/day) (Output DTN: GS031008312316.002).
Because of the large head losses discussed in the next section, the results from single-
well
hydraulic testing at 19D1 are considered to have a high degree of uncertainty in their 
absolute
values. It is recommended instead that values of transmissivity, and associated hydraulic
conductivity, obtained from cross-hole testing at the ATC, which is discussed in Section 
6.4.2,
be used for the saturated alluvium.
R2 = 0.8581
0
50
100
150
200
250
300
350
0 0.2 0.4 0.6 0.8 1 1.2
Lw/b
Transmissivity (ft^2/d)
ANL-NBS-HS-000039, REV 00 325 December 2003
6.4.1.4 Step-Drawdown Tests to Determine Head Losses
A step-drawdown test was conducted prior to the hydraulic test in each interval. On July 
6,
2000, prior to the open-alluvium hydraulic test starting on July 7, a step-drawdown test 
was
conducted in the open-alluvium in well 19D1. Two methods were attempted to analyze 
the data
as presented below.
The drawdown in the well itself (as opposed to the drawdown in the aquifer at the well 
wall) is
given by the following equation (modified from Bouwer 1978 [162675], p. 83, Equation 
4.38):
s * B?Q * C ?Qn (Eq. 28)
where
s = the drawdown
Q = the pumping rate
B, C, and n are coefficients.
B?Q represents the laminar flow that describes groundwater flow movement occurring in 
the
aquifer and C ?Qn represents the turbulent flow and associated head losses caused by 
water
entering the borehole on its way from the aquifer to the pump intake. Jacob assumed n = 
2
(Bouwer 1978 [162675], p. 83, Equation 4.39) to obtain:
s * B?Q * C?Q2. (Eq. 29)
The idea is to calculate B and C and then to calculate the fractional efficiency as the 
laminar
drawdown divided by total (laminar plus turbulent) drawdown. Efficiency would, thus, be
B?Q/(B?Q * C?Qn ), if Equation 28 is used, and B?Q/(B?Q * C?Q2) , if Equation 29 is 
used.
Calculations based on both equations were carried out on the data from the July 6, 2000, 
stepdrawdown
test in the open alluvium that indicate a negative value of B (a similar result is
obtained when analyzing a step-drawdown test conducted in screen #4 on January 7, 
2002). This
result, of course, is incorrect because a negative B leads to an indeterminate efficiency
calculation. Calculation of B is demonstrated below for the July 6, 2000, step-drawdown 
test.
Dividing Equation 29 by Q to obtain
s
Q
* B* C?Q (Eq. 30)
indicates that a plot of s/Q versus Q yields a linear relationship with an intercept of B and 
a slope
of C. Figure 6.4-14 is such a plot for the above step-drawdown test. It can be seen from 
the
figure that the intercept B is -0.1027 and the slope C is 0.004. Since the laminar flow
component, B?Q, cannot be negative, the negative value for B is taken to indicate that 
B?Q is
approximately zero.
ANL-NBS-HS-000039, REV 00 326 December 2003
DTN: GS020708312316.001 [162678] (data).
NOTE: Each data point represents an average of several drawdown and flow rate measurements at each 
nominal
pump rate. English units are shown in the figure because the analysis was conducted in English units.
However, parameter estimates are reported in metric units to downstream users.
Figure 6.4-14. Step-Drawdown Test in the Open Alluvium of NC-EWDP-19D1, July 6, 2000
The cause of this problem is believed to be that the step-drawdown test was carried out at 
a flowrate
range too high to permit calculation of the laminar groundwater flow component, B?Q. In
the flow-rate range for the test, 295 to 568 L/min (78 to 150 gpm), the turbulent head 
losses,
C ?Q2 , were so large that they dominated the much smaller laminar-flow-caused 
drawdown,
B?Q, which, at the accuracy of the test results, is approximately zero. To have been able 
to
calculate the laminar component and, therefore, quantify well efficiency, the step-
drawdown test
would have had to be run at a much lower range of flow rates than the range used, 
namely 295 to
568 L/min (78 to 150 gpm). However, the pump used, which was required for pumping 
up to
606 L/min (160 gpm) in the open-alluvium test and which was used in the screens #4 and 
#3
isolated interval tests, had a minimum operational rate of approximately 291 L/min (77 
gpm).
Because the 19D1 well efficiency could not be calculated from the step-drawdown tests
conducted in it, the efficiency was estimated by comparing results from single-well 
hydraulic
tests in that well with those of cross-hole tests. Single-well tests indicated a transmissivity 
of 28
m2/day (300 ft2/day) for the saturated alluvium at 19D1 (Output DTN: 
GS031008312316.002)
y = 0.004x - 0.1027
R2 = 0.9973
0
0.1
0.2
0.3
0.4
0.5
0.6
0 20 40 60 80 100 120 140 160
FLOW RATE IN GPM
Series1
Linear (Series1)
ANL-NBS-HS-000039, REV 00 327 December 2003
(Section 6.4.1.3), whereas cross-hole testing indicated a transmissivity of 306 m2/day 
(3,300
ft2/day) (Output DTN: GS031008312316.002) by analyzing the response in observation 
well
19IM2 (Section 6.4.2).
Drawdown is related to Q and transmissivity, T, by the relationship:
s * Q
4 ?T
W(u) (Eq. 31)
where
u = r2S/4Tt in which:
r[L] = radial distance from the pumping well
S[L0] = storativity
t[T] = elapsed time from the beginning of pumping
and
W(u) = * u
* ?{(e-u/u) du; W(u) is the well function, which can be a confined, unconfined,
or leaky well function.
Equation 31 is the same relationship as in Theis (1935 [150327], p. 520, Equation 4) 
except that
s is used for drawdown instead of v, and Q is used for the discharge rate instead of F.
Assuming that head losses in observation well 19IM2 in the cross-hole test when well 
19D1 was
being pumped (Section 6.4.2) to be negligible relative to those in the pumped well, the 
value of
306 m2/day (3,300 ft2/day) is considered to be the true transmissivity value of the 
alluvium
aquifer at the ATC (Output DTN: GS031008312316.002). Therefore, in the single-well 
tests at
well 19D1, by substituting 306 m2/day (3,300 ft2/day) into Equation 31, the drawdown in 
the
aquifer itself due to laminar flow is:
) (
) 306 ( 4 laminar u W
Q
s
?
* (Eq. 32)
The actual drawdown in well 19D1 is the total drawdown (laminar plus turbulent) that 
was used
to calculate a T of 28 m2/day (300 ft2/day), which when substituted into Equation 31 
yields:
) (
) 28 ( 4 turbulent laminar u W
Q
s s
?
* * (Eq. 33)
The well function, W(u), in both Equations 32 and 33 is the same because it pertains to 
the same
well and time history. Q is also the same; it is the actual pumping rate for the single-well 
testing.
The well efficiency for 19D1 (Output DTN: GS031008312316.002) is now calculated by
dividing Equation 32 by Equation 33:
% 1 . 9 091 . 0
306
28
Efficiency
turbulent laminar
laminar * * ?
?
?
s s
s
(Eq. 34)
ANL-NBS-HS-000039, REV 00 328 December 2003
6.4.1.5 Determination of Leakage From Screens #5, #6, and #7 to Screen #4
After single-well hydraulic and tracer tests in well 19D1, screen #4 had been selected to 
conduct
cross-hole tracer testing by pumping 19D1 and injecting tracers into 19IM1 and 19IM2. 
For that
reason, it was desirable to determine the upward contribution of the intervals below the 
alluvium
(screens #5, #6, and #7 in 19D1) to the water withdrawn from screen #4 in 19D1 during 
such a
cross-hole tracer test (see Figure 6.1-8 for location of screens and other lithologic 
information).
Such contribution from the intervals below the alluvium would be promoted by the 
natural
upward gradient at the site and the creation of a substantial additional vertical gradient by
pumping screen #4 in 19D1 and lowering its hydraulic head. Knowledge of this 
contribution is
necessary for the correct analysis of the results from cross-hole tracer testing in screen 
#4,
especially for effective porosity. The flow rate that should be used in calculating the 
effective
porosity when analyzing the results of cross-hole tracer testing should be the portion of 
the
pumped rate that is actually provided by screen #4 of the alluvium, that is, excluding the 
portion
contributed by the intervals below the alluvium.
To determine the component of flow from below screen #4, three "confirmatory" 
hydraulic tests
were conducted in 19D1. The results from these three tests will first be presented below,
followed by an analysis to determine the leakage rate from below the screen #4 interval.
In the first confirmatory test from December 18 to 20, 2001, the combined interval below 
the
alluvium containing screens #5, #6, and #7 was pumped at the nominal rate of 356 L/min 
(94
gpm) for 48 hr. During the test, the screen #4 interval and the combined interval 
containing
screens #1, #2, and #3 were monitored. The drawdown in the combined screens #5, #6, 
and #7
interval as a function of elapsed time is shown in Figure 6.4-15.
In the second confirmatory test from January 4 to 6, 2002, the screen #5 interval also 
(like the
screens #5, #6, and #7 interval test) was pumped at the nominal rate of 356 L/min (94 
gpm) for
48 hr. During the test, the combined screens #6 and #7 interval, the screen #4 interval, 
and the
combined screens #1, #2, and #3 interval were monitored. The drawdown in the screen 
#5
interval as a function of elapsed time is shown in Figure 6.4-16.
In the third confirmatory test from January 8 to 10, 2002, the screen #4 interval was 
pumped at
the nominal rate of 254 L/min (67 gpm) for 48 hr. During the test, the combined screens 
#5, #6,
and #7 interval, the screen #3 interval, and the combined screens #1 and #2 interval were
monitored. The drawdown in the screen #4 interval as a function of elapsed time is shown 
in
Figure 6.4-17.
Also for this confirmatory test in screen #4, the recovery for the screens #5, #6, and #7 
interval is
shown in Figure 6.4-18 because it is needed in the following analysis of leakage.
To determine the component of flow from below screen #4 to withdrawal from screen #4, 
a
comparison was made of the drawdown in screens #5, #6, and #7 when they were 
pumped at 356
L/min (94 gpm) in the December 18, 2001, test (Figure 6.4-15) with the drawdown in 
screens #5,
#6, and #7 in response to pumping screen #4 in the August 24, 2000, "screen #4" test 
(Figure
6.4-19).
ANL-NBS-HS-000039, REV 00 329 December 2003
Figure 6.4-20 presents the comparison. The responses are very similar with a ratio of 153 
in the
drawdown values. These are both drawdowns in the same intervals (i.e., screens #5, #6, 
and #7):
one in response to direct pumping at 356 L/min (94 gpm) and the other in response to an
unknown leakage rate from screens #5, #6, and #7 to screen #4. Thus,
s5,6,7(12 /18 / 01)
s5,6,7(8 / 24 / 00 )
?153 (Eq.35)
where s5,6,7(12 /18 / 01) is the drawdown for the combined screens #5, #6, and #7 interval on
December 18, 2001, and so forth.
DTN: GS020908312316.002 [162679] (data).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users
Figure 6.4-15. Drawdown Versus Elapsed Time Since Pumping Started for the Confirmatory 
Hydraulic
Test in Which the Combined Screens #5, #6, and #7 Interval in NC-EWDP-19D1 Was Pumped
48 HOUR PUMPING TEST IN INTERVALS 5,6,7 (TUFF & TERTIARY SEDIMENTS) IN 19D1
STARTING AT 2PM ON 12/18/01
0
50
100
150
200
250
0 6 12 18 24 30 36 42 48 54 60 66 72 78
ELAPSED HOURS SINCE 2 PM ON 12/18/01
Series1
ANL-NBS-HS-000039, REV 00 330 December 2003
DTN: GS020908312316.002 [162679] (data).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-16. Drawdown as a Function of Elapsed Time for the Confirmatory Hydraulic Test in 
Which
the Screen #5 Interval in NC-EWDP-19D1 Was Pumped
48 HOUR TEST IN SCREEN #5 OF NC-EWDP-19D1 STARTING AT 10:30 AM ON 1/4/02
0
50
100
150
200
250
0 6 12 18 24 30 36 42 48 54 60 66 72 78
ELAPSED HOURS SINCE 10:30 AM ON 1/4/02
Series1
ANL-NBS-HS-000039, REV 00 331 December 2003
DTN: GS020908312316.002 [162679] (data).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-17. Drawdown as a Function of Elapsed Time in Screen #4 During Pumping and 
Recovery in
the Confirmatory Hydraulic Test in That Screen, January 8 to 10, 2002
0
20
40
60
80
100
120
140
160
180
0 10 20 30 40 50 60 70 80 90 100
ELAPSED HOURS SINCE START OF PUMPING AT 10:30 AM ON 1/8/02
Series1
ANL-NBS-HS-000039, REV 00 332 December 2003
DTN: GS020908312316.002 [162679] (data).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-18. Recovery Versus Elapsed Time for the Screens #5, #6, and #7 Interval During the
Confirmatory Hydraulic Test in Screen #4 of NC-EWDP-19D1, January 8 to 10, 2002
0
0.5
1
1.5
2
2.5
3
3.5
0 5 10 15 20 25 30 35 40 45 50
ELAPSED HOURS SINCE END OF PUMPING AT 11:30 AM ON 1/10/02
ANL-NBS-HS-000039, REV 00 333 December 2003
DTN: GS020708312316.001 [162678] (data).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-19. Drawdown in the Screens #5, #6, and #7 Interval During the August 24 to 31, 
2000,
Pumping Test in Screen #4
DRAWDOWN IN SCREENS #5,6,7 DURING THE 8/24/00 PUMPING TEST IN SCREEN #4
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 10 20 30 40 50 60
ELAPSED HOURS SINCE START OF PUMPING AT 12 PM ON 8/24/00
DRAWDOWN IN THE SCREENS #5, 6, 7 INTERVAL IN
FEET
ANL-NBS-HS-000039, REV 00 334 December 2003
DTNs: GS020708312316.001 [162678] and GS020908312316.002 [162679] (data).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users
Figure 6.4-20. Comparing Drawdown in the Screens #5, #6, and #7 Interval While It Was Pumped 
During
the December 18, 2001, Test With the Drawdown in the Same Interval During the August 24 to 
31, 2000,
Pumping Test in Screen #4
A correction should be made, however, to the drawdown in the screens #5, #6, and #7 
interval
during the December 18, 2001, test, based on the approximately 9% well efficiency of 
19D1, as
determined by Equation 34. This efficiency indicates that the laminar component of the
drawdown occurring in the aquifer is only 9% of the total drawdown recorded in the 
screens #5,
#6, and #7 interval of 19D1 when that interval was directly pumped during the December 
18,
2001, test. In other words, using a prime to indicate laminar drawdown in the aquifer and
multiplying the drawdown by the well efficiency (decimal equivalence 0.09) in order to 
calculate
9 percent of drawdown is mathematically expressed as,
* ?s 5,6,7(12 /18 / 01) * (0.09)s5,6,7(12/18 / 01) (Eq. 36)
On the other hand, negligible head losses are assumed in the screens #5, #6, and #7 
interval when
it was not pumped directly but leaked to the screen #4 interval when the latter was 
pumped in the
12/18/01 TEST IN SCREENS #5,6,7 COMPARED WITH 8/24/00 RESPONSE ALSO IN #5,6,7
0
50
100
150
200
250
300
0 10 20 30 40 50 60
ELAPSED HOURS SINCE START OF PUMPING
DRAWDOWN IN FEET
#5,6,7 DD, 12/18/01 TEST, 94 GPM
SCREENS 5,6,7 DD DURING 8/24/00 TEST, TIMES 153
ANL-NBS-HS-000039, REV 00 335 December 2003
August 24, 2000, test-that is, if we do not subtract any drawdown for well inefficiency, 
then s
prime equals s, which is mathematically expressed as
* ?s 5,6,7(8 / 24 / 00 ) * s5,6,7(8 / 24 / 00 ). (Eq. 37)
Therefore, the ratio of drawdowns occurring in the aquifer itself for the above two 
contrasted
tests is
* ?s 5,6,7(12 /18 / 01)
* ?s 5,6,7(8 / 24 / 00 )
* (0.09)
s5,6,7(12 /18 / 01)
s5,6,7(8/ 24 / 00)
* (0.09)(153) ?13.77 (Eq. 38)
Assuming that the transmissivity of the screens #5, #6, and #7 interval is the same during 
the
August 24, 2000, and December 18, 2001, tests, the ratio of the two drawdown responses, 
which
is 13.77, should be the same as the ratio of the flow rates that produced them-that is, 
from
Equation 31 (Theis 1935 [150327]),
) (
4
356
) 01 / 18 / 12 ( 7 , 6 , 5 u W
T
s
?
* * ?(Eq. 39)
and
) (
4
) 00 / 24 / 8 ( 7 , 6 , 5
) 00 / 24 / 8 ( 7 . 6 . 5 u W
T
Q
s
?
* * ?(Eq. 40)
where Q5,6,7(8/24/00) is the "withdrawal" rate from the screens #5, #6, and #7 interval that 
occurred
while pumping screen #4, that is, the leakage from screens #5, #6, and #7 to screen #4 
during the
August 24 to 31, 2000 test. Dividing Equation 39 by Equation 40 gives
) 00 / 24 / 8 ( 7 , 6 , 5 ) 00 / 24 / 8 ( 7 , 6 , 5
) 01 / 18 / 12 ( 7 , 6 , 5 356
Q s
s
?
* 
* 
(Eq. 41)
or, using the value for the ratio of 13.77 from Equation 38, we find that
77 . 13
356
) 00 / 24 / 8 ( 7 , 6 , 5 * Q = 25.8 L/min or (6.83 gpm). (Eq. 42)
In other words, when screen #4 was pumped at the rate of 299 L/min (79 gpm) during the 
August
24, 2000 test, 25.8 L/min (6.83 gpm) of the 299 L/min (79 gpm) withdrawn (or 8.65%) 
actually
came from the screens #5, #6, and #7 interval.
The same analysis can be done by comparing the drawdown in the screens #5, #6, and #7
interval when it was pumped in the December 18, 2001 test (Figure 6.4-15) with the 
recovery in
the same interval in response to pumping the screen #4 interval in the January 8, 2002, 
test
(Figure 6.4-18).
ANL-NBS-HS-000039, REV 00 336 December 2003
Figure 6.4-21 presents the comparison. The responses are very similar with a ratio of 69 
in the
drawdown values-that is,
s5,6,7(12 /18 / 01)
s5,6,7(1/ 8 / 02)
* 69. (Eq. 43)
These are both drawdowns in the same intervals (i.e., the combined screens #5, #6, and 
#7)-one
in response to direct pumping at 356 L/min (94 gpm) and the other in response to an 
unknown
leakage rate from screens #5, #6, and #7 to screen #4.
DTN: GS020908312316.002 [162679] (data).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-21. Comparing Drawdown in the Screens #5, #6, and #7 Interval While It Was Pumped 
During
the December 18, 2001 Test with the Recovery in the Same Interval After Cessation of Pumping 
in
Screen #4 During the January 8, 2002 Test
0
50
100
150
200
250
300
0 5 10 15 20 25 30 35 40 45 50
ELAPSED HOURS SINCE PUMPING OR RECOVERY STARTED
69 X RECOVERY IN SCs 5,6,7 AFTER PUMPING SC 4, 1/8/02 TEST
DD IN SCs 5,6,7 DURING 12/18/01 TEST
ANL-NBS-HS-000039, REV 00 337 December 2003
Negligible head losses are assumed in the screens #5, #6, and #7 interval when it was not
pumped directly but leaked to the screen #4 interval when the latter was pumped in the 
January
8, 2002 test-that is,
) 02 / 8 / 1 ( 7 , 6 , 5 ) 02 / 8 / 1 ( 7 , 6 , 5 s s * * ?. (Eq. 44)
Assuming that the transmissivity of screens #5, #6, and #7 is the same during the 
December 18,
2001 and January 8, 2002 tests, the ratio of the two drawdown responses, which is 38.8, 
should
be the same as the ratio of the flow rates that produced them-that is, from Equation 31 
(Theis
1935 [150327], p. 520, Equation 4),
) (
4
356
) 01 / 18 / 12 ( 7 , 6 , 5 u W
T
s
?
* * ?, (Eq. 45)
which is the same as Equation 39 (Theis 1935 [150327], p. 520, Equation 4), and
* ?s 5,6,7(1/ 8 / 02) ?
Q5,6,7(1/ 8/ 02 )
4 ?T
W (u) , (Eq. 46)
where Q5,6,7(1/ 8 / 02) is the "withdrawal" rate from the screens #5, #6, #7 interval that was 
occurring
during the pumping of screen #4 (that is, the leakage from screens #5, #6, and #7 to 
screen #4)
during the January 8, 2002, test. Dividing Equation 45 by Equation 46 (Theis 1935 
[150327],
p. 520, Equation 4) gives
) 02 / 8 / 1 ( 7 , 6 , 5 ) 02 / 8 / 1 ( 7 , 6 , 5
) 01 / 18 / 12 ( 7 , 6 , 5 356
Q s
s
?
* 
* 
. (Eq. 47)
Substituting 0.09 s 5,6,7( 12/ 18 / 01 ) for s'5,6,7( 12/ 18 / 01 ) from Equation 36, and s5,6,7( 1/ 8 / 02 ) for s'5,6,7( 
1/ 8/ 02 )
from Equation 44, into Equation 47, and then further substituting 69 from Equation 43 for 
the
resulting ratio of s 5,6,7( 12/ 18 / 01 ) / s 5,6,7( 1/ 8 / 02 ), we obtain:
Q 5,6,7( 1/ 8 / 02 ) = 356 / (0.09 x 69) = 57.3 L/min (15.14 gpm) (Eq. 48)
In other words, when screen #4 was pumped at the rate of 254 L/min (67 gpm) during the
January 8, 2002 test, 57.3 L/min (15.14 gpm) of the 254 L/min (67 gpm) withdrawn (or 
22.6%)
actually came from the screens #5, #6, and #7 interval.
The increase in calculated leakage from screens #5, #6, and #7 to screen #4 in the January 
8,
2002 test, 22.6%, compared to the calculated leakage in the August 24, 2000 test, 8.65%, 
is a
result of the drop of efficiency of borehole 19D1 (at least in screen #4) in the time period
between the two tests. When the screen #4 drawdown of the January 8, 2002 test is 
analyzed by
the Neuman (1975 [150321] (Neuman.vi V 1.0, STN: 10972-1.0-00 [162754]) solution, a
transmissivity of 4.4 m2/day (48 ft2/day) is obtained compared with the 28 m2/day (300 
ft2/day)
obtained by analyzing the August 24, 2000, screen #4 interval test. Both of these 
transmissivities
were estimated without accounting for leakage from screens #5 to #7 to screen #4; the
transmissivities would be somewhat smaller if leakage were accounted for. This result 
indicates
ANL-NBS-HS-000039, REV 00 338 December 2003
that the 19D1 (screen #4) well efficiency during the January 8, 2002, test could have been 
as low
as 16% (4.4/28) of the well efficiency during the August 24, 2000, test. Loss of well 
efficiency
causes increased drawdown in the pumped interval, screen #4, which causes an increase 
in the
upward gradient, and resultant leakage, from screens #5, #6, and #7 to screen #4.
Based on the two analyses above that compare the drawdown in the screens #5, #6, and 
#7
interval when it was directly pumped during the December 18, 2001, test with the 
drawdown in
the screens #5, #6, and #7 interval in response to pumping screen #4 in both the August 
24, 2000,
and January 8, 2002, tests, it is concluded that up to 23% (upper envelope of 8.65% and 
22.6%)
of the flow rate may have been a contribution from the screens #5, #6, and #7 interval 
when
pumping screen #4 in 19D1 (DTN: GS020708312316.001 [162678]; DTN:
GS020908312316.002 [162679]; Output DTN: GS031008312316.002).
6.4.2 ATC Cross-Hole Hydraulic Testing
Two cross-hole hydraulic tests were conducted at the ATC in January 2002. In both tests,
borehole 19D1 was pumped in the open-alluvium section while 19IM1 and 19IM2 were 
used as
monitoring wells. The surface configuration of the three wells is shown in Figure 6.1-7, 
and
Figure 6.1-8 shows the construction/completion of the wells. Cross-hole hydraulic 
responses in
19IM1 were not analyzed quantitatively for this scientific analysis report because data 
collection
in this well was not conducted in strict accordance with YMP QA procedures.
In the first cross-hole hydraulic test, conducted from January 26 to 28, 2002, in 19D1, 
both
19IM1 and 19IM2 were packed off, each isolating four intervals in the alluvium section. 
In the
January 29 to February 4, 2002, test, 19IM1 was packed off while 19IM2 had only one 
packer
inflated isolating the alluvium section from the intervals below it. Only results from the 
January
29 to February 4, 2002, test are presented in this report because the total transmissivity of 
the
alluvium is less ambiguously obtained in this test than in the earlier test with isolated 
intervals in
the observation wells.
The drawdown in the alluvium section of 19IM2 resulting from pumping the same 
section in
well 19D1 at 109 gpm from January 29 to February 4, 2002, is presented in Figure 6.4-
22. This
drawdown exhibits the characteristics of a confined aquifer, and the fit to the type curve 
of Theis
(1935 [150327]) (Neuman.vi V 1.0, STN: 10972-1.0-00 [162754]) is presented in Figure 
6.4-23.
The fact that the response at 19IM2 is that of a confined aquifer whereas the response of 
singlewell
testing in 19D1 conformed to the Neuman (1975 [150321]) unconfined response 
indicates
that there may be a unit causing confinement at 19IM2 that pinches out at 19D1. The 
possibility
was considered that the drawdown in 19IM2 was so small relative to the saturated 
thickness at
this observation well (~2%) that the response followed that of a confined aquifer even 
though the
aquifer was unconfined. However, attempts to fit the Neuman (1975 [150321]) 
(Neuman.vi V
1.0, STN: 10972-1.0-00 [162754]) unconfined aquifer solution to the drawdown response
indicated that the test had been conducted long enough to exhibit the flattening in 
drawdown at
late times that would be expected if the aquifer were unconfined. Because this flattening 
did not
occur, it appears likely that a confining layer influenced the response near 19IM2.
ANL-NBS-HS-000039, REV 00 339 December 2003
The fit to the Theis (1935 [150327]) curve presented in Figure 6.4-23 results in an 
estimated
transmissivity value of 306 m2/day (3,300 ft2/day) (Output DTN: GS031008312316.002) 
and a
storativity of 0.00045 (Output DTN: GS031008312316.002). The transmissivity estimate 
is
approximately an order-of-magnitude higher than the 28 m2/day (300 ft2/day) value 
obtained
from single-well testing in 19D1 (Section 6.4.1.2). This difference is the result of large 
head
losses in the single-well testing, and the ratio of the single-well to the cross-hole 
transmissivities
is shown in the discussion leading to Equation 34 to be the efficiency of well 19D1. The 
tested
interval in 19IM2 from the water table to the bottom of screen #4 is approximately 133 m 
(437
ft). Therefore, the hydraulic conductivity is 306 m/day/133 m (3,300 ft2/day/437 ft), 
which is
approximately 2.3 m/day (7.5 ft/day) (Output DTN: GS031008312316.002).
The storativity estimate above allows calculation of the specific storage that is needed for
calculation of total porosity in Section 6.4.3. The above storativity estimate of 0.00045 is 
for the
entire open-alluvium thickness at 19IM2, which is 133.1 m (436.6 ft) (depth to bottom of 
sand at
the bottom of screen #4, 242.5 m [795.6 ft], minus depth to water, 109 m [359 ft]). These
numbers give a value for the specific storage, Ss, of 0.00045/ 133.1 m = 0.00000338 m-1
(0.00045/436.6 ft = 0.000001031 ft-1) (Output DTN: GS031008312316.002).
DTN: GS020908312316.002 [162679] (data).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-22. Drawdown in the Open-Alluvium Section of Observation Well NC-EWDP-19IM2 
While
Pumping NC-EWDP-19D1 at the Nominal Rate of 109 gpm
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0 1 2 3 4 5 6 7
ELAPSED DAYS SINCE 4:30 PM ON JANUARY 29, 2002
IM2 DRAWDOWN IN THE OPEN-ALLUVIUM SECTION (FEET)
IM2 DRAWDOWN IN FEET
ANL-NBS-HS-000039, REV 00 340 December 2003
DTN: GS020908312316.002 [162679] (data); Output DTN: GS031008312316.002 (analysis).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-23. Fit to the Theis (1935) Confined-Aquifer Solution of the Drawdown in NC-EWDP-
19IM2
Resulting from Pumping NC-EWDP-19D1 at 109 gpm
6.4.2.1 Qualitative Discussion of Horizontal Anisotropy of the Hydraulic 
Conductivity
The drawdown pattern at 19IM1 and 19IM2 in response to pumping 19D1 in both of the 
above
cross-hole tests clearly indicated anisotropy in the horizontal hydraulic conductivity. It 
showed
that the direction of the major principal hydraulic conductivity tensor is oriented in the 
northeast
to southwest direction (Output DTN: GS031008312316.002). With only two observation 
wells,
however, the degree of horizontal anisotropy and its precise orientation cannot be 
quantified. It
should be noted that because the apparent transmissivity between 19D1 and IM2 was 
greater
than the transmissivity between -19D1 and 19IM1, the estimate of well efficiency in 
Section
6.4.1.5 would have been greater if the transmissivity between 19D1 and 19IM1 had been 
used
instead of the transmissivity between 19D1 and 19IM2.
1 00 .0 00
0 .0 00
0 .0 01
0 .0 10
0 .1 00
1 .0 00
10 .0 00
10 00 0 .0 0 .1 1 .0 10 .0 1 0 0 .0 10 00 .0
P lot 0
P lot 1 D raw d ow n (fe e t ) v s. time (min u te s)
T IM E S IN CE PU M PIN G ST AR T ED , IN M IN U T ES
D
R
A
W
D
O
W
N
I
N
F
E
E
T
T h e is type c urv e
D raw dow n in IM 2
ANL-NBS-HS-000039, REV 00 341 December 2003
6.4.3 Obtaining Total Porosity from Specific Storage and Barometric Efficiency
An estimate of total porosity was obtained by combining the specific storage value from 
crosshole
testing, namely Ss = 0.00000338 m-1 (0.000001031 ft-1) (Section 6.4.2), with a value of
barometric efficiency, BE, obtained from analyzing background water-level monitoring.
Calculation of total porosity is done through use of a relationship derived for a confined 
aquifer
in De Wiest (1965 [162674], p. 191, Equation 4.77). This equation is also presented in 
Geldon et
al. (1997 [156827], p. 15, Equation 14) and attributed to Jacob. Using the notation of 
Geldon et
al. (1997 [156827]) and rearranging terms of his equation, an expression for total 
porosity, ?, can
be written as:
* ?Ss(BE)
* 
(Eq. 49)
where
* = the unit weight of water = = 1000 kg/m3 (0.434 lb/in2/ft [62.496 lb/ft3]) (Lohman 
1972
[150250], Constants in Equations 20 and 21).
* = the compressibility of water = 4.69 x 10-9 m2/kg (3.3 x 10-6 in2/lb [2.29167 x 10-8 
ft2/lb])
(Lohman 1972 [150250], Constants in Equations 20 and 21).
The barometric efficiency, BE, was obtained by analyzing background water-level 
monitoring
conducted between May 1 and July 3, 2002 (DTN: GS020908312316.003 [162680]).
The atmospheric pressure is first subtracted from the absolute-pressure transducer values 
to
obtain the hydraulic pressure (represented in equivalent feet of water.) The hydraulic 
pressure
and atmospheric pressure (also represented as equivalent feet of water) records for the 
period of
monitoring (DTN: GS020908312316.003 [162680]) are then filtered (Output DTN:
GS031008312316.002; Software: Filter.vi V 1.0, STN: 10970-1.0-00 [162668]) to 
remove all
oscillations with frequencies higher than 0.8 cycles/day. This step removes the effects of 
all
semidiurnal atmospheric pressure changes and all earth tides on the hydraulic-pressure 
record. It
also removes the semidiurnal atmospheric pressure fluctuations from the atmospheric-
pressure
record. What remains are the low-frequency atmospheric pressure fluctuations associated 
with
weather systems and the oscillations they cause in the hydraulic pressure record. The 
changes in
the low-frequency hydraulic pressure record is then plotted against the changes in the 
lowfrequency
atmospheric pressure record as shown in Figure 6.4-24.
The slope of the best-fit line through the data in Figure 6.4-24 is -56.54%, indicating that 
for any
incremental change in the atmospheric pressure at the 19D1 location, a corresponding 
change in
the hydraulic pressure occurs, which is opposite in sign to the atmospheric pressure 
change and
equal to 56.54% of its magnitude. In other words, the barometric efficiency, BE, of the 
aquifer at
the 19D1 location is 56.54%, or 0.5654 (Output DTN: GS031008312316.002).
ANL-NBS-HS-000039, REV 00 342 December 2003
Substituting BE = 0.5654 from above and Ss = 0.00000338 m-1 (0.000001031 ft-1) (from 
Section
6.4.2) into Equation 49 (along with the values for * and * listed under that equation) 
gives
(Output DTN: GS031008312316.002):
* 
(0.00000338 m?1)(0.5654)
(1000 kg/m3 )(4.69 x 10?9 m2/kg)
* 0.407 * 40.7% (Eq. 50)
DTN: GS020908312316.003 [162680]. (data); Output DTN: GS031008312316.002 (analysis).
NOTE: English units are shown in the figure because the analysis was conducted in English units. However,
parameter estimates are reported in metric units to downstream users.
Figure 6.4-24. Relation of Low-Frequency Hydraulic-Pressure Change in NC-EWDP-19D1 to 
Low-
Frequency Atmospheric-Pressure Change at the NC-EWDP-19D1 Location: Data and 
Regression Line
The largest total porosity value obtained from grain-size distributions in well 19D1 is 
0.33,
occurring at the 152- to 154-m (500- to 505-ft) depth interval (DTN: 
LA0201JS831421.001
[162613], Output DTN: GS031008312316.002). The largest total porosity value obtained 
from
the Borehole Gravity Meter survey done in NC-EWDP-19D1, presented in Section 6.5.5, 
is 0.29,
occurring at approximately 198 m (650 ft) of depth. The above values would indicate that 
the
upper limit for total porosity in the alluvium at the 19D1 location ranges from 29% to
approximately 40%. (The total porosity from grain-size distribution is obtained through 
the
Regression Line:
y = -0.5654x + 4E-05
R2 = 0.9559
-0.0010
-0.0008
-0.0006
-0.0004
-0.0002
0.0000
0.0002
0.0004
0.0006
0.0008
0.0010
-0.0010 -0.0008 -0.0006 -0.0004 -0.0002 0.0000 0.0002 0.0004 0.0006 0.0008 0.0010
CHANGE IN BAROMETER (FEET)
CHANGE IN 19D HYDRAULIC PRESSURE HEAD (FEET)
ANL-NBS-HS-000039, REV 00 343 December 2003
relation, Porosity = 0.255 (1 + 0.83C), where C, the coefficient of uniformity, is the ratio 
of the
60th grain-size percentile to the 10th percentile.) (Kasenow 2002 [164666], p. 72).
There are many assumptions involved in the derivation of Equation 49 (De Wiest 1965 
[162674],
pp. 189 to 191). Uncertainties in the estimate of total porosity using this equation depend
primarily on the extent to which these assumptions hold true in the saturated alluvium.
Unfortunately, the data and information necessary to evaluate the validity of these 
assumptions
were not available. Barometric efficiency was believed to be determined quite accurately 
from
the large number of barometer and water-level measurements, and the storativity estimate
obtained from cross-hole hydraulic testing at the ATC is considered less uncertain than 
the
assumptions inherent in Equation 49. A formal analysis of uncertainty in the porosity 
estimate
was not conducted.
6.4.4 Summary of Hydraulic Parameters in Alluvium
The single-hole testing indicated an overall transmissivity for the alluvium of 28 m2/day 
(300
ft2/day) with an associated hydraulic conductivity of 0.20 m/day (0.67 ft/day) (Output 
DTN:
GS031008312316.002). This is a horizontal hydraulic conductivity value with no 
directional
dependence. The transmissivity and hydraulic conductivity estimates were also estimated
without assuming any near-wellbore head losses, which apparently were very significant,
possibly because of the narrow slots in the well screens and the relatively small particle 
size of
the sand packs in 19D1, among other reasons (well efficiency is determined to be 9.1% 
[Output
DTN: GS031008312316.002]; see Section 6.4.1.4, Equation 34). Thus, the true 
transmissivity
and hydraulic conductivity are believed to be approximately an order-of-magnitude 
higher than
the single-hole apparent values.
Vertical hydraulic conductivities could not be estimated from the single-well testing, 
although
they were presumably small, because none of the intervals above or below the isolated 
intervals
in the hydraulic tests showed any pressure response during pumping (with the exception 
of
interval #5 in the tuffs, which responded slightly to pumping interval #4). Also, there was
minimal response in 19P when pumping any of the intervals in 19D1 except for screen #1 
and
the combined-interval test.
Estimates of transmissivity and horizontal hydraulic conductivity were greatly improved 
after
cross-hole hydraulic testing was conducted at the 19D1 location (Section 6.4.2). The 
cross-hole
tests indicated a transmissivity of 306 m2/day (3,300 ft2/day) (hydraulic conductivity of 
2.0
m/day [6.7 ft/day]), which is about an order of magnitude higher than the transmissivity 
and
hydraulic conductivity values obtained from single-well hydraulic tests. Because of well 
losses
in 19D1 (well efficiency of 9.1%), the cross-hole transmissivity value of 306 m2/day 
(3,300
ft2/day) is considered to be much more representative of the saturated alluvium in the 
vicinity of
19D1 than the single-well transmissivity values of ~28 m2/day (~300 ft2/day). The cross-
hole
tests also provided storativity estimates as well as qualitative information on horizontal
anisotropy of hydraulic conductivity in the saturated alluvium.
ANL-NBS-HS-000039, REV 00 344 December 2003
6.5 TRANSPORT PROPERTIES OF THE ALLUVIUM (ATC)
6.5.1 Introduction and Alternative Conceptual Transport Models
Three single-well injection-withdrawal tracer tests were conducted in screen #1 (the 
uppermost
screened interval) of NC-EWDP-19D1 between December 2000 and April 2001 (see 
Figure 6.1-
8 for diagram showing well completion and lithology; note that well NC-EWDP-19D1 
will be
referred to by its abbreviated form (19D1) in the remainder of this document; see Table 
1). The
primary objective of these tests was to distinguish between alternative conceptual 
transport
models for the saturated alluvium south of Yucca Mountain. A secondary objective was 
to
obtain estimates of key transport parameters associated with the appropriate conceptual 
model.
A fourth single-well injection-withdrawal tracer test was conducted in screen #4 of 19D1 
in
February and March of 2002. This test is only briefly discussed in this report (Section 
6.5.4.5)
because it was conducted for the purposes of comparing and contrasting parameter 
estimates
obtained from single-well and cross-hole tests, but the cross-hole tests were not 
conducted.
Detailed documentation of the tracer tests is contained in Umari (2003 [164573]) and 
Reimus
(2003 [165128]).
The three conceptual transport models that were considered for the saturated valley-fill 
deposits
located south of Yucca Mountain prior to single-well tracer testing at 19D/D1 are 
depicted in
Figure 6.5-1 (with some additional variations/combinations). The first model assumes 
purely
advective transport through a porous medium with no diffusive mass transfer into either 
the
grains of the medium or between advective and nonadvective regions of the aquifer. This 
model
does not necessarily imply a homogeneous flow field, but it does preclude a system with
alternating layers of relatively narrow thickness and significant permeability contrasts. 
Such a
conceptual model might be valid in a sandy aquifer with grains of relatively low porosity. 
The
second model is similar to the first except that it assumes diffusive mass transfer into the 
grains
of the porous medium. These grains have significant internal porosity, but the porosity is 
not
well-connected over the scale of the grains; therefore, the grains transmit negligible flow. 
The
third model assumes diffusive mass transfer between advective and nonadvective layers 
in the
aquifer. In this model, the flow system is assumed to alternate between high and low
conductivity layers, a simplified representation that is consistent with some depositional
scenarios. Diffusive mass transfer in this case is only between the two layers, not into 
grains
within the layers. However, one variation of this model is to assume that diffusion also 
occurs
into grains in both the advective and nonadvective layers. This variation is essentially a
combination of the second and third conceptual models, with an additional level of 
complexity
allowing for diffusion in the nonadvective layer into both the inter- and intragranular pore
spaces.
Pre-test predictions of the single-well injection-withdrawal tracer tests conducted at 19D1 
are
presented in Section 6.5.2. Pre-test predictions of cross-hole tracer test responses in the 
alluvium
are provided in Section 6.5.3. The results and preliminary interpretations of the three 
single-well
injection-withdrawal tests conducted in FY 2001 are presented in Section 6.5.4. Finally, 
Section
6.5.5 presents the results and interpretations of several laboratory experiments that have 
been
conducted to support the ATC testing effort.
ANL-NBS-HS-000039, REV 00 345 December 2003
For illustration purposes only
NOTE: Red arrows in (c) indicate diffusive mass transfer options that were exercised in this scientific 
analysis, and
black arrows indicate options that were not exercised.
Figure 6.5-1. Schematic Illustration of Alternative Conceptual Transport
Models for the Valley-Fill Deposits South of Yucca Mountain
ANL-NBS-HS-000039, REV 00 346 December 2003
6.5.2 Pre-Test Predictions of Single-Well Tracer Responses for Each Conceptual 
Model
Prior to conducting the single-well tracer tests in 19D1, the MULTRAN model (Section
6.3.9.2.2) was used to simulate tracer responses, assuming each of the three alternative
conceptual models of Figure 6.5-1. Simulations were conducted for each of three planned
single-well tests: a zero rest-period test, a 2-day rest-period test, and a 30-day rest-period 
test
(where "rest period" refers to the time period after injection that is allowed to elapse 
before
starting to pump the well). In each of these tests, it was anticipated that approximately 
11,000 L
(3,000 gallons) of tracer solution would be injected into the test interval followed by
approximately 95,000 L (25,000 gallons) of tracer-free "chase" water to push the tracer 
solution
out of the wellbore and gravel pack into the formation. The well would then be pumped 
for
several days to several weeks after the prescribed rest period. Each of the three tracer 
tests was
to include both a halide (bromide, chloride, or iodide) and a fluorinated benzoate (FBA) 
so that
any diffusion from flowing water into stagnant water could be identified from differences 
in the
tracer responses.
In single-well simulations using MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]), only 
one end
of the domain is modeled as a well-mixed borehole; the other end becomes a zero-
concentrationgradient
boundary. However, to minimize boundary effects, an initial calculation establishes a
node spacing in the radial (r) direction that results in a tracer "plume" that never reaches 
the edge
of the domain. Furthermore, the numerical calculations are carried out assuming 
cylindrical
coordinates with flow only in the radial direction (with a flow velocity that varies as 1/r), 
instead
of Cartesian coordinates. Ambient flow during single-well tests, which is superimposed 
on the
radial flow induced by injection into and pumping of the well, is not accounted for in the 
current
version of MULTRAN. Thus, the advection-dispersion equation in the flow direction 
solved by
MULTRAN for single-well tests is (Bear 1979 [105038], p. 247):
* 
?
* * 
* 
* 
* 
* * 
* 
* * 
* 
* 
r
c
rD
r r r
c
r V
t
c 1
) ( - (Eq. 51)
where
c = tracer concentration (mol/L)
r = radial coordinate, cm
V(r) = flow velocity as a function of r (cm/hr)
D = dispersion coefficient (cm2/hr).
Single-well tracer test responses for all three single-well tests were simulated for both a 
generic
halide (bromide or iodide) and a generic fluorinated benzoate, with the assumption that 
the
halide has a factor-of-three larger diffusion coefficient than the benzoate. The response of 
a
counter cation (potassium was assumed in all cases) was also simulated, as well as the 
responses
of the cations with which it exchanges. Also, a flow interruption of several hours was 
simulated
for the test with zero rest period to illustrate the additional information that can be 
obtained by
doing a planned flow interruption during the latter portion of the test.
ANL-NBS-HS-000039, REV 00 347 December 2003
The MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) simulations associated with the 
different
conceptual transport models illustrate how the appropriate conceptual transport model 
can be
best determined by comparing the responses of the nonsorbing tracers with different 
diffusion
coefficients for each of the different rest periods. The differences in the responses of the 
tracers
with different diffusion coefficients as a function of rest period can provide information 
on the
relative volumes of flowing and stagnant water in the system, which is very important for
determining the ability of the alluvium to attenuate the transport of nonsorbing 
radionuclides.
The MULTRAN simulations also illustrate how cation responses (both injected and 
exchanged
cations) could potentially provide useful information on CEC and, hence, cation sorption 
in the
system. The flow system parameters that were assumed for the three different conceptual
models are listed in Table 6.5-1. Other input parameters that do not pertain to the flow 
system
are listed in Table 6.5-2.
Figure 6.5-2 illustrates the tracer responses that can be expected in each of the three 
tracer tests if
an homogeneous single-porosity medium is assumed (conceptual model of Figure 6.5-
1a). Only
one response is shown because there is no difference between the predicted responses of 
the
nonsorbing tracers of different diffusion coefficients or the predicted responses after the 
different
rest periods. Although not shown in Figure 6.5-2, there is also no change in predicted 
tracer
concentrations immediately after a flow interruption. The lack of a difference between 
tracers,
and between tracer responses for different rest periods, as well as the lack of a response 
after a
flow interruption are all indications of very little or no diffusive mass transfer in the flow 
system.
Table 6.5-1. Flow System Parameters Used in the Single-Well Simulations
Parameter Figure 6.5-1a
Model
Figure 6.5-1b
Model
Figure 6.5-1c
Model
Porosity in advective layers 0.25 0.25 0.25
Porosity in nonadvective layers N/A N/A 0.25
Porosity of grains N/A 0.15 N/A
Width of advective layers (cm) N/A N/A 10.0
Width of nonadvective layers (cm) N/A N/A 24.0
Grain diameter in advective layers (mm) N/A 3.0 (2.2) (b) N/A
Grain diameter in nonadvective layers (mm) N/A N/A N/A
Halide diffusion coefficient in advective Layers (cm2/sec) (a) N/A 3 X 10-6 3 X 10-6
Halide diffusion coefficient in nonadvective layers (cm2/sec) (a) N/A N/A 1 X 10-6
Halide diffusion coefficient in grains (cm2/sec) (a) N/A 1 X 10-6 N/A
Drift velocity (cm/sec) 0 (c) 0 (c) 0 (c)
Output DTN: LA0303PR831231.001.
NOTE: (a) The FBA diffusion coefficient is always assumed to be one-third of the halide diffusion coefficient
(Section 6.3.8).
(b) The number in parentheses is the standard deviation of ln (diameter) used for a lognormal distribution
of grain sizes in one set of simulations (see text).
(c) Drift velocity is assumed to be zero because of the small apparent hydraulic gradient in the vicinity of
NC-EWDP-19D/D1.
ANL-NBS-HS-000039, REV 00 348 December 2003
Table 6.5-2. Non-Flow-System Input Parameters for the Single-Well Simulations
Parameter Value
Volume of injection interval (including gravel pack) (L) 500
Radius of gravel pack (cm) 18
Duration of injection pulse (hr) 3
Duration of chase (hr) 28
Flow interruption duration (zero-rest-period test only) (hr) 24
Flow rate during injection and pumping (L/min [gpm}) ~57 (~15)
Output DTN: LA0303PR831231.001.
Output DTN: LA0303PR831231.001.
Figure 6.5-2. Normalized Concentration Response of Any Nonsorbing Tracer
in a Single-Well Test in a Porous Medium with No Diffusive Mass Transfer
and/or No Stagnant Water (the conceptual model of Figure 6.5-1a).
ANL-NBS-HS-000039, REV 00 349 December 2003
Figure 6.5-3 shows the tracer responses (normalized to injection concentrations) that can 
be
expected in each of the three single-well tracer tests if a homogeneous system with 
porous grains
is assumed (conceptual model of Figure 6.5-1b). In this case, a uniform grain diameter of 
3 mm
was assumed, which corresponds to the mass-weighted mean diameter of the material 
collected
from four different intervals in 19P. A mass-weighted mean diameter was used because 
tracer
storage capacity in grains is proportional to mass, not number of grains. Cuttings 
collected from
19D (D1) were not used for grain-size analysis because the mud-rotary-drilling method 
used in
this hole tended to truncate the upper and lower ends of the size range. Figure 6.5-3 
shows that
there is a slight difference in the responses of the halide and FBA in each test, with the 
halide
having a slightly higher peak concentration and a shorter tail than the FBA. These 
differences
qualitatively indicate that there is some diffusion into stagnant water in the system. 
However,
the fact that the halide has a higher peak concentration and a shorter tail than the FBA 
indicates
that the characteristic diffusion lengths must be relatively short. Both tracers effectively 
diffused
throughout the grains during the time that they were injected and chased into the system, 
so the
responses primarily reflect the diffusion rates of the tracers back out of the grains, which 
is faster
for the halide. The tracer mass recoveries (not presented) were very high (over 95%) in 
all of
these simulations, with the recoveries of the two tracers being essentially the same at the 
end of
the simulations. The halide initially had a higher recovery than the FBA (during the peak)
because it diffused more rapidly out of the grains, but the FBA recovery approached that 
of the
halide as pumping continued into the tails of the responses. Given a long enough 
pumping
period, the recoveries of both tracers would have approached 100%.
Another indication of the short diffusion lengths is the lack of an increase in tracer
concentrations after the flow interruption in the test with no rest period. If a significant 
amount
of tracer remained in the grains at the time of the flow interruption, an increase in 
concentration
would be expected upon resumption of flow due to the tracer diffusing out of the grains 
during
the rest period. An additional indication of the relatively short diffusion distances in the 
system
is the fact that both the halide and the FBA have essentially the same response in the 2-
day rest
period test as the 30-day rest period test. This result suggests that the tracers were able to
effectively diffuse throughout the grains during the 2-day rest period so that very little 
additional
diffusion occurred during the 30-day rest period.
ANL-NBS-HS-000039, REV 00 350 December 2003
Output DTN: LA0303PR831231.001.
NOTE: The rest periods are zero (top), 2 days (middle), and 30 days (bottom); a 3-mm fixed grain diameter 
was
used. X axis extends to 160 hr for zero-rest-period test because of 24 hours flow interruption.
Figure 6.5-3. Normalized Concentration Responses of a Halide and a FBA in Single-Well Tests
for the Conceptual Transport Model of Figure 6.5-1b Using a Fixed Grain Diameter
ANL-NBS-HS-000039, REV 00 351 December 2003
Figure 6.5-4 shows the measured grain-size distribution of the material collected from 
19P. A
qualitative fit of a lognormal distribution to the data is also shown. Clearly, there is a 
relatively
wide distribution of grain sizes that are not accounted for when a single mean grain size 
is
assumed, as in the simulations that generated the tracer responses shown in Figure 6.5-3. 
Figure
6.5-5 shows the results of incorporating the lognormal distribution of grain sizes shown 
in Figure
6.5-4 into the MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) simulations. The only
difference between Figures 6.5-3 and 6.5-5 is that the grain size in the former is uniform 
(equal
to the mean), whereas in the latter, it is varied over the lognormal distribution of Figure 
6.5-5. It
is apparent that the inclusion of larger grain sizes in the simulations greatly increases the 
length
of the tails of both tracers. Additional simulations confirmed that the elimination of the 
smaller
grain sizes in the lognormal distribution had very little effect on the tracer responses. The
increase in the lengths of the tails is a result of the greater diffusion distances associated 
with the
larger grains. Because of the greater distances, it takes longer for the tracer mass to 
diffuse back
out into the advective pathways, resulting in the extended tailing. The longer diffusion 
distances
are also indicated by the noticeable increase in tracer concentrations after the flow 
interruption in
the test with no rest period. Note that in all cases the FBA still has a longer/higher tail 
than the
halide, indicating that the responses are still dominated by diffusion back out of the 
grains. The
mass recoveries of both tracers were slightly lower than in the simulations of Figure 6.5-3 
(for
the same pumping time). However, by the end of the simulations, both tracer recoveries 
were
well over 95%.
Figure 6.5-6 shows the tracer responses that can be expected in each of the three single-
well
tracer tests if a layered dual-porosity system is assumed (Figure 6.5-1c). Grains in both 
the
advective and nonadvective regions were assumed to be nonporous for these simulations. 
The
differences in the responses of the halide and the FBA in the tests and the fact that the 
peak
concentrations decrease while the lengths of the tails increase as the rest period increases 
all
indicate relatively long diffusion lengths. However, in contrast to the results shown in 
Figures
6.5-3 and 6.5-5, the FBA has a higher peak concentration and a shorter/lower tail than the 
halide
during the pumpback phase. This result is primarily due to the relatively wide advective 
flow
pathways (10 cm), which tracers can only slowly diffuse out of because of the long 
distance to
the nonadvective region. It is the slower diffusion of the FBA out of these advective 
pathways
that is primarily responsible for the higher peak concentrations and lower tails of the FBA
relative to the halide.
ANL-NBS-HS-000039, REV 00 352 December 2003
DTN: LA0201JS831421.001 [162613].
NOTE: The above data are a composite of four depth intervals.
Figure 6.5-4. Measured and Fitted Grain Size Distributions from NC-EWDP-19P
0
20
40
60
80
100
10 100 1000 10000 100000
Grain Diameter, ?m
Percent Less Than
Data
Fit of Lognormal Dist.
ANL-NBS-HS-000039, REV 00 353 December 2003
Output DTN: LA0303PR831231.001.
NOTE: The rest periods are zero (top) days, 2 days (middle), and 30 days (bottom); a mean grain diameter 
of 3 mm
was used with a standard deviation for ln (diameter) of 2.2. X axes have different scales to reflect the
different pumping durations planned for the three tests.
Figure 6.5-5. Normalized Concentration Responses of a Halide and a FBA in Single-Well Tests
for the Conceptual Transport Model of Figure 6.5-1b Using a Grain Size Distribution
ANL-NBS-HS-000039, REV 00 354 December 2003
Output DTN: LA0303PR831231.001.
NOTE: The rest periods are zero (top) days, 2 days (middle), and 30 days (bottom). X axes have different 
scales to
reflect the different pumping durations planned for the three tests.
Figure 6.5-6. Normalized Concentration Responses of a Halide and an FBA
in Single-Well Tests for the Conceptual Transport Model of Figure 6.5-1c
ANL-NBS-HS-000039, REV 00 355 December 2003
The value of comparing the responses of the FBA and halide to help distinguish between
alternative conceptual models is made apparent in Figure 6.5-7, which shows the 
simulated
responses of the FBA in the 2-day-rest period tests with the diffusion-into-grains model 
(Figure
6.5-5) and the diffusion-into-layers model (Figure 6.5-6). Other than a slightly broader 
peak in
the diffusion-into-grains response (which could be attributed to hydrodynamic dispersion 
or
tracer drift with the natural gradient), the two responses are very similar, and it would be 
difficult
to distinguish between the two models on the basis of either one of these responses alone.
However, by knowing whether the halide has a higher or lower tail, it will be possible to 
make a
distinction between the models. The additional information obtained from the test with a 
longer
rest period will also help in making this distinction. Also, quantitative estimates of 
diffusive
mass-transfer rates and diffusion distances can be best made using the MULTRAN V 1.0 
(STN:
10666-1.0-00 [159068]) model to fit simultaneously the tracer responses from each test 
with the
constraint that the halide has a factor-of-three larger diffusion coefficient than the FBA.
Output DTN: LA0303PR831231.001.
NOTE: The rest period was 2 days.
Figure 6.5-7. Comparison of FBA Responses for the Layered Conceptual Model (Figure 6.5-1c)
and the Grain-Diffusion Model (Figure 6.5-1b) with a Lognormal Distribution of Grain Sizes
Table 6.5-3 summarizes the tracer-response characteristics from single-well tracer tests 
that are
consistent with the different conceptual transport models of Figure 6.5-1, including a 
diffusioninto-
grains model (Figure 6.5-1b) with a relatively wide distribution of grain sizes (see Figure
6.5-4 and 6.5-5). This table serves as a guide for how the appropriate conceptual transport 
model
can be identified from the qualitative nature of the tracer responses in the three planned 
singlewell
tracer tests.
ANL-NBS-HS-000039, REV 00 356 December 2003
Table 6.5-3. Single-Well Tracer Test Response Characteristics
that are Consistent with the Conceptual Models of Figure 6.5-1
Conceptual Model Single-Well Tracer Test Response Characteristics
Single-Porosity
(Figure 6.5-1a)
* All nonsorbing tracers have the same normalized concentration
responses
* Response curves are independent of rest period (unless there is
significant tracer drift during the rest period, but even then, there will
be little or no difference in the response curves of different
nonsorbing tracers)
* No increase in tracer concentrations after a flow interruption in the
tail of the response curves
Diffusion into Small Grains
-Short Diffusion Distances
(Figure 6.5-1b)
* Tracer with larger diffusion coefficient will tend to have higher peak
concentration and lower tail concentration than tracer with smaller
diffusion coefficient
* Relatively minor differences in response curves of each individual
tracer as a function of rest period (unless there is significant tracer
drift during the rest period)
* Relatively minor increase in tracer concentrations after a flow
interruption in the tail of the response curves
Diffusion into Variable-Sized
Grains-Combination of Short and
Long Diffusion Distances, but
Relatively Narrow Advective Flow
Pathways
(Figure 6.5-1b, with grain size
distribution of Figure 6.5-4)
* Either tracer (large or small diffusion coefficient) could have the
higher peak concentration, with the larger diffusion coefficient tracer
tending to have the higher peak concentration as grain sizes
decrease or rest periods increase
* Tracer with smaller diffusion coefficient will tend to have the higher
concentration in the tails of the responses
* Noticeable differences in response curves of each individual tracer
as a function of rest period, with longer, higher tails as rest period
increases
* Significant increase in tracer concentrations after a flow interruption
in the tail of the response curves
Diffusion into Layers-
Long Diffusion Distances and
Relatively Wide Advective Flow
Pathways
(Figure 6.5-1c)
* Tracer with smaller diffusion coefficient will tend to have higher peak
concentration and lower tail concentration than tracer with larger
diffusion coefficient
* Significant differences in response curves as a function of rest
period, with longer, higher tails as rest period increases
* Significant increase in tracer concentrations after a flow interruption
in the tail of the response curves
Output DTN: LA0303PR831231.001.
NOTE: The characteristics in this table apply when tracer concentrations are normalized to injection 
concentrations.
Although sorption parameters for sorbing tracers are much more easily obtained from 
cross-hole
tracer tests, Figure 6.5-8 shows how information on cation sorption can also be obtained 
from a
single-well tracer test. In this case, the counter-cation (assumed to be potassium ion) 
injected
with the nonsorbing anion tracers exchanges with sodium and calcium, the two 
predominant
cations in the system. The potassium ion initially responds more quickly than the 
nonsorbing
anions because it traveled a shorter distance into the system during injection (due to ion
exchange). This behavior results in an initial depression of the sodium and calcium
concentrations because they displace potassium as the system is pumped back and also 
because
ANL-NBS-HS-000039, REV 00 357 December 2003
charge balance must be maintained. As the anions respond, the concentrations of sodium 
and
calcium increase and peak at the same time as the anions. In principle, the magnitude of 
the
fluctuations of the sodium and calcium concentrations, as well as the response of the 
countercation,
can provide qualitative estimates of ion-exchange parameters for the counter-cation in the
system.
Output DTN: LA0303PR831231.001.
NOTE: The Na+ and Ca++ responses are the result of cation exchange with K+.
Figure 6.5-8. Molar Responses of Injected Tracers (K+, halide, FBA) and Naturally Occurring
Cations (Na+ and Ca++) in the 2-Day-Rest-Period Test Assuming the Model of Figure 6.5-1b
6.5.3 Pre-Test Predictions of Cross-Hole Tracer Test Responses
After the single-well tracer tests were completed, Nye County drilled two additional 
wells (NCEWDP-
19IM1 and NC-EWDP-19IM2, known as 19IM1 and 19IM2) in the immediate vicinity
of 19D1 to allow for cross-hole hydraulic and tracer testing. These wells were completed
similarly to 19D1 so that they could be used interchangeably as production, injection, or
observation wells. Cross-hole tracer tests were to be conducted immediately after cross-
hole
hydraulic testing was completed (Section 6.4.2). However, water discharge and tracer 
injection
permits issued by the State of Nevada were rescinded before tracer testing could be 
initiated.
ANL-NBS-HS-000039, REV 00 358 December 2003
In lieu of presenting results from the planned cross-hole tracer tests, this section provides 
a
summary of the plans for testing as well as pre-test predictions of tracer responses in the 
crosshole
tests, with emphasis on (1) expected tracer arrival times under various assumptions, and 
(2)
predicted lithium transport behavior given results of lithium sorption testing onto 
alluvium in the
laboratory. The pre-test predictions served to satisfy environmental permitting 
requirements and
address a key technical issue (KTI) raised by the NRC (KTI RT 2.04).
The cross-hole tracer tests were expected to provide additional information on diffusive 
masstransfer
properties and the appropriate conceptual transport model for the saturated valley-fill
system. They were also expected to provide field estimates of several transport 
parameters for
performance-assessment calculations that cannot be obtained from single-well tracer 
testing,
including effective flow porosity, longitudinal dispersivity, sorption parameters, and 
colloid
transport parameters. Because sorbing radionuclides of interest to Yucca Mountain 
performance
assessments cannot be used in field tests, sorption parameters were to be obtained for a 
weakly
sorbing cation tracer, lithium ion. Although lithium transport is not of immediate interest 
to the
project, its field-sorption behavior was to be compared to its laboratory-sorption behavior 
to
determine whether laboratory-derived parameters provide reasonable estimates of field-
scale
retardation. If that proved to be the case, or if the laboratory parameters resulted in
underestimation of field-scale sorption, the Project would gain credibility in its approach 
of using
laboratory-derived radionuclide sorption parameters in performance-assessment 
calculations. On
the other hand, if the field transport behavior of lithium indicated that lithium was 
sorbing less
than predicted from laboratory experiments, then conceptual models and 
parameterizations of
radionuclide sorption might have to be revisited to account for differences between lab 
and field
observations.
Cross-hole testing would have involved the simultaneous injection of several tracers into 
a
screened interval of one well while a nearby well was continuously pumped. The plan 
was to
establish a partial-recirculation flow pattern between the injection well and the 
production well
prior to tracer injection and then maintain that recirculation pattern for at least one month 
after
the injection. Partial recirculation means that a portion of the produced water would be
recirculated into the injection well. This type of flow pattern ensures that the injected 
tracers are
pushed out into the formation and do not linger in the injection well, which would result 
in
biased estimates of transport parameters.
The tracer mixture would have included two nonsorbing solute tracers (probably bromide 
ion
and an FBA), a weakly sorbing tracer (lithium ion), and at least one type of polystyrene
microsphere as a colloid tracer. The sorption parameters for lithium and filtration 
parameters for
the microspheres were to be determined by comparing the cross-hole responses of these 
tracers
to that of the two nonsorbing solutes.
Cross-hole tracer-test predictions were conducted primarily to estimate how long a cross-
hole
test may take to conduct for scheduling and budgeting reasons. However, pre-test 
predictions
were also a requirement imposed by the State of Nevada to obtain an environmental 
permit for
tracer injections. Emphasis was placed on the sensitivity of the predictions to variables 
such as
interwell separation, interval thickness, flow porosity, production rate, longitudinal 
dispersivity,
2-D vs. 3-D flow conditions, and most importantly, lithium sorption parameters. 2-D flow
conditions refers to a situation where a well fully penetrates a confined aquifer and, 
therefore,
ANL-NBS-HS-000039, REV 00 359 December 2003
there is no flow in the vertical direction, whereas 3-D flow conditions refer to a situation 
in
which a well is open to only a small fraction of the thickness of an aquifer so that flow 
occurs in
all three dimensions without being influenced by upper and lower boundaries (e.g., 
confining
layers). These represent two extremes of flow conditions (in a homogeneous, isotropic 
medium)
with respect to cross-hole tracer travel times.
Many of these sensitivities can be effectively captured using a simple analytical 
expression for
nonsorbing tracer travel times in radial convergent flow to a pumping well in a 2-D
homogeneous, isotropic medium (i.e., a rearrangement of Equation 10) (Guimera and 
Carrera
2000 [156830], Equation 6):
Q
T r 2
L
* 
* ?(Eq. 52)
where
* = mean travel time, hr
* = effective flow porosity
rL = distance between injection and production wells, m
T = formation thickness, m
Q = production flow rate, m3/hr.
Of course, any real flow system will never be completely homogeneous or isotropic, but 
this
equation serves as a useful starting point for estimating travel times. It is clear that, all 
other
things being equal, mean travel times will vary linearly with effective flow porosity and
formation thickness, with the square of the distance between wells, and inversely with the
production flow rate. Equation 52 does not account for any delays associated with 
diffusion into
stagnant water in the system, although these delays are not expected to affect first arrival 
times
and peak arrival times of tracers significantly in the valley-fill deposits, which are of 
greater
practical interest than the mean arrival time.
The first arrival times and peak arrival times of tracers were estimated as a function of 
mean
travel time and dispersivity using the RELAP V 2.0 computer code (STN: 10551-2.0-00
[159065]). A set of response curves showing the effect of dispersivity (or, more 
specifically,
Peclet number, which is equal to the travel distance/dispersivity) on the first and peak 
arrival
times for a given mean tracer residence time is shown in Figure 6.5-9. The ratio of first 
arrival
time to mean arrival time and the ratio of peak arrival time to mean arrival time were 
both found
to have a relatively smooth dependence on the Peclet number of the system. By obtaining 
a
polynomial fit to these ratios as a function of Peclet number, the first and peak arrival 
times
could be estimated from the mean arrival time obtained from Equation 52 for any 
assumed value
of dispersivity. Plots of these ratios and the polynomial fits as a function of Peclet 
number are
shown in Figure 6.5-10.
.
ANL-NBS-HS-000039, REV 00 360 December 2003
Output DTN: LA0303PR831231.004.
NOTE: Peclet number is travel distance/dispersivity; mean arrival time is 100 hr; and flow is assumed to be 
linear,
not radial.
Figure 6.5-9. Relative Responses in a Single-Porosity Medium to
a Pulse Function Input for Different Peclet Numbers
Output DTN: LA0303PR831231.004.
NOTE: Equations are polynomial fits to the "data." First arrival time is defined as the arrival time 
corresponding to
1% of the peak concentration.
Figure 6.5-10. Ratios of First Arrival Time to Mean Arrival Time and
Peak Arrival Time to Mean Arrival Time for Different Peclet Numbers
y = -2E-08x4 + 5E-06x3 - 0.0005x2 + 0.0243x + 0.0405
y = -2E-10x6 + 6E-08x5 - 7E-06x4 + 0.0004x3 - 0.0104x2 + 0.1442x + 0.0628
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 10 20 30 40 50
Peclet Number
Arrival Time/Mean Time
First Arrival Time
Peak Arrival Time
0
500
1000
1500
2000
0 50 100 150 200 250
Time, hr
Relative Concentration
Pe = 1
Pe = 50
Pe = 10
Pe = 2
Pe = 5
ANL-NBS-HS-000039, REV 00 361 December 2003
To obtain estimates of the mean, first, and peak arrival times for a sorbing tracer, the
corresponding arrival times for a nonsorbing tracer can be multiplied by the retardation 
factor, R,
given by (Freeze and Cherry 1979 [101173], p. 404, Equation 9.14):
R * 1 ?
?B
?
Kd (Eq. 53)
where
Kd = linear partition coefficient, mL/g
?B = bulk density of medium, g/cm3
* = porosity of medium
To obtain an estimate of travel times in an unbounded 3-D flow system, the 
2WELLS_3D V 1.0
computer code was used (STN: 10667-1.0-00 [159036]). 2WELLS_3D is a particle-
tracking
code that simulates tracer transport between two wells in a homogeneous, isotropic 
medium. It
assumes that flow streamlines between the injection and production well follow 
trajectories
given by the prolate spheroidal coordinate system, shown in Figure 6.5-11. This 
coordinate
system reduces to spherical coordinates in the limit of a = 0 (i.e., a point source instead of 
a line
source). A number of 2WELLS_3D simulations with zero dispersion were conducted to
determine mean nonsorbing tracer residence times as a function of the ratio of well 
separation to
interval length (i.e., length of screen or gravel pack). Because 2WELLS_3D 
superimposes tracer
movement (as particles) onto an analytical solution of the 3-D flow field, there is 
effectively no
numerical dispersion in the simulated tracer responses. In the limit of a very large interval 
length
relative to well separation, the arrival times approached those given by Equation 52 for 
radial
flow in cylindrical coordinates; and in the limit of a very small interval length relative to 
well
separation, the arrival times approached what would be expected for spherical flow 
(derivation
found in Reimus 2003 [165129], pp. 116 to 122):
Q
r
3
4
3
L * * * (Eq. 54)
where the symbols are defined the same as in Equation 52.
ANL-NBS-HS-000039, REV 00 362 December 2003
Source: Happel and Brenner (1965 [156833], Appendix A, Figure A-17.1(a)).
NOTE: * and * are coordinate designations by Happel and Brenner; they have no relation to * and * elsewhere in this 
report.
Figure 6.5-11. Prolate Spheroidal Coordinate System Used for
Unbounded 3-D Flow and Transport Calculations Using the 2WELLS_3D Code
ANL-NBS-HS-000039, REV 00 363 December 2003
The ratio of mean arrival time in unbounded 3-D flow to mean arrival time in 2-D flow 
was
found to have a relatively smooth dependence on the ratio of well separation to interval 
length.
This dependence and a piecewise fit to the simulated data are shown in Figure 6.5-12. 
Using the
piecewise fit, it was possible to "correct" the mean arrival times obtained from Equation 
52 to
obtain corresponding arrival times for unbounded 3-D flow. The relationship shown in 
Figure
6.5-12 was obtained from 2WELLS_2D V 1.0 (STN: 10665-1.0-00 [159067]) and 
2WELLS_3D
V 1.0 (STN: 10667-1.0-00 [159036]) simulations, assuming zero longitudinal and 
transverse
dispersivity. However, the same correction factors were assumed to apply to the first and 
peak
arrival times in cases where the dispersivity was not zero.
A final "correction" applied to the calculations described above was to account for shifts 
in first
and peak tracer arrival times due to recirculation of produced water. Recirculation 
establishes a
dipole flow pattern (Figure 6.5-13) that causes some of the tracer mass to arrive earlier 
and some
later than in the case of no recirculation. A correction factor for various recirculation 
ratios
(ratios of recirculation flow rate to production flow rate) was obtained by simulating a 
series of
tracer responses with different recirculation ratios using the 2WELLS_2D V 1.0 code 
(STN:
10665-1.0-00 [159067]). This code is very similar to the 2WELLS_3D V 1.0 code (STN:
10667-1.0-00 [159036]) except that it simulates cross-hole responses in two-dimensional 
(2-D)
flow using a cylindrical coordinate system instead of three-dimensional (3-D) flow. 
These
simulations assumed no longitudinal or transverse dispersion, so the travel-time shifts 
reflected
only the changing flow patterns. As in the case of 2WELLS_3D, 2WELLS_2D 
superimposes
tracer movement (as particles) onto an analytical solution of the 2-D flow field, so there 
is
effectively no numerical dispersion in the simulated tracer responses. A subset of the 
resulting
response curves is shown in Figure 6.5-14. In reality, the response curves for the larger 
amounts
of recirculation (greater than about 20%) should all have multiple tracer peaks that are 
equally
spaced in time due to tracer recirculation. However, all but the first peak for each 
response curve
was suppressed from the 2WELLS_2D output to clarify Figure 6.5-14. With typical 
amounts of
dispersion, these secondary peaks would be highly damped relative to the first peak 
anyway.
Note that because there was no dispersion assumed for the simulations associated with 
Figure
6.5-14, the first and peak arrival times nearly coincide. The correction factor for both first
arrival times and peak arrival times was taken to be the ratio of peak recirculation arrival 
time to
the peak arrival time without recirculation. These correction factors as a function of
recirculation ratio, as well as a polynomial fit to the simulated data, are plotted in Figure 
6.5-15.
The methods described above for estimating first and peak arrival times while accounting 
for
dispersion, sorption, unbounded 3-D flow, and recirculation ratio in cross-hole tracer tests 
are
amenable to simple spreadsheet calculations once adequate expressions/fits are obtained 
for the
dependence of the correction factors on the appropriate input parameters. A Microsoft 
Excel
spreadsheet was set up for this purpose (Output DTN: LA0303PR831231.001). It should 
be
noted that the spreadsheet calculations assume that the correction factors are linearly 
independent
and commutative. That is, corrections are made by multiplying the mean arrival time 
(given by
Equation 52) by each of the appropriate correction factors for a given set of test 
conditions.
ANL-NBS-HS-000039, REV 00 364 December 2003
Output DTN: LA0303PR831231.004.
NOTE: A piecewise polynomial fit to the "data" is shown.
Figure 6.5-12. Ratio of Mean Arrival Time in Unbounded 3-D Flow to Mean Arrival Time
in 2-D Flow as a Function of Distance Between Wells Divided by Interval Thickness
For illustration purposes only
NOTE: In the above pattern, the injection well is on the right, the production well is on the left, and the 
injection flow
rate is 30% of the production flow rate. A homogeneous isotropic medium is assumed.
Figure 6.5-13. Tracer Streamlines in a Weak Dipole Flow Pattern
y = 1.0253x + 0.2583
y = 0.734x2 - 0.3827x + 1.0381
0
2
4
6
8
10
12
0 2 4 6 8 10
Distance between wells / Interval thickness
3D Arrival / 2D Arrival
Pieced together
at this point
ANL-NBS-HS-000039, REV 00 365 December 2003
Output DTN: LA0303PR831231.004.
NOTE: The numbers next to the curves above are the recirculation fractions; local dispersivity was set equal 
to
zero; and secondary tracer peaks associated with tracer recirculation are not shown. The sharp early
arrivals occur because of the zero longitudinal and transverse dispersion assumed in the simulations. The
long tails are the result of a small number of flow streamlines having very long residence times.
Figure 6.5-14. Predicted Nonsorbing Tracer Responses in a 2-D Homogeneous
Isotropic Medium as a Function of the Recirculated Fraction of Produced Water
Output DTN: LA0303PR831231.004.
Figure 6.5-15. Tracer Arrival Times as a Function of Fraction Recirculation
in a 2-D Homogeneous Isotropic Medium
0
0.1
0.2
0.3
0.4
0.5
0 0.2 0.4 0.6 0.8 1 1.2 1.4
Fraction of Mean Residence Time
Relative Concentrations
1.0
0.5
0.2
0.1
0.05
0.02
0.0
y = 3.7486x4 - 8.8629x3 + 7.4471x2 - 2.9566x + 0.9714
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 0.2 0.4 0.6 0.8 1
Fraction Recirculation
Arrival Time/ Arrival Time
w/ no Recirc.
ANL-NBS-HS-000039, REV 00 366 December 2003
A final feature added to the Excel spreadsheet was the propagation of uncertainties of two 
key
input parameters: flow porosity and well separation. Flow porosity is an uncertain 
parameter
because it is an unknown property of the flow system, and well separation is uncertain 
because
of vertical deviations that can occur during well drilling, which can result in significantly
different separations at depth than planned. The propagation of these uncertainties was
accounted for using standard error propagation methods and assuming that the 
uncertainties were
not correlated (i.e., linearly independent). Without derivation, when these methods are 
applied to
Equation 52, they yield the following result for the relative standard deviation of the 
travel time
of a nonsorbing tracer as a function of standard deviation of the flow porosity and well
separation (flow derivation found in Reimus 2003 [165129]):
4 2
L
2
2
2
r
L r ?
?
?
?
* * * * * (Eq. 55)
where
?i = standard deviation of variable i
* = mean residence time, hr
* = flow porosity
rL = well separation, m.
To provide a measure of travel time uncertainties, the Excel spreadsheet calculates mean, 
first,
and peak tracer travel times associated with * * * ?(i.e., travel times that are plus and 
minus one
standard deviation from the best estimate).
An additional parameter of considerable uncertainty is the Kd sorption parameter for 
sorbing
tracers. However, a formal propagation of uncertainty calculation for this parameter was 
not
included in the spreadsheet. Rather, it is left to the analyst to evaluate this uncertainty by
manually entering different Kd values and determining what effect these have on 
predicted travel
times.
As mentioned at the beginning of this section, all simulations using the RELAP V 2.0 
(STN:
10551-2.0-00 [159065]), 2WELLS_2D V 1.0 (STN: 10665-1.0-00 [159067]), and 
2WELLS_3D
V 1.0 (STN: 10667-1.0-00 [159036]) codes assumed a single-porosity system with no 
diffusive
mass transfer into nonadvective water. Two sets of paired MULTRAN V 1.0 (STN: 
10666-1.0-
00 [159068]) simulations were conducted to illustrate the impact of relaxing this 
assumption on
predicted cross-hole responses. One set used sorption parameters corresponding to the 
strongest
lithium sorption that has been observed in laboratory batch sorption tests with 19P or 19D
material, and the other set used parameters corresponding to the weakest lithium sorption
observed. Of the two simulations in each pair, one used parameters corresponding to the 
singleporosity
system for the single-well tracer test simulations (conceptual model of Figure 6.5-1a)
ANL-NBS-HS-000039, REV 00 367 December 2003
and the other used parameters corresponding to the layered flow system for the single-
well
simulations (Figure 6.5-1c). The latter system had the greatest predicted mass loss from
advective flow pathways of the three conceptual models shown in Figure 6.5-1 in the 
single-well
simulations. The predicted cross-hole responses of a halide, an FBA, and lithium ion for 
each
type of flow system are shown in Figures 6.5-16 and 6.5-17 for the cases of weak and 
strong
lithium sorption, respectively. A mean tracer residence time of 150 hr (for nonsorbing 
tracers)
and a Peclet number of 10 were arbitrarily chosen for the simulations. There was no
recirculation in the simulations. The 150-hr mean residence time corresponds to a 
relatively low
effective flow porosity or a relatively high production flow rate in the valley-fill deposits 
if a
well separation of 20 to 25 m is assumed and if the flow intervals are assumed to be 8 to 
40 m
thick, which is approximately the range of gravel-pack thicknesses in the valley-fill 
deposits in
19D. Table 6.5-4 provides combinations of flow system parameters and production flow 
rates
that result in mean nonsorbing tracer residence times of 150 hr based on Equation 52.
It is apparent in Figures 6.5-16 and 6.5-17 that the differences in first and peak arrival 
times of
any given tracer as a function of the system conceptualization (single porosity vs. layered
system) are trivial. However, the first and peak arrival times for lithium are quite 
different in the
two figures depending on whether weak (Figure 6.5-16) or strong (Figure 6.5-17) 
sorption is
assumed. Also, the tails of the tracer responses are significantly different for the different 
system
conceptualizations because the layered system has a secondary porosity that tracers 
diffuse into
and out of, which results in the long tailing behavior typical of a dual-porosity system. 
The
parameters assumed for the layered system are the same as those listed in Table 6.5-1. 
The
single-porosity system was assumed to have the same geometry and parameters as the 
layered
system except that the nonadvective region was assigned a porosity of zero so that it 
played no
part in tracer transport. The parameters used to describe cation exchange between lithium,
sodium, and calcium are listed in the figure captions (see Equations 21 and 22). These
parameters are representative of the smallest (Figure 6.5-16) and largest (Figure 6.5-17) 
amounts
of lithium exchange observed in laboratory batch-sorption experiments conducted to date 
(see
Section 6.5.6).
ANL-NBS-HS-000039, REV 00 368 December 2003
Output DTN: LA0303PR831231.001.
NOTE: Lithium sorption parameters are Q1 = 0.17, Q2 = 0.019 L/kg, CEC = 0.024 eq/kg (see Equations 21, 
22, and
24); the two systems have the same mean tracer residence time of 150 hr; and the peak lithium
concentration occurs at about 190 hr, whereas the peak FBA and halide concentrations occur at about 110
hr.
Figure 6.5-16. Predicted Cross-Hole Responses for a Halide, FBA, and Lithium Ion
in a Single-Porosity System and a Layered System with Weak Lithium Sorption
Output DTN: LA0303PR831231.001.
NOTE: Lithium sorption parameters are Q1 = 0.35, Q2 = 0.005 L/kg, CEC = 0.345 eq/kg (see Equations 21, 
22, and
24); the two systems have the same mean tracer residence time of 150 hr; the peak lithium concentration
occurs at about 390 hr, whereas the peak FBA and halide concentrations occur at about 110 hr; and the
peak lithium concentration is ~1.75 times lower than in Figure 6.5-16.
Figure 6.5-17. Predicted Cross-Hole Responses for a Halide, FBA, and Lithium Ion
in a Single-Porosity System and a Layered System with Strong Lithium Sorption
ANL-NBS-HS-000039, REV 00 369 December 2003
Table 6.5-4. Combinations of Flow-System Parameters and Production Flow Rate that Result in
a Mean Nonsorbing Tracer Residence Time of 150 Hours in a Cross-Hole Tracer Test
Well Separation (m) Interval Thickness (m) Flow Porosity Production Flow Rate
(L/min [gpm])
25 40 0.1 874 [231]
25 40 0.3 2,619 [692]
20 40 0.1 560 [148]
20 40 0.3 1,677 [443]
25 8 0.1 174 [46]
25 8 0.3 522 [138]
20 8 0.1 114 [30]
20 8 0.3 337 [89]
Output DTNs: LA0303PR831231.004; LA0303PR831231.005.
6.5.4 Results and Interpretation of Single-Well Tracer Tests in Alluvium
Three single-well injection-withdrawal tracer tests were conducted in the saturated 
alluvium at
NC-EWDP-19D1 between December 2000 and April 2001. Detailed documentation of 
these
tracer tests is contained in Umari (2003 [164573]) and Reimus (2003 [165128]). In each 
of the
three tracer tests, two nonsorbing solute tracers with different diffusion coefficients were
simultaneously injected (a halide and an FBA dissolved in the same solution). The three 
tests
were conducted in essentially the same manner except for the time that was allowed to 
elapse
between the cessation of tracer and chase water injection and the initiation of pumping, 
that is,
the so-called "rest" or "shut-in" period. The rest period was systematically varied from 
~0.5 hr,
to ~2 days, to ~30 days in the tests to vary the time allowed for tracers to diffuse into 
stagnant
water in the flow system and for the tracers to migrate with the natural groundwater flow. 
Test
interpretations were based on comparing the responses of the different tracers in the same 
test
and in different tests ("responses" refers to tracer concentrations normalized to injection 
mass as
a function of time or volume pumped). As demonstrated in Section 6.5.2, the differences
between the responses of two tracers with different diffusion coefficients in the same test 
and in
tests with different rest periods can yield valuable information on diffusive mass transfer
between flowing and stagnant water in the flow system and on the relative volumes of 
flowing
and stagnant water in the system. In this section, it will be shown that differences in the
responses of tracers with the same (or similar) diffusion coefficients in tests with 
different rest
periods can provide information on ambient groundwater flow velocities in the flow 
system.
All three tests were conducted in the uppermost screened interval of 19D1, which ranges 
from
approximately 15 to 21 m (50 to 70 ft) below the water table (gravel pack from 
approximately 14
to 23 m [45 to 75 ft] below the water table). The static water table is approximately 107 
m (350
ft) below land surface at this location. The tracer solution volume injected in each test 
was
approximately 11,000 L (2,900 gallons), and the volume of chase water (untraced water 
injected
immediately after the tracer solution) was approximately 83,000 L (22,000 gallons). The 
chase
water was intended to push the tracers into the formation so as to minimize the influence 
of the
wellbore and gravel pack on the test results. Actual distances penetrated by the tracer 
solution
ANL-NBS-HS-000039, REV 00 370 December 2003
into the formation ultimately depend on the effective porosity of the formation and its 
spatial
variability in hydraulic conductivity, which are uncertain quantities at this time.
The tracers used in each test and their injection concentrations and recoveries, the 
injection and
withdrawal flow rates (averages), and the volumes pumped during each test are listed in 
Table
6.5-5. Tracer solutions were prepared by adding tracers to groundwater that had been 
withdrawn
from 19D1 prior to any of the tests. Tracer concentrations were kept low and the 
solutions were
heated to roughly match the ambient groundwater temperature to minimize density 
contrasts
between the injection and chase solutions and the groundwater.
Table 6.5-5. Summary of Tracers and Test Conditions in
the Three Single-Well Tracer Tests in NC-EWDP-19D1
Rest Period (Test) 0.5 hr 2 days 30 days
Dates 1/5/01-1/12/01 12/1/00-12/18/00 1/27/01-4/25/01
Tracers (concentration)*
2,4-DFBA (0.46 g/L)
Cl- (0.62 g/L NaCl)
640-nm microspheres
2,6-DFBA (0.46 g/L)
I- (0.64 g/L KI)
PFBA (0.46 g/L)
Br- (0.64 g/L NaBr)
Injection rate (L/min [gpm]) 56.8 [15.0] 56.8 [15.0] 56.8 [15.0]
Average pumping rate (L/min
[gpm]) 50.3 [13.3] 41.3 [10.9] 51.67 [13.65]
Pumping duration (days) 7 14 54
Total liters (gallons) pumped 510,600 [134,900] 833,000 [220,000] 4,024,000 [1,063,000]
Tracer recovery (FBA) 0.864 0.928 0.913
DTNs: GS020708312316.001 [162678] (data); UN0109SPA008IF.006 [162442] (data); UN0109SPA008KS.005 [162681] 
(data);
UN0109SPA008KS.007 [162615] (data); UN0109SPA008KS.008 [162616] (data).
NOTE: *DFBA = difluorobenzoate, PFBA = pentafluorobenzoate
6.5.4.1 Single-Well Tracer Test Results
Figures 6.5-18, 6.5-19, and 6.5-20 show the normalized tracer responses in the each of 
the three
tracer tests. The two solute tracers had essentially identical responses (within 
experimental
error) in each test. This result is consistent with very little diffusive mass transfer 
between
flowing and stagnant water in the aquifer over the time scales of the tests. It is, therefore,
consistent with a single-porosity conceptualization of the saturated alluvium. The flow
interruptions during the tailing portions of the two longer tests provided additional 
evidence for
very little diffusive mass transfer in the aquifer. If diffusive mass transfer were an 
important
process, the tracer concentrations would have increased significantly immediately after 
the flow
interruptions due to tracers diffusing out of stagnant water and into flowing water during 
the
interruptions. The microspheres used in the shortest rest period test (Figure 6.5-18) 
provided
information on colloid filtration and detachment rates in the flow system (see Section 
6.5.4.6).
Figure 6.5-21 shows how the responses of the FBAs differed as a function of volume 
pumped in
each of the three tracer tests. Because diffusion can be ruled out as having caused these
differences, the most plausible explanation is that the differences are due to drift during 
the
different rest periods. These different responses and the assumption that they are due to 
drift
form the basis of three separate methods of estimating drift or seepage velocities in the 
aquifer.
ANL-NBS-HS-000039, REV 00 371 December 2003
DTNs: UN0109SPA008IF.006 [162442] (2,4-DFBA and Cl), LA0207PR831352.001 [162431] (microspheres).
NOTE: Microspheres were 640-nm diameter carboxylate-modified latex (CML) polystyrene spheres tagged 
with a
UV-excited fluorescent dye for detection. The figure is plotted in English units because the data were
obtained in those units. However, parameter estimates are reported in metric units to downstream users.
Figure 6.5-18. Normalized Concentrations of Tracers in Production Water from NC-EWDP-19D1
as a Function of Gallons Pumped After a Rest Period of ~0.5 Hours
DTN: UN0102SPA008KS.003 [162614]. Output DTN: LA0303PR831231.002 (volumes).
NOTE: The tracer responses are almost identical, so it is difficult to distinguish between the two responses. 
The
figure is plotted in English units because the data were obtained in those units. However, parameter
estimates are reported in metric units to downstream users.
Figure 6.5-19. Normalized Concentrations of Tracers in Production Water from NC-EWDP-19D1
as a Function of Gallons Pumped After a Rest Period of ~2 Days
0
0.0005
0.001
0.0015
0.002
0.0025
0.003
0.0035
0.004
0.0045
0.005
0 20000 40000 60000 80000 100000 120000 140000
Gallons Pumped
Norm. Conc., mg/L-g injected
2,4 DFBA
Cl - bckgrd subtracted
Microspheres
0
0.0005
0.001
0.0015
0.002
0.0025
0.003
0.0035
0.004
0 40000 80000 120000 160000 200000
Gallons Pumped
Norm. Conc., mg/L-g injected
2,6 DFBA
Iodide
20-hr Flow Interruption
ANL-NBS-HS-000039, REV 00 372 December 2003
DTNs: UN0109SPA008KS.007 [162615] (PFBA), UN0109SPA008KS.008 [162616] (Br). Output DTN: 
LA0303PR831231.002.
(volumes).
NOTE: The tracer responses are almost identical, so it is difficult to distinguish between the two responses. 
The
figure is plotted in English units because the data were obtained in those units. However, parameter
estimates are reported in metric units to downstream users.
Figure 6.5-20. Normalized Concentrations of Tracers in Production Water from
NC-EWDP-19D1 as a Function of Gallons Pumped After a Rest Period of ~30 Days
0
0.0005
0.001
0.0015
0.002
0.0025
0.003
0 200000 400000 600000 800000 1000000
Gallons Pumped
Norm. Conc., mg/L-g injected
PFBA
Bromide
68.5-hr Flow Interruption
ANL-NBS-HS-000039, REV 00 373 December 2003
DTNs: UN0109SPA008IF.006 [162442] (2,4-DFBA), UN0102SPA008KS.003 [162614] (2,6-DFBA), 
UN0109SPA008KS.007 [162615] (PFBA). Output DTN: LA0303PR831231.002.
(volumes).
NOTE: On the right-hand plot, circles indicate volumes associated with mean arrival times (for each tracer 
response), squares indicate volumes associated with
alternate mean arrival times, and triangles indicate volumes associated with "late" arrival times. The left-
most symbol is always associated with the 0.5-hr
rest-period test, and the right-most symbol is associated with the 30-day rest-period test. The bases for 
these different arrival times/volumes are
discussed in detail in Section 6.5.4.2. The figure is plotted in English units because the data were obtained 
in those units. However, parameter estimates
are reported in metric units to downstream users.
Figure 6.5-21. Normalized Concentrations of Fluorinated Benzoates as a Function
of Gallons Pumped in Each of the Three Single-Well Tracer Tests in NC-EWDP-19D1
0
0.0005
0.001
0.0015
0.002
0.0025
0.003
0.0035
0.004
0.0045
0.005
0 20000 40000 60000 80000 100000
Gallons Pumped
Normalized Conc., mg/L/g injected
2,4 DFBA - 0.5-hr Rest
2,6 DFBA - 2-day Rest
PFBA - 30-day Rest
0.000001
0.00001
0.0001
0.001
0.01
1000 10000 100000 1000000
Gallons Pumped
Normalized Conc., mg/L/g injected
68.5-hr Flow Interruption
20-hr Flow Interruption
ANL-NBS-HS-000039, REV 00 374 December 2003
6.5.4.2 Estimation of Groundwater Velocity
Four methods were used to obtain groundwater velocity estimates from the single-well 
tracer
tests. The first three methods involve relatively simple spreadsheet calculations that, 
given
various simplifying assumptions, solve for groundwater velocities that are consistent with 
the
observed differences in the following:
(1) Peak tracer concentration arrival times.
(2) "Late" arrival times, defined as the times in each test when the fractional tracer mass
recovery was equal to the final recovery in the test having the lowest overall mass
recovery. Given that the total mass recoveries in the three tests were 0.864, 0.928, and
0.913 (Table 6.5-5), then the late arrival time in each test was the time at which the mass
recovery was 0.864.
(3) "Mean" arrival times of tracer mass recovered at the same arbitrarily-selected high
fractional recovery in each test. Two different fractional recoveries were selected to
calculate mean arrival times: 0.864, the lowest fractional recovery in any of the tests, and
0.913, the fractional recovery in the 30-day-rest-period test. In the latter case, the tracer
responses in the test with a mass recovery of 0.864 were extrapolated to 0.913 (see
Section 6.5.4.2.3 for details) to allow a calculation of the mean arrival time. This
alternative method of calculating the mean arrival time was employed because the 30-day
test had the largest calculated mean arrival time, and it was therefore considered to have
the greatest amount of information pertinent to groundwater velocity estimates.
Note that these three times also correspond to volumes pumped, and because the pumping 
rates
varied in the different tests, the relationship between times and volumes is different for 
each test.
The peak, late, and mean arrival times (and corresponding volumes) for each test are 
listed in
Table 6.5-6. The points on the tracer breakthrough curves corresponding to the mean and 
late
arrival times in each test are identified in the right-hand plot of Figure 6.5-21. The fourth
method involved detailed analytical calculations of tracer migration during the tests by 
linking
together solute transport solutions that assume a 2-D homogeneous and isotropic aquifer.
Because the peak tracer concentration occurred earliest in the test with the longest rest 
period,
the tracer mass corresponding to the peak probably moved upgradient during injection 
and then
drifted back toward the well during the rest period. In contrast, the tracer mass 
corresponding to
times at which fractional recoveries were high (i.e., mass recovered far out in the tails of 
the
responses) probably moved downgradient during injection and arrived late because of the
competing effects of drift that moved the tracer further from the well and pumping the 
tracers
toward the well. The mean tracer arrival time represents a compromise between these two 
cases,
as the mean is influenced by both early- and late-arriving tracer mass. However, for 
asymmetric
long-tailed distributions, the mean is more strongly influenced by late-arriving mass than 
earlyarriving
mass, so it was assumed that the differences in mean arrival times were due mainly to
tracer mass that had moved downgradient during injection.
ANL-NBS-HS-000039, REV 00 375 December 2003
Table 6.5-6. Times and Pumped Volumes Associated with Each of the Arrival Times
Used in the Different Methods of Estimating Groundwater Velocities
Arrival Time (hr)/Volume (L [gal])
Rest Period (Test): 0.5 hr 2 days 30 days
Peak arrival 24 / 76,000 [20,000] 30.5 / 76,000 [20,000] 12.2 / 38,600 [10,200]
Late arrival (a) 168 / 511,000 [135,000] 225 / 556,000 [147,000] 639 / 1,780,000
[471,000]
Mean arrival (b) 52 / 161,000 [42,500] 71 / 178,000 [46,500] 109 / 344,000 [91,000]
Alternate mean arrival (c) 61.5 / 189,000 [50,000] 81 / 201,000 [53,000] 149 / 469,000 [124,000]
DTNs: UN0109SPA008IF.006 [162442] (0.5 hr); UN0102SPA008KS.003 [162614] (2 days); UN0109SPA008KS.007 
[162615] (30
days). Output DTN: LA0303PR831231.002 (volumes).
NOTE: (a) Time/volume associated with ~86.4% mass recovery in each test (the final recovery in the 0.5-hr 
rest
period test, which had the lowest final recovery of any test).
(b) Mean arrival time calculated by truncating all tracer response curves at ~86.4% recovery in each test.
(c) Alternate mean arrival time calculated by extrapolating the tracer response curves in the 0.5-hr rest
period test to 91.3% and truncating the response curves in the 2-day rest period test to 91.3% recovery
(the final recovery in the 30-day rest period test).
In all four estimation methods, it is assumed that injection into and pumping from the 
well
results in a 2-D radial flow field in which the flow velocity varies as 1/r:
r 2h
Q
v(r)
* 
* (Eq. 56)
where
v(r) = linear velocity as a function of radial position, m/hr
Q = injection or production flow rate, m3/hr (negative number for production)
h = interval thickness, m
* = flow porosity
r = radial distance from the well, m.
For the first three methods, the ambient groundwater flow is superimposed on the radial 
flow
induced by injection or pumping, and it is present during the rest period when there is no 
radial
flow component. The ambient flow is assumed to be unidirectional.
Flow fields resulting from injection and pumping will not be ideally radial unless the 
aquifer is
perfectly homogeneous, isotropic, and 2-D. Figure 6.5-22 shows a hypothetical 
representation of
how injected tracer solution and chase water might be distributed in the aquifer 
immediately after
injection. Figure 6.5-22 represents only one of many possibilities for how heterogeneity 
might
affect tracer distribution in the system, and all of these possibilities must be considered 
equally
likely given the present knowledge of the flow system. Although it may not be strictly 
correct,
the radial flow assumption is qualitatively consistent with the picture of heterogeneity 
shown in
Figure 6.5-22 because the flow velocity will maintain a ~1/r dependence as long as the 
flow
cross-sectional area "fans out" such that it increases approximately linearly with r. Only 
highly
ANL-NBS-HS-000039, REV 00 376 December 2003
channelized flow that does not increase significantly in cross-sectional area with r will 
have a
velocity that does not decrease as ~1/r. In pipeline flow, the extreme case of channelized 
flow,
there is no dependence of velocity on r.
Alternatively, if the system is not 2-D (confined aquifer will fully-penetrating well), the 
flow
cross-sectional area could increase with more than a linear dependence on r, with the 
extreme
case being spherical flow where the velocity decreases as 1/r2 (at sufficiently large 
distances
from the well). However, this latter possibility was ignored because (1) there is 
qualitative
evidence (both lithologic and from hydraulic testing) of layering in the aquifer that could 
cause
considerable vertical confinement, and (2) the injection volumes were small enough 
relative to
the interval thickness and potential flow porosities that the tracer injection distances into 
the
formation should have been relatively short compared to what it would take to 
approximate a
spherical flow condition.
For illustration purposes only
Figure 6.5-22. Depiction of How Tracer and Chase Water Might be Distributed
after Injection into a Heterogeneous Porous Medium
6.5.4.2.1 Peak-Arrival-Time Analysis
For the analysis comparing the peak tracer arrival times, the mass contributing to the 
peak was
assumed to move directly upgradient during injection. That is, the radial flow pushing the 
mass
was assumed to be in the exact opposite direction as the ambient groundwater flow 
(Figure 6.5-
23). Any estimate of groundwater drift velocity using this assumption should be 
considered a
lower bound because the peak mass will have the greatest decrease in arrival time as the 
rest
period is increased when the mass is injected directly upgradient. Trigonometric 
calculations
show that if the tracer mass corresponding to the peak concentration were injected at 
some angle
relative to the ambient gradient direction, the groundwater velocity would have to be 
greater to
result in the same decrease in arrival time (assuming a reasonably homogeneous system).
Plan View
Side View
Well
Screen
= Penetration of Tracer Plus Chase Water
Well
ANL-NBS-HS-000039, REV 00 377 December 2003
For illustration purposes only
NOTE: The shape of the distribution is not important; the key assumption is that the tracer mass associated 
with
the peak concentration is located directly up-gradient.
Figure 6.5-23. Depiction of Assumed Tracer Mass Distribution Immediately After Injection
Given the assumption of the peak tracer mass moving strictly upgradient, the distance 
that the
tracer mass moved into the formation during the injection and chase phase is given by
(derivations of Equations 57 to 66 are documented in Reimus 2003 [165129]):
Q
) V V (0.5
v
h
) V V (0.5
r
inj
chase tracer
GW
chase tracer
inj
* ?
* -
* 
(Eq. 57)
where
rinj = upgradient injection distance, m
Vtracer = volume of tracer solution injected, m3
Vchase = volume of chase water injected, m3
vGW = ground water velocity (seepage velocity), m/hr
Qinj = injection flow rate, m3/hr
h = interval thickness, m
* = flow porosity
The first term in Equation 57 accounts for the distance injected under pure radial flow
conditions, and the second term accounts for the drift back toward the well during 
injection.
Only half of the tracer solution volume is used in Equation 57 because it is assumed that 
the
tracer mass resulting in the peak should have corresponded to approximately the midpoint 
of the
injection volume. However, the calculations are not sensitive to this assumption because 
the
tracer solution volume in all tests was small relative to the chase volume. Because the 
tracer and
chase volumes and the injection rates were essentially the same in the three tests, the 
injection
distance given by Equation 57 is the same for all three tests.
The radial distance, rrest, between the peak tracer mass and the well at the end of the rest 
period is
given by:
Well
Ambient Gradient
x
Plan View
Tracer
Chase Peak Mass
ANL-NBS-HS-000039, REV 00 378 December 2003
rest GW inj rest t v - r r * (Eq. 58)
where trest = duration of the rest period, hr.
The time required to pump the peak tracer mass back to the well after the rest period, 
tpump, is
calculated from the following integral:
* * ?0
r pump
rest v(r)
dr
t (Eq. 59)
where
GW
pump v -
r 2h
Q
- v(r)
* 
?
Qpump = production flow rate, m3/hr.
The solution to this integral (with v(r) from Equation 56 inserted and using the 
appropriate upper
and lower limits) is (Weast and Astle 1981 [100833], p. A-36, Equations 84 and 85):
0 r
r r
GW
pump
2
GW
pump
GW
pump
rest
r v
h 2
Q
ln
h v 2
Q
v
r
t
?
?
* ?
?
?
* ?
?
?
* ?
?
?
* ?
?
?
* * * ?
* * ?
(Eq. 60)
tpump can be converted to a volume corresponding to the arrival time of the peak 
concentration
using:
Vpump = tpump pump Q . (Eq. 61)
The pertinent equations above were encoded into an Excel spreadsheet for the analysis 
(Output
DTN: LA0303PR831231.002). The only unknown variables for each of the three tests 
were the
ground-water velocity, vGW, and the flow porosity, ?, both of which were assumed to be 
the
same in all three tests. The procedure for obtaining an estimate of vGW involved selecting 
* and
then varying vGW by trial-and-error until the calculated peak arrival volumes in the three 
tests had
approximately the same ratios as in the actual field tests. It was considered more 
important to
match the ratios of times rather than to match the actual times, although the calculated 
times
were generally in reasonable agreement with the actual times, once the ratios were 
matched.
Also, greater emphasis was placed on matching the volume ratio between the 30-day-
rest-period
test and the ~0.5-hr-rest-period test than on matching the volume ratios in any other pair 
of tests,
particularly the two shorter tests. The uncertainty associated with a groundwater velocity
estimate obtained from the two shorter duration tests was considered to be far greater 
than
estimates obtained using the 30-day test results because of the much greater time allowed 
for
drift to take place in the 30-day test.
ANL-NBS-HS-000039, REV 00 379 December 2003
The process of estimating vGW was repeated for three different values of * - 0.05, 0.18, 
and 0.3.
These values are approximately the lowest, expected (mean), and highest values, 
respectively,
used for alluvium flow porosity in Yucca Mountain performance assessment simulations. 
The
value of vGW was different in each case because of the dependence of Equations 57 and 60 
on ?.
For each case, a specific discharge, vS, was calculated from vGW using VS = * vGW.
6.5.4.2.2 Analysis of Late Arrival Times (Associated With High Fractional Tracer
Recoveries)
The analysis of late arrival times (arrival times associated with high fractional tracer 
recoveries)
was similar to the analysis of peak arrival times except that the tracer mass associated 
with the
late arrival time was assumed to have been injected downgradient rather than upgradient. 
This
assumption seems reasonable, given that any mass injected upgradient should arrive 
earlier than
the mean tracer arrival time, not later. Analogous to the peak arrival-time analysis, it was
assumed that the mass was injected directly downgradient (in the same direction as the 
ambient
groundwater flow). Any estimate of groundwater velocity using this assumption should 
be
considered an upper bound because the late-arriving mass will have the greatest increase 
in
arrival time as the rest period is increased when the mass is injected directly 
downgradient.
The times/volumes associated with the final recovery in the ~0.5-hr-rest-period test 
(0.864),
which had the lowest recovery of the three tests, were used as the basis of comparison of 
the late
arrival times for the three tests. Although this is a somewhat arbitrary definition of the 
late
arrival time because it depends on when pumping was stopped in the ~0.5-hr-rest-period 
test, it
was considered to be the most objective measure because times associated with 
recoveries
greater than 0.864 would require an extrapolation of the tracer responses in the 0.5-hr 
test.
Clearly, if the 0.5-hr test had been pumped longer, the late arrival times in the tests would 
have
all been greater, and the estimates of groundwater velocities would be slightly different.
However, the pumped volumes associated with the arrival times would also have been 
greater,
which would tend to have a moderating effect on the changes in velocity estimates.
The analysis requires that Equations 57, 58, and 59 be modified as shown in Equations 
62, 63,
and 64, respectively.
inj
chase tracer
GW
chase tracer
inj Q
) V (V
v
h
) V (V
r
?
?
?
?
* ?(Eq. 62)
rest GW inj rest t v r r * * (Eq. 63)
0 r
r r
GW
pump
2
GW
pump
GW
pump
rest
r v
h 2
Q
ln
h v 2
Q
v
r
t
?
?
* ?
?
?
* ?
?
?
* ?
?
?
* ?
?
?
* * ?
* * ?
(Eq. 64)
ANL-NBS-HS-000039, REV 00 380 December 2003
The modifications are primarily changes in sign associated with the vGW terms because the
groundwater drift velocity is now assumed to push the tracer mass further from the well 
during
injection and slow down the movement of the mass toward the well during pumping. 
Also, the
mass associated with the high fractional recovery is assumed to be on the leading edge of 
the
tracer injection volume rather than at the midpoint of the volume (Equation 62). One 
additional
difference between the peak- and late-arrival analyses that does not involve equation
modifications is that the flow interruption times were added to trest for the late-arrival 
analyses
because the tracer mass associated with the latter analyses arrived after the flow 
interruptions.
As with the peak arrival time analyses, vGW was varied to achieve matches to the ratios of 
the
arrival volumes, rather than the actual volumes. However, unlike the peak analyses, the
calculated volumes were typically much smaller than the actual volumes associated with 
the late
recoveries. The most likely reason for this discrepancy is that this simple analysis does 
not
account for any hydrodynamic dispersion during any of the three test phases (injection, 
rest
period, withdrawal). Dispersion during each of these three phases could have 
significantly
increased late-recovery arrival times relative to those calculated without dispersion 
because a
fraction of the tracer mass should always disperse further away from the well at any 
given time.
However, if it is assumed that dispersion during each test had approximately the same 
effect on
the tracer plume (disregarding the expected slight increase in dispersion for the longest 
test), then
a comparison of the ratios of the late arrival times should still yield a reasonable estimate 
of
groundwater velocity.
6.5.4.2.3 Mean-Arrival-Time Analysis
The mean tracer arrival-time analysis was essentially identical to the analysis of the late-
recovery
arrival time, with the only exception being that the mass associated with the mean tracer 
mass
was assumed to be at the midpoint of the tracer injection volume rather than at the 
leading edge.
Thus, Equation 62 was modified to
inj
chase tracer
GW
chase tracer
inj Q
) V V (0.5
v
h
) V V (0.5
r
?
?
?
?
* ?(Eq. 65)
The primary difference between the mean and late arrival time analyses was in how the
times/volumes used for comparison with the calculations were obtained from the actual 
field
tracer data. For the late-recovery time analysis, it was a simple matter to extract the
times/volumes associated with a specific (though arbitrary) tracer recovery. However, for 
the
mean analysis, it was necessary to calculate a meaningful estimate of the mean arrival
time/volume from the data. Without 100% tracer recovery, it is impossible to calculate a 
true
mean, so a mean for comparison purposes was calculated by truncating the tracer 
responses in
the two longer-rest-period tests at the final recovery of the ~0.5-hr-rest-period test 
(0.864). The
mean volume was calculated by:
) f - f (
V ) f - f (
i
1 - i i
i
i pump 1 - i i
* 
* 
* * (Eq. 66)
ANL-NBS-HS-000039, REV 00 381 December 2003
where
* = mean volume, m3
fi = mass fraction recovered at volume Vpump i
fi-1 = mass fraction recovered at volume Vpump i-1.
However, because the mean times/volumes are sensitive to the tails of the tracer response 
curves,
an alternative method of calculating the mean arrival time was devised to include all the 
data
from the 30-day-rest-period test, which had the largest mean of the three tests and, 
therefore, was
considered to contain the greatest amount of information pertinent to ambient 
groundwater
velocities. Although this method required that the data from the ~0.5-hr rest-period-test 
be
extrapolated until the fractional recovery in that test matched the final recovery in the 30-
day test
(0.913), the extrapolation was considered justified in light of the additional information
contained in the tracer responses from the 30-day test. Also, it was desirable to determine 
the
sensitivity of the ambient groundwater velocity estimates to different methods of 
calculating the
mean arrival time.
The extrapolation of the ~0.5-hr test data was accomplished by doing the mathematical
equivalent of linearly extending the tail of the tracer response curve on a log-log plot. The
means were then recalculated using Equation 66. The recalculated means for all three 
tests
increased significantly relative to the means calculated from the breakthrough curves that 
were
truncated at a fractional tracer recovery of 0.864. However, the mean for the 30-day test
increased by the greatest percentage (about 36% compared to 18% and 15% for the ~0.5-
hr and
2-day tests, respectively). The (re)calculated mean for the ~0.5-hr test was found to be 
relatively
insensitive to the slope of the line used to extrapolate the tracer data. This insensitivity 
was
probably due to the relatively steep slope of the tail of the response curve in this test.
6.5.4.2.4 Linked Analytical Solutions
Three different analytical solutions of the advection-dispersion equation, with appropriate
boundary conditions representing the three distinct single-well tracer test phases 
(injection/chase,
drift, and pump back) were combined into one Personal Computer-based Windows 
program with
a user interface, called Injection-Pumpback.vi V 1.0 (STN: 10675-1-00 [162749]). 
Injection-
Pumpback.vi is a "LabView" program, where LabView is the graphical-programming 
language
"G" as implemented by National Instruments, Inc. The linked analytical solutions were 
intended
to provide an alternative, more rigorous, method of estimating groundwater drift 
velocities in the
alluvium from single-well tracer tests than the analytical approaches described in 
Sections
6.5.4.2.1 through 6.5.4.2.3. This method was also intended to provide estimates of other
transport parameters derived from single-well tracer testing in the alluvium (flow 
porosity,
dispersivity) given an assumption of a homogeneous and isotropic flow system. The 
method was
chosen instead of numerical modeling approaches because of the relative simplicity of the
analysis and the desire to avoid numerical dispersion that occurs in numerical models. A
description of the three analytical solutions that constitute the program Injection-
Pumpback.vi
and the application of the program to analyze the three injection-pumpback tracer tests
conducted in borehole 19D1 follows.
ANL-NBS-HS-000039, REV 00 382 December 2003
The tracer injection and chase phase was analyzed using simple flow displacement 
calculations
combined with a 1-D uniform-flow solution of the advection-dispersion equation by 
Crank (Bear
1979 [105038], p. 266, Equation 7-123) to determine the location and width of the "tracer 
ring"
resulting from the outward radial flow. The inner radius of the ring was calculated 
directly from
the volume of chase water injected, and the 1-D solution was then used to determine the 
width
and, hence, outer radius, of the ring. This approach is only approximate because the 1-D 
column
solution assumes a constant velocity flow field whereas a divergent radial flow field has a
decreasing velocity with increasing distance from the injection well. In the 1-D column 
solution,
dispersion of the "plume" results in the leading and trailing edges of the plume being 
essentially
equidistant from the plume center of mass. However, in an outward radial flow field, the 
leading
edge will tend to be closer to the center of mass than the trailing edge because of the 
velocity
decrease in the radial direction. Given this approximation, the analysis of the tracer 
injection and
chase phase is conducted as follows.
The column solution by Crank (Bear 1979 [105038]) is given by:
* * ?
* * ?
* ?
t 4D
x'
exp
t) D (4
M/
t) x, ( C
h
2
1/2
h
CR ?

(Eq. 67)
where
CCR(x,t) = concentration of solute at a point x meters from the point of tracer injection 
(top of
the column) at t minutes after injection (kg/m3)
M = mass of tracer injected per unit cross-sectional area in kilograms (kg/m2)
* = flow porosity
Dh = coefficient of hydrodynamic dispersion (longitudinal) as given by Equation 68 
(m2/sec)
x' = distance in meters from the top of the column (where the tracer slug is introduced at 
time
t=0) to the centroid of the slug at time t as given by Equation 69 (m)
t = 27.6 hours (for this application), the time it took to inject the tracer volume, 10,600 L
(2,800 gallons), followed by the chase volume, 83,000 L (22,000 gallons), at an
injection rate of 56.8 L/min (15 gpm).
If molecular diffusion is ignored, Dh (m2/min) is given by (Bear 1979 [105038], p.264):
Dh = ?L |q| / * (Eq. 68)
ANL-NBS-HS-000039, REV 00 383 December 2003
where
?L = longitudinal dispersivity (m)
q = specific discharge in cubic meters per minute for a unit area of one meter squared
(m/sec).
For 1-D flow in a column, x' is given by Bear (1979 [105038], p. 266, Equation 7-120):
x' = x - (q/ ?) t . (Eq.69)
where x = distance from top of column (m).
Equations (67 to 69), representing movement of a tracer slug in a 1-D column 
experiment, were
modified to represent outwardly-divergent flow from an injection well as follows. The 
radial
distance from the center of the well, r, was converted to an equivalent linear column 
length x by
calculating the length of a column whose volume is equivalent to that of a cylinder 
centered at
the well with height equal to the test-interval thickness, h, and with radius r. This cylinder 
has
radial cross-sectional areas increasing from a minimum of 2?rwh at the well, (where r = 
rw (the
well radius, m)), to 2?rh at a radius of r from the center of the well. The equivalent 
column is
defined as having a constant cross-sectional area of 2?rwh (representing the cross-
sectional area
of the aquifer in contact with the well) and a volume equal to that of the cylinder. For the 
same
porosity, this equivalent column would contain the same volume of water as the cylinder.
The volume of the above cylinder, VCYL, is given by:
VCYL = * r2 h (Eq. 70)
where h = interval thickness (m).
The volume of the equivalent linear column, VCOL, is:
VCOL = ACOL x (Eq. 71)
where ACOL = cross-sectional area of the column (m2), which is 2?rwh, by definition.
Setting VCYL equal to VCOL and ACOL equal to 2?rwh in Equations 70 and 71, and solving 
for x,
results in Equation 72:
x = * r2 h / 2?rwh = r2 / (2rw) (Eq. 72)
where rw = injection well radius (m).
So, for a particular radius r* Equation 72 is used to calculate the equivalent linear column
distance, x. This value of x is used to calculate x' in Equation 69, and then Equation 67 is 
used
to calculate the concentration CCR(x,t) (kg/m3), according to Crank (Bear 1979 [105038], 
p. 266,
Equations 7-120 and 7-123). CCR(x,t) = CCR(r,t), obtained in this manner, describes the 
change
of concentration as a function of radial distance from the injection well.
ANL-NBS-HS-000039, REV 00 384 December 2003
The specific discharge, q (m/sec), used in Equations 68 and 69 is obtained by dividing the
injection rate, QINJ = 56.8 L/min (15 gpm), by the cross-sectional area of the aquifer in 
contact
with the well, 2?rwh:
q = QINJ /(2?rwh) (Eq. 73)
By defining a threshold concentration at which a sharp edge of the tracer ring starts at its 
inner
circumference and ends at its outer circumference (5 mg/L or 5 x 10-9 kg/m3 for this 
analysis), a
width can be determined for the tracer ring from the modified Equation 67. In summary, 
the
modified solution has been used to define the width of the tracer ring (formed by the 
chase fluid
pushing the tracer outward from the well) as a function of the assumed effective porosity 
and
longitudinal dispersivity. The tracer ring is then positioned with its inner radius at a 
distance rC
(radius of chase zone) calculated from the assumed effective porosity and known volume 
of
chase water, Vc (rC from Vc = 83,000 L [22,000 gallons] = ?rC
2h ?) and with its width as
determined from the analytical solution by Crank (Bear 1979 [105038], p. 266, Equation 
7-123).
The superposition of the ambient groundwater flow on the outward-radial flow caused by 
tracer
injection and chase was ignored (i.e., it was assumed that the injection and chase 
dominated the
flow field). Given that the tracer injection and chase phase in all the single-well tests was
relatively short compared to the drift plus pumpback phase, this approximation should 
not
preclude obtaining reasonable estimates of groundwater velocity for the purposes of 
comparing
with the analytical methods of Sections 6.5.4.2.1 through 6.5.4.2.3. Figure 6.5-24 shows a
LabView depiction of the tracer "plume" after injection and chase.
A 2-D analytical solution of the advection-dispersion equation for a tracer slug injected in 
a
uniform flow field (Bear 1979 [105038], as given in Bachmat et al. (1988 [162534], p. 
149,
Equation 11) was used to calculate tracer movement during the "drift" phase of each 
single-well
test:
y ) t V - x (
t 4V
1
- exp
t V ) ( 4
h / M
) t , y , (x C
T
2 1
L
2
1 o 1
1 o 1 o
2 / 1
T L
1
1 1 1 i * 
* * 
* * * * ?
?
* 
?
* ?
* * * * ?
* (Eq. 74)
where
Ci(x1,y1,t1) = concentration at one of the grid blocks (with transformed coordinates (x1, 
y1) -
see below) in Figure 6.5-25 resulting from drift of a mass M1 kg initially positioned at the
centroid of the particular wedge, wedge i (i = 1 through 18) of Figure 6.5-24. Wedge
numbering is not unique and the index "i" is only used here to indicate enumeration of
wedges.
x1 and y1 are the coordinates of this grid block relative to an orthogonal system centered at
the centroid of wedge i. For this orthogonal coordinate system, the positive x1
axis is
oriented parallel to streamlines of the ambient flow field and in the direction of flow.
?L = longitudinal dispersivity (m)
?T = transverse dispersivity (m)
Vo = interstitial velocity caused by the ambient gradient (m/sec)
t1 = duration of drift allowed before pumpback (hr).
ANL-NBS-HS-000039, REV 00 385 December 2003
DTNs: GS020708312316.001 [162678] (data); GS020908312316.002 [162679] (data). Output DTN: 
GS031008312316.003
(analysis).
Figure 6.5-24. Tracer Ring (red-hatched area) and Chase Ring (green-hatched area) Around the
Injection Well NC-EWDP-19D1
In essence, Equation 74 is solved in the transformed coordinate system to obtain the 
distribution
of tracer mass resulting from the drift of tracer initially located in each of the wedge-
shaped
volume elements of Figure 6.5-24. Then, the solutions for all 18 wedge-shaped volume 
elements
are superimposed to obtain the overall distribution of tracer mass after the drift phase. 
The
relatively coarse discretization of the tracer mass at the centroid of the 18 wedges of 
Figure 6.5-
24 at the beginning of the drift phase is an inherent approximation in the method. The 
resultant
concentration field representing the drifted plume is shown in Figure 6.5-25.
ANL-NBS-HS-000039, REV 00 386 December 2003
DTNs: GS020708312316.001 [162678] (data); GS020908312316.002 [162679] (data); UN0109SPA008IF.006 [162442] 
(conc.);
UN0109SPA008KS.005 [162681] (conc.) UN0109SPA008KS.007 [162615] (conc.); UN0109SPA008KS.008 [162616]
(conc.);Output DTN: GS031008312316.003 (analysis).
NOTE: The x and y axes indicate the number of blocks counted from an origin 10 m west and 10 m south of 
the
injection well; the blocks are 0.5 m on a side; and the well is, therefore, at coordinate (20, 20).
Concentrations are calculated using the Bear (1979 [105038]) two-dimensional drift solution.
The x-y plots to the left of the main 2-D plot show the tracer concentration distribution along linear profiles in
the east-west (top) and north-south (bottom) directions through the grid point corresponding to the location
of the well (20,20).
The x1 direction is the direction of ambient flow.
Figure 6.5-25. Concentration Distribution of Tracer Plume Resulting
from a 30-Day Drift of the Tracer Ring Shown in Figure 6.5-24
For each block, the total concentration, C1 + C2 + C3 + . . . + C18 , is multiplied by the 
volume of
the block, 0.5m x 0.5m x h, times the porosity, ?, to obtain the mass of the tracer slug, 
Mslug ,
used at that block for the pumpback phase. A radial solution of the advection-dispersion
equation for a cross-hole convergent tracer test with slug injection (Moench 1989 
[101146], pp.
440 to 443; 1995 [148784], pp. 1824 to 1827) was then used to calculate tracer 
movement during
the pumpback phase of each test.
2 6 .7 1
0 .0 0
1 .3 2
2 .2 0
3 .6 5
5 .2 2
7 .5 4
1 0 .5 6
1 3 .0 1
1 4 .8 7
1 7 .8 1
1 9 .7 4
2 2 .4 9
2 3 .8 8
2 5 .1 4
4 0
0
5
1 0
1 5
2 0
2 5
3 0
3 5
4 0 0 5 1 0 1 5 2 0 2 5 3 0 3 5
C o n c e n tra tio n s in m g / L U sin g th e B e a r (1 9 7 9 ) 2 -D d rif t s o lu t io n
Concentration distribution of the plume resulting from a 30-day drift of the tracer
ring shown in the tracer- and chase-rings figure. ( The x and y axes indicate the
number of 0.5 m x 0.5 m blocks counted from an origin 10 m west and 10 m
south of the injection well. The well is, therefore, at coordinates 20,20)
2 0 .0
5 .0
7 .5
1 0 .0
1 2 .5
1 5 .0
1 7 .5
4 0 0 1 0 2 0 3 0
ro w 2 0
2 5 .0
0 .0
5 .0
1 0 .0
1 5 .0
2 0 .0
4 0 0 1 0 2 0 3 0
c o lum n 2 0
x1 direction x direction
ANL-NBS-HS-000039, REV 00 387 December 2003
The mass in each of the 0.5 m x 0.5 m blocks of the calculation grid of Figure 6.5-25 was
considered a slug injection in a convergent flow field towards the pumped well located at
coordinates 20, 20 of the figure.
Moench (1989 [101146], pp. 440 to 443; 1995 [148784], pp 1824 to 1827) used the 
Laplace
transform method to solve the following dimensionless governing advection-dispersion 
equation
for horizontal, radial flow in an homogeneous, double-porosity aquifer:
D
D
2
wD
D 2
wD D
D
D
2
D
D
2
D t
C
) r - (1
2R
q'
) r - (1
2R
-
r
C
r
1
r
C
r Pe
1
* 
* * 
* 
* * 
* 
* ?(Eq. 75)
where
Pe = rL/?L , the Peclet number, and rL = distance from the tracer injection point (normally 
a
well) to the pumped well
rD = r/rL is the dimensionless radial distance from the pumping well, where r is the
dimensional distance from the pumping well
CD = dimensionless concentration, which for a slug injection is given by CD = C/Ci, where 
C
= concentration at r, and Ci = reference concentration given by Ci = Mslug / [?h * (rL
2 ?
rw
2)] in which rw = radius of the pumping well
rwD = rw/rL , the dimensionless well radius
tD = dimensionless time, t/ta, where ta is the advection travel time given by ta = (?rL
2h ?)/Q in
which Q = pumping rate
R = retardation factor
D q' = dimensionless distributed sources or sinks of tracer due to diffusion of the tracer into
stagnant porosity.
Moench (1989 [101146] , pp. 440 to 443; 1995 [148784], 1824 to 1827) provided a 
FORTRAN
program, rcv2amos.exe V 1.0 (STN: 10583-1.0-00 [162750]), that computes the Laplace
transform of Equation 75 and then the inverse Laplace transform to finally give 
dimensionless
concentration, CD, versus dimensionless time, tD, at the pumped well in the form of two
numerical arrays. The CD versus tD dimensionless theoretical breakthrough curve is then
converted to a dimensional curve of C versus t using the above relation. Injection-
Pumpback.vi
V 1.0 (STN: 10675-1-00 [162749]) uses rcv2amos.exe to obtain the effect at the pumping 
well of
a slug of mass Mslug placed at each block of the calculation grid of Figure 6.5-25. It then
superposes all of these solutions to obtain the final effect at the pumping well of a slug of 
mass
Mslug placed at each block of the calculation grid of Figure 6.5-25, and then superposes all 
of
these solutions to obtain the final calculated breakthrough. The superposition of the 
ambient
groundwater flow on the radial flow caused by the pumping well was ignored (i.e., it was
assumed that the pumping dominated the flow field). This approximation clearly 
introduces
some error to the analysis. However, given that the curve-matching procedure discussed 
below
is heavily influenced by tracer data obtained early in the pumpback phase of each test 
(the tracer
peaks occur within a day), the error should not preclude reasonable estimates of 
groundwater
velocity for the purposes of comparing with the analytical methods of Sections 6.5.4.2.1 
through
6.5.4.2.3.
ANL-NBS-HS-000039, REV 00 388 December 2003
The complete analysis involves adjusting the flow porosity, longitudinal dispersivity, 
transverse
dispersivity, and specific discharge in all three computational stages (keeping them the 
same in
each stage) until simulated tracer responses offer a reasonable match to the observed 
tracer
responses in each single-well test. The results of such a match to the three injection-
pumpback
tracer responses in well 19D1 are shown in Figure 6.5-26. The analysis indicates a flow 
porosity
value of 0.10, a longitudinal dispersivity of 5 m, and a specific discharge of 1.5 m/yr 
(Output
DTN: GS031008312316.003). Although a rigorous sensitivity analysis to evaluate the
uniqueness of the solution was not conducted, many combinations of parameter values 
were
considered, and there appeared to be qualitative convergence to these values. The top 
three plots
in Figure 6.5-26 present dimensional (actual) concentrations, whereas the bottom three 
plots
present concentrations normalized relative to maximum concentrations. The assumed 
input
parameter combination yields a reasonable fit to all three single-well tracer data sets.
The flow porosity value of 0.10 should be less than the total porosity and is, therefore, 
consistent
with three estimates of total porosity presented in different sections of this report: (1) a 
value of
0.29 obtained from the Borehole Gravity Meter survey in 19D1, presented in Section 
6.5.5; (2) a
value of 0.41 obtained from estimates of barometric efficiency and specific storage, 
presented in
Section 6.4.3; and (3) a value of 0.33 obtained from grain-size-distribution analysis, 
presented in
Section 6.4.3.
DTN: UN0109SPA008IF.006 [162442] (0-day test), UN0102SPA008KS.003 [162614] (2-day test), 
UN0109SPA008KS.007
[162615] (30-day test); Output DTN: GS031008312316.003 (analysis).
NOTE: The plots are fits of three injection-pumpback tracer tests with theoretical curves that result from 
three
solutions to the advection-dispersion equation for the three phases of injection, drift, and pumpback. The
red curves are the model fits and the blue curves are the data curves. The three top graphs are actual
concentrations versus elapsed days, and the bottom three graphs are normalized concentrations versus
elapsed days. The parameters used in the calculations are: flow porosity = 0.1, matrix porosity = 0.0,
longitudinal dispersivity = 5.05 m, transverse dispersivity = 1.00 m, test interval thickness = 9.75 m (32.0 ft),
tracer volume injected = 10,600 L (2,800 gal), chase volume injected = 83,000 L (22,000 gal), injection rate
56.8 L/min = (15.0 gpm), mass injected = 5.0 kg, natural gradient = 0.002 m/m, T for gradient = 20.0 m2/d,
specific discharge = 1.5 m/yr, the Q values for the 0-, 2-, and 30-day tests are 13.41, 11.00, and 13.50,
respectively.
Figure 6.5-26. Fitting the Injection-Pumpback Tracer Tests in Screen #1 of NC-EWDP-19D1
Using the Linked-Analytical Solutions Method
ANL-NBS-HS-000039, REV 00 389 December 2003
6.5.4.3 Groundwater Velocity Analysis Results
Table 6.5-7 lists the results obtained for both vGW and the specific discharge, vS (= * vGW), 
as a
function of assumed flow porosity ( ?) by all four methods of estimation. As expected, of 
the
first three methods, the peak analysis method offers the smallest estimates, and the 
analysis of
late-arriving mass (high recovery) offers the largest. The range of the estimates from the 
four
methods spans about a factor of three for a given assumed value of flow porosity. The 
velocity
estimate from the linked analytical solutions is in very good agreement with the peak 
analysis
method. The peak-analysis method yields a velocity estimate of 17.5 m/yr (specific 
discharge of
1.75 m/yr), as compared to 15 m/yr (1.5 m/yr specific discharge) from the linked 
analytical
solutions, when a flow porosity of 0.10 is assumed (the flow porosity obtained from the 
linked
analytical solutions).
The specific discharge estimates of Table 6.5-7 are in good agreement with the range of 
1.9 to
3.2 m/yr derived from SZ flow-model calibrations (to head and hydraulic conductivity 
data),
which assume a wide range of potential anisotropy in horizontal hydraulic conductivity 
(BSC
2003 [164870], Table 6-6). The range of values in Table 6.5-7 has been factored into the
probability distribution used for specific discharge in the alluvium in Yucca Mountain
performance assessment simulations (BSC 2003 [164870], Figure 6-7).
Table 6.5-7. Specific Discharges and Seepage Velocities Estimated from
the Different Drift Analysis Methods as a Function of Assumed Flow Porosity
Specific Discharge (m/yr) / Seepage Velocity (m/yr)
Assumed Flow Porosity(a) 0.05 0.18 0.3
Peak Arrival Analysis 1.2 / 24.5 2.4 / 13.1 3.0 / 9.9
Late Arrival Analysis(b) 3.9 / 77.1 7.3 / 40.4 9.4 / 31.3
Mean Arrival Analysis(c) 2.0 / 40.3 3.8 / 20.9 4.9 / 16.4
Mean Arrival Analysis(d) 2.5 / 49.1 4.6 / 25.8 6.0 / 20.2
Linked Analytical Solutions 1.5 / 15 with a flow porosity of 0.10 and a longitudinal dispersivity of 5 m.
Output DTN: LA0303PR831231.002.
NOTE: (a)The three values are approximately the lowest, expected, and highest values of the alluvium flow 
porosity
used in Yucca Mountain performance assessments (BSC 2003 [164870]).
(b)Time/Volume associated with ~86.4% recovery in each test (the final recovery in the 0.5-hr rest period
test, which had the lowest final recovery of any test).
(c)Mean arrival time calculated by truncating all tracer response curves at ~86.4% recovery in each test.
(d)Alternative mean arrival time calculated by extrapolating the tracer response curves in the 0.5-hr rest
period test to 91.3% and truncating the response curves in the 2-day rest period test to 91.3% recovery
(the final recovery in the 30-day rest period test).
6.5.4.4 Discussion of Groundwater-Velocity Analyses
Some significant uncertainties are associated with each of the estimation methods for vGW 
and vS
described in this report. Although it would be of interest to determine which of the 
methods
provides the best estimate, a detailed analysis of uncertainties was not conducted. In the
ANL-NBS-HS-000039, REV 00 390 December 2003
discussion that follows, qualitative comments are provided on several uncertainties, and 
some
advantages and potential pitfalls of the different methods are discussed.
The linked-analytical-solution method offers the advantage of providing estimates of 
flow
porosity and longitudinal dispersivity, which are very important parameters for repository
performance assessment, in addition to providing flow velocity estimates. Although the
parameter estimates in Table 6.5-7 for this method were obtained after many trials using 
various
values of flow porosity, dispersivity, and groundwater flow velocity to fit the three tracer
responses simultaneously, an exhaustive sensitivity analysis to evaluate the uniqueness of 
the
matches was not conducted. With such an analysis, it is possible that other combinations 
of flow
porosity, dispersivity, and groundwater-flow velocity could yield essentially equally good
matches to the tracer responses.
The value of longitudinal dispersivity obtained from the linked analytical solutions (5 m)
intuitively seems large given that calculated injection distances from the well should have 
been
only about 5 to 6 m with a flow porosity of 0.1. This large dispersivity probably reflects 
that the
aquifer was not truly homogeneous and isotropic as assumed, and a large dispersivity was 
the
only way the analytical solutions could account for tracer plume spreading that occurred 
due to
flow heterogeneity.
The impact of ignoring tracer drift during the injection and pumpback phases of testing 
for the
linked-analytical-solution method is not clear. The error introduced by this assumption 
may be
important for the two tests with the shortest rest periods, as the injection and pumpback 
phases
were collectively longer than the rest period in both tests. The remaining discussion is 
focused
on the other three estimation methods, although some aspects of it also apply to the 
linkedanalytical-
solution method.
The peak-analysis method would intuitively seem to have considerable uncertainty 
associated
with it because of the inability to determine whether the tracer mass associated with the 
peak
remained upgradient of the well during the rest period or if it drifted back downgradient 
of the
well during the rest phase. The former case was assumed here, as it provides the lowest 
estimate
of groundwater velocity and specific discharge. If the latter case were assumed, the 
estimated
velocity would have been about twice the estimates obtained by the other methods 
instead of
about half the other estimates. Another uncertainty associated with the peak-analysis 
method is
that at least part of the shift in the peak-arrival time/volume may have been due to 
hydrodynamic
dispersion in the system rather than pure advection (as was assumed). A considerable 
amount of
dispersion during the rest phase could have shifted the peak-arrival time without 
significant
translation of the tracer plume's "center of mass" due to advection. However, some 
advection is
necessary for dispersion to occur.
Both the analyses of late-arrival times and mean-arrival times are potentially highly 
sensitive to
diffusion into stagnant water and to density-driven flow resulting from density contrasts 
between
the injection solution and the ambient groundwater. Both of these phenomena can 
dramatically
increase tailing in the tracer response curves and, hence, increase the late-arrival or mean-
arrival
times/volumes. Although the nearly identical responses of the tracers with different 
diffusion
coefficients in all three tests provide strong evidence that diffusion did not play an 
important role
in the observed tailing behavior in the tests, density contrasts cannot be ruled out. If the 
tracer
ANL-NBS-HS-000039, REV 00 391 December 2003
solution was more or less dense than the ambient groundwater during injection (due to 
either
concentration or temperature differences), a portion of the tracer mass could have moved 
upward
or downward into nearly stagnant regions of the aquifer by density-driven flow. Under 
these
conditions, a portion of the tracer mass could remain in the aquifer for an extended period 
of
time because pumping will not rapidly "draw" the tracer out of the nearly-stagnant 
regions.
Despite the disadvantages mentioned above, the peak-analysis method offers an 
advantage in this
situation because the peak-arrival time should be relatively unaffected by such "artificial" 
tailing
behavior.
Assuming that diffusion can either be neglected or corrected for and that the effects of 
density
contrasts are negligible, the mean-arrival-time analysis would intuitively seem to be the 
method
least affected by hydrodynamic dispersion in the system. In theory, dispersion should not 
affect
the mean-arrival time, whereas it will affect the other arrival times. However, the mean-
arrivalanalysis
method has the disadvantage that complete recoveries are seldom achieved in field
tracer tests, so the mean must generally be estimated somewhat arbitrarily from either a 
truncated
or an extrapolated distribution, as in the analyses described in this report.
Finally, some practical considerations associated with hypothetically possible test results 
are
worth discussing. Consider a case in which the heterogeneity in aquifer hydraulic 
conductivity
in the vicinity of the well is such that the entire tracer mass moves upgradient of the well 
during
injection. In this situation, it is possible that both the mean and late arrival volumes could 
be less
than the sum of the injection and chase volumes. Under these circumstances, the test 
analyst will
have to recognize that the equations used in both the late- and mean-arrival analyses 
should be
modified to account for groundwater flow moving the tracer mass back toward the well. 
The
late-arrival-analysis method will also be sensitive to dispersion in this case.
If the tracer mass moves primarily perpendicular to the direction of ambient ground-water 
flow
during injection but slightly upgradient, the peak-, late-, and mean-arrival methods all 
have the
potential to underestimate groundwater velocities because drift may only slightly alter the
separation distance between the tracer mass and the well before pumping starts (Figure 
6.5-27).
Each of the first three methods will work best if the "center of mass" of the tracer plume 
is
injected either directly upgradient or downgradient. Intuitively, it also seems likely that 
the
uncertainty associated with all the methods should decrease as the difference between the 
rest
periods of the tests, and, hence, the difference in the amount of drift in the tests, 
increases. An
increase in the difference in drift should result in a greater difference in each of the 
arrival times,
which should make the analyses less sensitive to subtle differences in the 
injection/withdrawal
procedures or other non-idealities in the tests.
Additional insights into uncertainties associated with the estimation methods could 
probably be
obtained by (1) generating random-stochastic-hydraulic-conductivity fields having 
statistics
consistent with the current knowledge of the alluvium, and then (2) numerically 
simulating
injection-withdrawal tests in these fields (for various assumed drift velocities). These 
methods
could ultimately yield more refined estimates of groundwater velocities in the alluvium.
ANL-NBS-HS-000039, REV 00 392 December 2003
For illustration purposes only
NOTE: The dashed lines connect the well with the center of mass of the tracer "plume" before and after the 
rest
period.
Figure 6.5-27. Depiction of a Tracer Injection Scenario that
Could Result in Underestimation of Groundwater Velocity
6.5.4.5 Conclusions From Groundwater-Velocity Analyses
Four methods of estimating groundwater velocities from multiple single-well 
injectionwithdrawal
tracer tests conducted with varying rest periods in the saturated alluvium south of
Yucca Mountain, Nye County, Nevada are presented in this report. The resulting 
estimates of
groundwater velocity and specific discharge vary over a range of about a factor of 3 for a 
given
assumed flow porosity and by about a factor of 8 for a reasonable range of flow 
porosities. The
estimates of specific discharge range from 1.3 to 9.4 m per year, which falls within the 
range of
specific discharges being used in Yucca Mountain performance assessments (obtained 
using
potentiometric head and hydraulic conductivity data). Flow porosity and longitudinal
dispersivity estimates of 0.10 and 5 m, respectively (Output DTN: 
GS031008312316.003), were
obtained using a linked-analytical-solution method.
The same aquifer parameter values obtained from analyzing the three injection-pumpback 
tracer
tests in screen #1 above were used to fit the theoretical breakthrough curve of the above 
linkedanalytical-
solutions method to the actual breakthrough curve from the screen #4 injectionpumpback
tracer test (detailed documentation contained in Umari (2003 [164573]). The results
are shown in Figure 6.5-28. The close fit indicates that the same aquifer parameters that 
were
suitable for screen #1 in well 19D1 are also suitable for screen #4 in the same well.
Well
Ambient Gradient
Tracer After Injection Tracer After Drift
ANL-NBS-HS-000039, REV 00 393 December 2003
DTNs: MO0205UCC008IF.001 [162617] (data); Output DTN: GS031008312316.003 (analysis).
Figure 6.5-28. Fitting the Theoretical Breakthrough Curve from the Linked-Analytical-Solutions
Method to the Actual Breakthrough Curve from the Injection-Pumpback Tracer Test in
Screen #4 of NC-EWDP-19D1
0
1
2
3
4
5
6
7
8
9
10
11
12
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
ELAPSED DAYS SINCE 5:45 PM ON THURSDAY 2/28/02
CONCENTRATION OF 2,4 DFBA IN PPM
INJECTION-PUMPBACK TEST IN SCREEN #4, PUMPBACK STARTED
AT 5:45 PM ON 2/28/02
THEORETICAL BREAKTHROUGH CURVE FOR THE ASSUMED
PARAMETERS
ANL-NBS-HS-000039, REV 00 394 December 2003
6.5.4.6 Estimate of Colloid Detachment Rate Constant from Microsphere Response 
in
Single-Well Test
A rough estimate of the effective detachment rate constant for the 640-nm-diameter 
polystyrene
microspheres that were injected in the zero-rest-period single-well tracer test at 19D1 
(Figure
6.5-18) was made as follows. First, the assumption was made that after 90 hr of pumping, 
the
microsphere response is entirely the result of detachment from the alluvium. At this time, 
about
72% of the solutes had been recovered but only 26% of the microspheres (the final 
recoveries
were 87% and 32%, respectively). In fact, there may have been some spheres recovered 
after 90
hr that were not truly detaching (they were just making their way out of the system 
without ever
having become attached), so counting these as being detached spheres increases the 
estimate of
the detachment rate constant.
The following simple mass action equation was assumed to apply:
Q C * krM[(1- fsphere ) - (1- fsolute )] (Eq. 76)
where
C = concentration of spheres in water produced from well, number/L
Q = production rate from well = 3066 L/hr
kr = detachment rate constant, 1/hr
M = total number of spheres injected (a known value)
fsphere = fraction of spheres recovered (so (1 - fsphere) is the fraction not recovered)
fsolute = fraction of solutes recovered.
Equation 76 assumes that the spheres remaining on the alluvium surfaces are equal to the 
total
number of spheres injected times the fraction of spheres not recovered (1 - fsphere) minus 
the
fraction of solutes not recovered (1 - fsolute). Subtracting (1 - fsolute) from (1 - fsphere) is a 
correction
that accounts for the fraction of spheres that would not have been recovered at a given 
time even
if they did not interact with alluvium surfaces. The quantity [(1 - fsphere) - (1 - fsolute)] 
averages
about 0.5 over the last 77 hr of the test (0.46 at 90 hr and 0.545 at 167 hr).
Rearranging Equation 76 to solve for kr yields the following:
kr ?
Q
[(1- fsphere ) - (1- fsolute )]
* ?
* ?
* ?
* ?
C M
* ?
* ?
* ?
* * (Eq. 77)
ANL-NBS-HS-000039, REV 00 395 December 2003
The quantity C/M is the normalized concentration plotted in Figure 6.5-18. It has a value 
of
approximately 0.0000002/L during the latter portion of the test. Using the average 
pumping rate
during the test of 3066 L/hr, Equation 77 yields a value of 0.0012/hr for kr (Output DTN:
LA0303PR831352.001). This estimate of the detachment-rate constant can be considered 
high
(upper bound) because dC/dt slowly decreased as the test proceeded and the fractional 
recovery
of solutes increased faster than the microsphere recovery (which means that the estimate 
of the
number of spheres remaining on the surfaces according to Equations 76 and 77 actually
increased with time-a physical impossibility). The latter contradiction could be 
remedied by
simply setting (1 - fsolute) equal to zero, which would lower the detachment-rate constant 
estimate
by about 30%.
6.5.4.7 Conclusions from Single-Well Tracer Testing in Alluvium
The fact that there was virtually no difference in the normalized responses of the halide 
and FBA
tracers in the three single-well tracer tests conducted in 19D1 strongly suggests that a 
singleporosity
conceptual model is appropriate for modeling radionuclide transport in the saturated
alluvium south of Yucca Mountain. Differences in the tracer responses for the different 
rest
periods in the three tests were apparently the result of groundwater drift during the rest 
periods,
not the result of diffusion between flowing and stagnant water. Further evidence for a 
singleporosity
flow/transport system was provided by the lack of an increase in tracer concentrations
after flow interruptions during the tailing portions of the tracer responses in two of the 
tests.
This lack of increase in tracer concentrations indicates a lack of diffusive mass transfer 
between
flowing and stagnant water in the flow system.
Four methods were used to estimate groundwater drift velocities from the three single-
well tracer
tests. The resulting estimates of groundwater velocity and specific discharge vary over a 
range
of about a factor of three. The estimates are in reasonably good agreement with estimates
obtained using potentiometric head and hydraulic conductivity data. It is doubtful that 
these
estimates would be improved significantly by more sophisticated modeling without more
detailed information on the distribution of tracer mass after the injection and rest phases 
of the
single-well tests. However, the generation of random-stochastic-hydraulic-conductivity 
fields
having statistics consistent with the current knowledge of the alluvium, followed by the
numerical simulation of injection-withdrawal tests within these fields (for various 
assumed drift
velocities), would probably yield considerable additional information on the uncertainties
associated with the estimation methods.
ANL-NBS-HS-000039, REV 00 396 December 2003
6.5.5 Total Porosity Obtained from Borehole Gravimetry at NC-EWDP-19D1
Standard suites of geophysical logs were conducted during, and after, completion of all 
wells at
the ATC. In addition, borehole gravimetry (BHGM) logging of 19D1 was conducted by
EDCON, Inc. in September 2000 (DTN: MO0105GPLOG19D.000 [163480]). BHGM 
logs
provide bulk density as a function of depth, from which total porosity as a function of 
depth can
be estimated if grain density is known or assumed. The total porosities deduced from 
BHGM
logging are reported here because they serve as useful upper bounds for effective flow 
porosity
in the alluvium. These estimates can be compared with the estimates of flow porosity 
obtained
from analysis of single-well tracer tests in the alluvium, which are presented in Section 
6.5.4.
Other estimates of total porosity in the alluvium, obtained from specific storage and 
barometric
efficiency and from grain size distributions, are discussed in Section 6.4.3.
For a water-saturated sample of alluvium, the mass of solids plus the mass of water is 
equal to
the total mass of the sample, i.e.:
Vs ?s + Vv ?w = ?b VT (Eq. 78)
where
Vs is the volume of solids
?s is the density of solids (grain density)
Vv is the volume of voids (filled with water for a saturated medium)
?w is the density of water, ?b is the saturated (wet) bulk density of the sample
VT is the total volume of the sample.
By algebraic manipulation, the porosity, ?, which is defined as Vv/VT, can be obtained 
from
Equation 78 as:
* = Vv/VT = (?s - ?b)/( ?s - ?w) (Eq. 79)
Using Equation 79 with ?s = 2.52 g/cm3 (USGS n.d. [154495]) and ?w * 1.0 g/cm3 (ranges 
from
0.9986 g/cm3 at 18oC to 0.9959 g/cm3 at 29oC; (Dean 1992 [100722], p. 5.87)), one can 
calculate
* from various values of ?b. For the minimum ?b of 2.082 g/cm3 and the maximum ?b of 
2.244
g/cm3 in the alluvium section at 19D1 (DTN: MO0105GPLOG19D.000 [163480]), a 
maximum
porosity of 0.29 and a minimum porosity of 0.18 (Output DTN: GS031008312316.003) 
are
obtained from Equation 79.
Using the entire set of bulk densities for the entire section of 19D1 logged by the BHGM 
(DTN:
MO0105GPLOG19D.000 [163480]) for ?b in Equation 79 and the values of ?s and ?w, 
given
above, total porosities as a function of depth are obtained as shown in Figure 6.5-29.
ANL-NBS-HS-000039, REV 00 397 December 2003
DTN: MO0105GPLOG19D.000 [163480]. Output DTN: GS031008312316.003.
NOTE: The figure is plotted in English units because the data were obtained in those units. However, 
parameter
estimates are reported in metric units to downstream users.
Figure 6.5-29. Total Porosities as a Function of Depth Below Land Surface at NC-EWDP-19D1, 
Obtained
from the Borehole Gravity Meter (BHGM) Survey Conducted in September 2000
POROSITY
0.1 0.2 0.3 0.4 0.5 0.6 DEPTH, IN FEET
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
ANL-NBS-HS-000039, REV 00 398 December 2003
6.5.6 Laboratory Transport Tests in the Alluvium
Laboratory measurements of lithium-ion sorption onto alluvium material and tracer 
transport
tests in alluvium-packed columns were carried out in parallel with field tracer testing at 
the ATC.
The objectives of the laboratory tests are the same as for the laboratory testing conducted 
to
support C-wells tracer testing in fractured tuffs: (1) to obtain transport parameter 
estimates that
can help constrain interpretations of the field tracer tests, and (2) to obtain laboratory 
estimates
of lithium sorption parameters that can be compared to field-derived sorption parameter
estimates. The latter will allow an assessment of the ability to predict field-scale sorption 
in the
alluvium using laboratory-derived sorption parameters, which is important because 
laboratoryscale
sorption parameters must be used for field-scale predictions of radionuclide transport.
Detailed documentation of both the batch and column laboratory tests (the remainder of 
Section
6.5) is contained in Sullivan (2002 [164623]).
6.5.6.1 Alluvium Cation-Exchange-Capacity Measurements and Lithium Batch-
Sorption
Experiments
6.5.6.1.1 Alluvium Samples and Their Characteristics
CEC and lithium batch-sorption measurements were conducted on alluvium samples 
collected
from several different depth intervals in wells 19D1 and 19P. The intervals from which 
material
was collected were (in meters [feet] below land surface) 123 to 125 m (405 to 410 ft), 
128 to 130
m (420 to 425 ft), 152 to 154 m (500 to 505 ft), 177 to 178 m (580 to 585 ft), 201 to 203 
m (660
to 665 ft), 207 to 209 m (680 to 685 ft), 219 to 221 m (720 to 725 ft), and 238 to 239 m 
(780 to
785 ft) in 19D1, and 125 to 126 m (410 to 415 ft) and 128 to 130 m (420 to 425 ft) in 
19P.
Particle-size distributions of samples collected from 123 to 125 m and 128 to 130 m in 
19D1 and
from 125 to 126 m and 128 to 130 m in 19P were determined by a wet-sieve method. 
Particlesize
distributions in all other intervals (all of which were in 19D1) were determined by dry
sieving. Well 19P was drilled by a reverse-circulation air hammer method, so the high 
and low
ends of the particle size distribution were considered more representative than in the 
samples
from 19D1, which was drilled using a rotary bit with water as the lubricant. The rotary bit
probably broke up the larger particles, and the water washed out most of the smaller 
particles
from the 19D1 samples. Figure 6.5-30 shows a size distribution comparison for material 
from
approximately the same depth intervals in wells 19D1 and 19P.
For the CEC and lithium batch-sorption experiments, measurements were made on 
material that
had been wet- or dry-sieved to a size range between 75 and 2000 ?m and also on 
material that
was wet or dry-sieved to less than 75 ?m in size. The materials from 19P and from the 
two
uppermost intervals in 19D1 (123 to 125 m and 128 to 130 m) were wet-sieved, and all of 
the
remaining material was dry-sieved. Quantitative minerals abundance analysis using x-ray
diffraction (QXRD) (Chipera and Bish 1995 [105075]) was conducted on each fraction 
used for
testing (Table 6.5-8). Not surprisingly, the samples sieved to the smaller size range 
tended to be
richer in smectite clays and zeolites, which have higher CECs than the other minerals 
listed in
Table 6.5-8. Specific surface areas of the samples were measured by a single-point 
Brunauer-
Emmet-Teller (BET) nitrogen adsorption/desorption method (Brunauer et al. 1938 
[156646], pp.
309 to 319). The BET surface areas are listed in Table 6.5-9 for each sample. Table 6.5-9 
also
lists the lithium and cesium CECs of the samples, which are discussed in Section 
6.5.6.1.5.
ANL-NBS-HS-000039, REV 00 399 December 2003
DTN: LA0201JS831421.001 [162613].
NOTE: The mass-weighted particle size distributions above for the two wells are from the same depth 
interval of
123 to 130 m (405 to 425 ft) below land surface; and the size distributions were determined by dry-sieve
analyses.
Figure 6.5-30. Particle Size Distributions of Material in NC-EWDP-19D and NC-EWDP-19P
NC-EWDP-19D
EWDP-19D
0
20
40
60
80
100
10 100 1000 10000 100000
Grain Diameter, ?m
Percent Less Than
Data
Fit of Lognormal Dist.
EWDP-19P
0
20
40
60
80
100
10 100 1000 10000 100000
Grain Diameter, ?m
Percent Less Than
Data
Fit of Lognormal Dist.
ANL-NBS-HS-000039, REV 00 400 December 2003
Table 6.5-8. Mineralogy of Alluvium Samples Used in the Cation-Exchange-Capacity and
Lithium Batch-Sorption Experiments Determined by Quantitative X-ray Diffraction
Sample Label* Smectite
Clinoptilolite
Kaoli-
nite Mica Tridymite
Cristob-
alite Quartz Feld-
spar Calcite Hem-
atite
Hornblende
Total
19D 405-410 <75 ?m 20  6 10  1 1  1 Trace 3  1 7  2 14  1 39  6 1  1 1  1 - 96  9
19D 405-410 >75 ?m 4  1 7  1 1  1 1  1 5  1 13  1 17  1 53  8 - 1  1 - 102  8
19P 410-415 <75 ?m 34  10 26  2 1  1 Trace 3  1 5  1 8  1 28  5 1  1 - Trace 106  12
19P 410-415 >75 ?m 5  2 7  1 1  1 1  1 4  1 15  1 18  1 49  7 - Trace - 100  8
19D 420-425 <75 ?m 16  5 8  1 1  1 Trace 5  1 8  2 13  1 42  6 2  1 1  1 Trace 96  8
19D 420-425 >75 ?m 6  2 6  1 1  1 Trace 6  1 16  1 20  2 44  6 1  1 Trace - 100  7
19P 420-425 <75 ?m 40  12 24  2 1  1 Trace 2  1 4  1 8  1 24  4 - Trace - 103  13
19P 420-425 >75 ?m 11  3 6  1 1  1 Trace 4  1 11  1 22  2 45  7 - 1  1 1  1 102  8
19D 500-505 <75 ?m 10  3 10  1 1  1 Trace 5  1 9  3 16  1 43  6 1  1 1  1 - 96  8
19D 500-505 >75 ?m 5  2 6  1 1  1 Trace 5  1 15  1 20  2 43  6 - Trace - 95  7
19D 580-585 <75 ?m 7  2 24  2 1  1 Trace 3  1 7  2 16  1 44  7 1  1 1  1 Trace 104  8
19D 580-585 >75 ?m 5  2 10  1 1  1 Trace 4  1 14  1 18  1 45  7 - Trace - 97  8
19D 660-665 <75 ?m 21  6 24  2 1  1 1  1 2  1 5  1 10  1 36  6 - Trace 1  1 101  9
19D 660-665 >75 ?m 3  1 10  1 1  1 1  1 4  1 12  1 18  1 49  7 - Trace Trace 98  7
19D 680-685 <75 ?m 12  4 41  2 Trace Trace 3  1 6  1 8  1 29  5 - - 1  1 100  7
19D 680-685 >75 ?m 4  1 14  1 1  1 1  1 3  1 14  1 19  1 48  7 - Trace - 104  7
19D 725-730 <75 ?m 17  5 42  3 1  1 Trace 2  1 5  1 11  1 21  4 Trace - Trace 99  7
19D 725-730 >75 ?m 5  2 15  1 1  1 Trace 3  1 14  1 24  2 41  6 - Trace - 103  7
19D 780-785 <75 ?m 16  5 31  2 Trace Trace 2  1 8  2 12  1 34  6 1  1 - Trace 104  8
19D 780-785 >75 ?m 6  2 11  1 Trace - 3  1 14  1 21  2 47  7 - Trace Trace 102  8
DTN: LA0201JS831321.001 [162623].
NOTE: Bold entries denote material used in column experiments.
Mineral abundances are in weight percent.
Errors are 2-sigma values.
- = not detected; Trace = trace amount at less than 0.5 wt%.
Materials from NC-EWDP-19P and the two uppermost intervals in NC-EWDP-19D1 (123 to 125 m [405 to
410 ft] and 128 to 130 m [420 to 425 ft]) were wet-sieved; all other materials were dry-sieved.
*Sample Labels include the interval in feet because the data were collected using English units.
ANL-NBS-HS-000039, REV 00 401 December 2003
Table 6.5-9. Surface Areas and Lithium and Cesium Cation Exchange Capacities
(CEC) of Alluvium Samples Used in the Lithium Batch-Sorption Experiments
Interval +
(Well, ft below land surface, size)
BET Surface Area*
(m2/g)
Li CEC
(meq/kg)
Cs CEC
(meq/kg)
19D, 405-410, < 75 ?m 15.96 183 258
19D, 405-410, > 75 ?m 5.34 70 99
19P, 410-415, < 75 ?m NM 360 559
19P, 410-415, > 75 ?m NM 126 141
19D, 420-425, < 75 ?m 9.80 175 231
19D, 420-425, > 75 ?m 5.64 89 119
19P, 420-425, < 75 ?m NM 395 667
19P, 420-425, > 75 ?m 8.67 171 186
19D, 500-505, < 75 ?m 10.15 125 171
19D, 500-505, > 75 ?m 6.17 137 229
19D, 580-585, < 75 ?m NM 204 285
19D, 580-585, > 75 ?m 5.17 132 279
19D, 660-665, < 75 ?m NM 303 130**
19D, 660-665, > 75 ?m 5.16 119 368
19D, 680-685, < 75 ?m 11.16 257 663
19D, 680-685, > 75 ?m 3.99 118 439
19D, 720-725, < 75 ?m NM 424 620
19D, 720-725, > 75 ?m 5.66 114 433
19D, 780-785, < 75 ?m NM 237 131**
19D, 780-785, > 75 ?m 4.43 78 366
DTNs: LA0201JS831421.002 [162625] (BET data); LA0201JS831341.001 [162627] (CEC data).
NOTE: *Surface areas were determined using the nitrogen BET technique.
**Suspected erroneous measurements.
Bold denotes material used in column experiments.
NM: not measured, generally because of insufficient material quantity.
Materials from NC-EWDP-19P and the two uppermost intervals in NC-EWDP-19D1 (123 to 125 m [405 to
410 ft] and 128 to 130 m [420-425 ft]) were wet-sieved; all other materials were dry-sieved.
+ The interval is listed in feet because the data were collected using English units.
6.5.6.1.2 Cation-Exchange-Capacity Measurements
CECs of the alluvium from the different depth intervals in well 19D1 were measured 
using a
three-step process of saturating the alluvium surface sites with lithium ion, modified from 
that of
Ming and Dixon (1987 [156842]). Half-gram samples of alluvium were placed in contact 
with
~30 mL of 1 M LiBr solution prepared in deionized water. The alluvium-solution mixture 
was
shaken for at least 1 hr, centrifuged, and the supernatant was decanted off into a 
collection
container. This treatment was repeated two more times, with the supernatant from each 
step
ANL-NBS-HS-000039, REV 00 402 December 2003
being combined with that from the previous steps. The final solution (~90 mL) was 
analyzed for
Na+, Ca++, K+, and Mg++ using ICP-AES to determine the total number of equivalents of 
cations
that lithium had displaced from the alluvium surfaces. This total number of equivalents 
divided
by the mass of the alluvium sample is the CEC of the alluvium, expressed as eq/kg or 
meq/g.
It is well known that CECs of materials are dependent on the cation used to saturate the 
material
surfaces (Anghel et al. 2002 [164635], Section 3.1, pp. 821 to 822). The Cs+ ion is often 
used to
obtain a measure of the "total" CEC of a material because Cs+ sorbs very strongly to 
mineral
surfaces and will displace most exchangeable cations encountered in nature. To obtain an
estimate of the Cs+-exchangeable CEC, the above procedure was repeated on each of the 
halfgram
alluvium samples that had been subjected to LiBr solution treatments using 1 M CsCl as
the saturating solution. However, the CEC determined from the lithium saturation steps 
was the
value used in subsequent modeling of the batch-sorption and column experiments 
(Section
6.5.6.2) because only cations displaced by lithium are of practical interest when lithium is 
the
sorbing species.
6.5.6.1.3 Batch-Sorption Experiments
Lithium batch-sorption experiments were conducted on each of the sieved alluvium 
samples.
Duplicate measurements were conducted at starting lithium concentrations of 
approximately 1, 3,
10, 30, 100, and 300 mg/L Li+ for each material to obtain a sorption isotherm over a 2.5-
orderof-
magnitude range of concentrations. Starting solutions were prepared by dissolving a 
known
mass of LiBr in a known volume of 19D1 well water and then diluting by weight with 
well water
to the desired starting concentrations. In all of the batch tests, 20 mL of lithium solution 
was
placed in contact with approximately 5 g of alluvium material in 50-mL polycarbonate 
Oak
Ridge centrifuge tubes that were shaken for 48 hr on an orbital shaker. Separate control 
samples
(lithium-spiked solutions in centrifuge tubes without any alluvium material) and blanks
(nonspiked well water in contact with alluvium) were processed in parallel with the tubes
containing both lithium and alluvium. The controls were used to verify that lithium 
sorption to
tube walls was insignificant, and the blanks were used to measure any lithium 
background that
might be leached out of the alluvium samples. After shaking, the tubes were centrifuged 
at
30,000 xg for 1 hr, and then an aliquot of supernatant was pipetted off for cation and 
bromide
analyses. Cations (Li, Na, K, Ca, and Mg) were analyzed by inductively-coupled ICP-
AES, and
bromide (nonsorbing tracer) was analyzed by liquid chromatography with a conductivity
detector.
The starting lithium concentration for each measurement was determined from both the
corresponding bromide and lithium concentrations in the control samples. In general, 
lithium
concentrations measured in the control samples were in good agreement with those 
determined
from the bromide measurements, indicating that lithium sorption to centrifuge tube walls 
was
negligible. The mass of lithium sorbed per unit mass of alluvium material was determined 
from:
S ?
V C0 * C * ?
M
(Eq. 80)
ANL-NBS-HS-000039, REV 00 403 December 2003
where
S = lithium mass sorbed per unit mass of alluvium, mg/g
V = volume of solution in contact with alluvium, L
M = mass of alluvium in contact with solution, g
C0 = initial concentration of lithium in solution prior to sorption, mg/L
C = final concentration of lithium in solution after sorption, mg/L.
6.5.6.1.4 Interpretation of Batch-Sorption Experiments
It became apparent very early in the batch-sorption experiments that only two cations, 
Na+ and
Ca++, exchanged significantly with Li+. K+ was exchanged to a minor degree, but the 
amount
was so small relative to Na+ and Ca++ that it was considered reasonable to lump the K+ 
with the
Na+ as a generic "monovalent cation." Thus, a simplified three-component cation-
exchange
model analogous to the three-component exchange model used in the MULTRAN V 1.0 
code
(STN: 10666-1.0-00 [159068]) (Equations 21 through 24 in Section 6.3.9.1.3) was used 
to
interpret the batch experiments.
A simple FORTRAN program called EQUIL_FIT V 1.0 (STN: 10668-1.0-00 [159064]) 
was
developed to obtain the best simultaneous fit to the Li+, Na+, and Ca++ data obtained in 
the batchsorption
experiments using Q1 and Q2 from Equations 21 and 22 as adjustable parameters. The
CEC was set equal to the measured lithium CEC of the alluvium samples. The fits were
optimized by minimizing the sum of squares of the differences between the logarithms of 
the
model-predicted concentrations and the experimental concentrations. Logarithms were 
used in
the optimization algorithm so that the fits would not be biased toward the data obtained at 
the
highest lithium concentrations.
6.5.6.1.5 Results of Cation-Exchange-Capacity Measurements
The lithium and cesium CECs of the materials from the sampled alluvium intervals in 
wells
19D1 and 19P are listed in Table 6.5-9. Only the lithium CEC results were used to 
interpret the
lithium batch-sorption and column transport tests (Section 6.5.6.2) because only cations
displaced by lithium are of practical interest in these experiments. It is apparent that the 
smallersize
fraction material generally had a larger CEC value than the larger-size fraction material 
from
each interval that was tested. Also, the wet-sieved 75- to 2000-?m material from the two
uppermost intervals in 19D1 had relatively low CECs compared to the other samples,
presumably because the wet-sieving procedure removed many of the clays and zeolite 
minerals
that have high CEC values.
6.5.6.1.6 Results of Batch-Sorption Experiments
The Q1 and Q2 values yielding the best simultaneous fits to the Li+, [Na+ + K+], and Ca++ 
data
obtained in the lithium batch-sorption experiments are listed in Table 6.5-10 along with 
the
lithium CEC values for each alluvium material tested. Two sets of Q1 and Q2 values are 
listed
for each material: (1) one obtained using a direct measurement of the starting lithium
concentration as the initial lithium concentration in each experiment and (2) one obtained 
by
using a bromide concentration measurement to determine the starting lithium 
concentration (the
ANL-NBS-HS-000039, REV 00 404 December 2003
lithium was introduced as LiBr). The differences between these two sets of values are
sometimes quite large for a given alluvium interval. These differences reflect the 
uncertainty in
the Q1 and Q2 values due to analytical errors in tracer concentration measurements, and 
they also
reflect the relative insensitivity of the fits to the Q values. Table 6.5-10 also lists the 
Freundlich
isotherm parameters (Equation 12) that yielded the best fits to the lithium sorption data. 
Larger
values of the KF parameter tend to reflect greater lithium sorption.
Table 6.5-10. Cation Exchange Coefficients (CEC) and Freundlich Isotherm Parameters 
Resulting in
Best Fits to the Li+, Na+, and Ca++ Data from the Lithium Batch-Sorption Experiments for Alluvium 
Material
Li as Starting
Conc.
Br as Starting
Conc.
Li as Starting
Conc.
Br as Starting
Conc. Interval*
(well, ft below land
surface, size)
i CEC
meq/k
g) Q1 Q2
(L2/kg2) Q1 Q2
(L2/kg2)
KF
(mL/g)
n(g/g)
n
KF
(mL/g)
n(g/g)
n
19D, 405-410, < 75 ?m 183 0.06 0.22 0.06 0.22 0.58 0.82 0.41 0.78
19D, 405-410, > 75 ?m 70 0.07 0.03 0.06 0.02 0.35 0.85 0.26 0.82
19P, 410-415, < 75 ?m 360 0.13 0.004 0.22 0.003 1.48 0.86 0.82 0.81
19P, 410-415, > 75 ?m 126 0.11 0.003 0.17 0.003 0.47 0.84 0.26 0.77
19D, 420-425, < 75 ?m 175 0.05 0.15 0.04 0.09 0.75 0.89 0.31 0.78
19D, 420-425, > 75 ?m 89 0.05 0.07 0.04 0.04 0.58 0.94 0.23 0.84
19P, 420-425, < 75 ?m 395 0.04 0.5 0.04 0.5 1.25 0.84 1.08 0.82
19P, 420-425, > 75 ?m 171 0.05 0.01 0.07 0.002 0.77 0.90 0.38 0.82
19D, 500-505, < 75 ?m 125 0.07 0.03 0.06 0.02 0.44 0.79 0.55 0.85
19D, 500-505, > 75 ?m 137 0.05 0.03 0.04 0.012 0.43 0.83 0.20 0.78
19D, 580-585, < 75 ?m 204 0.07 0.63 0.06 0.49 0.32 0.71 0.56 0.78
19D, 580-585, > 75 ?m 132 0.07 0.09 0.06 0.06 0.05 0.55 0.13 0.66
19D, 660-665, < 75 ?m 303 0.28 0.002 0.24 0.002 0.47 0.74 0.74 0.80
19D, 660-665, > 75 ?m(1) 119 0.13 0.09 0.13 0.05 3.67 1.03 2.99 1.01
19D, 680-685, < 75 ?m 257 0.16 0.1 0.14 0.04 1.31 0.80 1.10 0.77
19D, 680-685, > 75 ?m 118 0.17 0.05 0.16 0.03 0.64 0.78 0.46 0.74
19D, 720-725, < 75 ?m 424 0.13 0.011 0.14 0.009 1.25 0.78 1.10 0.77
19D, 720-725, > 75 ?m 114 0.21 0.017 0.23 0.01 0.67 0.78 0.48 0.73
19D, 780-785, < 75 ?m 237 0.09 0.27 0.09 0.27 0.71 0.77 0.50 0.73
19D, 780-785, > 75 ?m 78 0.26 0.03 0.26 0.013 0.52 0.75 0.38 0.74
DTN: LA0201JS831341.001 [162627] (CEC values). Output DTN: LA0303PR831341.002 (sorption parameters).
NOTE: Bold denotes material used in column experiments.
Materials from NC-EWDP-19P and the two uppermost intervals in NC-EWDP-19D1 (123 to 125 m [405 to
410 ft] and 128 to 130 m [420 to 425 ft]) were wet-sieved; all other materials were dry-sieved.
Estimates of the uncertainties in the parameter values listed in this table were not rigorously obtained
because these uncertainties are not critical for Performance Assessment calculations. Values represent
best estimates only.
Q1 is dimensionless.
(1) The sorption parameters derived for this alluvium material are suspect because there were very few data
points to analyze.
*The interval is given in feet because the data were collected using English units.
ANL-NBS-HS-000039, REV 00 405 December 2003
Figures 6.5-31 and 6.5-32 show the best fits to the Li+, [Na+ + K+], and Ca++ data obtained 
for
the wet-sieved 75- to 2000-?m material from the two uppermost intervals in NC-EWDP-
19D1
(123 to 125 m [405 to 410 ft] and 128 to 130 m [420 to 425 ft], respectively). These two
materials were combined in a 50:50 mass ratio and used to pack the columns described in
Section 6.5.6.2. The data and fits to the data for both the lithium-based starting 
concentrations;
the bromide-based starting concentrations are shown in these figures.
DTN: LA0302JS831341.001 [162628]. (data). Output DTN: LA0303PR831361.002 (model results).
NOTE: The alluvium material is from a depth below the land surface of 123 to 125 m (405 to 410 ft) with a 
size
distribution of 75 to 2000 ?m; parameters yielding the fits are listed in Table 6.5-10.
Figure 6.5-31. Best Fits of the Three-Component Cation-Exchange Model to the Lithium Sorption
Isotherm (left) and the [Na+ + K+] and Ca++ Concentration Data (right) for Alluvium Material
from NC-EWDP-19D1 at 123 to 125 m (405 to 410 ft)
0.0001
0.001
0.01
0.1
0.0001 0.001 0.01 0.1
Li C, mol/L
Li S, mol/kg
Li-based data
Br-based data
Li-based fit
Br-based fit
0.0001
0.001
0.01
0.0001 0.001 0.01 0.1
Li C, mol/L
Ca or Na+K C, mol/L
Na + K data
Ca data
Li-based Na+K fit
Br-based Na+K fit
Li-based Ca fit
Br-based Ca fit
ANL-NBS-HS-000039, REV 00 406 December 2003
DTN: LA0302JS831341.001 [162628] (data). Output DTN: LA0303PR831341.002 (model results).
NOTE: The alluvium material is from a depth below the land surface of 128 to 130 m (420 to 425 ft) with a 
size
distribution of 75 to 2000 ?m; and parameters yielding the fits are listed in Table 6.5-10.
Figure 6.5-32. Best Fits of the Three-Component Cation-Exchange Model to the Lithium Sorption
Isotherm (left) and the [Na+ + K+] and Ca++ Concentration Data (right) for Alluvium Material
from NC-EWDP-19D1 at 128 to 130 m (420 to 425 ft)
6.5.6.2 Transport Tests in Alluvium-Packed Columns
This section presents the results and interpretations of several column transport 
experiments
using groundwater and alluvium obtained from the site of the ATC well 19D1 (Figures 
6.1-6).
These experiments involved injecting lithium bromide as pulses at three different 
concentrations
spanning the range of concentrations expected in the field. The multicomponent 
numerical
transport model, MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) (see Section 
6.3.9.2.2), was
used to describe lithium transport through the columns. Companion batch lithium 
sorption and
CEC measurements are discussed in Section 6.5.6.1.
6.5.6.2.1 Materials and Methods
All experiments were conducted using groundwater batches collected from well 19D1 in 
June
2000 or November 2000. The batches had slightly different chemistries because they 
were
collected from different depth intervals (Table 6.5-11). Batch 1 was used for all 
experiments
except the column experiments with the intermediate LiBr injection concentration. Both 
waters
are essentially sodium-bicarbonate waters that are nearly saturated with respect to silica 
and with
a pH > 8. The groundwater was filter-sterilized using a 0.2-?m filter before use.
The alluvium used in the experiments was obtained from well 19D1 at the depth intervals 
of 123
to 125 m (405 to 410 ft) and 128 to 130 m (420 to 425 ft) below ground surface (bgs),
approximately 15 to 23 m (50 to 75 ft) below the water table. Cuttings samples were wet-
sieved
0.0001
0.001
0.01
0.1
0.0001 0.001 0.01 0.1
Li C, mol/L
Li S, mol/kg
Li-based data
Br-based data
Li-based fit
Br-based fit
0.0001
0.001
0.01
0.0001 0.001 0.01 0.1
Li C, mol/L
Ca or Na+K C, mol/L
Na + K data
Ca data
Li-based Na+K fit
Br-based Na+K fit
Li-based Ca fit
Br-based Ca fit
ANL-NBS-HS-000039, REV 00 407 December 2003
(using 19D1 well water) in the laboratory, and the size range between 75 ?m and 2000 
?m was
retained for testing. Material from the two intervals was combined in a 50:50 mass ratio 
for the
column experiments because there was not enough material from the individual intervals 
to pack
the columns. Table 6.5-8 gives the bulk mineralogy of the alluvium from the two 
intervals (in
bold) as determined by QXRD (Chipera and Bish 1995 [105075]). Table 6.5-9 lists the 
surface
area of the samples (again, in bold) determined by a single-point BET nitrogen
adsorption/desorption method (Brunauer et al. 1938 [156646]).
Table 6.5-11. Major Ion Chemistry of NC-EWDP-19D1 Water Used in the Experiments
Species Batch 1 (a) (mg/L) Batch 2 (b) (mg/L)
Ca++ 2.2 7.5
Na+ 118 75.5
K+ 5.2 4.1
Mg++ 1.13 0.65
Li+ 0.15 0.09
Si 52.5 27.1
HCO3
- 193 168
CO3
2- 43.8 0
SO4
2- 25.9 23.0
Cl- 5.7 5.6
F- 2.1 1.8
pH 9.2 8.1
DTN: LA0303PR831232.001 [162781].
NOTE: (a) Batch 1 was collected in June 2000 from an open borehole.
(b) Batch 2 was collected from two isolated screened intervals in
the upper 46 m (150 ft) of the saturated zone. This batch was
used only for the 0.006 M LiBr column experiments.
Column experiments were conducted in duplicate using separate 30-cm long by 2.5-cm 
diameter
glass columns equipped with polytetrafluoroethylene (PTFE) end fittings, including a 20-
?m end
frit and PTFE tubing. Each column was presoaked in deionized water to remove any 
residual
ions. The columns were packed dry with a 50:50 mass ratio of the wet-sieved alluvium 
from the
two intervals that were used in batch-sorption and CEC testing. The columns then were
saturated by flushing with deaerated groundwater until air bubbles were no longer visible. 
They
also were packed in ice for 8 hr to promote oxygen and nitrogen dissolution in the water. 
The
saturated versus dry weights of the columns indicated a final porosity of about 40% with 
a pore
volume of about 60 mL in each column.
Three transport experiments were conducted in each column at a flow rate of 
approximately 10
mL/hr with the two columns run in parallel. Each experiment involved the injection of
approximately one pore volume of a tracer solution containing LiBr and 2 mg/L of an 
FBA
(either PFBA or 2,4-difluorobenzoate) dissolved in 19D1 groundwater. The experiments
ANL-NBS-HS-000039, REV 00 408 December 2003
differed in the concentrations of LiBr in the injection pulses. The first duplicate set of
experiments was conducted using an injection concentration of 0.0275 M LiBr (190 mg/L 
Li+),
the second set had a concentration of 0.006 M LiBr (42 mg/L Li+), and the third set had a
concentration of 0.0013 M LiBr (9 mg/L Li+). These concentrations were selected so that 
Li+
dominated the cation equivalents in solution in the first case (91% of total cation 
equivalents),
accounted for about half of the cation equivalents in the second case (61%), and were a 
relatively
minor fraction of the total cation equivalents in the third case (24%). These three 
situations
represent a range of conditions that will likely occur during field testing, with relatively 
high
concentrations present near the injection well immediately after injection and 
concentrations
decreasing as the tracer pulse advects and disperses through the flow system.
The tracer solutions were injected simultaneously into the two columns using a syringe 
pump
(Harvard Systems). After one pore volume of tracer was injected, tracer-free groundwater 
was
injected at 10 mL/hr using a piston pump (SciLog). Column effluent samples were 
collected
using an automatic fraction collector (Gilson) set up to collect samples simultaneously 
from both
columns in pre-weighed test tubes at pre-set time intervals. The samples were analyzed 
for the
same cations (Li, Na, K, Ca, and Mg) that were analyzed in the batch-sorption 
experiments using
ICP-AES. Bromide and the FBAs were analyzed by liquid chromatography, with the 
latter being
quantified by UV absorption. Samples were diluted as necessary for the tracer analyses.
6.5.6.2.2 Interpretive Modeling Approach
The column transport experiments were simulated using the MULTRAN V 1.0 (STN: 
10666-
1.0-00 [159068]) multicomponent ion-exchange transport model (Section 6.3.9.2.2). The
columns were modeled as single-porosity systems because the FBAs and bromide had 
essentially
identical normalized concentration responses in all experiments, indicative of a system 
that lacks
secondary (stagnant) storage porosity (see Section 6.5.2). The mean residence time and 
Peclet
number (dispersivity) were adjusted to achieve a qualitative fit to the bromide responses 
in each
experiment. The lithium responses were then fitted by adjusting the CECs, Q1 and Q2 (see
Section 6.5.6.1.3) while setting the CEC of the alluvium equal to the average CEC of the 
two
materials used to pack the columns (80 meq/kg; see Table 6.5-9).
6.5.6.2.3 Experimental Results and Analyses
The breakthrough curves of Br-, Li+, Na+, and Ca++, expressed as meq/L versus volume 
eluted
through the columns, are shown in Figures 6.5-33, 6.5-34, and 6.5-35, for the 
experiments
conducted at each of the three LiBr injection concentrations, respectively. These figures 
also
show the MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) fits to each data set. The 
FBA data
are not shown in these figures because it was essentially identical to the bromide data 
when
normalized to the injection concentration. However, the FBA concentrations were 
accounted for
in the MULTRAN modeling. A negligible concentration shift of the tracers after a flow
interruption in test 2 (Figure 6.5-34, at ~ 500 mL eluted) verified the lack of diffusive 
mass
transfer into secondary storage porosity in the system that was suggested by the identical
normalized concentration responses of the bromide and FBA. The apparent slight 
perturbation in
Na+ concentrations after the flow interruption, with column A showing a minor decrease 
and
column B showing an minor increase, is unexplained. Analyses of additional cations and 
anions
would have been necessary to better understand this phenomenon.
ANL-NBS-HS-000039, REV 00 409 December 2003
Column B
0
5
10
15
20
25
30
0 100 200 300 400 500 600 700 800 900 1000
Volume Eluted, ml
meq/L
Br
Li
Na
Ca
Br Fit
Li Fit
Na Fit
Ca Fit
DTN: LA0201JS831361.001 [162629] (data). Output DTN: LA0303PR831361.002 (model results).
Figure 6.5-33. Column Data and MULTRAN Fits for Experiments with a LiBr
Injection Concentration of 0.0275 M
Column A
0
5
10
15
20
25
0 100 200 300 400 500 600 700 800 900 1000
Volume Eluted, ml
meq/L
Br
Li
Na
Ca
Br Fit
Li Fit
Na Fit
Ca Fit
ANL-NBS-HS-000039, REV 00 410 December 2003
DTN: LA0201JS831361.007 [162630] (data). Output DTN: LA0303PR831361.002 (model results).
Figure 6.5-34. Column Data and MULTRAN Fits for Experiments
with a LiBr Injection Concentration of 0.006 M
Column B
0
1
2
3
4
5
6
7
8
0 100 200 300 400 500 600 700 800 900 1000
Volume Eluted, ml
meq/L
Br
Li
Na
Ca
Br Fit
Li Fit
Na Fit
Ca Fit
Column A
0
1
2
3
4
5
6
7
8
0 100 200 300 400 500 600 700 800 900 1000
Volume Eluted, ml
meq/L
Br
Li
Na
Ca
Br Fit
Li Fit
Na Fit
Ca Fit
ANL-NBS-HS-000039, REV 00 411 December 2003
DTN: LA0201JS831361.005 [166205] (data). Output DTN: LA0303PR831361.002 (model results).
Figure 6.5-35. Column Data and MULTRAN Fits for Experiments
with a LiBr Injection Concentration of 0.0013 M
Column B
0
1
2
3
4
5
0 100 200 300 400 500 600 700 800 900 1000
Volume Eluted, ml
meq/L
Br
Li
Na
Ca
Br Fit
Li Fit
Na Fit
Ca Fit
Column A
0
1
2
3
4
5
0 100 200 300 400 500 600 700 800 900 1000
Volume Eluted, ml
meq/L
Br
Li
Na
Ca
Br Fit
Li Fit
Na Fit
Ca Fit
ANL-NBS-HS-000039, REV 00 412 December 2003
The MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) model parameters resulting in the 
best fits
shown in Figures 6.5-33, 6.5-34, and 6.5-35 are listed in Table 6.5-12. As with the 
interpretation
of the batch-sorption experiments, the lithium CEC was fixed to 0.08 eq/kg for all of the
experiments, and Q1 and Q2 were adjusted to fit the data. The dispersivity in the column 
was
also adjusted to obtain a reasonable fit to the bromide response curve. The fits were found 
to be
quite sensitive to the background concentrations assumed in the simulations, which were 
variable
in the experiments because the columns were re-used to conduct subsequent experiments, 
and
residual concentrations of the cations varied somewhat. As Tables 6.5-10 and 6.5-12 
indicate,
the best-fitting ion-exchange constants for lithium exchange with both sodium/potassium 
(Q1)
and calcium (Q2) were generally higher in the column experiments than in the batch 
experiments.
The use in MULTRAN of the Q1 and Q2 values obtained from the batch experiments 
consistently
overpredicted lithium responses and underpredicted sodium and calcium responses than 
were
observed.
Table 6.5-12. MULTRAN Model Parameters Associated with the Fits to the Column Transport 
Data
Experiment Dispersivity (cm) Q1 Q2 (L2/kg2)
0.0275 M LiBr, Column A (Figure 6.5-33) 5.4 0.06 0.12
0.0275 M LiBr, Column B (Figure 6.5-33) 1.8 0.045 0.22
0.006 M LiBr, Column A (Figure 6.5-34) 5.4 0.104 0.083
0.006 M LiBr, Column B (Figure 6.5-34) 1.8 0.104 0.083
0.0013 M LiBr, Column A (Figure 6.5-35) 5.4 0.104 0.083
0.0013 M LiBr, Column B (Figure 6.5-35) 1.8 0.104 0.083
Output DTNs: LA0303PR831361.002; LA0303PR831231.005.
NOTE: The model parameters above do not include mean residence times. The column transport data are 
shown
in Figures 6.5-33, 6.5-34, and 6.5-35. The lithium CEC value was assumed to be 0.08 eq/kg for all
simulations.
Estimates of the uncertainties in the parameter values listed in this table were not rigorously obtained
because these uncertainties are not critical for Performance Assessment calculations. Values represent
best estimates only.
Q1 is dimensionless.
The Q1 and Q2 values obtained for each experiment within a given column or for the 
different
columns at a given LiBr injection concentration were in reasonably good agreement, 
especially
after the first set of tests (Table 6.5-12). In principle, these values should not change from
column to column or from experiment to experiment because the columns contained 
exactly the
same material. The MULTRAN V 1.0 (STN: 10666-1.0-00; [159068]) fits were not 
obtained
using a least-squares minimization or optimization algorithm, but rather they were 
obtained by
manually adjusting parameters to obtain a good visual fit to the data.
ANL-NBS-HS-000039, REV 00 413 December 2003
6.5.6.2.4 Discussion
Examination of the MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) model fits shown 
in
Figures 6.5-33, 6.5-34, and 6.5-35, indicates that the model describes well the transport 
behavior
of the cations through the columns, even though the response curves varied significantly 
for the
three different LiBr injection concentrations. Furthermore, the model parameters did not 
have to
be changed significantly for the different injection concentrations to achieve good fits. 
This
result suggests that the model accurately represented the transport processes occurring in 
the
columns.
The partial nonsorbing transport behavior of lithium ion at high injection concentrations 
(e.g.,
Figure 6.5-33) is a consequence of both the limited lithium sorption capacity of the 
alluvium and
the requirement that local charge balance must be maintained throughout the columns. 
When the
concentration of lithium ion was a significant fraction of the total cation concentrations in 
the
injection solution (in eq/L), some of the lithium was forced to move without sorbing 
through the
columns with the nonsorbing anion tracers to maintain charge balance. This phenomenon
occurred because the CEC and the cation exchange constants (Q1 and Q2) of the alluvium 
were
not so large that all of the injected lithium could be exchanged for sodium and calcium 
ions to
balance the anion tracer charge. The fraction of early-arriving lithium in the column tests
decreased as the LiBr injection concentration decreased; and when the Li+ concentration 
was
only 24% of the total cation eq/L, the lithium was essentially completely retarded (Figure 
6.5-
35). The lithium responses at the lowest LiBr injection concentration were the only 
responses
that could be adequately modeled when a simple linear partition coefficient, (Kd = mass 
sorbed
per unit mass of solid/solution concentration) was assumed (fits not shown). Such a 
model
assumes that lithium transport is independent of all other species in solution, which is 
clearly
inaccurate at higher injection concentrations for which it becomes a significant fraction of 
the
total cation equivalents in solution.
6.5.6.2.5 Implications of Column Experiment Results for Field Testing
The lithium transport behavior observed in the column experiments and depicted in 
Figures 6.5-
33 through 6.5-35 has important implications for potential cross-hole field tracer testing 
in the
alluvium south of Yucca Mountain. It is common practice to inject large masses and, 
hence,
high concentrations of sorbing tracers in field tests because the combination of sorption,
dispersion, and dilution can result in very low concentrations at the production well. 
Large
tracer injection masses and concentrations would, therefore, be used in cross-hole field 
tests to
ensure adequate detection and quantification of lithium concentrations at the production 
well.
This strategy means that lithium concentrations could tend to remain quite high for some 
time
(and distance) near the injection well, which could result in some of the lithium moving 
without
sorbing through the flow system until the tracer "slug" became dispersed and diluted.
There are two possible extremes of sorbing tracer transport in a cross-hole field tracer test 
that
could result in the same observed concentrations at the production well. The first is that 
the
injected tracer slug could disperse and dilute rapidly near the injection well, resulting in a 
low
average concentration throughout the flow system. The second is that the tracer slug 
could
remain relatively concentrated as it moves to the production well and then be diluted in 
the well
bore as a result of mixing with tracer-free water that is also being drawn into the well. 
There is
ANL-NBS-HS-000039, REV 00 414 December 2003
no way to distinguish between these two extremes, or any intermediate situation, when
nonsorbing tracer responses are analyzed. However, the results and interpretations of the 
column
experiments in this scientific analysis report suggest that the shape of a lithium 
breakthrough
curve in a cross-hole field tracer test may provide a good indication of whether dilution is
occurring early or late in the flow system. If dilution occurs early, a lithium response 
curve
similar to those in Figure 6.5-35 can be expected. However, if dilution occurs late, the 
lithium
response curve may look more like those of Figures 6.5-33 or 6.5-34, where there is some
asymmetry and nonsorbing transport, even though measured concentrations are quite low
because of dilution in the production wellbore. Knowing whether dilution occurs early or 
late is
important when making comparisons between laboratory and field transport behavior. If
concentrations remain high in the field test (late dilution), then the lithium may appear to 
be
transporting with less sorption than would be inferred from laboratory batch-sorption
measurements, even though the field transport behavior is consistent with the laboratory 
data if
the existence of high concentrations is recognized.
The ability to distinguish between early and late dilution could help refine or constrain 
estimates
of effective flow porosities derived from cross-hole tracer tests. When nonsorbing tracer
responses are analyzed, flow porosity estimates are typically based on first, mean, or peak 
arrival
times of nonsorbing tracers. Under ideal radial flow conditions in a 2-D aquifer, Equation 
10 can
be used to estimate effective flow porosity. Equation 10 (which is a rearrangement of 
Equation 6
of Guimera and Carrera 2000 [156830]) and the definitions of its variables are repeated 
here for
convenience:
T L2
Q
?
* * ?(Eq. 10)
where
* = flow porosity
Q = production flow rate, m3/hr
* = mean residence time of a nonsorbing tracer, hr
L = distance between wells, m
T = formation thickness (assumed to be well screen length).
If flow heterogeneity exists, causing the flow field to not be radial, then estimates using 
Equation
10 will be erroneous. For instance, if most of the flow to the production well is channeled 
from a
direction that does not intersect the tracer slug, then the interwell travel time for the slug 
can be
very long, even if flow occurs in only a small fraction of the system volume. In this case, 
a
considerable amount of dilution will occur late in the system (in the production well), and 
a
misleadingly high flow porosity will be deduced from Equation 10. If an asymmetric 
lithium
response curve with some apparent nonsorbing transport is detected at the production 
well, the
degree of asymmetry in the response can, in principle, be used to estimate the volume 
that the
tracer pulse flowed through within the system. Such an estimate can be obtained by first 
using
MULTRAN V 1.0 (STN: 10666-1.0-00 [159068]) in inverse mode to match the shape of 
the
response curve, given a known injection pulse concentration, injection duration, alluvium 
CEC
(estimated from laboratory tests), and a longitudinal dispersivity (estimated from the 
nonsorbing
ANL-NBS-HS-000039, REV 00 415 December 2003
tracer responses). Once a curve shape is matched given these constraints, the flow system
volume can be estimated by multiplying the volume of the injection pulse in the field test 
by the
ratio of flow system volume to injection pulse volume assumed in the MULTRAN 
simulations.
An estimate of flow porosity can then be obtained from:
T L
V
2 Q
?
* (Eq. 81)
where V = volume determined from MULTRAN matches to lithium response.
The flow porosity estimate given by Equation 81 is independent of tracer travel times 
and,
therefore, is not biased by flow channeling resulting from flow system heterogeneity. Of 
course,
if the lithium response curve shows no asymmetry, then the method described above can 
only be
used to establish a lower bound for the effective flow porosity. The method relies on the
assumption of fast ion exchange kinetics relative to travel times in the flow system (i.e., 
the local
equilibrium assumption), which should be satisfied unless travel times are less than a few 
hours.
Six-hour residence times in the laboratory columns were apparently long enough that the 
local
equilibrium assumption was satisfied.
ANL-NBS-HS-000039, REV 00 416 December 2003
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ANL-NBS-HS-000039, REV 00 417 December 2003
7. CONCLUSIONS
7.1 SUMMARY OF SCIENTIFIC ANALYSIS
This scientific analysis report documents the results of numerous in-situ field hydraulic 
and
tracer tests conducted in the saturated zone near Yucca Mountain over the past 10 years. 
These
tests were conducted to verify/validate conceptual models of flow and transport in the SZ 
and to
obtain field-scale estimates of flow and transport parameters to support the development 
of
parameter distributions used in process and TSPA models. This analysis report also 
documents
the results of several laboratory experiments conducted to help constrain field tracer test
interpretations and to provide comparisons between field- and laboratory-derived 
sorption
parameters for the lithium ion, which is a weakly-sorbing tracer.
The most significant conclusions from in-situ field testing with regard to barrier 
capability of the
saturated zone are the following.
* For flow modeling purposes, the saturated volcanic tuffs in the vicinity of Yucca
Mountain can be treated as an equivalent porous medium (at least locally). The fracture
networks in the tuffaceous rocks are apparently well enough connected that hydraulic
responses are similar to those observed in porous media. However, the flow system
exhibits layered heterogeneity with layers of high permeability often associated with
relatively narrow fractured intervals. Also, larger-scale hydraulic characteristics of the
saturated tuffs are strongly influenced by structural features such as faults. Hydraulic
parameters derived from cross-hole testing in the fractured volcanics are summarized in
Section 6.2, Tables 6.2-7 through 6.2-9.
* Horizontal anisotropy in hydraulic conductivity in the saturated fractured volcanic tuffs
near Yucca Mountain, as determined from drawdown responses in distant wells during
the 1996-1997 long-term pumping test in UE-25 c#3, is oriented roughly north-south
(direction of greatest conductivity) with an anisotropy ratio of about 4:1. A cumulative
distribution function for anisotropy ratio assuming a north-south orientation of anisotropy
is provided in Section 6.2.6, Figure 6.2-46.
* Solute tracer responses in cross-hole tracer tests at the C-wells were consistent with a
dual-porosity conceptual transport model. In this model, solute migration occurs
primarily in flowing fractures, but the solutes are effectively attenuated by diffusion into
stagnant water in the porous rock matrix (matrix diffusion). Solute transport parameters
derived from cross-hole tracer testing at the C-wells are summarized in Section 6.3,
Tables 6.3-2, 6.3-3, and 6.3-10.
* Apparent sorption of an ion-exchanging tracer (lithium) was generally greater in field
tracer tests in the volcanic tuffs than in laboratory tests using the same materials. These
results lend credibility to the practice of using laboratory-derived radionuclide sorption
parameters in performance assessment simulations, as they suggest that laboratory
parameters will tend to yield conservative predictions of radionuclide transport in the
tuffs. Comparisons of field and laboratory lithium sorption parameters are provided in
Section 6.3, Table 6.3-11.
ANL-NBS-HS-000039, REV 00 418 December 2003
* Polystyrene microsphere responses in cross-hole tracer tests at the C-wells suggest that
filtration processes effectively attenuate a large percentage of the microspheres over
relatively short distances. However, some of the filtered microspheres later detach from
fracture surfaces and continue to migrate. Also, flow transients appear to be capable of
initiating detachment. Estimates of microsphere transport parameters derived from the 
Cwells
tracer tests are provided in Section 6.3, Tables 6.3-8 and 6.3-9.
* Single-well hydraulic testing in the saturated alluvium at the NC-EWDP-19D1 location
south of Yucca Mountain has indicated that the alluvium behaves as an unconfined
aquifer. Preliminary horizontal hydraulic conductivity estimates from the hydraulic
testing in the alluvium are 0.15 to 0.23 m/day (0.5 to 0.75 ft/day) in Section 6.4.
* Single-well injection-withdrawal tracer testing in the saturated alluvium in the 
uppermost
screened interval of NC-EWDP-19D1 has indicated that the saturated alluvium at this
location behaves as a single-porosity medium. The tracer tests have yielded preliminary
detachment rate constants for polystyrene microspheres. They have also yielded
estimates of specific discharge that range from about 1 to 10 m/yr (see Section 6.5.4).
* All of these conclusions indicate that the saturated zone beneath and downgradient of 
the
Yucca Mountain repository should serve as an effective barrier to radionuclide transport.
In the context of the over-all predicted performance of the engineered and natural barrier
systems, the results documented in this analysis report and the uncertainties associated
with these results support the adequacy of the saturated zone to meet its performance
expectations. Section 7.3 lists specific locations in Section 6 where the reader can find
discussions of uncertainties associated with hydrologic and transport parameters that are
derived from SZ in-situ testing. These uncertainties are incorporated into probability
distributions for parameters that are documented primarily in the SZ transport model
abstraction report (BSC 2003 [164870]).
The SZ included Features, Events, and Processes (FEPs) supported by this scientific 
analysis
report are: 1.2.02.01.0A Fractures, 1.2.02.02.0A Faults, 2.2.03.02.0A Rock Properties of 
Host
Rock and Other Units, 2.2.07.13.0A Water-Conducting Features in the SZ, and 
2.2.07.15.0A
Advection and Dispersion in the SZ. These FEPs are addressed in more detail in Section 
6.1.3.
The specific acceptance criteria that relate to this report are discussed in Section 4.2.
7.2 OUTPUTS
Table 7-1 lists the output data for this scientific analysis report. The data will be used 
primarily
to support the development of cumulative distribution functions (CDFs) for various flow 
and
transport parameters used in TSPA simulations. These CDFs are documented in the SZ 
flow and
transport abstraction model report (BSC 2003 [164870]). The horizontal hydraulic 
conductivity
anisotropy ratio described in Section 6.2.6 will also be used to support flow model 
calibrations
described in the revision to the SZ flow model report, MDL-NBS-HS-000011 (BSC 2003
[162649]). Also, transport parameters and tracer breakthrough curves from C-wells tracer 
testing
(Section 6.3) will be used in the model validation section of the revision to the SZ 
transport
model report MDL-NBS-HS-000010 (BSC 2003 [162419]) and in the development of 
colloid
ANL-NBS-HS-000039, REV 00 419 December 2003
transport parameter distributions in the revision to the SZ colloid transport scientific 
analysis
report, ANL-NBS-HS-000031 (BSC 2003 [162729]).
Table 7-1. Output Data
Data Description Data Tracking Number Location of Output DTNs in
This Report
Filtered UE-25 ONC-1 water levels, April, 1995 to
December, 1997.
GS030208312314.001 Section 6.2.6.1.2
Section 6.2.6.2.1
Filtered UE-25 WT#3, UE-25 WT#14, and USW H-4
water levels, April, 1995 to December, 1997.
GS030208312314.002 Section 6.2.6.1.2
Section 6.2.6.2.1
PDF and CDF for in north-south/east-west
anisotropy ratio in fractured volcanics.
SN0302T0502203.001 Figure 6.2-46
Section 6.2.6.3
Analysis of hydrologic properties of fractured tuffs
(C-wells complex).
GS031008312314.004 Figures 6.2-1 to 6.2-45
Tables 6.2-1 to 6.2-10
Table 6.2-12
Analysis of hydraulic testing, ATC. GS031008312316.002 Figure 6.4-2
Figures 6.4-4 to 6.4-8
Figures 6.4-10 to 6.4-13
Figures 6.4-23 to 6.4-24
Sections 6.4.1.2 to 6.4.1.5
Sections 6.4.2, 6.4.2.1
Sections 6.4.3, 6.4.4
Analysis of tracer testing, C-wells, Bullfrog, and
Tram.
GS031008312315.002 Figure 6.3-1
Figures 6.3-3 to 6.3-9
Figures 6.3-12 to 6.3-13
Figures 6.3-15 to 6.3-16
Tables 6.3-2 to 6.3-3
Analysis of tracer testing, ATC. GS031008312316.003 Figures 6.5-24 to 6.5-26
Figures 6.5-28 to 6.5-29
Sections 6.5.4.2.4, 6.5.4.5
Section 6.5.5
Simulations/modeling of field tracer tests. LA0303PR831231.003 Figures 6.3-26 to 6.3-30
Figures 6.3-78 to 6.3-79
Tables 6.3-6 to 6.3-9
Fitting or simulations of lithium sorption to C-wells
tuffs.
LA0303PR831341.003 Figures 6.3-40 to 6.3-47
Figure 6.3-75
Table 6.3-18
Cation exchange capacity calculations for C-wells
tuffs.
LA0303PR831341.001 Figure 6.3-48
Table 6.3-19
DIFFCELL V 2.0 (STN: 10557-2.0-00 [159063])
simulations of diffusion cell data.
LA0303PR831362.001 Figures 6.3-50 to 6.3-57
Tables 6.3-20; 6.3-32
Simulations of crushed C-wells tuff column
experiments.
LA0303PR831361.003 Figures 6.3-58 to 6.3-66
Figure 6.3-76
Table 6.3-21
Simulations of C-wells fractured core experiments. LA0303PR831361.004 Figures 6.3-69 to 6.3-74
Figure 6.3-79
Tables 6.3-28 to 6.3-32
ANL-NBS-HS-000039, REV 00 420 December 2003
Table 7-1 (Continued). Output Data
Data Description Data Tracking Number Location of Output DTNs in
This Report
Calculations to obtain values reported in tables and
figures (generally combinations of other values
reported or unit conversions)
LA0303PR831231.005 Figure 6.3-79
Tables 6.3-6 to 6.3-8
Tables 6.3-10 to 6.3-11
Tables 6.3-28 to 6.3-31
Table 6.5-4
Table 6.5-12
Predictions of transport behavior in single-well and
cross-hole tracer tests in the saturated alluvium at
the ATC.
LA0303PR831231.001 Figures 6.5-2 to 6.5-3
Figures 6.5-5 to 6.5-8
Figures 6.5-16 to 6.5-17
Tables 6.5-1 to 6.5-3
Section 6.5-3
Predictions of transport behavior in cross-hole tracer
tests in single-porosity media.
LA0303PR831231.004 Figures 6.5-9 to 6.5-10
Figure 6.5-12
Figures 6.5-14 to 6.5-15
Table 6.5-4
Calculations to estimate ambient groundwater
velocity at NC-EWDP-19D1 from single-well tracer
test responses.
LA0303PR831231.002 Figures 6.5-19 to 6.5-21
Tables 6.5-6 to 6.5-7
Section 6.5.4.2.1
Calculations to determine microsphere detachment
rate constant in a single-well tracer test in saturated
alluvium at NC-EWDP-19D1.
LA0303PR831352.001 Section 6.5.4.6
Determination of cation exchange parameters from
EQUIL_FIT V 1.0 (STN: 10668-1.0-00 [159064]) fits
to cation concentration data from lithium batch
sorption measurements onto alluvium from different
intervals in NC-EWDP-19P and -19D.
LA0303PR831341.002 Figure 6.5-32
Table 6.5-10
Simulations of column transport experiments in
alluvium from NC-EWDP-19D.
LA0303PR831361.002 Figure 6.5-31
Figures 6.5-33 to 6.5-35
Table 6.5-12
C-wells tracer test sensitivity calculations. LA0304PR831231.001 Figures 6.3-31 to 6.3-38
Tables 6.3-13 to 6.3-14
7.3 UNCERTAINTIES
Discussions of uncertainties associated with the flow and transport parameters presented 
in this
analysis report can be found in the following sections.
* Uncertainties associated with hydraulic testing and test interpretations in saturated 
fractured
volcanics at the C-wells are discussed in detail in Section 6.2.5.
* Uncertainties associated with anisotropy of horizontal hydraulic conductivity in the 
fractured
volcanics are discussed in Section 6.2.6.
* Uncertainties associated with tracer testing and test interpretations at the C-wells are
discussed in detail in Section 6.3.5.
ANL-NBS-HS-000039, REV 00 421 December 2003
* Uncertainties associated with hydraulic testing and test interpretations in the saturated
alluvium at NC-EWDP-19D1 are discussed in Section 6.4.4.
* Uncertainties associated with single-well tracer testing and test interpretations at the 
ATC are
discussed in detail in Section 6.5.4.4.
With the exception of the north-south/east-west anisotropy ratio of horizontal hydraulic
conductivity in the fractured volcanics (presented in Section 6.2.6), this scientific analysis 
report
does not provide uncertainty distributions for SZ flow or transport parameters. 
Uncertainty
distributions for these parameters are provided in the SZ transport model abstraction 
report (BSC
2003 [164870]). The rationale for documenting the uncertainty distributions in the latter 
report
rather than this scientific analysis report is that the distributions are based only in part on 
the
parameters (and their uncertainties) presented in this report. Literature data, expert 
elicitation
input, and peer review input were also considered in the development of parameter 
distributions
because of the limited spatial representation of the SZ offered by the C-wells and ATC 
hydraulic
and tracer tests. Also, the time and distance scales of the C-wells and ATC tests were 
relatively
small compared to time and distance scales of performance assessment calculations (with 
the
exception of the long-term C-wells hydraulic test that led to the uncertainty distribution 
for
hydraulic conductivity anisotropy ratio over a ~21 km2 area). Thus, it was recognized that 
the
flow and transport parameters derived from the C-wells and ATC tests represent only 
discrete
points in continuous distributions of parameter values that are spatially distributed 
throughout the
SZ and that potentially have scale dependencies that would not be revealed by C-wells 
and ATC
testing. The parameter uncertainty distributions in the SZ model abstraction report (BSC 
2003
[164870]) are consistent with and supported by the parameters presented in this analysis 
report,
but they generally consist of a much wider range of potential values because of these 
issues of
representativeness and scale of the field tests.
ANL-NBS-HS-000039, REV 00 422 December 2003
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ANL-NBS-HS-000039, REV 00 423 December 2003
8. INPUTS AND REFERENCES
8.1 DOCUMENTS CITED
The following is a list of the references cited in this document. Column 1 below contains 
the
unique six-digit numerical identifier (the Document Input Reference System [DIRS] 
number),
which is placed in the text following the reference callout (e.g., BSC 2002 [158198]). The
purpose of these numbers is to assist the reader in locating a specific reference in the 
DIRS
database. Within the reference list, multiple sources by the same author or date (e.g., BSC 
2002)
are sorted alphabetically by title.
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122788 Benson, C.F. and Bowman, R.S. 1994. "Tri- and Tetrafluorobenzoates as
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153427 Benson, C.F. and Bowman, R.S. 1996. "Erratum, Tri- and Tetrafluorobenzoates 
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162675 Bouwer, H. 1978. Groundwater Hydrology. McGraw-Hill Series in Water
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156645 Bowman, R.S. 1984. "Evaluation of Some New Tracers for Soil-Water Studies."
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156646 Brunauer, S.; Emmett, P.H.; and Teller, E. 1938. "Adsorption of Gases in
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156647 Brusseau, M.L.; Hu, Q.; and Srivastava, R. 1997. "Using Flow Interruption to
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158198 BSC (Bechtel SAIC Company) 2002. Test Plan for Alluvial Testing Complex -
Single-Well, Multi-Well, and Laboratory Studies. SITP-02-SZ-003 REV 01. Las
Vegas, Nevada: Bechtel SAIC Company. ACC: MOL.20020404.0081.
158966 BSC (Bechtel SAIC Company) 2002. The Enhanced Plan for Features, Events, 
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163128 BSC (Bechtel SAIC Company) 2003. Features, Events, and Processes in SZ 
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162657 BSC (Bechtel SAIC Company) 2003. Geochemical and Isotopic Constraints on
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163228 BSC (Bechtel SAIC Company) 2003. Radionuclide Transport Models Under
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162729 BSC (Bechtel SAIC Company) 2003. Saturated Zone Colloid Transport. 
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HS-000031 REV 01. Las Vegas, Nevada: Bechtel SAIC Company. ACC:
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162649 BSC (Bechtel SAIC Company) 2003. Site-Scale Saturated Zone Flow Model. 
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162419 BSC (Bechtel SAIC Company) 2003. Site-Scale Saturated Zone Transport. 
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164870 BSC (Bechtel SAIC Company) 2003. SZ Flow and Transport Model Abstraction.
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156649 Callahan, T.J. 2001. Laboratory Investigations and Analytical and Numerical
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102046 Carr, M.D.; Waddell, S.J.; Vick, G.S.; Stock, J.M.; Monsen, S.A.; Harris, A.G.; 
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MOL.20000824.0084.
165124 Reimus, P. 2000. LA-CST-CW-NBK-98-001, YMP C-Wells Rocks. Scientific
Notebook SN-LANL-SCI-146-V1. ACC: MOL.20010308.0191.
164625 Reimus, P. 2000. LA-CST-CW-NBK-98-003, YMP C-Wells Sorption. Scientific
Notebook: SN-LANL-SCI-006-V1. ACC: MOL.20010308.0193.
165121 Reimus, P. 2000. YMP C-Wells Diffusion Cells. Scientific Notebook: SN-
LANLSCI-
007-V1 (LA-CST-CW-NBK-98-004). ACC: MOL.20010308.0195.
162852 Reimus, P. 2000. LANL C-Wells Prow Pass Field Notebook. Scientific 
Notebook
SN-LANL-SCI-233-V1. ACC: MOL.20000824.0066.
165129 Reimus, P. 2003. LA-CST-NBK-98-011, Modeling and Interpretation of 
Transport
Tests. Scientific Notebook SN-LANL-SCI-255-V1. ACC: MOL.20020206.0093;
MOL.20031027.0086; MOL.20031027.0087.
163760 Reimus, P. 2003. Laboratory Testing in Support of Saturated Zone 
Investigations.
Scientific Notebook SN-LANL-SCI-280-V1. ACC: MOL.20030227.0286.
101474 Reimus, P.W. 1995. The Use of Synthetic Colloids in Tracer Transport 
Experiments
in Saturated Rock Fractures. Ph.D. dissertation, University of New Mexico. LA-
13004-T. Los Alamos, New Mexico: Los Alamos National Laboratory. TIC:
240694.
162855 Reimus, P.W. 2000. C-Wells Bullfrog Multiple Tracer Test Notebook. Scientific
Notebook SN-LANL-SCI-223-V1. ACC: MOL.20000818.0075.
164624 Reimus, P. 2000. LA-EES-4-NBK-96-003(b), C-Wells Bullfrog Multiple Tracer
Test. Scientific Notebook for SN-LANL-SCI-224-V1. ACC: MOL.20000824.0094.
ANL-NBS-HS-000039, REV 00 433 December 2003
165126 Reimus, P.W. 2000. QA Notebook for C-Wells Tracer Testing (PFBA/C#2 Test).
Scientific Notebook SN-LANL-SCI-217-V1. ACC: MOL.20000818.0063.
165127 Reimus, P.W. 2000. QA Notebook Iodide/C#1 Tracer Test. Scientific Notebook 
SNLANL-
SCI-218-V1. ACC: MOL.20000818.0071.
165128 Reimus, P.W. 2003. Single-Well and Cross-Hole Alluvial Tracer Testing. 
Scientific
Notebook: SN-LANL-SCI-251-V1. ACC: MOL.20030213.0331 through
MOL.20030313.0334.
154705 Reimus, P.W. and Haga, M.J. 1999. Analysis of Tracer Responses in the 
BULLION
Forced-Gradient Experiment at Pahute Mesa, Nevada. LA-13615-MS. Los Alamos,
New Mexico: Los Alamos National Laboratory. TIC: 249826.
101154 Robinson, B. A. 1994. "A Strategy for Validating a Conceptual Model for
Radionuclide Migration in the Saturated Zone Beneath Yucca Mountain."
Radioactive Waste Management and Environmental Restoration, 19, (1-3), 73-96.
Yverdon, Switzerland: Harwood Academic Publishers. TIC: 222513.
156862 Skagius, K. and Neretnieks, I. 1986. "Porosities and Diffusivities of Some
Nonsorbing Species in Crystalline Rocks." Water Resources Research, 22, (3), 389-
398. Washington, D.C.: American Geophysical Union. TIC: 225291.
156863 Stetzenbach, K.J. and Thompson, G.M. 1983. "A New Method for Simultaneous
Measurement of Cl-, Br-, NO3
-, SCN-, and I- at sub-ppm Levels in Ground Water."
Ground Water, 21, (1), 36-41. Worthington, Ohio: Water Well Journal Publishing.
TIC: 252098.
150754 Streltsova-Adams, T.D. 1978. "Well Hydraulics in Heterogeneous Aquifer
Formations." Volume 11 of Advances in Hydroscience. Chow, V.T., ed. Pages 357-
423. New York, New York: Academic Press. TIC: 225957.
164623 Sullivan, E.J. 2002. Laboratory Testing in Support of Alluvial Tracer Testing.
Scientific Notebook SN-LANL-SCI-213-V1. ACC: MOL.20021015.0198.
101160 Tang, D.H.; Frind, E.O.; and Sudicky, E.A. 1981. "Contaminant Transport in
Fractured Porous Media: Analytical Solution for a Single Fracture." Water Resources
Research, 17, (3), 555-564. Washington, D.C.: American Geophysical Union. TIC:
225358.
150327 Theis, C.V. 1935. "The Relation Between the Lowering of the Piezometric 
Surface
and the Rate and Duration of Discharge of a Well Using Ground-Water Storage."
Transactions of the American Geophysical Union Sixteenth Annual Meeting, April 25
and 26, 1935, Washington, D.C. Pages 519-524. Washington, D.C.: National
Academy of Science, National Research Council. TIC: 223158.
ANL-NBS-HS-000039, REV 00 434 December 2003
100830 Thompson, J.L. 1989. "Actinide Behavior on Crushed Rock Columns." Journal 
of
Radioanalytical and Nuclear Chemistry-Articles, 130 (2), 353-364. Lausanne,
Switerzerland: Elsevier. TIC: 222698.
125967 Treher, E.N. and Raybold, N.A. 1982. The Elution of Radionuclides Through
Columns of Crushed Rock from the Nevada Test Site. LA-9329-MS. Los Alamos,
New Mexico: Los Alamos National Laboratory. ACC: NNA.199920922.0021.
100422 Triay, I.R.; Meijer, A.; Conca, J.L.; Kung, K.S.; Rundberg, R.S.; Strietelmeier, 
E.A.;
Tait, C.D.; Clark, D.L.; Neu, M.P.; and Hobart, D. E. 1997. Summary and Synthesis
Report on Radionuclide Retardation for the Yucca Mountain Site Characterization
Project. Eckhardt, R.C., ed. LA-13262-MS. Los Alamos, New Mexico: Los
Alamos National Laboratory. ACC: MOL.19971210.0177.
113901 Tsang, Y. W. 1992. "Usage of 'Equivalent Apertures' for Rock Fractures as 
Derived
from Hydraulic and Tracer Tests." Water Resources Research, 28, (5), 1451-1455.
Washington, D.C.: American Geophysical Union. TIC: 245891.
101060 Tucci, P. and Burkhardt, D.J. 1995. Potentiometric-Surface Map, 1993, Yucca
Mountain and Vicinity, Nevada. Water-Resources Investigations Report 95-4149.
Denver, Colorado: U.S. Geological Survey. ACC: MOL.19960924.0517.
164543 Umari, A.M.J.; Geldon, A.; Patterson, G.; Gemmell, J.; Earle, J.; and Darnell, J.
1994. "Use of an Analog Site Near Raymond, California, to Develop Equipment and
Methods for Characterizing a Potential High-Level, Nuclear Waste Repository Site at
Yucca Mountain, Nevada." High Level Radioactive Waste Management,
Proceedings of the Fifth Annual International Conference, Las Vegas, Nevada, May
22-26, 1994. 4, 2413-2422. La Grange Park, Illinois: American Nuclear Society.
TIC: 210984.
162858 Umari, M.J. 2002. Performing Various Hydraulic and Tracer Tests Using 
Prototype
Pressure Transducer and Packer Assemblies. Scientific Notebook SN-USGS-SCI-
036-V1. ACC: MOL.20020520.0364; MOL.20020520.0368; through
MOL.20020520.0382.
164573 Umari, M.J.; Earle, J.; and Darnell, J. 2003. Alluvium Testing Complex. 
SNUSGS-
SCI-123-V1 through V8. ACC: MOL.20010613.0239;
MOL.20010613.0240; MOL.20010613.0241; MOL.20021028.0352;
MOL.20030821.0216; MOL.20030821.0217; MOL.20030821.0218;
MOL.20030821.0219; MOL.20031021.0281; MOL.20031021.0282;
MOL.20031021.0284.
154495 USGS (U.S. Geological Survey) n.d. Bulk Density. [Denver, Colorado: U.S.
Geological Survey]. ACC: NNA.19940406.0076.
144579 Valocchi, A.J. 1985. "Validity of the Local Equilibrium Assumption for 
Modeling
Sorbing Solute Transport through Homogeneous Soils." Water Resources Research,
21, (6), 808-820. Washington, D.C.: American Geophysical Union. TIC: 223203.
ANL-NBS-HS-000039, REV 00 435 December 2003
156868 van Genuchten, M.T.; Wierenga, P.J.; and O'Connor, G.A. 1977. "Mass Transfer
Studies in Sorbing Porous Media: III. Experimental Evaluation with 2,4,5-T." Soil
Science Society of America Journal, 41, 278-285. Madison, Wisconsin: Soil Science
Society of America. TIC: 251016.
156867 Vaughan, D.E.W. 1978. "Properties of Natural Zeolites." Natural Zeolites,
Occurrence, Properties, Use, A Selection of Papers Presented at Zeolite, 76, an
International Conference on the Occurrence, Properties, and Utilization of Natural
Zeolites, Tucson, Arizona, June 1976. Sand, L.B. and Mumpton, F.A., eds. Pages
353-371. New York, New York: Pergamon Press. TIC: 206755.
100833 Weast, R.C. and Astle, M.J., eds. 1981. CRC Handbook of Chemistry and 
Physics.
62nd Edition. Boca Raton, Florida: CRC Press. TIC: 240722.
101366 Whitfield, M.S., Jr.; Thordarson, W.; and Eshom, E.P. 1984. Geohydrologic and
Drill-Hole Data for Test Well USW H-4, Yucca Mountain, Nye County, Nevada.
Open-File Report 84-449. Denver, Colorado: U.S. Geological Survey. ACC:
NNA.19870407.0317.
129796 Winterle, J.R. and La Femina, P.C. 1999. Review and Analysis of Hydraulic and
Tracer Testing at the C-Holes Complex Near Yucca Mountain, Nevada. San Antonio,
Texas: Center for Nuclear Waste Regulatory Analyses. TIC: 246623.
110491 Zyvoloski, G.A.; Robinson, B.A.; Dash, Z.V.; and Trease, L.L. 1997. Summary 
of
the Models and Methods for the FEHM Application-A Finite-Element Heat- and
Mass-Transfer Code. LA-13307-MS. [Los Alamos, New Mexico]: Los Alamos
National Laboratory. TIC: 235587.
104211 YMP (Yucca Mountain Site Characterization Project) 1998. Saturated Zone C-
Hole
Tracer Testing. Field Work Package FWP-SB-97-008, Rev. 1 Las Vegas, Nevada:
Yucca Mountain Site Characterization Office. ACC: MOL.19981029.0058.
8.2 CODES, STANDARDS, REGULATIONS, AND PROCEDURES
165855 10 CFR 50. 2002. Energy: Domestic Licensing of Production and Utilization
Facilities. Readily available.
156605 10 CFR 63. Energy. Disposal of High-Level Radioactive Wastes in a Geologic
Repository at Yucca Mountain, Nevada. Readily available.
164786 AP-2.22Q, Rev. 1, ICN 0. Classification Analyses and Maintenance of the Q-
List.
Washington, D.C.: U.S. Department of Energy, Office of Civilian Radioactive Waste
Management. ACC: DOC.20030807.0002.
165023 AP-SI.1Q REV 5, ICN 2, Software Management. Washington, D.C.: Department 
of
Energy, Office of Civilian Radioactive Waste Management. ACC:
DOC.20030902.0003.
ANL-NBS-HS-000039, REV 00 436 December 2003
166252 AP-SIII.9Q, REV. 1 ICN 2. Scientific Analyses. Washington, D.C.: U.S.
Department of Energy, Office of Civilian Radioactive Waste Management. ACC:
DOC.20031126.0001.
165687 AP-SV.1Q, Rev. 1, ICN 0. Control of the Electronic Management of Information.
Washington, D.C.: U.S. Department of Energy, Office of Civilian Radioactive Waste
Management. ACC: DOC.20030929.0004.
8.3 SOFTWARE
159064 LANL (Los Alamos National Laboratory) 2002. Software Code: EQUIL_FIT. V
1.0. PC, Windows 2000/NT 4.0/98. 10668-1.0-00.
159067 LANL (Los Alamos National Laboratory) 2002. Software Code: 2WELLS_2D. V
1.0. PC, Windows 2000/NT 4.0/98. 10665-1.0-00.
159036 LANL (Los Alamos National Laboratory) 2002. Software Code: 2WELLS_3D. V
1.0. PC, Windows 2000/NT 4.0/98. 10667-1.0-00.
159063 LANL (Los Alamos National Laboratory) 2002. Software Code: DIFFCELL. V 
2.0.
PC, Windows 2000/NT. 10557-2.0-00.
161725 LANL (Los Alamos National Laboratory) 2003. Software Code: FEHM. V 2.20.
SUN, PC. 10086-2.20-00. (Used as reference only.)
159068 LANL (Los Alamos National Laboratory) 2002. Software Code: MULTRAN. V 
1.0.
PC, Windows 2000/NT 4.0. 10666-1.0-00.
159065 LANL (Los Alamos National Laboratory) 2002. Software Code: RELAP. V 2.0.
PC, Windows 2000/NT. 10551-2.0-00.
159066 LANL (Los Alamos National Laboratory) 2002. Software Code: RETRAN. V 2.0.
PC, Windows 2000/NT. 10552-2.0-00.
162668 USGS (U.S. Geological Survey) 2002. Software Code: Filter.vi. V 1.0. PC,
Windows 2000/NT 4.0/98. 10970-1.0-00.
162749 USGS 2003. Software Code: Injection_Pumpback.vi. V 1.0. PC, Windows
2000/NT. 10675-1.0-00.
162750 USGS 2002. Software Code: Rcv2amos.exe and MOENCH.vi, Function(1). V 
1.0.
PC, Windows 2000/NT. 10583-1.0-00.
162752 USGS 2002. Software Code: MOENCH.vi, Function(2). V 1.0. PC, Windows
2000/NT. 10582-1.0-00.
162754 USGS 2002. Software Code: Neuman.vi. V 1.0. PC, Windows 2000/NT. 10972-
1.0-00.
ANL-NBS-HS-000039, REV 00 437 December 2003
164432 USGS 2003. Software Code: RECIRC.vi. V. 1.0. PC. Windows 98/NT 4.0/2000.
10673-1.0-00.
162756 USGS 2003. Software Code: Streltsova-Adams.vi. V 1.0. PC, Windows 2000/NT.
10971-1.0-00.
162758 USGS 2002. Software Code: Theis.vi. V 1.0. PC, Windows 2000/NT. 10974-1.0-
00.
161564 Watermark Computing 2002. Software Code: PEST. V 5.5. SUN, PC, Linux,
Windows 2000. 10289-5.5-00.
8.4 SOURCE DATA, LISTED BY DATA TRACKING NUMBER
155860 GS010508312315.001. Concentrations of Difluorobenzoic Acid and Pyridone 
from
Tracer Tests Conducted at the C-Well Complex, 1/8/97 - 7/11/97. Submittal date:
06/01/2001.
157067 GS010799992315.001. Injection and Production Flow Rates for the LANL Prow
Pass Test, 11/30/98 through 1/27/99. Submittal date: 07/25/2001.
158690 GS011008314211.001. Interpretation of the Lithostratigraphy in Deep Boreholes
NC-EWDP-19D1 and NC-EWDP-2DB Nye County Early Warning Drilling Program.
Submittal date: 01/16/2001.
162678 GS020708312316.001. NC-EWDP-19D, ATC Single-Hole Hydraulic Testing
Associated with the July 7, 2000 to April 26, 2001 Tracer Study. Submittal date:
09/10/2002.
162679 GS020908312361.002. Flow Rates, Pressures, and Temperatures for Hydraulic 
and
Tracer Testing at the NC-EWDP-19D, NC-EWDP-19IM1, and NC-EWDP-19IM2
Alluvial Testing Complex from December 18, 2001 to March 22, 2002. Submittal
date: 09/30/2002.
162680 GS020908312361.003. Background Pressures and Temperatures During 
Barometric
Monitoring at the NC-EWDP-19D, NC-EWDP-19IM1, and NC-EWDP-19IM2
Alluvial Testing Complex from May 1, 2002 through July 3, 2002. Submittal date:
10/15/2002.
164425 GS030508312314.003. Results of Hydraulic Tests in Miocene Tuffaceous Rocks 
at
the C-Hole Complex, 1995 to 1997, Yucca Mountain, Nevada. Submittal date:
05/08/2003.
166332 GS930908312313.008. Hydrologic Information from the C-hole Complex and 
the
Yucca Mountain Area. Submittal date: 09/16/1993.
164801 GS960108312313.001. 280 Gallon per Minute Pump Test at the C-Hole 
Complex.
Submittal date: 01/24/1996. (Used as reference only.)
ANL-NBS-HS-000039, REV 00 438 December 2003
159228 GS960108312313.002. 6/12/95 356 GPM Test in UE-25 C#3 with C#1 and C#2
Packed Off. Submittal date: 01/23/1996. (Used as reference only.)
159235 GS960808312315.001. Data Obtained from the Analysis of the Iodide-Tracer-
Test
Water Samples Collected During the 2/13/96 Convergent-Tracer Test Conducted at
the C-Well Complex. Submittal date: 08/12/1996.
161273 GS970308312314.002. Water-Level Altitude Data from Four Wells in the
Continuous Network, May through December, 1996. Submittal date: 03/13/1997.
107024 GS980608314221.002. Revised Bedrock Geologic Map of the Yucca Mountian
Area, Nye County, Nevada. Submittal date: 06/09/1998.
147068 GS981008312314.002. Pump Test Data Collected at the C-Wells Complex 
1/8/97-
3/31/97. Submittal date: 10/28/1998.
144464 GS981008312314.003. Pumping Test Data Collected at the C-Well Complex, 
5/7/96
- 12/31/96. Submittal date: 10/28/1998.
159238 GS990208312315.001. Tracer Recovery Data from Testing in the Prow Pass
Interval. Submittal date: 02/11/1999.
140115 GS990408312315.002. Transducer, Barometric Pressure, and Discharge Data
Collected from 4/18/98 through 11/24/98 in Support of the Ongoing Hydraulic and
Tracer Tests Being Conducted at the UE-25 C-Well Complex, Nevada. Submittal
date: 04/06/1999.
156043 LA0007PR831231.001. Bullfrog Reactive Tracer Test Data. Submittal date:
07/21/2000.
162623 LA0201JS831321.001. Alluvial Test Complex X-ray Diffraction Results. 
Submittal
date: 01/16/2002.
162627 LA0201JS831341.001. Alluvial Test Complex Cation Exchange Capacity Batch
Study, Wells 19D and 19P Alluvium; 10/31/00, 06/12/01, 08/12/01. Submittal date:
01/16/2002.
162629 LA0201JS831361.001. Alluvial Test Complex Column Study, Well 19D 
Alluvium
and Water, 12/13/00. Submittal date: 01/24/2002.
166205 LA0201JS831361.005. Alluvial Test Complex Column Study, Well 19D 
Alluvium
and Water, 02/22/01. Submittal date: 01/29/2002.
162630 LA0201JS831361.007. Alluvial Test Complex Column Study, Well 19D 
Alluvium
and Water, 04/02/01. Submittal date: 01/29/2002.
162613 LA0201JS831421.001. Grain Size Analysis of Alluvium Samples from Wells 
19D
and 19P of the Alluvial Testing Complex. Submittal date: 01/30/2002.
ANL-NBS-HS-000039, REV 00 439 December 2003
162625 LA0201JS831421.002. BET Surface Area Measurements for 19D and 19P 
Alluvium
Samples. Submittal date: 01/30/2002.
162431 LA0207PR831352.001. Microsphere Data from Single-Well Tracer Testing at 
NCEWDP
19D1 (ATC). Submittal date: 07/30/2002.
162607 LA0212PR831231.001. Breakthrough Curves of Iodide in Saturated Fractured 
Cores
from the C-Wells. Submittal date: 01/30/2003.
162608 LA0212PR831231.002. Breakthrough Curves of Sodium, Calcium, Copper, 
Iodide,
and Chloride in Saturated Fractured Cores from the C-wells. Submittal date:
01/21/2003.
162609 LA0212PR831231.003. Breakthrough Curves of Lithium, Bromide, and PFBA in
Saturated Fractured Cores from the C-wells. Submittal date: 01/21/2003.
166215 LA0212PR831231.005. Breakthrough Curves of Sodium, Iodide, Calcium, and
Chloride in Saturated Fractured Cores from the C Wells. Submittal date: 01/21/2003.
162603 LA0301PR831231.001. Bromide and Lithium Abundance Data from Column
Studies of Crushed Central Bullfrog Tuff, UE-25 C#2 at 2406 ft. with Filtered J-13
Water. Submittal date: 02/25/2003.
162628 LA0302JS831341.001. Final Cation Concentrations in Li/Br Batch Sorption
Experiments Involving Alluvium from Wells NC-EWDP-19D and NC-EWDP-19P.
Submittal date: 03/06/2003.
162605 LA0302PR831231.001. Batch Experiments to Measure Bromide and PFBA 
Sorption
onto C-Wells Tuffs. Submittal date: 03/06/2003.
162604 LA0302PR831341.001. Cation Exchange Capacity Measurements on C-wells 
Tuffs
Involving Displacement of Li and Other Cations by Cs. Submittal date: 03/06/2003.
162781 LA0303PR831232.001. Major Ion Chemistry of NC-EWDP-19D1 Waters Used 
in
Batch Sorption and Column Transport Experiments. Submittal date: 03/12/2003.
129623 LA9909PR831231.004. Laboratory Data from C-Wells Core. Submittal date:
09/02/1999.
140134 LAPR831231AQ99.001. Prow Pass Reactive Tracer Test Field Data. Submittal 
date:
02/10/1999.
151524 MO0007MAJIONPH.011. Major Ion Content of Groundwater from Selected 
Yucca
Mountain Project Boreholes Extracted from ANL-NBS-HS-000021, Geochemical
and Isotopic Constraints on Groundwater Flow Directions, Mixing and Recharge at
Yucca Mountain, Nevada. Submittal date: 07/27/2000. (Used as reference only.)
ANL-NBS-HS-000039, REV 00 440 December 2003
151530 MO0007MAJIONPH.013. Major Ion Content of Groundwater from Selected 
YMP
and Other Boreholes Extracted from ANL-NBS-HS-000021, Geochemical and
Isotopic Constraints on Groundwater Flow Directions, Mixing and Recharge at Yucca
Mountain, Nevada. Submittal date: 07/27/2000. (Used as reference only.)
153371 MO0012CATECHOL.000. Cation Exchange Capacity Data of C-wells Tuff from
UE-25 C#1 and UE-25 C#2. Submittal date: 12/05/2000.
159243 MO0012DIFFCHOL.000. Tracer Movement Measured in C/CO. The Unit C/CO
Represents the Effluent Concentration Divided by the Injection Concentration.
Submittal date: 12/05/2000.
153370 MO0012MINLCHOL.000. Mineral Abundance Data Using X-Ray Diffraction
Analyses of C-Well Tuffs from UE-25 C#1 and UE-25 C#2. Submittal date:
12/05/2000.
153368 MO0012PERMCHOL.000. Permeability Data (Using Filtered J-13 Water) from 
UE-
25 C#1, UE-25 C#2, and UE-25 C#3. Submittal date: 12/05/2000.
153376 MO0012POROCHOL.000. Porosity Data (Using Deionized Water) from UE-25
C#1, UE-25 C#2, and UE-25 C#3. Submittal date: 12/05/2000.
153375 MO0012SORBCHOL.000. Sorbing Element Concentration Data of J-13 and C-3
Well Water from UE-25 C#1 and UE-25 C#2. Submittal date: 12/05/2000.
163480 MO0105GPLOG19D.000. Geophysical Log Data from Borehole NC EWDP 
19D.
Submittal date: 05/31/2001.
157194 MO0107COV01057.000. Coverage: NCEWDPS. Submittal date: 07/18/2001.
(Used as reference only.)
157184 MO0112DQRWLNYE.014. Well Completion Diagram for Borehole NC-EWDP-
19P. Submittal date: 12/04/2001.
157187 MO0112DQRWLNYE.018. Well Completion Diagram for Borehole NC-EWDP-
19D. Submittal date: 12/05/2001.
162617 MO0205UCC008IF.001. Concentration Dataset for 2,4-Difluorobenzoic Acid 
(2,4-
DFBA) Tracer Used for the Feb/Mar 2002 Single-Well Tracer Test at the Alluvial
Tracer Complex. Submittal date: 05/01/2002.
161274 MO0212SPANYESJ.149. Nye County Well ONC-1 Temperature and Pressure 
Data
03/01/1996 Through 12/22/1997. Submittal date: 12/09/2002.
165876 MO0306NYE05259.165. Revised NC-EWDP-19IM1 Well Completion Diagram.
Submittal date: 07/02/2003.
ANL-NBS-HS-000039, REV 00 441 December 2003
165877 MO0306NYE05260.166. Revised NC-EWDP-19IM2 Well Completion Diagram.
Submittal date: 07/02/2003.
164527 MO0307SEPFEPS4.000. LA FEP List. Submittal date: 07/31/2003. (Used as
reference only.)
164821 MO0308SPATRCRC.000. Concentration Data for "2,3,4,5-Tetrafluorobenzoic
Acid" Used for Tracer Testing at the C-Well Complex. Submittal date: 08/19/2003.
162614 UN0102SPA008KS.003. Concentration Dataset for Tracers (2,6-Difluorobenzoic
Acid and Iodide) Used for 48-Hour Shut-in Tracer Test at the Alluvial Tracer
Complex in Nye County. Submittal date: 06/11/2001.
162442 UN0109SPA008IF.006. Concentration Dataset for Tracers (2,4-Difluorobenzoic
Acid and Chloride) Used for the 30-Day Shut-in Tracer Test at the Alluvial Tracer
Complex in Nye County, Nevada. Submittal date: 09/28/2001.
162681 UN0109SPA008KS.005. Concentration Data Set for Tracers (2,6-
Difluorobenzoic
Acid And Iodide) Used For The 48 Hour Shut-In Test at the Alluvial Tracer Complex
in Nye County, Nevada, in Samples Collected During the Period 02/27/01 through
04/25/01. Submittal date: 09/21/2001.
162615 UN0109SPA008KS.007. Concentration Dataset for Tracer (Pentafluorobenzoic
Acid) Used for the 30-Day Shut-in Tracer Test at the Alluvial Tracer Complex in Nye
County, Nevada. Submittal date: 09/21/2001.
162616 UN0109SPA008KS.008. Concentration Dataset for Tracer (Bromide) Used for 
the
30-Day Shut in Tracer Test at the Alluvial Tracer Complex in Nye County, Nevada.
Submittal date: 09/21/2001.
8.5 OUTPUT DATA, LISTED BY DATA TRACKING NUMBER
GS030208312314.001. Filtered Water Level Data for UE-25 ONC-1. Submittal date:
02/28/2003.
GS030208312314.002. Filtered Water Level Data For USW-H4, UE-25 WT#3 and UE-
25
WT#14. Submittal date: 02/28/2003.
GS031008312314.004. Hydraulic Parameters from Analysis of Hydraulic Tests 
Conducted in
the Fractured Tuff at the C-hole Complex from 1995 to 1999. Submittal date: 
10/09/2003.
GS031008312315.002. Transport Parameters from Analysis of Conservative (Non-
Sorbing)
Tracer Tests Conducted in the Fractured Tuff at the C-hole Complex from 1996 to 1999.
Submittal date: 10/09/2003.
GS031008312316.002. Hydraulic Parameters from Analysis of Hydraulic Tests 
Conducted in
the Alluvium at the Alluvial Testing Complex (ATC), and Total Porosity from Grain-size
Distribution and from Background Monitoring. Submittal Date: 10/09/2003.
ANL-NBS-HS-000039, REV 00 442 December 2003
GS031008312316.003. Transport Parameters and Specific Discharge from Analysis of 
Single-
Hole Tracer Tests Conducted in the Alluvium at the Alluvial Testing Complex (ATC), 
and Total
Porosity from the Borehole-Gravimetry Survey at NC-EWDP-19D1. Submittal Date:
10/09/2003.
LA0303PR831231.001. Simulations Conducted to Predict Tracer Responses from Single-
Well
and Cross-Hole Tracer Tests at the Alluvial Testing Complex. Submittal date: 
03/20/2003.
LA0303PR831231.002. Estimation of Groundwater Drift Velocity from Tracer 
Responses in
Single-Well Tracer Tests at the Alluvial Testing Complex. Submittal date: 03/18/2003.
LA0303PR831231.003. Solute Data From ER-20-6#3 in the BULLION Forced-Gradient 
Field
Tracer Test At The ER-20-6 Wells at NTS. Submittal date: 02/03/2003.
LA0303PR831231.004. Simulations Conducted to Generate a Spreadsheet that can be 
Used for
Predictions of Mean, Peak, and First Tracer Arrival Times in Field Tracer Tests. 
Submittal date:
04/08/2003.
LA0303PR831231.005. Simple Calculations for SZ In-Situ Testing AMR. Submittal 
date:
03/19/2003.
LA0303PR831352.001. Calculations to Determine Detachment Rate Constant of 
Microspheres
in a Single-Well Tracer Test in Saturated Alluvium. Submittal date: 03/31/2003.
LA0303PR831341.001. Calculations and Plots Associated with C-wells Cation Exchange
Capacity Measurements. Submittal date: 04/08/2003.
LA0303PR831341.002. Model Interpretations of Alluvium Testing Complex Lithium 
Sorption
Experiments. Submittal date: 04/16/2003.
LA0303PR831341.003. Model Interpretations of C-wells Lithium Sorption Experiments.
Submittal date: 04/16/2003.
LA0303PR831361.002. Model Interpretations of ATC Alluvium-Packed Column 
Transport
Experiments. Submittal date: 04/16/2003.
LA0303PR831361.003. Model Interpretations of C-wells Crushed Rock Column 
Experiments.
Submittal date: 04/16/2003.
LA0303PR831361.004. Model Interpretations of C-wells Fractured Core Transport
Experiments. Submittal date: 04/02/2003.
LA0303PR831362.001. Model Interpretations of C-wells Diffusion Cell Experiments.
Submittal date: 04/02/2003.
ANL-NBS-HS-000039, REV 00 443 December 2003
LA0304PR831231.001. C-wells Tracer Test Sensitivity Calculations. Submittal date:
04/17/2003.
SN0302T0502203.001. Saturated Zone Anisotropy Distribution Near the C-wells. 
Submittal
date: 02/26/2003.