Sand2016 7915 c contributed images on template 081616
1. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia
Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department
of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.
SAND2016-7915C.
7th US/German Workshop on Salt Repository
Research, Design, and Operation
Salt Images
Compiled by Laura A. Connolly
Sandia National Laboratories
Washington, DC
September 7-9, 2016
2. Dr. Enrique Adolfo Biurrun
Born in western Argentina on
September 8, 1950. Died in
Aachen, Germany on
March 25, 2016
2
DBE
7. DBE
Dr. Joachim Engelhardt made
impressive photos of salt
minerals:
Halite - The crystals grew due
to the dissolution of bischofite
(magnesiumchlorid-
hexahydrate) in a sodium
chloride saturated solution.
The height of the crystal
aggregate is about 20 mm.
Four shots are taken with a
Canon 350D camera and an
EF-S 60 mm macro lens.
The data were used to
calculate a picture with an
extended depth of focus.
7
8. 8
DBE
Dr. Joachim Engelhardt made
impressive photos of salt minerals:
Halite - The crystals grew due to the
dissolution of bischofite
(magnesiumchlorid-hexahydrate) in
a sodium chloride saturated
solution.
The height of the crystal aggregate
is about 20 mm.
Four shots are taken with a Canon
350D camera and an EF-S 60 mm
macro lens.
The data were used to calculate a
picture with an extended depth of
focus.
9. The following figures present:
results of computer topographical analyses (XCT)
and
nano-tomography (FIB-nT) of compacted crushed
rock salt samples
Objective:
visualization of the remaining pore space
Wilhelm Bollingerfehr
DBE 9
10. Visualization of two XCT data sets of a compacted crushed rock salt sample.
a) 3D reconstruction of the analyzed volume.
b) 3D reconstruction of pore space (green) and the anhydrite mineral with bright image contrast
(grey).
c) Reconstruction of anhydrite distribution.
DBE
10
Michael Jobmann compiled results of
• computer topographical analyses (XCT) and
• nano-tomography (FIB-nT) of compacted crushed rock salt samples
11. Visualization of two XCT data
sets of a compacted crushed
rock salt sample.
a) 3D reconstruction of the
analyzed volume.
b) 3D reconstruction of pore
space (green) and the
anhydrite mineral (grey).
11
DBEMichael Jobmann compiled results of
• computer topographical analyses (XCT) and
• nano-tomography (FIB-nT) of compacted crushed rock salt samples
12. Visualization of the FIB-nT
data set of a compacted
crushed rock salt sample.
a), b) and c) 3D
reconstructions of the
analyzed volume
documenting the granular
pore geometry.
d) 3D reconstruction of pore
space.
Visualization of the FIB data set of a
compacted crushed rock salt sample.
a) 3D reconstructions of the analyzed
volume
b) 3D reconstruction of pore space
showing a macropore and
numerous in plane fluid inclusions.
c) 3D reconstruction of pore space
documenting that the micropores
or fluid inclusions are aligned in
planes (i.e. sub-grain boundaries). 12
DBEMichael Jobmann compiled results of
• computer topographical analyses (XCT) and
• nano-tomography (FIB-nT) of compacted crushed rock salt samples
14. BGR salt scientists: About three generations of salt experts covering geology,
laboratory, numerical modeling, and safety assessment. From left to right: Otto
Schulze, Udo Hunsche, Werner Gräsle, Michael Langer, Maximilian Pusch, Sandra
Fahland, Stefan Heusermann, Manfred Wallner, Jörg Hammer, Dieter Stührenberg.
BGR 14
15. Lothar Hartwig, retired last year. He performed all of the
drilling and sample preparation to exactingprecision.
GRS 15
16. Coaxial salt concrete – Salt sample with salt paste in the annulus
after drying
GRS 16
17. Coaxial salt concrete – Salt sample after compressive
loading and brine injection
GRS 17
18. BGR
Stack über 400 µm
Fluid inclusion in WIPP-halite filled with brine and
crystals of polyhalite. Stacked image with z = 400 µm.
18
20. Pseudomorphs of
anhydrite and halite after
gypsum in WIPP-salt.
The former swallowtails
are still visible, but
replaced by anhydrite
and halite.
BGR
20
21. BGR
Stack über 1 mm
Fluid inclusions in WIPP-halite filled with brine and
gases. Stacked image with z = 1000µm.
21
22. BGR
Stack über 1,3 mm
22
Fluid inclusion in WIPP-halite filled with brine, crystals of anhydrite
and polyhalite and gases. Stacked image with z = 1300µm.
23. BGR
23
Stack über 160 µm
Bunches of polyhalite
at the contact to halite
on top of an aggregate
of clay and polyhalite
in WIPP-salt. Stacked
image with z = 160 µm.
24. BGR
Stack über 300 µm
Bunches of polyhalite at the contact to halite on top of an aggregate
of polyhalite in WIPP-salt. Stacked image with z = 300µm. 24
25. BGR
Stack über 900 µm
Cutout of fluid inclusions in a so called “Chevron” in WIPP-Halite filled with
brine and crossed by a crack due to preparation. Stacked image with z = 900µm.
25
28. BGR
Stack über 400 µm
Grain boundaries of halite crystals decorated with fluid inclusions of brine and hydrocarbons
from the main rocksalt in Gorleben (Germany). Stacked image with z = 400 µm.
28
29. BGR
Grain boundaries of halite crystals decorated with branched and planar fluid inclusions of brine and
hydrocarbons from the main rocksalt in Gorleben (Germany). Stacked image with z = 480 µm.
Stack über 480 µm
29
30. BGR
Grain boundaries of halite and cracks in halite decorated with branched fluid inclusions of brine, gases
and hydrocarbons from the main rocksalt in Gorleben (Germany). Stacked image with z = 400 µm.
Stack über 600 µm 30
31. BGR
Colorful cropped pieces of anhydrite
and a hypidiomorphic crystal of
dolomite in halite from themain
rocksalt in Gorleben (Germany).
31
32. BGR
Stack 2 - Kopie
Same image as the one below. The detail area of the
third image of this group is markedhere.
32
33. BGR
Stack 2 - Kopie
Fluorescing hydrocarbons at the grain boundaries of halite and anhydrite crystals
from the main rocksalt in Gorleben (Germany). Stacked image with z = about 200µm.
33
34. BGR
Gas bubble in a large brine filled fluid inclusion (5000 µm) from WIPP-halite.
34
39. Cavities in polyhalite from WIPP-salt filled with large,
idiomorphic needles of polyhalite surrounded by halite.
39
BGR
40. Deep-view to a brine filled fluid inclusions (3000 µm) within WPP-halite.
The square-shaped, white inclusions are filled with packed abrasive dust.
40
BGR
60. Melissa Mills, SNL
60
SEM photomicrograph of
WIPP salt, reconsolidated
unvented at 250°C and 20
MPa of confining pressure,
showing a tight triple-
junction and residual
moisture isolated in
occluded pores.
61. Ewoud Verhoef, Deputy Director of COVRA
I look forward to hosting the 8th
US/German Workshop to be held at
COVRA’s premises in Nieuwdorp,
the Netherlands in September 2017.
During the workshop, there is
opportunity to visit the storage
facilities and ‘stand on’ our Dutch
high-level heat-generating waste.
61
62. Erika Neeft, COVRA
Thickness Zechstein salt Netherlands:
The thickest salt occurrences on Earth
are of marine origin. In the Netherlands,
salt deposits mainly occur in Permian
and Triassic intervals. For geological
disposal, there is a focus on salt of
Permian age (260-254 million years old)
which attains greatest thickness and
belongs to the Zechstein Group.
Hart J, Prij J, Vis G-J, Becker DA, Wolf J, Noseck U,
Buhmann D: Collection and analysis of current
knowledge on salt-based repositories, OPERA-PU-
NRG221A, 2015
62
63. Erika Neeft, COVRA
Salt domes Netherlands: The salt
domes have been extracted from
the thickness map, by assuming a
minimum thickness of rock salt in
a salt dome of 1300 m. Also
indicated on this map are the
locations (in green) where salt is
present within 1500 m below the
surface and thicker than 300 m.
63
64. Erika Neeft, COVRA
Depth top Zechstein Group in the
Netherlands: The deep underground
distribution of Zechstein Group was
investigated in OPLA (Dutch acronym
for Research program for Disposal
Onshore: 1982-1993). In OPERA (Dutch
acronym for Research program into
Geological Disposal of radioactive
waste: 2011-2016), the depth maps of
the top and base of the Zechstein group
have been constructed on existing, but
recently updated data which are based
on interpreted seismic data (2D and 3D)
and borehole data.
64
65. 65
IfG
The miner preparing his drilling
machine for large block coring
(Cabanasas mine, Spain) is
Michael Wiedemann.
67. Bedded salt specimen used for direct
tension test (rocksalt with anhydrite
intercalations, core diameter: 100mm)
– Potash mine Zielitz (Saxony-Anhalt,
Germany)
IfG
67
68. IfG
68
Salt Dump at the former
potash mine Teutschenthal
(Saxony-Anhalt, Germany),
looking west from the shaft
building
78. The technician preparing the large salt specimen
(from a rock salt block recovered from the
Bernburg salt mine) on the "Karussel-lathe" is
Josef Fink, now retired.
78
80. Till Popp, IfG
Michael Wiedemann, a
mining engineer who
drilled at very strange
climate conditions a
hydro-frac borehole
within the large
"borehole" at the in-situ
test site of IfG in the
Merkers mine.
80
84. Frank Hansen, Thilo von Berlepsch, Christi Leigh,
Wilhelm Bollingerfehr, Walter Steininger
5th US/German Workshop in Santa Fe, New Mexico
84
85. Frank Hansen, Thilo von Berlepsch, Christi Leigh, Wilhelm Bollingerfehr,
Walter Steininger
5th US/German Workshop in Santa Fe, New Mexico
Frank Hansen, Thilo von Berlepsch, Christi Leigh,
Wilhelm Bollingerfehr, Walter Steininger
5th US/German Workshop in Santa Fe, New Mexico
85
86. Shannon Casey, Frank Hansen, LeAnn Mays, Christi Leigh, Dina Howell
5th US/German Workshop in Santa Fe, New Mexico
86
87. Structural geology of the Upper Rio Grande
5th US/German Workshop in Santa Fe, NewMexico
87
97. Steve Bauer and Frank Hansen
5th US/German Workshop in Santa Fe, New Mexico
97
98. Pillsbury Dough-Boy, Steven J. Bauer and Frank Hansen.
Friends, colleagues, researchers, and Aggies
5th US/German Workshop in Santa Fe, New Mexico
98
99. Frank Hansen, Andrew Orrell, Freiberg, Germany
6th US/German Workshop on Salt Repository Research, Design and Operation
99
100. Dave Sevougian, Frank Hansen, Andrew Orrell
TU Bergakademie Freiberg Reiche Zeche
6th US/German Workshop on Salt Repository Research, Design and Operation
100
101. Frank Hansen, Andrew Orrell
TU Bergakademie Freiberg Reiche Zeche
6th US/German Workshop on Salt Repository Research, Design and Operation
101
102. Microscopic Evidence of Grain Boundary Moisture During Granular Salt Reconsolidation
Rock salt is a favorable medium for nuclear waste
disposal because of its low permeability and plastic
behavior. Granular salt is likely to be used as back-fill
material and a seal system component. In these
applications, it is expected that granular salt will
reconsolidate to a low permeability comparable to the
intact native salt and completely encase the waste.
Understanding the consolidation process dependency on
stress state, moisture availability, and temperature is
important for predicting long-term repository
performance.
Background
As granular salt consolidates, the initial void reduction is
due to brittle processes of grain rearrangement and
cataclastic flow. Eventually, grain boundary processes and
crystal-plastic mechanisms control additional porosity
reduction. Reconsolidation of granular salt is
accomplished by a series of processes and mechanisms,
which includes dislocation glide, cross slip, climb, and
annealing/recrystallization. When present, fluid assists in
grain boundary processes and enhances consolidation.
Documentation of deformation mechanisms within
consolidating granular salt and particularly at grain
boundaries is essential to establish effects of moisture
and the reliance of consolidation on stress and
temperature.
Experimental
Mine-run granular salt from the Waste Isolation Pilot
Plant (WIPP) and Avery Island was used to create
cylindrical samples which were consolidated at 250°C
and confining pressures up to 20 MPa. The granular salt
was placed in copper and malleable soldered lead tubes
with caps. For the samples presented here, three
different conditions were used: top cap venting to the
atmosphere, no vented caps, and top cap venting to the
atmosphere with 1% moisture added to the salt.
Samples were placed in a pressure vessel where a
surrounding fluid was heated to 250°C, allowing thermal
expansion of the unconfined specimen. Isostatic tests
were conducted by simultaneously increasing confining
and axial pressures. Shear testing has also been
conducted.
Microstructures illustrated here are typical of
ongoing research. All tests at 250°C resulted in high
fractional density, low porosity, and tight cohesion
evidenced by fracture through the crystal structure
rather than at grain boundaries. Unvented
reconsolidation retains moisture at grain boundaries
as found ubiquitously on scanning electron
photomicrographs revealing an inhomogeneous
distribution of canals and pores. This observation
contrasts significantly with the vented samples,
which had virtually no remaining grain boundary
moisture and had visible escaping steam during
reconsolidation testing. All samples shown here
were impermeable; however, unvented samples
retained occluded porosity. Fluid inclusion migration
and hydrous mineralogy were sufficient to promote
fluid aided processes in WIPP salt, but is somewhat
obscured at temperatures employedhere.
Future Work
This work comprises one component of a research
program to better understand coupled thermal-
mechanical-hydrologic behavior of reconsolidating
granular salt. The goal is to assist in estimating the rate
of consolidation under different conditions by an
experimental program, including ongoing laboratory
experiments, microstructural observations, and pore
structure characterization. Future experiments will be
conducted at lower temperatures. The completed
work will provide data and parameters for a
constitutive model that can be incorporated into
numerical simulations. These numerical models will be
used to make predictions of long-term repository
performance.
Observational Techniques
After testing a diamond-wire saw was used to cut ends
of the samples, which were used to make impregnated
petrographic sections and freshly broken aggregated
grains. In the aggregate, grain boundary processes such
as pressure solution can be observed. Observational
approaches include optical and scanning electron
microscopy. Microstructure is highlighted by etching
techniques whereby the sample is either swiped quickly
with a damp Kim wipe or agitated in a solution of
methanol saturated with PbCl2 for a few seconds and
stopped by submersion in butanol.
WIPP-01 Vented Noadditional
moisture
WIPP-02 Unvented Noadditional
moisture
AveryIsland-
01
Vented Noadditional
moisture
AveryIsland-
02
Vented Additional1%
moisture
3-D image of unvented sample with occluded residual moisture pores
along tight grain boundaries.
Intersection of grains at near orthogonal orientation with tight
grain boundary achieved by crystalplasticity.
Residual fluid canals on grain boundaries.
Sharp crystal surface lacking evidence of moisture.
Fracture surface through crystal indicating tight cohesion. Note
intersected fluid inclusions.
Tight triple junction with canals of resided moisture displaying
occluded pores.
Thin section surface in reflected light etched with swipe of water
revealing simultaneous recrystallization, internal grain recovery,
and high energy grain boundaries.
Water-etched thin section surface in reflected light showing triple-
junction with recrystallized area in center and small subgrains
decorating tight grain boundaries.
Minor residual porosity. Cleavage fracture (left) and grain
boundary fracture(right).
Evidently tight grain boundary, but not high cohesion.Occluded fluid droplets and canals on cubic grain boundary at
slightly highermagnification
Grain boundary fracture on left and cleavage fracture on right. Tight cohesion with minor residual porosity.
Upper grain fractured through the crystal structure; lower grain
fractured on boundary. Minor residual porosity.
Residual fluid inclusions along healed boundary.
Acknowledgements: This material is based upon work supported under a Department of Energy Nuclear Energy University Programs Graduate Fellowship. Sandia National Laboratories is a multi-program laboratory managed
and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94L85000.
Melissa Mills1, Frank Hansen2, Stephen Bauer2, John Stormont1
1Departmentof CivilEngineering,Universityof New Mexico,Albuquerque,NM 87131
2SandiaNationalLaboratories,PO Box 5800, Albuquerque,NM 87185
Motivation Microstructural Observations Results & Conclusion
Water-etched thin section surface in reflected light showing multiple
grain boundaries. Recrystallized area with smaller subgrains emanating
through rest of crystal structure.
Thin section with water-etched surface in reflected light
displaying large recrystallized area as well as high energy grain
boundaries.
Use 3-D glasses to view 3-D SEMimage
102
103. SALT MECH VIII South Dakota School of Mines and
Technology - 2015 103
122. 122
Photo by Michael Bühler taken in Morsleben during the
technical tour of the 5th WS showing our colleagues Abe
and Enrique. Group front row from left: Gloria Kwong
(OECD/NEA), Christi Leigh (SNL), Abe van Luik (DOE),
Enrique Biurrun (DBE), Lupe Arguello (SNL); Back row from
left: Ralf Mauke (BfS), Andreas Hampel (Consultant), Prof.
Stahlmann (TU Braunschweig), Markus Stacheder(PTKA).
123. Abraham "Abe" Van Luik
Born in Nijmegen, The
Netherlands on December 16,
1944.
Died in Faywood, New Mexico
on July 9, 2016.
123
