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First results of the KOSINA-project: technical concepts and geological and
numerical modeling
T. Kühnlenz & KOSINA-TeamBGR, DBE TEC, GRS, IfG
Washington, DCSeptember 7-9, 2016
Background
• 2013 – The German Repository Site Selection Act• 1960 – 2014 - main focus of salt studies - salt diapirs
Necessity of additional geological data for bedded salt formations BGR-Projekt BASAL distribution and characterization of flat bedded salt formations
• April 2015 - R&D-projekt:
Concept development for a generic repository for heat generating waste in bedded salt formations as well as development and review of a safety and safety demonstration concept (KOSINA)
Organisations involved: – German Company for Construction and Operation of Waste Repositories (DBE TEC)– Company for Safety of constructions and reactors (GRS)– Institute for geomechanics (IfG)– Federal Institute for Geosciences and Mineral Ressources (BGR)
Objectives
safety and safety demonstration concept
(GRS)
repository concept, technical designs
(DBE TEC)
provide a technical-scientific basis for the safety oriented evaluation of repository systems in different host rocks according to the German site selection law
radiological consequences
(GRS)
operation safety (DBE TEC)
generic geological models
(BGR, IfG)
demonstration of geomechanical
integrity (BGR, IfG)
Development of technical concepts
having regard to the topics:
• Recoverability• Effects of increased temporary storage periods• Transport and operation technique• Disposal and recoverability technique• Backfill and sealing technique
5
Disposal options, flat-bedded salt
Horizontal borehole disposal of BSK (BSK-H)
Drift disposal of POLLUX® casks
Lifting from transport cart…
.. disposed at final position
Transport to the emplacement position
Disposal options, salt pillow
Vertical borehole disposal of steel canisters “BSK” (BSK-V) type
Direct disposal of transport and storage casks in short horizontal boreholes Cask transfer
to emplacement device
90° turn of the cask
Lock secured lowering of steel canisters
Construction of generic geological models
3D-models:Type „flat bedded salt
formation“Type „salt pillow“
Derivation of the reference profiles
Minimum requirements for the thickness of the geological barrier and for the depth of disposal mine
Current knowledge about bedded salt formations in Germany
Numerical modeling
Stratigraphic position of flat-bedded salt formations
Upper Jurassic (Malm) salt
Upper Triassic (Keuper) salt
Middle Triassic (Muschelkalk) salt
Tertiary salt
Upper Bunter (Röt) salt
Zechstein salt
Rotliegend salt
Stratigraphic position and description of salt formations with halite layers in Germany (/Menning 2002/ modified, from: /BGR 2014/)
On-shore-distribution of flat-bedded salt formations
RotliegendZechstein
Bunter (Röt)Muschelkalk
Keuper (Trias) Jurassic (Malm)Tertiary
Minimum requirements
10
Criteria or minimum requirements derivation of the data from still existing studies (AkEnd 2002, BGR 2004, Hammer et al. 2009, IfG 2010)
– Depth of repository mine between 500 m and 1.000 m below surface
– Thickness of the storage horizon thicker than 100 m
Distribution of flat-bedded Zechstein (upper Permian) salt formations in Germany
Occurrence• Southern part of Northern
Germany basin: Niederrhein-Basin Werra-Fulda-Basin Thüringer-Basin Solling-Basin Calvörde-Block
Schematic on-shore-distribution of halite-composed Zechstein salt in Germany (according to: KULICK ET AL. 1984, FREUDENBERGER & SCHWERD 1996, KRULL ET AL. 2004); Distribution of Zechstein salt structures (according to: REINHOLD ET AL. (2008))
Depth of Zechstein basin - Thuringian Basin
- margin of basin close to surface
- center of basin 2000 m (Zander & Huckriede 2011)
Thickness of Zechstein – Thuringian basin
- Staßfurt-Formation:
high thickness in the NE (up to 500 m in the salt structures) Inclusions of up to 20 m thick Kaliflöz Staßfurt
Geological section Werra-Fulda Basin
- Werra-Formation thickness up to 220 m- Top of Zechstein salt layers in a depth of 600 m to 1000 m (Ahorner & Sobisch 1988)
Specific characteristic of flat-bedded salt layersLayer inclination
Author: Hoppe (1958)
Profile in SW-Thuringia
S. David Sevougian, PhD Sandia National Laboratories. PFLOTRAN: Coupled THM Simulations. In: 6th US/German Workshop on Salt Repository Research, Design and Operation.
WIPP
Geological sequences for the reference profile
Host rocks Zechstein (z1, z2, z3,z4,z5-z7)
Storage horizon Staßfurt-Hauptsalz (z2HS)
3D geological modeling
Characterized by concordant bedding conditions
Origin salt migration pillow-like structureCharacteristic accumulation of salt through the mobilization of the lightweight salt layers (Staßfurt-Formation)
model B: Type „salt pillow"model A: Type „flat-bedded salt"
18
Generic geological profile for the model type „flat-bedded salt formations“
Depth of the basis of Staßfurt-Steinsalz from -700 m to -1200 mDepth of the top of Staßfurt-Steinsalz from -550 m to -1000 m
z2NA 150 265
Läng200-600e: 12,415 km
KOSINA 8. Projektgespräch – 25.05.2016
A A‘
Generic geological profile for the model type „salt pillow“
Depth of the basis of Staßfurt-Steinsalz from -600 m to -1200 mDepth of the top of Staßfurt-Steinsalz from -250 m to -1000 m
200-600z2NA 200 600
Overview of the modeling area
Model area: 2,6 km x 5 kmType „flat-bedded salt"
Model area: 9,9 km x 12,3 kmType „salt pillow"
Compilation of TM- and THM-material parameters for the numerical modeling
• Density for rock salt• Density for the host rocks and adjacent rocks• Thermal parameters
– Thermal parameters for salt rock• Thermal conductivity of salt rock• Specific thermal capacity of salt rock
– Thermal parameters for the host rocks and adjacent rocks• Mechanical parameters
– Elastic constants for salt rock– Elastic constants for the host rocks and adjacent rock– Steady state creep– Dilatant behavior
• Hydraulic parameters– Permeability of salt rock– Porosity of salt rock– Density ground water/ saline solutions
Material parameters (Report from BGR/IfG)
Materialeigenschaften:
Wärmeleistung der EB
Gesteinsschichten/Geologische Einheit
GesteinsschichtenHomogenbereich Symbol Dichte Teufendruc
k-gradientWärme-
leitfähigkeit
Spezifische Wärme-kapazität
Wärme-ausdehnungs-koeffizient
Elastizitäts-
modulPoissonza
hl
[kg/m3] [MN/m3] [W/(m∙K)] [J/(kg∙K)] [1/K] [MPa] [-]Quartaer Quartaer Q 2000 0,022 2,3 950 1,00E-05 100 0,33Tertiaer Tertiaer T 2100 0,022 2,1 905 1,00E-05 500 0,33
mittlerer BundsandsteinBuntsandstein S 2500 0,022 2,6 760 1,00E-05 15000 0,27unterer Bundsandstein
Ohre-SedimenteAller-Steinsalz
Aller-Steinsalz NA4 2235 0,022 5,2 860 4,00E-05 25000 0,27Roter Salzton_Pegmatitanhydrit
Schwadensalz_Tonmittelsalz Anhydritmittelsalz AM3 2275 0,022 5,0 860 3,50E-05 30000 0,27
Anhydritmittelsalz
Kalifloez Ronnenberg Kalifloez Ronnenberg K3 1850 0,022 1,5 903 2,50E-05 16000 0,26
Leine-Steinsalz Leine-Steinsalz NA3 2160 0,022 5,2 860 4,00E-05 25000 0,25Hauptanhydrit
Hauptanhydrit A3 2700 0,022 4,2 860 1,60E-05 60000 0,25Grauer Salzton
Kalifloez Stassfurt Kalifloez Stassfurt K2 1850 0,022 1,5 903 2,50E-05 17000 0,28Strassfurt-Steinsalz
Stassfurt-Steinsalz NA2 2160 0,022 5,2 860 4,00E-05 33000 0,25Strassfurt-Steinsalz_EB
Anhydrit Anhydrit/Karbonat A2/C2 2700 0,022 4,2 860 1,60E-05 30000 0,27KarbonatSandstein Rotliegendes R 2500 0,022 2,7 760 1,00E-05 17000 0,27
Rotliegendes
34
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 100000
10
20
30
40
50
60
70
80
90
100
110
120
130A (GOK)B (su/z5)C (z2SF/z2NA)D (Einlagerungshorizont)E (z2NA/z_Anh)F (z_Karb/Sand_Substr)G (Sand_Substr/Rotliegendes)
Zeit, Jahre
Tem
pera
ture
, °C
36
A
B
CDEFG
Calculation results
37
Q T S NA4 AM3 K3 NA3 A3 K2 NA2 A2/C2 R
Disposal drifts
Einlagerung von DWR Brennelementen in POLLUX®-10
Drift distance: 38 mContainer distance: 3 m Number of emplacement drift per field: 10Period of interim storage: 57 a
Axis of symmetry
38 m
Axisymmetric 2D model
39
G‘
H‘
C‘
B‘
A‘
D‘E‘F‘
495 isoparametric quad elements
Results perpendicular to emplacement horizon
40
G‘
H‘
C‘
B‘
A‘
D‘E‘F‘
98056 isoparametric quad elements
Results perpendicular to emplacement horizon
Set of basic design data and requirements accomplished (waste inventory, legal design requirements, description of geological situation for bedded salt, survey of existing safety and demonstration concepts)
Generic geologic model developed for both types of bedded salt (type A „flat-bedded salt„ and type B „salt pillow„)
Model parameters developed for type “flat-bedded salt”
Draft outline of a safety and safety demonstration concept
First preliminary numerical calculations
Repository concept, thermal design and technical design for the disposal options horizontal borehole disposal and drift disposal in flat-bedded salt developed
Interim Report (December 2015) on basic data and repository design requirements, on geologic models as well as on the outline of a safety and safety demonstration concept published
Achievements