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

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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"

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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"

Construction of the 3D model for the type „flat-bedded salt formations“

Creation of 3D layers Sandstone

Creation of 3D layers z1/2-carbonate

Creation of 3D layers z1/2-anhydrite

Creation of 3D layers z2NA

Creation of 3D layers z2SF

Creation of 3D layers z3GT

Creation of 3D layers z3HA

Creation of 3D layers z3NA

Creation of 3D layers z3RO

Creation of 3D layers z3AM

32

3D model for the type „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

35

C

C‘

C C‘

Depth of diposal horizont: -700 m NN

Disposal area within the 3d-model

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

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Results in emplacement horizon

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

1 km

160 m

x

z

Test model, slice modelSymmetry axis

Disposal drifts

20 a 40 a 60 a

Temperature development in the slice model

20 a 40 a 50 a

Uplift in the slice model

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