Task 4.1.2 Future evolution of the geological and geohydrological properties of the geosphere OPERA-PU-TNO412 Page 1 of 121 OPERA-PU-TNO412 Radioactive substances and ionizing radiation are used in medicine, industry, agriculture, research, education and electricity production. This generates radioactive waste. In the Netherlands, this waste is collected, treated and stored by COVRA (Centrale Organisatie Voor Radioactief Afval). After interim storage for a period of at least 100 years radioactive waste is intended for disposal. There is a world-wide scientific and technical consensus that geological disposal represents the safest long-term option for radioactive waste. Geological disposal is emplacement of radioactive waste in deep underground formations. The goal of geological disposal is long-term isolation of radioactive waste from our living environment in order to avoid exposure of future generations to ionising radiation from the waste. OPERA (OnderzoeksProgramma Eindberging Radioactief Afval) is the Dutch research programme on geological disposal of radioactive waste. Within OPERA, researchers of different organisations in different areas of expertise will cooperate on the initial, conditional Safety Cases for the host rocks Boom Clay and Zechstein rock salt. As the radioactive waste disposal process in the Netherlands is at an early, conceptual phase and the previous research programme has ended more than a decade ago, in OPERA a first preliminary or initial safety case will be developed to structure the research necessary for the eventual development of a repository in the Netherlands. The safety case is conditional since only the long-term safety of a generic repository will be assessed. OPERA is financed by the Dutch Ministry of Economic Affairs and the public limited liability company Electriciteits-Produktiemaatschappij Zuid- Nederland (EPZ) and coordinated by COVRA. Further details on OPERA and its outcomes can be accessed at www.covra.nl. This report concerns a study conducted in the framework of OPERA. The conclusions and viewpoints presented in the report are those of the author(s). COVRA may draw modified conclusions, based on additional literature sources and expert opinions. A .pdf version of this document can be downloaded from www.covra.nl OPERA-PU-TNO412 Title: Future evolution of the geological and geohydrological properties of the geosphere Authors: Johan ten Veen (TNO) Contributors: Joan Govaerts (SCK-CEN), Koen Beerten (SCK-CEN), Dario Ventra (TNO), Geert-Jan Vis (TNO) Date of publication: 17-07-2015 Keywords: future evolution, driving forces, processes, effects, Boom Clay predictive modeling, long-term safety assessment Page 2 of 121 OPERA-PU-TNO412 Summary ..................................................................................................7 Samenvatting .............................................................................................7 1. Introduction .........................................................................................9 1.1. Background ....................................................................................9 1.1.1. Isolation ...................................................................................9 1.1.2. Delay & attenuation of the releases ..................................................9 1.1.3. Engineered containment ............................................................. 10 1.2. Objectives .................................................................................... 10 1.3. Realization ................................................................................... 11 1.4. Explanation of contents .................................................................... 11 2. Driving forces ..................................................................................... 13 2.1. Introduction.................................................................................. 13 2.2. Future Climate .............................................................................. 14 2.2.1. Climate change mechanisms and timescales (BIOCLIM) .......................... 14 2.2.2. The role of climate change .......................................................... 15 2.2.3. Understanding past climate change ................................................ 16 2.2.4. Predicting future climate change ................................................... 17 2.2.1. Possible future climate types ........................................................ 18 2.2.2. Present-day Temperate Climate .................................................... 20 2.2.3. Boreal climate - Dfc - ZB VIII......................................................... 22 2.2.4. Periglacial - ZB IX - ET .............................................................. 23 2.2.5. Glacial - EF ............................................................................. 25 2.2.6. Mediterranean, warm/dry summer climate – Csb................................. 26 2.3. Future Tectonic processes ................................................................. 28 2.3.1. Origin of tectonic movements ....................................................... 28 2.3.2. The role of tectonics .................................................................. 28 2.3.3. Prediction of tectonic movements .................................................. 29 CLIMATE SECTION ................................................................................... 31 3. Glacial erosion and -deformation processes .................................................. 33 3.1. Introduction.................................................................................. 33 3.2. Current state of knowledge ............................................................... 33 3.3. Physical erosion and sediment production by ice sheets .............................. 34 3.3.1. Landscape analyses.................................................................... 35 3.3.2. Sediment fluxes ........................................................................ 36 3.3.3. Stratigraphic analysis ................................................................. 37 3.4. Glaciotectonic structures .................................................................. 38 3.4.1. Origin .................................................................................... 38 3.4.2. Classification ........................................................................... 38 3.4.3. Depth of deformation ................................................................. 38 3.5. Tunnel valleys: generalities and erosive potential ..................................... 39 3.6. Discussion .................................................................................... 42 3.6.1. Depth of the Boom Clay .............................................................. 42 3.6.2. Erosion potential ...................................................................... 42 3.7. Relevance and synthesis for the safety case: ........................................... 44 4. Effects of glacial loading and unloading ...................................................... 45 4.1. Coupled mechanical–hydraulic effects ................................................... 45 4.1.1. Isostasy vs. hydrology ................................................................. 47 4.2. Seismicity during deglaciation ............................................................ 48 4.2.1. Deglaciation effects below ice sheets .............................................. 48 4.2.2. Far field effects........................................................................ 50 4.3. Assessment of glacio isostasy and -seismicity in the Netherlands .................. 51 4.4. Summary of Dutch ice cover scenarios .................................................. 52 Page 3 of 121 OPERA-PU-TNO412 4.4.1. Ice sheet extent ....................................................................... 52 4.4.2. Ice sheet thickness .................................................................... 53 4.5. Relevance and synthesis for the safety case ............................................ 55 5. Permafrost ........................................................................................ 57 5.1. Literature study on permafrost in NW Europe during the last ice age .............. 57 5.1.1. Motivation .............................................................................. 57 5.1.2. New data on the stability of permafrost in Europe ............................... 57 5.1.3. Comparison of permafrost depth modeling results for NW Europe ............. 60 5.1.4. Implications for potential geological waste repositories in Belgium and the Netherlands ....................................................................................... 60 5.2. Assessment of input parameters for Permafrost modeling ........................... 60 5.2.1. Porosity prediction .................................................................... 60 5.2.1. Thermal parameters .................................................................. 61 5.2.2. Area selection and data delivery .................................................... 63 5.3. Permafrost depth modeling ............................................................... 65 5.3.1. Results .................................................................................. 65 5.3.2. Comparison with Boom Clay depth ................................................. 65 5.1. Relevance and synthesis for the safety case: ..........................................