High-level Waste Repository Research Articles

Cradle to grave: the importance of the fuel cycle to molten salt reactor sustainability

Advanced reactor technologies are being considered for the next-generation of nuclear power plants. These plants are designed to have a smaller footprint, run more efficiently at higher temperatures, have the flexibility to meet specific power or heating needs, and have lower construction costs. This paper offers a perspective on molten salt reactors, promoted as having a flexible fuel cycle and close-to-ambient pressure operation. A complexity introduced by reducing the reactor footprint is that it may require low-enriched fuel for efficient operation, available from enrichment of the feed salt or by reusing actinides from existing used nuclear fuel (UNF). Recycling UNF has the potential to reduce high-level waste, if done correctly. Release limits from UNF processing are stringent, and processes for waste reduction, fission gas trapping, and stable waste-form generation are not yet ready for commercial deployment. These complex processes are expensive to develop and troubleshoot because the feed is highly radioactive. Thus, fuel production and supply chain development must keep abreast of reactor technology development. Another aspect of reactor sustainability is the non-fuel waste streams that will be generated during operation and decommissioning. Some molten salt reactor designs are projected to have much shorter operational lifetimes than light-water reactors: less than a decade. A goal of the reactor sustainability effort is to divert these materials from a high-level waste repository. However, processing of reactor components should only be undertaken if it reduces waste. Economic and environmental aspects of sustainability are also important, but are not included in this perspective.

The influence of isotropic loading and unloading on anisotropic evolution of saturated hydraulic conductivity of bentonite-sand mixtures in a cube triaxial permeameter

Anisotropic permeability of bentonite mixtures governs water flow regime in buffer materials such as landfill cover systems, cutoff walls, and high-level waste repositories. Because of its widespread application, a series of 48 permeability tests were conducted in this study on specimens prepared from bentonite-sand mixtures with three bentonite contents. The tests were run along both isotropic loading and unloading paths to explore the evolution of anisotropic ratio from three distinct fabric anisotropy states. Accordingly, a new cubic sample-type, large-scale triaxial permeameter was introduced and employed. The results revealed an enhancement of as-compacted anisotropy ratio from 1 to almost 7 with bentonite contents. The anisotropy ratio was suppressed with isotropic loading for 40% and 70% bentonite while it was enhanced for 10% bentonite content. Unloading was revealed to reduce the anisotropy of higher bentonite contents due to the enhancement of fissures along horizontal and vertical directions. The practical implication in terms of the long-term performance of a landfill liner with medium to high bentonite contents is that despite a 10- to 30-fold reduction in permeability with loading, the leachate flow would be less anisotropic compared with the initial condition as supported by a reduction in the anisotropy ratio up to 3.5.

CD-A twin niches in the Mont Terri Rock Laboratory: Characterization and interpretation of hydraulic parameters with regard to safety aspects

In the Mont Terri Rock Laboratory (Switzerland), a comprehensive interdisciplinary exploration program is carried out to increase knowledge about long-term coupled hydraulic–mechanical effects in Opalinus Clay. As these effects are of significant interest regarding the stability and integrity of a potential storage facility for high radioactive waste, the “Influence of humidity on cyclic and longterm deformations” (CD-A) experiment aims to characterize the Opalinus Clay, especially its heterogeneous sandy facies, and to investigate the evolution of the water content, pressure and deformation in the formation. This article provides an overview of measurement examinations and geologic investigations carried out in the context of the CD-A experiment. The twin niches of the CD-A experiment are located in the upper sandy facies of the Opalinus Clay which is characterized by the existence of different subfacies types and fault zones. This contribution focuses on the detailed characterization of the claystone, while the evolution of the water content. Combined geophysical and geological investigations during the first two years after the excavation of the niches have been carried out. They indicate that the subfacies type and pre-existing fault zones do not affect the distribution of water content severely, which could be an essential finding in the context of detection procedures for potential high level waste (HLW) repositories. Furthermore, miniseismic as well as pulse tests indicate clearly, that the extent of the excavation damaged zone (EDZ) strongly depends on the climatic conditions in the underground galleries: After 1.5years the EDZ and the increase of permeability is much more pronounced in the open than in the closed twin. Future work aims on an increased process understanding based on a verified constitutive model for Opalinus Clay and a comprehensive system understanding considering long-term effects due to climatic conditions as well as the impact of geotechnical boundary conditions and heteregeneities.

Effect of temperature on the compressibility behavior of glass fiber-bentonite mixture

Effect of temperature on the compressibility behavior of glass fiber-bentonite mixture

Effect of hydrothermal alteration of Ca-bentonite in K-rich solutions with different pHs on the physicochemical, swelling, and Cs adsorption properties

Understanding the stability of the bentonite buffer when exposed to cement leachates at temperatures exceeding 100°C is crucial for optimizing the design of deep geological repositories (DGRs) for high-level radioactive wastes (HLRWs) and minimizing the required site area. Experiments were conducted under hydrothermal conditions at 150°C for 30–150 days using deionized (DI) water (pH 6) and K-rich solutions (1 mol/L KCl, pH 6 and 1 mol/L KOH, pH 13) on Ca-bentonite. The 1 mol K concentration is comparable to 15 times the cation exchange capacity (CEC) of raw bentonite. Using various analytical techniques, the mineralogical, physicochemical, swelling, and Cs adsorption characteristics of raw and reacted bentonite samples were determined. Almost no changes in the properties of bentonite reacted with DI water were found for a given reaction time. For bentonite reacted with a 1 mol/L KCl solution, the cation exchange of Ca by K was a primary alteration process, resulting in a slight decrease in swelling capacity. However, almost no mineralogical changes were observed and consequently, there was minimal change in the Cs adsorption capacity. In contrast, for the bentonite reacted with a 1 mol/L KOH solution, the dominant alteration process was the transformation of minerals in bentonite into zeolite minerals, which resulted in significant changes in physicochemical properties, in particular, a decrease in the swelling capacity. On the other hand, the Cs adsorption capacity increased up to 2 times compared with the raw bentonite.

Numerical modeling on nuclide transport around a nuclear waste repository under coupled thermo-hydro-mechanical condition

Coupled thermo-hydro-mechanical (THM) processes may raise the uncertainty of nuclide transport behavior in long-term operation of nuclear waste repository. A far-field modeling framework on nuclide transport around a nuclear waste repository under coupled THM conditions was developed and verified. Base on conceptual models of high-level waste repository in fractured rocks, a three-dimensional repository model including a vertical fault and a horizontal fracture was built, and influence of coupled THM processes on nuclide transport is numerically investigated. Effects of repository depth, fracture inclination, and internal aperture heterogeneity were investigated using the developed model. The results show that the coupled THM processes significantly affect nuclide transport behavior, especially in the early stages of nuclide leaching. The thermal stress induced by heat release of nuclear waste causes the reduction in fracture aperture around the repository. The nuclide transport under THM conditions is retarded before 103 years than that under hydraulic condition. The deeper locations of the candidate repository exhibit the lower rate of nuclide transport. The inclined fracture induces opposite flow directions between two fractures, which causes the delaying of nuclide transport. Fractures with heterogeneous apertures have preferential flow paths, which results in early arrivals of nuclide transport than fractures with homogenous apertures.

Multiphase flow modeling at the component level for the Swiss deep geological repository

Abstract. In a deep geological repository for radioactive waste, anaerobic corrosion of various metals lead to the formation of hydrogen. In Switzerland, the implementor (i.e., Nagra) is commissioned to describe and evaluate safety-relevant processes related to gas that can affect the long-term evolution of low- and intermediate-level waste (L/ILW), high-level waste (HLW), and combined L/ILW and HLW repositories. Key tasks include the evaluation of gas and radionuclide release pathways and the pressure and temperature evolution in the repository using multiphase and multicomponent flow and transport models. The Swiss repository design foresees the installation of multiple seals (engineered barriers) in the repository: (i) the V1 seals next to the waste emplacement caverns and tunnels, (ii) the V2 seals located in the access tunnels toward the emplacement caverns and tunnels, and (iii) the V3 seals positioned in the shafts of the repository. These seals are designed to satisfy a wide range of requirements, including requirements related to the hydraulic evolution of the repository and the associated transport of gas, water, and radionuclides. A modeling workflow is currently being developed that integrates modeling performed both at the repository scale using site-specific models and at the component scale using semi-generic models. The repository-scale models are built to assess the thermo-hydraulic evolution in the entire repository, whereas the component-scale models allow for more detailed evaluations of the gas and water flows in key structures of the repository, such as the V1, V2, and V3 seals as well as the emplacement caverns and tunnels. This conference contribution describes the methodology and workflow developed to integrate these models, with a focus on the development and functionality of the component-scale models.

Potential and challenges of applying artificial intelligence (AI) in geosciences to the search for a high-level waste repository in Germany

Abstract. In a science-based site selection procedure (StandAV), the Federal Republic of Germany is searching for a site with the best possible safety for a repository for high-level waste (HLW) over a period of 1 million years. This is a challenging task, given the size of Germany, its geological variability and the verification period required to ensure the best possible long-term safety. In addition, an enormous amount of heterogeneous geodata has to be processed. The application of artificial-intelligence-based methods in geosciences has great potential for dealing with large heterogeneous data sets. In the German Federal Office for the Safety of Nuclear Waste Management (BASE)-funded project “Application of artificial intelligence (AI) in the site selection process for a deep geological repository (FKZ 4721E03210)”, an interdisciplinary assessment tool is being developed to evaluate the applicability of AI methods in the geosciences. This contribution focuses on the potential and challenges of applying AI in geosciences with respect to key geological activities in the StandAV. Limitations that may arise from the use of AI with respect to key activities in the StandAV are highlighted. The necessary conditions for its future applicability are proposed. The results show that AI methods offer clear advantages over conventional methods for data management and handling large geological datasets and for modelling complex long-term and coupled geological processes. However, AI methods are generally only transferable to the geoscientific questions of the StandAV with methodological and subject-specific adaptations. Furthermore, the use of AI requires sufficient data, both in terms of quality and quantity. The study also shows that AI should only be used in a supportive way to address geological issues in key activities and should not have any decision-making power when used in StandAV. For example, AI can carry the risk of data and developer bias, which in turn can have serious consequences for the correct interpretation of results. High demands must be placed on the traceability of the AI methods used. AI methods that do not meet the transparency requirements of the StandAV carry a significant risk of jeopardising public confidence in the participation process. This could increase the general mistrust and scepticism towards AI in the public perception (Krob et al., 2023). It is strongly recommended that all methods should be evaluated and validated iteratively and that the results should be made available to the public when applied to the key activities of the StandAV.

Towards conditioning discrete fracture network models: a Monte Carlo simulation approach including existing site data

Abstract. Crystalline rocks are inherently more or less densely permeated by fractures at very different scales. They often represent the hydraulically dominant flow paths compared to the low-permeable matrix. Consequently, finding potential sites for high-level waste repositories in crystalline host rock is challenging. Fracture inter-connectivity significantly affects geomechanical integrity and radionuclide transport (Mönig et al., 2020). Hence, an accurate representation of the present-day fracture system is a prerequisite for describing future evolutions of a repository. However, information on fracture properties is spatially limited. This shows the necessity of combining existing fracture data and stochastic fracture network modelling. In this manner, spaces with a lack of information can be considered for modelling (Lei et al., 2017). In Mrugalla et al. (2020), generic geological models based on statistical parameters were used to test the methodology for a safety analysis in crystalline rock within the scope of the CHRISTA II project. By using representative outcrop data, discrete fracture network (DFN) models of 2D fractures were generated stochastically, upscaled, and mapped onto a finite-element grid. However, individual stochastic fracture network realizations seldom accurately represent geological reality. Additionally, data from existing fractures must be incorporated. This work aims to understand the uncertainties regarding the location, extent, and other geometrical properties of fractures such as the aperture governing flow patterns. The statistical distributions of these parameters can exhibit significant variations both laterally and depth-wise. Uncertainties are addressed by superimposing a large set of fracture network realizations. For this purpose, Monte Carlo methods are applied to derive a best-guess fracture network. An approximation of the real fracture system will require consideration of known fracture data (e.g. Dorn et al., 2013) from surface and subsequent underground explorations. Site-specific data will be used for demonstration purposes. The focus is on developing a holistic model based on the DFN model and its congruence with field observations. The methodological treatment of underlying data-collection methods, given their different resolutions, accuracies, and restrictions, will be an important aspect. Moreover, the implications of the effects on three-dimensional radionuclide transport will be exemplarily investigated in the generated model in the sense of what-if scenarios. This is done with special emphasis on matrix–fracture diffusion and adsorption as possible retention mechanisms and parameter sensitivities such as local aperture changes.

Radionuclide Transport in Channel Networks with Radial Diffusion in the Porous Rock Matrix

Water flows in only a small fraction of the total area of the fractures in fractured rocks. The width of the “channels” is often in the range of centimeters to tens of centimeters. Nuclides can diffuse into and out of the porous rock matrix, which causes them to be significantly retarded compared to the water velocity. In discrete facture networks, diffusion is modeled to be linear and perpendicular to the fracture surface. From a narrow channel, the diffusion cloud would then be as wide as the channel. When the nuclide has propagated farther than the channel width, the diffusion will become essentially radial, which allows the nuclide flux to increase enormously. For the times of interest for a repository for high-level nuclide waste, this will increase nuclide flux into the matrix by tens to thousands of times, and consequently, the nuclide retardation in the flowing water. Radial diffusion was not invoked in the performance assessment of the Forsmark site, which in January 2022 was chosen by the government to locate Sweden’s high-level waste repository. It is shown, using data from this site, that the effect of radial diffusion from the narrow channels considerably increases the retardation of any escaping radionuclides, potentially allowing for the use of thinner copper canisters.

Fractional Advection Diffusion Models for Radionuclide Migration in Multiple Barriers System of Deep Geological Repository

Based on the multiple barriers concept of deep geological disposal of high-level waste, fractional advection diffusion equations for radionuclide migration in multiple layers low-permeability porous media are proposed in this work. The presented fractional advection diffusion models in terms of different definitions of fractional derivative are analytically addressed via the Laplace integral transform method. This work provides a theoretical foundation for further simulations of radionuclide migration in the multiple barriers system of the high-level waste repository.

Re-passivation rate and conduction mechanism of surface film on copper in nitrite solutions

In this work, an effort was put to verify the usefulness of the potential step re-passivation technique in studying the stress corrosion cracking (SCC) susceptibility of copper in environments simulating the final repository of high-level nuclear waste. Validation experiments in NaNO2 solutions (0.005, 0.05 and 1.0 M) showed that the technique is applicable with certain boundary conditions. In addition, conduction mechanism of passive films on Cu in nitrites is studied with impedance spectroscopy and quantitatively modeled by the Mixed-Conduction Model for oxide films. As a result, possible correlations between electrochemically derived parameters and SCC susceptibility are found and discussed.

Lithology-Controlled Hydrodynamic Behaviour of a Fractured Sandstone–Claystone Body in a Radioactive Waste Repository Site, SW Hungary

The fracture network modelling and hydrogeological assessment were performed in an 845 m deep borehole of the potential high-level waste repository formation and its caprock. The geometry of the fracture network was simulated using the discrete fracture network (DFN) modelling method, which is based on the geometric characteristics of the individual fractures. The hydrogeological evaluation was based on changes in porosity and permeability along the borehole using flow zone indicator (FZI) values that denote hydraulic flow units (HFU) within the rock body. Fracture network characteristics and hydrogeological features are mainly determined by the wellbore lithology, which can be divided into three zones. The sandstone body was intersected in the upper 300 m of the borehole, which forms a single HFU. The second zone was developed along with the transition zone between the sandstone and the underlying claystone bodies. Here the predominant rock type is claystone, but the characteristics of the fracture network are distinctly different from the deeper parts of this rock body. Below 400 m is the third zone, where distinct and extensive HFU-s could not form, probably due to different water–rock interaction processes that could have changed the porosity and permeability from point to point in the claystone.

Selenide [Se(-II)] Immobilization in Anoxic, Fe(II)-Rich Environments: Coprecipitation and Behavior during Phase Transformations.

The radionuclide selenium-79 (Se-79) is predicted to be a key contributor to the long-term radiologic hazards associated with geological high-level waste (HLW) repositories; hence its release is of pertinent concern in the safety assessment of repositories. However, interactions of reduced Se species with aqueous Fe(II) species and solid phases arising from the corrosion of a steel overpack could play a role in mitigating its migration to the surrounding environment. In this study, we examined the immobilization mechanisms of Se(-II) during its interaction with aqueous Fe(II) and freshly precipitated Fe(OH)2 at circumneutral and alkaline conditions, respectively, its response to changes in pH, and its behavior during aging at 90 °C. Using microscopic and spectroscopic techniques, we observed β-FeSe precipitation, regardless of whether Se(-II) reacts with aqueous species or solid phases, and that modifying the pH following initial immobilization did not remobilize Se(-II). These observations indicate that Se(-II) migration beyond the overpack can be effectively and rapidly retarded via interactions with Fe(II) species arising from overpack corrosion. Thermodynamic calculations, however, showed that iron selenides became metastable at alkaline conditions and will dissolve in the long term. Aging experiments at 90 °C showed that Se(-II) can be completely retained via the crystallization of ferroselite at circumneutral conditions, while it will be largely remobilized at alkaline conditions. Our results show that Se(-II) mobility can be significantly influenced by its interactions with the corrosion products of the steel overpack and that these behaviors will have to be considered in repository safety assessments.

AREHS: effects of changing boundary conditions on the development of hydrogeological systems: numerical long-term modelling considering thermal–hydraulic–mechanical(–chemical) coupled effects

Abstract. Within the framework of the “Gesetz zur Suche und Auswahl eines Standortes für ein Endlager für hochradioaktive Abfälle” (Repository Site Selection Act – StandAG), the geoscientific and planning requirements and criteria for the site selection for a repository for high-active nuclear waste are specified. This includes, among others, the modelling of hydrogeological scenarios such as how future cold and warm periods and associated glaciation events can change the (petro-)physical properties specified in the StandAG as well as the natural hydrogeological properties of the overall system through, for example, reactivation of faults or changes in hydraulic gradients and consequently flow directions. The main objective of the AREHS (Effects of Changing Boundary Conditions on the Development of Hydrogeological Systems) project, funded by BASE (Federal Office for the Safety of Nuclear Waste Management; FKZ 4719F10402), is to model the effects of changing external boundary conditions on the hydrogeologically relevant parameters and effects (e.g. hydraulic permeability, porosity, migration pathways, fluid availability, hydraulic gradients) of a generic geological repository in Germany in all three potential host rocks (clay, salt and crystalline rocks) and its surrounding hydrogeological setting (Table 1). Special attention is paid to the cyclic mechanical loading and unloading due to glaciation events and the resulting stress changes (M), as well as induced temperature effects (T) due to permafrost and warm periods. As such processes can cause changes in the coupled far-field regime with groundwater flow and groundwater supply (H), as well as fluid transport due to thermal (T) and chemical (C) gradients, and reactivate faults/fractures (M) and thus create new/additional pathways, they are particularly relevant to the integrity of a repository over a period of 1 million years and must be properly captured with coupled THM(C) modelling. Before a model is set up for the different host rocks, a detailed assessment of relevant processes has been conducted based on NEA-2019 FEP catalogue (NEA, 2019) for high-level waste repositories. The modelling is performed using generic 3D models of typical host rock formations satisfying the StandAG criteria. Although the models for salt and clay rock have been adapted from generic models from recent research projects, for crystalline rock a new generic model had to be developed (Fig. 1) considering discontinuities of different scales that have to be incorporated into the THM(C) models explicitly as DFN (Discrete Fracture Network) networks. This is done by coupling two numerical codes: DFN-lab and 3DEC. A central phase in the overall modelling process is the benchmarking of the models with data from existing models and with field-scale studies. This is done separately for all three host rocks. In addition to extending the modelling capacities for glaciation processes and verifying by corresponding benchmarking tests (analytical solutions and literature comparisons), automated workflows have been developed to generate OpenGeoSys models from GOCAD structure models. Script-based automated workflows improve software quality for site investigation, especially in a sense of modularization as well as reproducibility. The generic workflow concept is currently being tested for the literature-based benchmarks and will, therefore, support a persistent and sustainable benchmarking procedure in the future.

Analysis of double-layered buffer in high-level waste repository

Buffer is the main component of the engineering barrier system (EBS) in high-level radioactive waste (HLW) disposal repository. Reliable EBS performance assessment requires the delicate numerical modeling of the buffer layer. This study presents the sensitivity analysis of thermal and hydraulic parameters in the repository by using COMSOL Multiphysics, and proposes a new buffer barrier with double layers consisting of buffer-A with higher heat conductivity closing to the HLW canister and buffer-B with lower hydraulic conductivity closing to surrounding rock. From results of the sensitivity analysis, it is concluded that the thermal conductivity and hydraulic conductivity are high sensitivity parameters, and specific heat capacity, water density and water compressibility are low sensitivity parameters. The increase of the thermal conductivity in buffer-A results in effectively reducing the peak temperature in the buffer. Therefore, the double-layer buffer is advantageous and effective for improving the repository safety.

Optimal mixing scheme for graphite–bentonite mixtures used as buffer materials in high-level waste repositories

Optimal mixing scheme for graphite–bentonite mixtures used as buffer materials in high-level waste repositories

Model tests and corresponding numerical simulations on cave model subjected to thermo-mechanical loading

Geological repository of high-level nuclear waste (HLNW), the most feasible approach for the safe and permanent treatment of HLNW without human intervention, has been investigated for years by many researchers. In some countries, real facilities for the geological repository are already under construction. In Japan, however, due to complicated geologic conditions, especially underground water and fractured rock masses, and the high risk of natural disasters, ensuring the long-term stability of the method remains a struggle. The influential factors include underground water, heat generation from radioactive waste, and thermal and chemical weathering of the surrounding rock mass as a natural barrier. It is difficult to estimate and verify the long-term stability for up to one hundred thousand years, a complicated thermal–hydraulic-mechanical-chemical coupling behavior, via any field test. The objective of the study is to develop a numerical method for predicting the long-term stability of geological repositories. As the first step toward realizing this objective, heating and loading tests on cave model made of man-made rock specimens that are composed of diatoms, gypsum, and water, which are viscoplastic materials, were conducted, based on which a newly proposed numerical method with finite element method (FEM) was used to describe the thermal, mechanical, and time-dependent behavior of the model tests for a geological repository. To ensure the accuracy of the numerical calculations, all the material parameters in the thermoelasto-viscoplastic model with consideration of overconsolidation, the structure, and the influence of intermediate stress were determined via triaxial compression/creep tests under various temperatures, confining stresses, and loading rates. Finally, the validity of the numerical method was demonstrated by model tests over a limited time span.

Numerical analysis of the influence of the number of waste canister in borehole on the temperature, stress, and displacement in the near field of the high-level waste repository

Safe disposal of high-level waste is a challenging problem facing the scientific, technological, and engineering communities. The actual high-level waste disposal is closely related to the number of waste canisters in a single borehole. The influence of the number of waste canisters in a single borehole on the near-field temperature, stress, and displacement of the repository is directly related to the safety and cost of waste disposal. In this paper, based on the conceptual model of the high-level waste repository, the influence of the number of waste canisters in a single vertical borehole on the near-field temperature, stress, and displacement of the high-level waste repository was calculated and analyzed by using the 3DEC program. The results show that as the number of waste canisters in a single borehole increases, its heat release capacity is enhanced, and the temperature in the same area near the repository increases gradually; the temperature gradient increases gradually. The more waste canisters in a single borehole, the higher the temperature of the observation point near the same location of the repository (about 30°C), the temperature difference is getting larger and larger, and the average increase of temperature difference at observation point is about 8.1°C. The change of normal stress at the observation point is obvious when the waste canister releases heat for about 0–1 year; after that, the compressive stress decreased slightly, and then the stress and time curve was basically horizontal; the stress difference is getting larger and larger; the average increase of stress difference is about 0.0545MPa.The general trend of observation point displacement is that when the waste canister releases heat for about 0–1 year, displacement increases greatly, and then displacement increases less and presents a linear distribution trend; the displacement difference is getting larger and larger; the average increase of displacement difference is about 0.00034m. The thermal superposition effect of waste canisters added in a single borehole in engineering design cannot be ignored, and it showed that attention should be paid to the number of waste canisters in the disposal pit.

Seismic response of canisters embedded in a repository analyzed through centrifuge modeling

High-level waste (HLW), one of the most poisonous materials known to science, includes spent fuel from nuclear power plants. Therefore, nuclear engineers seek to isolate HLW from the Earth's biosphere by using multibarrier systems, including engineered and natural barriers deep below the surface of the earth. Typically, disposal holes are drilled into intact rocks. Canisters and buffer materials are then placed in the drilled holes. These highly stable canisters should not be easily affected by the natural environment, human activities, and tectonic movement. However, Taiwan is located in the Ring of Fire of the Pacific Ocean; thus, earthquakes threaten Taiwan frequently. Consequently, scholarly investigations must expand knowledge regarding the effects of earthquake-induced vibration on the canisters and buffer materials placed in the drilled holes and on the disposal system. This study assumes that the relevant disposal holes are created in granite deposit layers and have no deformations and cracks. The methods and geometry of the KBS-3 V system were examined; in this study a physical apparatus one-tenth the size of the KBS-3 V system was designed. The one-tenth-scale physical apparatus was subjected to an artificial acceleration field of 10 g as a simulation of the in-situ stress between the canisters and buffer material. The physical model was positioned on a shaking table and subjected to simulated seismic events. During shaking, sensors measured the acceleration, pore water pressure, and total pressure values to determine the interactive behavior between canisters and buffer materials during seismic activity. Six models were developed with different initial water content and hydration conditions; these models simulated the state of the buffer material after construction, after underground water invasion of the disposal hole, and after saturation of the buffer material. After centrifuge modeling had been conducted, the container was disassembled to check for crack development in the surrounding buffer material. The results can be used to distinguish the difference between each stage of buffer blocks and to determine the behavior of canisters during shaking; thus, these results can be employed to design HLW repositories in seismically active zones.