A Multimodel Framework for Quantifying Flow and Advective Transport Controlled by Earthquake-Induced Canister Failures in a Reference Case for Radioactive Waste Geological Disposal

Abstract

Characterizing flow and transport for earthquake-induced shear canister failure is critical for the performance and safety assessment of radioactive waste geological disposal. The study presents a modeling framework that integrates multiple models to account for fractures produced by shear displacements, evaluate canister failures, and simulate flow and advective transport in a conceptual repository site based on a selected reference case in an offshore island in western Taiwan. The typical KBS-3 disposal concept associated with 500 realizations of the shear-induced fracture properties is employed to quantify the uncertainty of flow and advective transport in the geological disposal site. The radionuclides in canisters are assumed to migrate through the shear-induced fractures surrounding the deposition holes. The results from 500 realizations show that two types of fractures produce a high potential to destroy canisters induced by the shear displacements. The earliest canister failure time influenced by possible shear movements is 0.23 million years for the reference case. The modeling framework identifies five canisters and the associated shear-induced fractures for flow and advective transport simulations. Based on the results of the density-dependent flow fields, the particle tracking algorithm enables the calculations of flow and transport parameters, including equivalent initial flux, equivalent flow rate, path length, travel time, and flow-related transport resistance for the identified five canisters. These parameters are critical for the performance and safety assessments of buffer erosion and canister corrosion near the disposal repository and the far field of the radioactive waste disposal site.

Verification of Particle Tracking and In Situ Tracer Experiment for the Gravel and Cholan Formation Composite in Northwest Taiwan

“…The transport resistance, often referred to as the "F-factor", is a parameter that describes the potential for retention and retardation of particle transport along a travel path [36][37][38]. This parameter is influenced by formation properties and flow-related characteristics, and it can be estimated based on the velocity of particle travel within the formation.…”

Review of the Modelling of Corrosion Processes and Lifetime Prediction for HLW/SF Containers—Part 1: Process Models

“…• Calculation of the time-dependent internal pressure due to hydrogen diffusion through the wall of a carbon steel container during the long-term anaerobic phase. Internal pressurisation offsets the compressive load from the buffer swelling and hydrostatic pressures, but will also lead to an increased risk of hydrogen-induced cracking due to internal or embedded flaws [227]; • The use of multiple models to determine the number and timing of canister failures due to earthquakes and shear across deposition holes in a KBS-3-type repository in crystalline rock [228].…”

“…Consequences of canister failure due to seismic activity Multiple Use of multiple models to determine the number and timing of canister failures due to earthquakes and shear across deposition holes in a KBS-3 type repository in crystalline rock in Taiwan. A total of five canisters are predicted to fail, with the first failure after 230,000 yr. [228] * Arranged in chronological order of publication.…”