Numerical interpretation of transient permeability test in tight rock

Pulse-decay method has been widely used to estimate the fluid transport properties of low-permeability geomaterials. In this context, radial flow transient pulse test is conducted to measure the water permeability of Cobourg limestone hollow cylinder. The proposed method applies hydraulic pulses to the sealed central cavity and then the cavity pressure dissipates as the fluid migrates into the saturated rock matrix. The influence of entrapped air bubbles within the pressurized cavity is crucial to interpreting permeability from transient pulse test. The modeling results indicate that the air inclusions can significantly increase the fluid compressibility and thus delay the hydraulic pulse decay process, which may lead to the underestimation of the rock permeability

Scenario Analysis for the Safety Assessment of Nuclear Waste Repositories: A Critical Review

A major challenge in scenario analysis for the safety assessment of nuclear waste repositories pertains to the comprehensiveness of the set of scenarios selected for assessing the safety of the repository. Motivated by this challenge, we discuss the aspects of scenario analysis relevant to comprehensiveness. Specifically, we note that (1) it is necessary to make it clear why scenarios usually focus on a restricted set of features, events, and processes; (2) there is not yet consensus on the interpretation of comprehensiveness for guiding the generation of scenarios; and (3) there is a need for sound approaches to the treatment of epistemic uncertainties