Transient boundary conditions in the frame of high level radioactive waste disposal at deep geological repository

2nd _{Petrus-OPERA Conference on Radioactive Waste Management and Geological Disposal}

71

Transient boundary conditions in the frame of high level radioactive

waste disposal at deep geological repository

Abhishek Rawat1, Weibke Baille1 and Tom Schanz1*

1_{Chair of Foundation Engineering, Soil and Rock Mechanics, Department of Civil and Environment}

Engineering, Ruhr-Universität Bochum 44780, Germany Abstract

The deep geological disposal concept is considered as a viable option for permanent disposal for high level radioactive waste. In this concept, the waste canisters are buried in a stable geological media with multi layer engineered barriers. The functionality of each component of such engineered barrier systems must be ensured for entire design period. Compacted bentonite-sand mixture is considered as a key component of such multi layer engineered barrier system. Considerable research has been carried out to evaluate the phenomenological evaluation of compacted buffer material on field scale and laboratory scale. The main objective is to predict the material behaviour over a large time span using constitutive modeling approach. Field scale experiments have their own pros and cons. In spite of economical issues, the major drawback is to control the repository relevant boundary conditions. In this regards, a small scale column experiment setup is designed at Ruhr Universität Bochum. The novelty of the experiment set up is the ability to control the thermal and hydraulic boundary conditions in a precise manner and to capture the transient profile of key state parameters like temperature, relative humidity, swelling pressure and water content.