In recent years, geological disposal of radioactive waste has focused on placement of highand intermediate-level wastes in mined underground caverns at depths of 500–800 m. Notwithstanding the billions of dollars spent to date on this approach, the difficulty of finding suitable sites and demonstrating to the public and regulators that a robust safety case can be developed has frustrated attemp...

A model for single-phase flow in porous media that are hierarchically fissured in regular patterns was derived by a recursive asymptotic expansion technique in [16] and part of [24]. This work rigorously justifies that model. Through recursive homogenization, we extend the doubleporosity model in [5], which has one fracture system and a matrix (rock) block system, to a triple-porosity model tha...

This review provides a comprehensive evaluation of the state-of-knowledge of radiation effects in crystalline ceramics that may be used for the immobilization of high-level nuclear waste and plutonium. The current understanding of radiation damage processes, defect generation, microstructure development, theoretical methods, and experimental methods are reviewed. Fundamental scientific and tech...

The TOUGH2/iTOUGH2 family of codes is being used to analyze various processes and phenomena in the unsaturated zone at the proposed high-level nuclear waste repository at Yucca Mountain, Nevada. Various models have been developed that help quantify properties of the volcanic tuffs, water flow, seepage into drifts, and thermally driven coupled processes arising from the heat emitted by radioacti...

EUROTRANS is a European research program for the transmutation of high level nuclear waste in an accelerator-driven system (ADS). As proposed, the driver linac needs to deliver a 2.5–4 mA, 600 MeV continuous-wave (CW) proton beam and later a 20 mA, 800 MeV one to the spallation target in the prototype-scale and industrial-scale demonstration phases, respectively. This paper is focusing on the c...

Conceiving of nuclear energy as a social experiment gives rise to the question of what to do when the experiment is no longer responsible or desirable. To be able to appropriately respond to such a situation, the nuclear energy technology in question should be reversible, i.e. it must be possible to stop its further development and implementation in society, and it must be possible to undo its ...

The concept of disposal of high-level radioactive waste in deep boreholes, and probabilistic performance assessment (PA) of a generic disposal system are described. A series of preliminary PA simulations, conducted to evaluate the possible migration of radionuclides to an accessible environment, are presented. The PA simulations provide estimates of radionuclide releases and mean annual radiati...

In this paper, risk tolerance with regard to nuclear waste is investigated. It is shown that Swedish respondents did not readily accept a local high-level nuclear waste repository, contrary to claims based on polling data. The important role played in Sweden by misleading survey questions is pointed out and demonstrated on empirical data where formulations and procedures are varied. The accepta...

Mixed radioactive and chemical wastes stored in tanks across the DOE complex generate hydrogen, ammonia, nitrous oxide, and nitrogen by a complex series of radiolytic and thermolytic reactions. Flammable conditions may result when these gases accumulate in the dome space of the waste tanks. A phenomenological model was developed that successfully predicts gas generation rates for many of Hanfor...