Search results for "Radioactive waste"
showing 10 items of 34 documents
Antineutrino monitoring of spent nuclear fuel
2016
Military and civilian applications of nuclear energy have left a significant amount of spent nuclear fuel over the past 70 years. Currently, in many countries world wide, the use of nuclear energy is on the rise. Therefore, the management of highly radioactive nuclear waste is a pressing issue. In this letter, we explore antineutrino detectors as a tool for monitoring and safeguarding nuclear waste material. We compute the flux and spectrum of antineutrinos emitted by spent nuclear fuel elements as a function of time, and we illustrate the usefulness of antineutrino detectors in several benchmark scenarios. In particular, we demonstrate how a measurement of the antineutrino flux can help to…
2019
Final disposal of spent nuclear fuel (SNF) from nuclear power plants (NPPs) is an ethical issue with implications within and across generations. We address this issue from the perspective of nuclear communities that host nuclear waste disposal sites. These are primarily the communities that face injustice due to the potential radiological risks. A resident survey (n = 454) was conducted in two Finnish nuclear communities, i.e. Eurajoki and Pyhajoki, that are being considered as alternative sites for a second repository for SNF. The nuclear waste management (NWM) company Posiva is already building a repository in Eurajoki, the first in Finland. These communities are in different stages of th…
2021
Facing a Toxic Object
2021
AbstractOver the past decades, industrial societies have produced a range of substances whose effects humans increasingly identify as toxic—a prominent example is radioactive waste and the question of its disposal. This fabricated “object of modernity” not only calls for the knowledge of the natural sciences, it also affects society at large in its immense challenge of figuring out how to dispose of this material and altogether “detoxify” society from its hazardous activity. The contribution develops a heuristic perspective on toxic objects, exemplified by analyzing documents with a focus on how different societal actors in Germany problematize high-level radioactive waste (HLW) in the cont…
On the physico-chemical evolution of low-pH and CEM I cement pastes interacting with Callovo-Oxfordian pore water under its in situ CO2 partial press…
2014
International audience; Abstract Within the framework of geological repositories for radioactive waste, structural concretes must be adapted to the underground chemical conditions. CEM I cement-based materials are characterised by high pH that may produce an alkaline plume in the near-field of the repository. In order to avoid this problem, low-pH cements have been designed. This study compares the physico-chemical behaviour of a low-pH material with a CEM I cement paste, both being subjected to leaching by an aqueous solution. An original experimental setup was designed to reproduce the underground conditions using a specific CO2 regulation device. Under these conditions, the low-pH materi…
Optimization of Radioactive Waste Cementation for Decommissioning of Salaspils Research Reactor
2011
This paper deals with information on the radioactive waste cementation technology for decommissioning of Salaspils Research Reactor (SRR). Dismantled and segmented radioactive materials were cemented in concrete containers using tritiated water-cement mixture. The viscosity of water-cement mortar, mechanical tests of solidified mortar’s samples, change of temperature of the samples during solidification time and long time leakage of 137Cs, 14C, 60Co and 3T radionuclides was studied for different water-cement compositions with additives. The pH and electro conductivity of the solutions during leakage tests were controlled. It was shown, that water/cement ratio significantly influences on wat…
Extraction of lanthanides and actinides by a magnetically assisted chemical separation technique based on CMPO-calix[4]arenes
2001
A novel particulate system carrying CMPO ligands pre-organised on a calixarene scaffold has been synthesised and demonstrated to extract Eu3+, Am3+ and Ce3+ at high efficiency from simulated nuclear waste streams.
Hydro-mechanical behaviour of shallow Opalinus Clay shale
2019
In Switzerland, Opalinus Clay shale has been selected as the host formation for radioactive waste disposal. The minimum required depth of the repository is related to the long-lasting isolation required for the disposal (1 million years). During this period, possible erosion scenarios affecting the repository need to be analysed. Opalinus Clay from shallow depths (< 70 m) was sourced from a borehole in Northern Switzerland, where the formation was affected by a considerable exhumation process. This work aims to investigate the impact of the mentioned phenomenon on the hydro-mechanical behaviour of Opalinus Clay through one-dimensional consolidation and permeability measurements. Laboratory …
Trust, mistrust and distrust as blind spots of Social Licence to Operate: illustration via three forerunner countries in nuclear waste management
2021
The notion of social licence to operate (SLO) has become a widely applied concept for companies in mining and resource extraction industries to manage their social and community relations, in the face of local criticism and opposition. SLO literature and practice have highlighted earning the trust of the local community as a key requirement for an SLO. This article addresses three weaknesses in how the current SLO literature addresses trust. The arguments are illustrated via examples from nuclear waste management in Finland, France and Sweden–three forerunners in implementing high-level nuclear waste repository projects. Nuclear waste management constitutes a relevant case for analysis, as …
Increasing understanding and confidence in THM simulations of engineered barrier systems
2020
Previous studies on the modelling of coupled thermo-hydro-mechanical (THM) processes in bentonite-based engineered barrier systems (EBSs) showed the sensitivity of the output quantities to changes in the input parameters. To investigate the effects of uncertainties on the modelling results, to improve the understanding of the coupled processes active in the repository near field and to gain in-depth understanding of model uncertainties of different codes, a sensitivity analysis and code comparison of EBS simulations was performed within the Task Force on Engineered Barrier Systems. The analysis included variations in material parameter values, boundary and initial conditions, considered phy…