Filtered generated 217 hits.
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2017:34 Human capability to cope with unexpected events är publicerad
Background In the light of the Fukushima accident, it stood clear that the challenge of the unexpected is of great importance to both regulators and licensees. For SSM, as for many other national regulators, there was a selfevident need to learn more about the capabilities and actions of people when the unexpected arises and conditions are potentially extreme. A task group was set up within...
Content type: Publications -
2023:11 Study of degradation of spent fuel’s structural material and core components under long-term wet storage
SSM perspective Background Sweden is managing the spent nuclear fuel and core components from its commercial nuclear reactors with a national strategic plan. The fuel and core components are initially stored at the reactor site. After an on-site storage period to comply with transportation limits on decay heat and radiation, these materials are shipped to the Clab (Central Interim Storage...
Content type: Publications -
2023:14 Effect of gamma-irradiation on the redox states of the structural iron in bentonite clay
SSM perspective Background Bentonite clay is used as buffer and backfill material which form engineered barrier in the spent fuel repository. The buffer material surrounding the copper canister will be exposed to gamma and neutron radiations, especially during the first few hundred years after closure of the repository. The redox states of the structural iron in montmorillonite, the dominant...
Content type: Publications -
2024:17 Atomistic studies on the adsorption and desorption of radionuclides on fuel crud and system surfaces in Light Water Reactors
SSM perspective Background Radiation safety is of particular concern during power plant maintenance. Radionuclides produced by the neutron bombardment in the core during operation may accumulate on system surfaces such as the filter system or piping and contribute to the radiation field. Some ions that are prone to neutron capture often become trapped in the deposits on the fuel cladding...
Content type: Publications -
2024:18 Modelling Environmental Sensitization of Chromia Forming Nickel Base Alloys Toward Stress Corrosion Cracking in Light Water Reactors by Atomistic Simulations
SSM perspective Background Stress corrosion cracking (SCC) in load bearing structures has been a longstanding issue both in pressurized and boiling water reactors. The specific environment in nuclear power applications consists of high temperatures and pressures that together with the effects of the radiation field on the coolant composition provide tough conditions for the materials used in...
Content type: Publications -
2013:07 Corrosion of copper in distilled water without molecular oxygen and the detection of produced hydrogen
In this report, results are presented for copper which has been exposed to pure anoxic water in the temperature interval of 21 °C to 55 °C up to a total of 19 000 hours. Characterisations of copper surfaces after exposure have been performed ex-situ, meaning after termination of the experiment and exposing the specimen to normal atmospheric environment. Ideally characterisation of surfaces...
Content type: Publications -
2012:11 Issues in the corrosion of copper in a Swedish high level nuclear waste repository
The objective with this research project was to increase knowledge in the area of copper corrosion in the planned repository environment and obtain information on how copper corrosion evolves during the assessment period of 100 000 years. The equilibrium chemical composition of groundwater close to the canister as a function of temperature has been calculated by use of a thermodynamics code...
Content type: Publications -
2011:26 The influence of temperature and fluid pressure on the fracture network evolution around deposition holes of a KBS-3V concept at Forsmark, Sweden
In preparation for the review of SKB’s license application for disposal of spent nuclear fuel, SSM is conducting studies to evaluate the performance of the multi-barrier principle on which the KBS-3 concept is based. Copper canisters containing the spent nuclear fuel are placed into granitic bedrock at about 500 m depth and embedded in clay. Thus, the rock, the clay and the copper canister...
Content type: Publications -
2011:12 Analysis of Barrier Performance: Modelling of Copper corrosion scenarios with and without buffer erosion
The purpose of this project was to develop a numerical modelling capacity to address the corrosion of the copper canister under gradually changing transport conditions caused by buffer erosion and removal of buffer mass. Due to the complexity of this task, such a model cannot be realistic in all respects, but the present effort should address the feasibility of solving numerical and...
Content type: Publications -
2011:11 Handling Interfaces and Time-varying Properties in Radionuclide Transport Models
Quintessa’s QPAC code has been used to investigate the Qeq approach. The conclusions from this simulation study are the following. The basic approach to calculating Qeq values is sound, however, narrow channels could lead to the same release as larger fractures with the same pore velocity, so a channel enhancement factor of √10 should be considered. A spalling zone that increases the area of...
Content type: Publications