Radioelement Solubilities in SR-Site, the Influence of Variability and Uncertainty

2013 ◽  
Vol 1518 ◽  
pp. 179-184
Author(s):  
Christina Greis Dahlberg ◽  
Patrik Sellin ◽  
Mireia Grivé ◽  
Lara Duro ◽  
Kastriot Spahiu
Keyword(s):  
Thermodynamic Data ◽  
Safety Assessment ◽  
Groundwater Chemistry ◽  
Critical Element ◽  
Spent Fuel ◽  
Safety Critical ◽  
Water Composition ◽  
Assessment Period ◽  
The Impact

ABSTRACTIf groundwater enters a damaged canister and comes in contact with the spent fuel, radionuclides are released into the water in the void inside the canister when fuel dissolves. Solubility limits restrict the amount of radioelements that may migrate with the water flowing from the canister. In this study the impact of variability in groundwater chemistry compositions and the impact of uncertainties in thermodynamic data on solubility limits for Np, Pb, Pu, Ra, Se, Th, U and Zr were looked into. The solubility limits for all the studied radioelements seemed to be more sensitive to uncertainties in thermodynamic data than to differences in groundwater chemistry. The sole exception was radium, where variability in water composition has a somewhat larger impact. Radium is also the most safety critical element in the safety assessment SR-Site and groundwater compositions are expected to vary during the assessment period of one million years.

Sorption Behavior of Nickel and Palladium in the Presence of NH3(aq)/NH4+

2013 ◽  
Vol 1518 ◽  
pp. 231-236
Author(s):  
Taishi Kobayashi ◽  
Takayuki Sasaki ◽  
Ken-you Ueda ◽  
Akira Kitamura
Keyword(s):  
Thermodynamic Data ◽  
Safety Assessment ◽  
Sorption Behavior ◽  
Ammine Complexes ◽  
Surface Complexation Model ◽  
Nuclear Reprocessing ◽  
D Values ◽  
The Impact ◽  
Pumice Tuff ◽  
Low Level Radioactive Waste

ABSTRACTIt is necessary to assess the impact of nitrate salts and their reduction products (e.g. NH3(aq)/NH4+) contained in low-level radioactive waste generated from nuclear reprocessing process for the safety assessment of geological disposal of the waste. In the present study, sorption behavior of Ni and Pd on pumice tuff was investigated in the presence of NH3(aq)/NH4+. Under various NH3(aq)/NH4+ concentration, pH and ionic strength conditions, distribution coefficient (Kd) of Ni and Pd on pumice tuff was determined by a batch experiment. For Ni system, the Kd values showed no significant dependence on initial NH4+ concentration ([NH4+]ini < 1 M) in neutral pH region, which agreed with the prediction from thermodynamic data. For Pd system, the Kd values decreased with an increase of [NH4+]ini, suggesting the formation of stable ammine complexes (Pd(NH3)m2+ (m: 1 – 4)). The obtained Kd values for Ni and Pd were analyzed using a surface complexation model. By taking complexes predicted by thermodynamic data into account, sorption behavior of Ni and Pd in the presence of NH3(aq)/NH4+ were well explained.

Radionuclide Transport Calculations in the Safety Assessment SR 97

2000 ◽  
Vol 663 ◽  
Author(s):  
M. Lindgren ◽  
F. Lindström
Keyword(s):  
Input Data ◽  
Safety Assessment ◽  
Spent Nuclear Fuel ◽  
Near Field ◽  
Radionuclide Transport ◽  
Spent Fuel ◽  
Release Rates ◽  
Dose Limits ◽  
The Impact ◽  
Different Parts

ABSTRACTThis study treats radionuclide transport calculations for a canister defect scenario in the safety assessment SR 97, which concerns a deep repository for spent nuclear fuel of the KBS-3 type in Sweden. The aims of the calculations are to:Quantitatively describe the radionuclide transport.Show the impact of uncertainty in input data and show which parameters govern the calculated release rates.Compare three different real sites in Sweden (Aberg, Beberg and Ceberg) with each other and with dose limits given in Swedish regulations (none of the sites is considered in the on-going localization process). Only briefly described in this paper.Illustrate the impact of the different barriers in the system.Deterministic calculations illustrate the radionuclide transport for reasonable conditions. Uncertainty cases show the influence of the uncertainty for data related to different parts of the repository system by systematically giving them pessimistic values while all others are reasonable. Simplified probabilistic calculations have also been performed.The analysis shows that the most important parameters in the near field are the number of defective canisters and the instant release fraction. In the far field the most important uncertainties affecting release and retention are connected to permeability and connectivity of the fractures in the rock. The dose rate in the biosphere is essentially controlled by the possibilities of dilution.The calculated maximum doses for the hypothetical repositories are well below the dose limits, and hence they meet the acceptance criteria for a deep repository for spent fuel.

scholarly journals The Impacts of Groundwater Chemistry on Wetland Vegetation Distribution in the Northern Qinghai–Tibet Plateau

2019 ◽  
Vol 11 (18) ◽  
pp. 5022 ◽  
Author(s):  
Junju Zhou ◽  
Juan Xiang ◽  
Lanying Wang ◽  
Guoshuang Zhong ◽  
Guofeng Zhu ◽  
...  
Keyword(s):  
Multiple Scales ◽  
Groundwater Chemistry ◽  
Ion Concentration ◽  
Tibet Plateau ◽  
Distribution Data ◽  
Vegetation Distribution ◽  
Chemical Parameters ◽  
Weakly Alkaline ◽  
Artemisia Frigida ◽  
The Impact

Groundwater chemistry has an important impact on the vegetation distribution in inland areas. An in-depth understanding of the impact of groundwater chemistry on vegetation can help in developing an effective management strategy to protect the inland ecosystem. The aim of this study was to identify the influence of groundwater chemicals on species diversity and the distribution characteristics of wetland plants at multiple scales based on the groundwater chemical data from 15 sampling points and the distribution data of 13 plants in the Sugan Lake Wetland in 2016. The results show that the groundwater of the Sugan Lake Wetland is weakly alkaline, with high salinity and hardness; the water chemical type is Na-SO4-Cl; the concentration of the major water chemical parameters is significantly different and is the highest in the northwest, followed by the southwest, and is the lowest in the east; with an increase in the groundwater depth, the concentration of major water chemical parameters first showed an increasing trend followed by a decreasing trend; Artemisia frigida Willd, Poa annua L. and Triglochin maritimum L. were adapted to the environment with a higher ion concentration of the groundwater, and their salt resistance was the strongest; Blysmus sinocompressus and Polygonum are more adapted to the environment with lower salinity and hardness of groundwater; Thermopsis lanceolata has stronger adaptability to the ion concentration, salinity, and hardness of groundwater; other plants are adapted to environments where the ion concentration, salinity, and hardness of the groundwater are moderate.

The education system in the era of the fourth industrial revolution: developing skills and thinking for learning

2021 ◽  
Vol 83 (1) ◽  
pp. 44-51
Author(s):  
S. Bespalyy ◽  
◽  
Ye. Ifutina ◽  
Keyword(s):  
Higher Education ◽  
Labor Market ◽  
Education System ◽  
Industrial Revolution ◽  
Digital Technologies ◽  
Professional Activity ◽  
Critical Element ◽  
Higher Education System ◽  
Fourth Industrial Revolution ◽  
The Impact

Computer systems and technologies are changing our society significantly. These changes are interconnected with both social and production spheres. Innovative digital technologies have a huge impact on the labor market and professional activity, contributing to their transfer to the electronic environment. Using digital technologies, modern people set new goals and solve problems with an increasing speed of problem solving, capitalizing on the possibilities of collaborative distributed actions within networks. In this regard, new competencies of specialists are in demand. Purpose: The purpose of this study was to establish the impact of the fourth industrial revolution on the education system and the development of skills and thinking for learning. Methods: When conducting scientific research, economic and statistical methods were used. These methods were also used in comparative analysis, as well as in assessing data and indicators of the higher education system, taking into account the impact of the fourth industrial revolution. The analytical method was used to consider the characteristics and factors influencing the development of skills and thinking for learning in modern conditions. The abstract-logical method is used to identify problems affecting the development of the labor market under the influence of digital technologies. Results and their value: The result of the study is that conclusions are drawn about the upcoming changes. Automation and digitalization are likely to lead to significant unemployment in most countries, so adaptation innovation policies are needed to help offset unemployment due to digitalization. Governments need to invest heavily in higher education as an economic development tool for their citizens. Lifelong learning should be identified as a critical element of success in the era of the fourth industrial revolution. Curricula should develop digital skills and address workforce disruptions due to automation.

Sensitivity of the neutron multiplication factor to water ingress into a spent fuel cask

Kerntechnik ◽  
2020 ◽  
Vol 85 (1) ◽  
pp. 38-53
Author(s):  
M. J. Leotlela ◽  
I. Petr ◽  
A. Mathye
Keyword(s):  
Gradual Increase ◽  
Primary Objective ◽  
Fuel Pellet ◽  
Main Body ◽  
Spent Fuel ◽  
Reactivity Effect ◽  
Water Ingress ◽  
Accident Scenarios ◽  
The Impact ◽  
Gain Access

Abstract An essential component of safety analyses is the investigation of accident scenarios. In this paper water ingress scenarios of spent fuel containers, as they may occur during transport or storage, are examined. In the main body of this paper, a number of paths are studied through which water can gain access to the spent fuel cask and eventually reach the fuel pellet, potentially resulting in an increase in reactivity as a result of over-moderation. The primary objective of this project was to perform an assessment of what, in the unlikely event of a Fukushima- type accident, the impact would be on the reactivity of the cask by analyzing a gradual increase in water level in the spent fuel casks. In addition, the way the keff of the system responds to such an increase is discussed. The paper also provides the results of an assessment of the reactivity effect of water ingress via various pathways/channels.

scholarly journals Spent UO2 TRISO coated particles – instant release fraction and microstructure evolution

2015 ◽  
Vol 103 (6) ◽  
Author(s):  
Hildegard Curtius ◽  
Gabriele Kaiser ◽  
Norman Lieck ◽  
Murat Güngör ◽  
Martina Klinkenberg ◽  
...  
Keyword(s):  
Microstructure Evolution ◽  
Spent Fuel ◽  
Coated Particles ◽  
The Impact ◽  
Very High

AbstractThe impact of burn-up on the instant release fraction (IRF) from spent fuel was studied using very high burn-up UO

An Integrated Approach to Welding, AUT and ECA for Pipeline Construction

2014 ◽  
Author(s):  
David Horsley ◽  
Jing Ma ◽  
Jan van der Ent ◽  
Casper Wassink ◽  
Martin Fingerhut
Keyword(s):  
Integrated Approach ◽  
Final Outcome ◽  
Critical Element ◽  
Unified Approach ◽  
Acceptance Criteria ◽  
Pipeline Construction ◽  
Girth Welds ◽  
Design Options ◽  
The Impact ◽  
Welding Productivity

An integrated approach for the development of welding, inspection, and alternative weld flaw acceptance criteria, as used for girth welds during pipeline construction is presented. Welding is typically the pace limiting step during pipeline construction and is critical element of pipeline integrity. As such it is vital that it be completed efficiently and with high quality. Each of these three elements is vitally important to welding productivity and quality. At the core of the approach is the coordination of the three elements such that they are developed in concert. By this coordinated effort, all design options are considered leading to optimization of the final outcome. The approach is described by providing an example alternative weld flaw acceptance criteria, and giving the logic pertaining to choices of welding setup, AUT setup, the standard used for design and construction, and the impact of choices within these three elements on the final outcome. The paper illustrates the importance of a unified approach on weld productivity and quality.

scholarly journals The Impact of Water Loss by Evaporation and Calcite Precipitation on the Sodium Adsorption Ratio (SAR) and an Alternative Method of Estimating the SAR of Irrigation Drainage Water

2020 ◽  
Author(s):  
Qiyu Zhou ◽  
William Bleam ◽  
Douglas Soldat
Keyword(s):  
Hazard Assessment ◽  
Water Loss ◽  
Irrigation Water ◽  
Drainage Water ◽  
Sodium Adsorption Ratio ◽  
Calcite Precipitation ◽  
Water Composition ◽  
Soluble Calcium ◽  
Irrigation Drainage ◽  
The Impact

Soil water loss by evaporation influences the sodium adsorption ratio (SAR) of irrigation drainage water. Evaporation concentrates sodium and magnesium but calcite precipitation has a more complicated effect on soluble calcium and alkalinity. Here we propose a revised sodicity hazard assessment that quantifies the impact of evaporative water loss and calcite precipitation on drainage water SAR. This paper shows sodicity hazard is determined by the initial composition of irrigation water as originally suggested by previous researchers, and provide a simple, accurate way to identify the potential sodicity hazard of any irrigation water. In particular, the initial equivalent concentration of alkalinity and calcium determine the salinization pathway followed during evaporation. If the irrigation water alkalinity exceeds soluble calcium expressed as equivalent concentrations, drainage water SAR approaches an upper limit determined by the initial relative concentration of sodium and magnesium. If irrigation water alkalinity is less than soluble calcium, drainage water SAR approaches a lower limit determined by the initial calcium, magnesium and sodium. In both cases the SAR is scaled by the square root of the concentration factor &radic;Fc quantifying soil water loss. To assess the impact of evaporation and calcite precipitation on the SAR and test the accuracy of the new sodicity hazard assessment, we evaluated data from previously published lysimeter studies. We plotted water composition boundaries for each source water, comparing these boundaries to the drainage water composition recorded in the lysimeter studies. As salinity increased by evaporation, each drainage water followed a distinct salinization path.

scholarly journals Strengthening the SSTC NRS Scientific and Technical Potential through Participation in the IAEA Coordinated Research Projects

2021 ◽  
pp. 5-13
Author(s):  
Yu. Balashevska ◽  
D. Gumenyuk ◽  
Iu. Ovdiienko ◽  
O. Pecherytsia ◽  
I. Shevchenko ◽  
...  
Keyword(s):  
Best Practices ◽  
Safety Assessment ◽  
Radiation Safety ◽  
Research Projects ◽  
Spent Fuel ◽  
Research Activities ◽  
Technical Potential ◽  
Technical Issues ◽  
Fuel Characterization ◽  
Definition Of

The State Scientific and Technical Center for Nuclear and Radiation Safety (SSTC NRS), a Ukrainian enterprise with a 29-year experience in the area of scientific and technical support to the national nuclear regulator (SNRIU), has been actively involved in international research activities. Participation in the IAEA coordinated research activities is among the SSTC NRS priorities. In the period of 2018–2020, the IAEA accepted four SSTC NRS proposals for participation in respective Coordinated Research Projects (CRPs). These CRPs address scientific and technical issues in different areas such as: 1) performance of probabilistic safety assessment for multi-unit/multi-reactor sites; 2) use of dose projection tools to ensure preparedness and response to nuclear and radiological emergencies; 3) phenomena related to in-vessel melt retention; 4) spent fuel characterization. This article presents a brief overview of the abovementioned projects with definition of scientific contributions by the SSTC NRS (participation in benchmarks, development of methodological documents on implementing research stages and of IAEA technical documents (TECDOC) for demonstration of best practices and results of research carried out by international teams).

Sign in / Sign up

Export Citation Format

Share Document