Corrosion Behaviour of Bare and NiCrAlY Coated Alloy 214 in Supercritical Water at 700 °C

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Suzan Bsat ◽  
Xiao Huang ◽  
Sami Penttila
Keyword(s):  
Supercritical Water ◽  
Nuclear Energy ◽  
Fossil Fuels ◽  
Corrosion Behaviour ◽  
Thermodynamic Efficiency ◽  
Coated Alloy ◽  
Core Components ◽  
Corrosion Behaviors ◽  
Supercritical Water Cooled Reactor

Concerns with greenhouse gas emissions and the uncertainty of long-term supply of fossil fuels have resulted in renewed interest in nuclear energy as an essential part of the energy mix for the future. Many countries worldwide including Canada, China, and EU are currently undertaking the design of generation IV supercritical water-cooled reactor (SCWR) with higher thermodynamic efficiency and considerable plant simplification. The identification of appropriate materials for in-core and out-of-core components to contain the supercritical water (SCW) coolant is one of the major challenges for the design of SCWR. This study is carried out to evaluate the oxidation/corrosion behaviors of bare alloy 214 and NiCrAlY coated 214 under SCW at a temperature of 700 °C/25 MPa for 1000 h. The results show that chromium and nickel based oxide forms on the bare surface after exposure in SCW for 1000 h. A dense and adhered oxide layer, consisting of Cr2O3 with spinel (Ni(Cr, Al)2O4), was observed on NiCrAlY surface after 1000 h in SCW.

Fission Product Release Under Supercritical Water-Cooled Reactor Conditions

2016 ◽  
Vol 2 (2) ◽  
Author(s):  
D. Guzonas ◽  
L. Qiu ◽  
S. Livingstone ◽  
S. Rousseau
Keyword(s):  
Supercritical Water ◽  
Fission Products ◽  
Fuel Pellet ◽  
Product Release ◽  
The Core ◽  
Fuel Pellets ◽  
Simulated Fuel ◽  
Core Components ◽  
High Concentrations ◽  
Supercritical Water Cooled Reactor

Most supercritical water-cooled reactor (SCWR) concepts being considered as part of the Generation IV initiative are direct cycle. In the event of a fuel defect, the coolant will contact the fuel pellet, potentially releasing fission products and actinides into the coolant and transporting them to the turbines. At the high pressure (25 MPa) in an SCWR, the coolant does not undergo a phase change as it passes through the critical temperature in the core, and nongaseous species may be transported out of the core and deposited on out-of-core components, leading to increased worker dose. It is therefore important to identify species with a high risk of release and develop models of their transport and deposition behavior. This paper presents the results of preliminary leaching tests in SCW of U-Th simulated fuel pellets prepared from natural U and Th containing representative concentrations of the (inactive) oxides of fission products corresponding to a fuel burnup of 60  GWd/ton. The results show that Sr and Ba are released at relatively high concentrations at 400°C and 500°C.

scholarly journals The Supersafe© Reactor: A Small Modular Pressure Tube SCWR

2012 ◽  
Vol 1 (2) ◽  
pp. 13-18 ◽  
Author(s):  
M. Yetisir ◽  
J. Pencer ◽  
M. McDonald ◽  
M. Gaudet ◽  
J. Licht ◽  
...  
Keyword(s):  
Research And Development ◽  
Supercritical Water ◽  
Nuclear Energy ◽  
Energy Systems ◽  
Full Scale ◽  
Development Effort ◽  
Gen Iv ◽  
Energy Grid ◽  
Supercritical Water Cooled Reactor ◽  
Primary Contribution

The SUPERSAFE© Reactor (SSR) is proposed as a small modular version of the Canadian supercritical water-cooled reactor (SCWR). The SCWR is Canada’s primary contribution to the Generation-IV (GEN-IV) International Forum’s (GIF) research and development effort toward the study and eventual deployment of advanced nuclear energy systems. All GEN-IV concepts, including the SCWR, have enhanced safety, improved economics, improved sustainability and enhanced security compared to contemporary reactors. The SUPERSAFE© Reactor (SSR) concept incorporates the enhanced features of the SCWR in a smaller core which could be deployed in areas with sparsely distributed population bases where it is impractical to have a full scale SCWR or large centralized energy grid. An overview of the SSR concept is presented in this work.

Various Design Aspects of the Canadian Supercritical Water-Cooled Reactor Core

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Metin Yetisir ◽  
Rui Xu ◽  
Michel Gaudet ◽  
Mohammad Movassat ◽  
Holly Hamilton ◽  
...  
Keyword(s):  
Supercritical Water ◽  
Thermal Efficiency ◽  
Nuclear Reactor ◽  
Reactor Core ◽  
Operating Conditions ◽  
Stress Distributions ◽  
Light Water Reactors ◽  
Core Components ◽  
Water Reactors ◽  
Supercritical Water Cooled Reactor

The Canadian Supercritical Water-Cooled Reactor (SCWR) is a 1200 MW(e) channel-type nuclear reactor. The reactor core includes 336 vertical pressurized fuel channels immersed in a low-pressure heavy water moderator and calandria vessel containment. The supercritical water (SCW) coolant flows into the fuel channels through a common inlet plenum and exits through a common outlet header. One of the main features of the Canadian SCWR concept is the high-pressure (25 MPa) and high-temperature (350°C at the inlet, 625°C at the outlet) operating conditions that result in an estimated thermal efficiency of 48%. This is significantly higher than the thermal efficiency of the present light water reactors, which is about 33%. This paper presents a description of the Canadian SCWR core design concept; various numerical analyses performed to understand the temperature, flow, and stress distributions of various core components; and how the analyses results provided input for improved concept development.

scholarly journals Special Issue: Materials for Nuclear Waste Immobilization

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3611 ◽  
Author(s):  
Hyatt ◽  
Ojovan
Keyword(s):  
Power Generation ◽  
Nuclear Waste ◽  
Nuclear Energy ◽  
Fossil Fuels ◽  
Spent Nuclear Fuel ◽  
Cementitious Materials ◽  
Special Issue ◽  
Waste Immobilization ◽  
Nuclear Waste Immobilization

Nuclear energy is clean, reliable, and competitive with many useful applications, among which power generation is the most important as it can gradually replace fossil fuels and avoid massive pollution of environment. A by-product resulting from utilization of nuclear energy in both power generation and other applications, such as in medicine, industry, agriculture, and research, is nuclear waste. Safe and effective management of nuclear waste is crucial to ensure sustainable utilization of nuclear energy. Nuclear waste must be processed to make it safe for storage, transportation, and final disposal, which includes its conditioning, so it is immobilized and packaged before storage and disposal. Immobilization of waste radionuclides in durable wasteform materials provides the most important barrier to contribute to the overall performance of any storage and/or disposal system. Materials for nuclear waste immobilization are thus at the core of multibarrier systems of isolation of radioactive waste from environment aimed to ensure long term safety of storage and disposal. This Special Issue analyzes the materials currently used as well as novel materials for nuclear waste immobilization, including technological approaches utilized in nuclear waste conditioning pursuing to ensure efficiency and long-term safety of storage and disposal systems. It focuses on advanced cementitious materials, geopolymers, glasses, glass composite materials, and ceramics developed and used in nuclear waste immobilization, with the performance of such materials of utmost importance. The book outlines recent advances in nuclear wasteform materials including glasses, ceramics, cements, and spent nuclear fuel. It focuses on durability aspects and contains data on performance of nuclear wasteforms as well as expected behavior in a disposal environment.

scholarly journals A Novel Iron Chloride Red-Ox Concentration Flow Cell Battery (ICFB) Concept; Power and Electrode Optimization

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1109
Author(s):  
Robert Bock ◽  
Björn Kleinsteinberg ◽  
Bjørn Selnes-Volseth ◽  
Odne Stokke Burheim
Keyword(s):  
Energy Storage ◽  
Large Scale ◽  
Fossil Fuels ◽  
Flow Cell ◽  
Iron Chloride ◽  
Carbon Electrodes ◽  
Concentration Difference ◽  
Term Energy ◽  
Short And Long Term

For renewable energies to succeed in replacing fossil fuels, large-scale and affordable solutions are needed for short and long-term energy storage. A potentially inexpensive approach of storing large amounts of energy is through the use of a concentration flow cell that is based on cheap and abundant materials. Here, we propose to use aqueous iron chloride as a reacting solvent on carbon electrodes. We suggest to use it in a red-ox concentration flow cell with two compartments separated by a hydrocarbon-based membrane. In both compartments the red-ox couple of iron II and III reacts, oxidation at the anode and reduction at the cathode. When charging, a concentration difference between the two species grows. When discharging, this concentration difference between iron II and iron III is used to drive the reaction. In this respect it is a concentration driven flow cell redox battery using iron chloride in both solutions. Here, we investigate material combinations, power, and concentration relations.

scholarly journals Study of the Synchrotron Photoionization Oxidation of Alpha-Angelica Lactone (AAL) Initiated by O(3P) at 298, 550, and 700 K

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4070
Author(s):  
Golbon Rezaei ◽  
Giovanni Meloni
Keyword(s):  
Atomic Oxygen ◽  
Fossil Fuels ◽  
Reaction Products ◽  
Photoionization Mass Spectrometry ◽  
Natural Substances ◽  
Primary Products ◽  
Major Reaction ◽  
Angelica Lactone ◽  
Significant Attention

In recent years, biofuels have been receiving significant attention because of their potential for decreasing carbon emissions and providing a long-term renewable solution to unsustainable fossil fuels. Currently, lactones are some of the alternatives being produced. Many lactones occur in a range of natural substances and have many advantages over bioethanol. In this study, the oxidation of alpha-angelica lactone initiated by ground-state atomic oxygen, O(3P), was studied at 298, 550, and 700 K using synchrotron radiation coupled with multiplexed photoionization mass spectrometry at the Lawrence Berkeley National Lab (LBNL). Photoionization spectra and kinetic time traces were measured to identify the primary products. Ketene, acetaldehyde, methyl vinyl ketone, methylglyoxal, dimethyl glyoxal, and 5-methyl-2,4-furandione were characterized as major reaction products, with ketene being the most abundant at all three temperatures. Possible reaction pathways for the formation of the observed primary products were computed using the CBS–QB3 composite method.

scholarly journals Edible Energy Production and Energy Return on Investment—Long-Term Analysis of Global Changes

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1011
Author(s):  
Bartłomiej Bajan ◽  
Joanna Łukasiewicz ◽  
Agnieszka Poczta-Wajda ◽  
Walenty Poczta
Keyword(s):  
Energy Efficiency ◽  
Return On Investment ◽  
Food Production ◽  
Energy Production ◽  
Crop Production ◽  
Fossil Fuels ◽  
Animal Production ◽  
Global Changes ◽  
Energy Return On Investment

The projected increase in the world’s population requires an increase in the production of edible energy that would meet the associated increased demand for food. However, food production is strongly dependent on the use of energy, mainly from fossil fuels, the extraction of which requires increasing input due to the depletion of the most easily accessible deposits. According to numerous estimations, the world’s energy production will be dependent on fossil fuels at least to 2050. Therefore, it is vital to increase the energy efficiency of production, including food production. One method to measure energy efficiency is the energy return on investment (EROI), which is the ratio of the amount of energy produced to the amount of energy consumed in the production process. The literature lacks comparable EROI calculations concerning global food production and the existing studies only include crop production. The aim of this study was to calculate the EROI of edible crop and animal production in the long term worldwide and to indicate the relationships resulting from its changes. The research takes into account edible crop and animal production in agriculture and the direct consumption of fossil fuels and electricity. The analysis showed that although the most underdeveloped regions have the highest EROI, the production of edible energy there is usually insufficient to meet the food needs of the population. On the other hand, the lowest EROI was observed in highly developed regions, where production ensures food self-sufficiency. However, the changes that have taken place in Europe since the 1990s indicate an opportunity to simultaneously reduce the direct use of energy in agriculture and increase the production of edible energy, thus improving the EROI.

scholarly journals Potential for Farmers’ Cooperatives to Convert Coffee Husks into Biochar and Promote the Bioeconomy in the North Ecuadorian Amazon

2021 ◽  
Vol 11 (11) ◽  
pp. 4747
Author(s):  
Mario A. Heredia Salgado ◽  
Ina Säumel ◽  
Andrea Cianferoni ◽  
Luís A. C. Tarelho
Keyword(s):  
Fossil Fuels ◽  
Agricultural Waste ◽  
The North ◽  
Income Sources ◽  
Ecuadorian Amazon ◽  
Specific Standard ◽  
The Government ◽  
Post Harvesting ◽  
Term Maintenance

Improving the livelihoods of communities living in fragile ecosystems, such as tropical forests, is among the main strategies to promote their conservation and preserve wildlife. In the Ecuadorian Amazon, farmers’ cooperatives are recognized as an important mechanism to improve the socioeconomic conditions of local communities. This study analyzes the integration of pyrolysis processes to convert agricultural waste into biochar as a way to implement the bioeconomy in these organizations. We found that post-harvesting processes in the studied farmers’ cooperatives are similar, and coffee husks are a potential feedstock to produce biochar. Although the environmental policies in Ecuador consider the valorization of agricultural waste, we did not find any specific standard to regulate the operation of pyrolysis facilities. Nonetheless, conversion of agricultural waste into biochar can contribute to (i) replacement of subsidized fossil fuels used in drying processes, (ii) prevention of environmental pollution caused by accumulation of waste, (iii) emergence of new income sources linked with the provision of carbon sequestration services, and (iv) the long-term maintenance of soil fertility. Currently, demonstration projects are needed to stimulate collaboration among farmers’ cooperatives, academia, the government, international cooperation agencies, and existing forest conservation initiatives.

Semantic Desktop for the End-UserSemantic Desktop für Anwender

i-com ◽  
2009 ◽  
Vol 8 (3) ◽  
pp. 25-32 ◽  
Author(s):  
Gunnar Aastrand Grimnes ◽  
Benjamin Adrian ◽  
Sven Schwarz ◽  
Heiko Maus ◽  
Kinga Schumacher ◽  
...  
Keyword(s):  
Knowledge Management ◽  
Knowledge Work ◽  
Personal Knowledge ◽  
Term Study ◽  
The Core ◽  
Personal Knowledge Management ◽  
Long Term Study ◽  
Core Components

AbstractThis article describes the Semantic Desktop. We give insights into the core services that aim to improve personal knowledge management on the desktop. We describe these core components of our Semantic Desktop system and give evaluation results. Results of a long-term study reveal effects of using the Semantic Desktop on personal knowledge work.

Sign in / Sign up

Export Citation Format

Share Document