Simulation of the Super Critical Water Loop Using ATHLET Code During an Abnormal Scenario

2021 ◽  
Vol 7 (2) ◽  
Author(s):  
Guido Mazzini ◽  
Alis Musa ◽  
Rostilav Fukac
Keyword(s):  
Supercritical Water ◽  
Neutron Field ◽  
Operating Conditions ◽  
Test Channel ◽  
The Czech Republic ◽  
Material Compatibility ◽  
High Temperature And Pressure ◽  
State Office ◽  
Research Organizations ◽  
Temperature And Pressure

Abstract Supercritical water (SCW) has advantages like high thermal efficiency and can operate at high temperature and pressure. At the same time, however, these properties bring up related issues, such as material compatibility and corrosion resistance. In an effort to fully investigate the operating conditions, and solutions to these issues, test facilities are being built by many research organizations. One such organization, the Research Center Řež (CVR) located in the Czech Republic, has developed an experimental supercritical water loop (SCWL). The purpose of this loop is to provide experimental data from material testing in various conditions, including operating under the neutron field. This will be achieved by inserting a test channel into the existing experimental reactor light water reactor 15 (LVR-15), which will require a license from the state nuclear regulator (State Office for Nuclear Safety (SUJB)). Part of the licensing documentation is the safety analysis, which combines results from developed models using the thermohydraulic code ATHLET 3.1 A patch 1, as well as the experimental out of pile data. Among the postulated scenarios, an abnormal sequence (labeled A2—Loss of power in the loop) was analyzed in order to provide a preliminary benchmark. This scenario is similar to the postulated in-pile A2 and it was used for the benchmark activity. The aim of this paper is to present this activity including the adopted assumptions in the model. In particular, the paper presents, how these assumptions influenced the results indicating the discrepancies obtained in the first part of the transient.

Influence of Alloying Element on Corrosion Behavior of Hastelloy C-276 in Supercritical Water

2014 ◽  
Vol 525 ◽  
pp. 40-44
Author(s):  
Xing Ying Tang ◽  
Shu Zhong Wang ◽  
Yan Hui Li ◽  
Li Li Qian
Keyword(s):  
High Temperature ◽  
Synergistic Effect ◽  
Supercritical Water ◽  
Graphite Furnace ◽  
Corrosion Mechanism ◽  
Alloying Element ◽  
High Temperature And Pressure ◽  
Graphite Furnace Atomic Absorption ◽  
Temperature And Pressure ◽  
Low Solubility

The corrosion tests of Cr, Fe and Ni of Hastelloy C-276 were studied at high temperature and pressure with different aggressive components. The results were investigated by means of graphite furnace atomic absorption spectrophotometer (AAS). The Cr forms stable oxide and NiO is unstable. There is a synergistic effect between salt and oxygen leading to a severe loss of metals. The PO43- can improve the resistance to corrosion for Hastelloy C-276 due to the low-solubility phosphates. The colors of effluences can better support the changed concentrations of metals. The lost metals can reveal the corrosion mechanism of Ni-based alloys.

scholarly journals Oxidation Behavior of Nickel Based Alloys in Supercritical Water Environment

2020 ◽  
Vol 71 (9) ◽  
pp. 182-189
Author(s):  
Florentina Galan ◽  
Marian Catalin Ducu ◽  
Manuela Fulger ◽  
Denis Aurelian Negrea
Keyword(s):  
Supercritical Water ◽  
Corrosion Test ◽  
Water Environment ◽  
Future Research ◽  
Test Protocol ◽  
X Ray ◽  
High Temperature And Pressure ◽  
Temperature And Pressure ◽  
Materials Used ◽  
Real Challenge

Corrosion resistance is a key performance factor for engineering materials used in the supercritical water-cooled reactors (SCWR). Choosing the materials with the best characteristics in the corrosive environment for SCWR, at high temperatures and pressures, is a real challenge for many researchers. Therefore, this paper aims to test two nickel-based alloys (Incoloy 800HT and Inconel 718) and to analyze the microstructures of the samples following exposure in a supercritical environment. Oxidation tests were performed at high temperature and pressure (550oC, 25MPa) for up to 70 days. The samples were investigated using gravimetric corrosion test and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX). The results obtained can be used in future research of the test protocol to identify alloys that could be used for SCWR components.

Numerical Simulation on the Effect of Mist on Impingement Cooling of Double Chamber Model

2013 ◽  
Vol 483 ◽  
pp. 154-157
Author(s):  
Guang Jie Liu ◽  
Tao Xu ◽  
Hai Chao Ge ◽  
Zheng Lei Yu ◽  
Tatsuo Yoshino
Keyword(s):  
Operating Conditions ◽  
Simplified Model ◽  
Maximum Enhancement ◽  
Cooling Effectiveness ◽  
Impingement Cooling ◽  
High Temperature And Pressure ◽  
Adiabatic Cooling ◽  
Chamber Model ◽  
Temperature And Pressure ◽  
Double Chamber

As a continuous effort to develop a realistic mist impingement cooling scheme, this paper focuses on simulating mist impingement cooling under typical gas turbine operating conditions of high temperature and pressure in a simplified model of transform piece (double chamber model). Based on the heat-mass transfer analogy, the results of mist cases compare with the none droplet case could be enhanced 320% (the maximum enhancement of adiabatic cooling effectiveness) cooling effectiveness and reduce 108 K of wall temperature.

scholarly journals Sub- and Supercritical Extraction of Slovenian Hops (Humulus lupulus L.) Aurora Variety Using Different Solvents

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1137
Author(s):  
Katja Bizaj ◽  
Mojca Škerget ◽  
Iztok Jože Košir ◽  
Željko Knez
Keyword(s):  
Sulfur Hexafluoride ◽  
Total Yield ◽  
Extraction Yield ◽  
Operating Conditions ◽  
Influence Of Process Parameters ◽  
Humulus Lupulus L ◽  
Bitter Acids ◽  
Temperature And Pressure ◽  
Carbon Dioxide Co2 ◽  
The Mathematical Model

This work investigates the efficiency of supercritical fluid extraction of hops with a variety of solvents including carbon dioxide (CO2), propane, sulfur hexafluoride (SF6), and dimethyl ether (DME) at various densities (low-density and high-density). Operating parameters were 50 bar, 100 bar and 150 bar and 20 °C, 40 °C, 60 °C and 80 °C for all solvents, respectively. The influence of process parameters on the total yield of extraction and content of bitter acids in the extracts has been investigated. The mathematical model based on Fick’s second law well described the experimental extraction results. Furthermore, HPLC analysis has been used to determine α- and β-acids in extracts. The yield of bitter compounds in hop extracts was largely influenced by the type of solvent, the temperature and pressure applied during extraction. The results show that CO2 and propane were roughly equivalent to DME in solvating power, while SF6 was a poor solvent at the same conditions. The highest yield as well as the highest concentration of bitter acids in extracts were obtained by using DME, where the optimal operating conditions were 40 °C and 100 bar for the extraction of α-acids (max. concentration 9.6%), 60 °C and 50 bar for the extraction of β-acids (4.5%) and 60 °C and 150 bar for the maximum extraction yield (25.6%).

scholarly journals Lead Recovery from Solid Residues of Copper Industry Using Triethylenetetramine Solution

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 546
Author(s):  
Mateusz Ciszewski ◽  
Andrzej Chmielarz ◽  
Zbigniew Szołomicki ◽  
Michał Drzazga ◽  
Katarzyna Leszczyńska-Sejda
Keyword(s):  
Lead Extraction ◽  
Pressure Leaching ◽  
Base Metals ◽  
Lead Carbonate ◽  
Pure Lead ◽  
Industrial Processing ◽  
High Temperature And Pressure ◽  
Lead Recovery ◽  
Temperature And Pressure ◽  
Increasing Temperature

Industrial processing of mineral ores and concentrates generates large amounts of solid residues, which can be landfilled or further processed to recover selected elements depending on its economical profitability. Pressure leaching is a technology enabling high recovery of base metals like copper and zinc, transferring others like lead and iron to the solid residue. High temperature and pressure of such leaching leads to formation of sparingly soluble lead jarosite (plumbojarosite). The load of lead landfilled as solid residues resulting from such operation is so big that its recovery is perspective and crucial for waste-limiting technologies. This paper is devoted to lead extraction from pressure leaching residues using triethylenetetramine solution and then its precipitation as a commercial lead carbonate. The highest obtained recovery of lead was 91.3%. Additionally, presented technology allows to manage and recycle amine solution and reuse solid products. Produced pure lead carbonate can be directly added to smelting, not increasing temperature within the furnace.

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