Stability Validation Based on the OECD/NEA Oskarshamn-2 BWR Benchmark With Toshiba TRAC Version

2016 ◽  
Author(s):  
Takanori Fukunaga ◽  
Noriyuki Yoshida ◽  
Akira Mototani
Keyword(s):  
Initial Conditions ◽  
Safety Analysis ◽  
High Accuracy ◽  
Measured Data ◽  
Regulatory Body ◽  
Neutron Kinetics ◽  
The Core ◽  
Power Oscillations ◽  
Advanced Version ◽  
Good Agreement

We have developed a best-estimate transient code Toshiba TRAC version, a Toshiba advanced version of the TRAC code for BWR. This code is expected to be capable of simulating thermal hydraulic and neutron kinetics phenomena three-dimensionally with high accuracy for BWR transients. A licensing topical report for this code’s validation analyses will be submitted to the Japanese regulatory body for application to future licensing safety analysis. As one of the validation analyses, analysis for BWR stability is also important, and this code’s validation analyses for BWR stability based on the international OECD/NEA Oskarshamn-2 BWR benchmark have been implemented. The Oskarshamn-2 BWR experienced a core instability event, which culminated in diverging power oscillations with a decay ratio greater than 1.3 on February 25, 1999. This paper shows this code’s validation analyses of the core instability event. In conclusion, the initial conditions and the results of the instability event are also in good agreement with the measured data. This code is capable of simulating instability events well.

Validation of the Coupled System Code ATHLET/BIPR-VVER on Local Core Measured Data

2008 ◽  
Author(s):  
S. Nikonov ◽  
M. Lizorkin ◽  
S. Langenbuch ◽  
K. Velkov
Keyword(s):  
Experimental Data ◽  
Reactor Core ◽  
Coupled System ◽  
High Accuracy ◽  
Measured Data ◽  
Coolant Temperature ◽  
Data Sets ◽  
One Dimensional ◽  
Neutron Kinetics ◽  
Core Data

The modern coupled thermal-hydraulics neutron–kinetics code systems require validation by comparison with measured local core data. Measured assembly coolant temperatures at core outlet are applied for this purpose in this study. Experimental data have been collected during the commissioning phase of the NPP Kalinin-3. One of the experimental data sets is selected to be used for international benchmark purposes (1). The new modelling capabilities of the ATHLET/BIPR-VVER code as well as the validation on plant measurements are discussed in the paper. The detailed modelling features of the reactor core allow to predict the coolant temperature at the assembly outlet within a rather high accuracy even though ATHLET code is based on one dimensional thermal-hydraulic pipe models.

scholarly journals An Improved PV Output Forecasting Model by Using Weight Function: A Case Study in Cambodia

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Songkiate Kittisontirak ◽  
Aekkawat Bupi ◽  
Perawut Chinnavornrungsee ◽  
Kobsak Sriprapha ◽  
Pairash Thajchayapong ◽  
...  
Keyword(s):  
Weight Function ◽  
High Accuracy ◽  
Measured Data ◽  
Forecasting Model ◽  
Pv Module ◽  
Improve Accuracy ◽  
Software Programs ◽  
One Year ◽  
Good Agreement

This paper proposes a new concept to improve accuracy of PV forecasting model. The model was implemented by MATLAB/Simulink software using solar irradiance and module temperature as measurement parameters for calculation. The model was developed by single-diode equivalent circuits (5-p model) for simulated PV module power output and compared with other software programs for validation which showed correct PV characteristics. To achieve high accuracy, the model was improved by weight function using one-year measured data. The accuracy of our developed model was verified by comparison with four commercial simulator software programs and the results from real system which were measured and recorded for 1 year. It was found that the model output was in a good agreement with the measured data. This research can be utilized in another area by adjusting the PV equation with weight function of that area.

Modeling the Molten Salt Reactor Experiment With the GOTHIC Code

2020 ◽  
Author(s):  
Rodney Harvill ◽  
Jeff Lane ◽  
John Link ◽  
Anita Gates ◽  
Tom Kindred
Keyword(s):  
Measured Data ◽  
Reactor Power ◽  
Molten Salt Reactor ◽  
Delayed Neutron ◽  
Control Rod ◽  
Decay Heat ◽  
The Core ◽  
Thermal Output ◽  
Fuel Salt ◽  
Good Agreement

Abstract GOTHIC 8.3(QA) includes capabilities for modeling advanced, non-light water cooled reactors. Important capabilities introduced in GOTHIC 8.3(QA) include fluid property tables for various molten salts, an enhancement to the tracer tracking module to allow radioactive decay energy to be released locally in the carrier fluid and other improvements to the neutron kinetics module. With these new capabilities in place, GOTHIC is used to benchmark steady-state and transient conditions in the Molten Salt Reactor Experiment (MSRE), which operated at Oak Ridge National Laboratory from 1965 to 1969. In this experimental reactor, UF4 fuel was dissolved in molten fluoride salt, and criticality could be achieved only in the graphite moderated core. An air-cooled radiator transferred fission and decay heat to the environment. The design thermal output of the MSRE was 10 MWt, but the radiator design limited the output to 8 MWt. The original design parameters neglected the impact of decay heat on system temperatures. GOTHIC is used to benchmark system operating parameters at both the 10 MWt design condition and the 8 MWt operating condition, both with and without decay heat. The cases that include decay heat apply 7% of the nominal thermal output using the eleven decay heat precursors from ASB 9-2 as tracers. The results of the benchmark exhibit good agreement with design and operating data and demonstrate heat-up due to decay heat in the fuel salt outside the core. In the MSRE, delayed neutron precursors are not confined to the core because the fuel and fission products flow through the system. As a result, there are different values for (effective) delayed neutron fraction with and without flow, and the decay of delayed neutron precursors outside the core under full-flow conditions reduces reactivity by 0.212 % δk/k. Zero power physics testing included fuel salt pump start-up and coast-down transients with a control rod automatically moving to maintain criticality. The control rod motion calculated by GOTHIC is a reasonable match to measured data from these transients. Low power testing included a natural convection transient with no control rod motion such that reactor power was responding to heat load demand from the radiator. The reactor power and fuel salt and coolant salt temperatures calculated by GOTHIC exhibit good agreement with measured data.

Use of a three-dimensional model to predict heavy metal (copper) fluxes in the Oujiang estuary

2014 ◽  
Vol 69 (6) ◽  
pp. 1334-1343 ◽  
Author(s):  
Shasha Lu ◽  
Ruijie Li ◽  
Xiaoming Xia ◽  
Jun Zheng
Keyword(s):  
River Discharge ◽  
Water Surface ◽  
Three Dimensional ◽  
Measured Data ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Pollutant Concentrations ◽  
Suspended Sediment Concentrations ◽  
Adsorption Desorption ◽  
Good Agreement

Measuring pollutant concentrations in major tributaries is the standard method for establishing pollutant fluxes to the sea. However, this method is costly and difficult, and may be subject to a great deal of uncertainty due to the presence of unknown sources. This uncertainty presents challenges to managers and scientists in reducing contaminant discharges to water bodies. As one less costly method, a three-dimensional model was developed and used to predict pollutant fluxes to the sea. The sorptive contaminant model was incorporated into hydrodynamic and sediment models. Adsorption–desorption of copper by sediments in the Oujiang estuary were described using Henry's law. The model was validated using measured data for water surface elevations, flow velocity/direction, suspended sediment concentrations, and the proportion of copper sorbed to sediment. The validated model was then applied to predict fluxes of copper. Combined with the measured data, the copper concentration in the Oujiang River discharge was calculated as 13.0 μg/L and copper fluxes were calculated as 52 t in 2010. This copper flux prediction was verified using measured dissolved copper concentrations. Comparisons between the modeled and measured results showed good agreement at most stations, demonstrating that copper flux prediction in the Oujiang estuary was reasonably accurate.

Identification and Compensation of Geometric and Elastic Errors in Large Manipulators: Application to a High Accuracy Medical Robot

1998 ◽  
Author(s):  
Marco A. Meggiolaro ◽  
Constantinos Mavroidis ◽  
Steven Dubowsky
Keyword(s):  
High Accuracy ◽  
Measured Data ◽  
Experimental Results ◽  
Geometric Errors ◽  
Medical Robot ◽  
Error Sources ◽  
End Effector ◽  
Positioning Errors ◽  
Structural Deformations ◽  
Manufacturing Tolerances

Abstract A method is presented to identify the source of end-effector positioning errors in large manipulators using experimentally measured data. Both errors due to manufacturing tolerances and other geometric errors and elastic structural deformations are identified. These error sources are used to predict, and compensate for, the end-point errors as a function of configuration and measured forces. The method is applied to a new large high accuracy medical robot. Experimental results show that the method is able to effectively correct for the errors in the system.

On New Aspects of Nested Carbon Nanotubes as Gigahertz Oscillators

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
R. Ansari ◽  
B. Motevalli
Keyword(s):  
Carbon Nanotubes ◽  
Initial Velocity ◽  
Initial Conditions ◽  
Strong Dependence ◽  
Interaction Force ◽  
Arbitrary Length ◽  
Oscillatory Frequency ◽  
Analytical Expression ◽  
System Parameters ◽  
The Core

Nested carbon nanotubes exhibit telescopic oscillatory motion with frequencies in the gigahertz range. In this paper, our previously proposed semi-analytical expression for the interaction force between two concentric carbon nanotubes is used to solve the equation of motion. That expression also enables a new semi-analytical expression for the precise evaluation of oscillation frequency to be introduced. Alternatively, an algebraic frequency formula derived based on the simplifying assumption of constant van der Waals force is also given. Based on the given formulas, a thorough study on different aspects of operating frequencies under various system parameters is conducted, which permits fresh insight into the problem. Some notable improvements over the previously drawn conclusions are made. The strong dependence of oscillatory frequency on system parameters including the extrusion distance and initial velocity of the core as initial conditions for the motion is shown. Interestingly, our results indicate that there is a special initial velocity at which oscillatory frequency is unique for any arbitrary length of the core. A particular relationship between the escape velocity (the minimum initial velocity beyond which the core will leave the outer nanotube) and this specific initial velocity is also revealed.

Prediction of Cavitation Inception Within Regions of Flow Separation

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Eduard Amromin
Keyword(s):  
Experimental Data ◽  
Turbulent Flow ◽  
Flow Separation ◽  
Computational Method ◽  
Average Flow ◽  
Cavitation Inception ◽  
The Core ◽  
Good Agreement

Cavitation within regions of flow separation appears in drifting vortices. A two-part computational method is employed for prediction of cavitation inception number there. The first part is an analysis of the average flow in separation regions without consideration of an impact of vortices. The second part is an analysis of equilibrium of the bubble within the core of a vortex located in the turbulent flow of known average characteristics. Computed cavitation inception numbers for axisymmetric flows are in the good agreement with the known experimental data.

scholarly journals Reliable Iterative Method for solving Volterra - Fredholm Integro Differential Equations

2021 ◽  
Vol 26 (2) ◽  
Author(s):  
Samaher Marez
Keyword(s):  
Exact Solution ◽  
Differential Equations ◽  
Iterative Method ◽  
Iterative Process ◽  
Initial Conditions ◽  
High Accuracy ◽  
Series Solutions ◽  
Math Program ◽  
The Right

  The aim of this paper, a reliable iterative method is presented for resolving many types of Volterra - Fredholm Integro - Differential Equations of the second kind with initial conditions. The series solutions of the problems under consideration are obtained by means of the iterative method.  Four various problems are resolved with high accuracy to make evident the enforcement of the iterative method on such type of integro differential equations. Results were compared with the exact solution which exhibit that this technique has compatible with the right solutions, simple, effective and easy for solving such problems. To evaluate the results in an iterative process the MATLAB is used as a math program for the calculations.

scholarly journals METODOLOGI PROGRAM RISET IMRE LAKATOS

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Ahmad Saka Falwa Guna ◽  
Fitria Ramadhani
Keyword(s):  
Research Program ◽  
Initial Conditions ◽  
Human Mind ◽  
Theory Theory ◽  
Previous Theory ◽  
Imre Lakatos ◽  
The Core ◽  
Library Research ◽  
Hardcore Functions ◽  
Protective Belt

This research was based on the limitations of the human mind itself in providing and obtaining reasonable explanations, because at that time the desire to know something was obstructed from various myths which existedin that society so that myths were embedded in human mind. The focus of this research was on the methodology of the Imre Lakatos research program. The purpose of this study was to determine the process of research program methodology from Imre Lakatos. The method used in this research was library research, where the researchers looked for and read sources that match the title to be studied, such as books, articles, writings and journals that were relevant.The results of this study in the Imre Lakatos research program methodology included: First, the core (hardcore) functions as a negative heuristic. Second, the protective-belt which consisted of auxiliary hypotheses in the initial conditions. Third, a series of theories (a series theory), theory linkages where the next theory was the result of the auxiliary clauses added from the previous theory.

scholarly journals Validation of Doppler Temperature Coefficients and Component Power Distribution for the Advanced Neutronics Component Program KYLIN V2.0

2021 ◽  
Vol 9 ◽  
Author(s):  
Lei Jichong ◽  
Xie Jinsen ◽  
Chen Zhenping ◽  
Yu Tao ◽  
Yang Chao ◽  
...  
Keyword(s):  
Engineering Design ◽  
Power Distribution ◽  
Nuclear Power ◽  
Nuclear Engineering ◽  
Temperature Coefficients ◽  
The Core ◽  
Fuel Assemblies ◽  
Design Requirements ◽  
Design Software ◽  
Good Agreement

This work is interested in verifying and analyzing the advanced neutronics assembly program KYLIN V2.0. Assembly calculations are an integral part of the two-step calculation for core design, and their accuracy directly affects the results of the core physics calculations. In this paper, we use the Doppler coefficient numerical benchmark problem and CPR1000 AFA-3G fuel assemblies to verify and analyze the advanced neutronics assembly program KYLIN V2.0 developed by the Nuclear Power Institute of China. The analysis results show that the Doppler coefficients calculated by KYLIN V2.0 are in good agreement with the results of other well-known nuclear engineering design software in the world; the power distributions of AFA-3G fuel assemblies are in good agreement with the results of the RMC calculations, it’s error distribution is in accordance with the normal distribution. It shows that KYLIN V2.0 has high calculation accuracy and meets the engineering design requirements.

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