Numerical analysis of parallel-channel density wave instabilities in a supercritical water reactor

2020 ◽  
Vol 42 (3) ◽  
Author(s):  
Raghvendra Upadhyay ◽  
Neetesh Singh Raghuvanshi ◽  
Goutam Dutta
Keyword(s):  
Numerical Analysis ◽  
Supercritical Water ◽  
Density Wave ◽  
Parallel Channel ◽  
Water Reactor ◽  
Channel Density ◽  
Wave Instabilities ◽  
Supercritical Water Reactor

Transient Three-Dimensional Stability Analysis of Supercritical Water Reactor Rod Bundle Subchannels by a Computatonal Fluid Dynamics Code

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
M. Sharabi ◽  
W. Ambrosini ◽  
S. He ◽  
Pei-Xue Jiang ◽  
Chen-Ru Zhao
Keyword(s):  
Fluid Dynamics ◽  
Supercritical Water ◽  
Density Wave ◽  
Three Dimensional ◽  
Heating Rates ◽  
Rod Bundles ◽  
Water Reactor ◽  
Rod Bundle ◽  
Computational Fluid Dynamics Cfd ◽  
Supercritical Water Reactor

The paper describes the application of computational fluid dynamics (CFD) in simulating density wave oscillations in triangular and square pitch rod bundles. The FLUENT code is used for this purpose, addressing typical conditions proposed for supercritical water reactor (SCWR) conceptual design. The RELAP5 code and an in-house 1D linear stability code are also adopted to compare the results for instability thresholds obtained by different techniques. Transient analyses are performed both by the CFD code and RELAP5, with increasing heating rates and constant pressure drop across the channel, up to the occurrence of unstable behavior. The obtained results confirm that the density wave mechanism is similar in rod bundle and in axisymmetric configurations.

Numerical Analysis to Investigate the Effects of Thermal-Hydraulic Instabilities on Deterioration Heat Transfer and Wall Temperature in the CANDU Supercritical Water Reactor

2015 ◽  
Vol 1 (4) ◽  
Author(s):  
Goutam Dutta ◽  
Chao Zhang ◽  
Jin Jiang
Keyword(s):  
Heat Transfer ◽  
Supercritical Water ◽  
Wall Temperature ◽  
Stability Boundary ◽  
Density Wave ◽  
Operating Regime ◽  
Maximum Temperature ◽  
Water Reactor ◽  
Heating Section ◽  
Supercritical Water Reactor

The present work analyzes the thermal-hydraulic behavior of the CANDU supercritical water reactor (SCWR) using a 1-D numerical model. The possibility of a static instability, the Ledinegg excursion, is investigated, which reveals it can occur only in a hypothetical condition, far from the proposed operating regime of the CANDU SCWR. The investigation demonstrates the possibility of density wave oscillations (DWOs), a dynamic instability, in the operating regime of the CANDU SCWR and its marginal stability boundary (MSB) is obtained. The phenomenon of the deterioration in heat transfer is observed, and the related investigation shows that the strong buoyancy effect is responsible for its appearance inside the heating section of the channel of the CANDU SCWR core. The MSB is found to be inadequate in determining the safe operating zone of the reactor because the wall temperature can exceed the allowable limit from metallurgical consideration. The investigations also determine the safe as well as stable zone where the CANDU SCWR should operate in order to avoid the maximum temperature limit and DWOs.

scholarly journals Analysis of numerical studies on the thermal-hydraulic and neutronic thermal-hydraulic stability of supercritical water reactors

2021 ◽  
Vol 7 (4) ◽  
pp. 311-318
Author(s):  
Artavazd M. Sujyan ◽  
Viktor I. Deev ◽  
Vladimir S. Kharitonov
Keyword(s):  
Supercritical Water ◽  
Nuclear Power ◽  
Power Plants ◽  
Negative Impact ◽  
Reactor Core ◽  
Resistance Coefficient ◽  
Coolant Flow ◽  
Water Reactor ◽  
Hydraulic Stability ◽  
Supercritical Water Reactor

The paper presents a review of modern studies on the potential types of coolant flow instabilities in the supercritical water reactor core. These instabilities have a negative impact on the operational safety of nuclear power plants. Despite the impressive number of computational works devoted to this topic, there still remain unresolved problems. The main disadvantages of the models are associated with the use of one simulated channel instead of a system of two or more parallel channels, the lack consideration for neutronic feedbacks, and the problem of choosing the design ratios for the heat transfer coefficient and hydraulic resistance coefficient under conditions of supercritical water flow. For this reason, it was decided to conduct an analysis that will make it possible to highlight the indicated problems and, on their basis, to formulate general requirements for a model of a nuclear reactor with a light-water supercritical pressure coolant. Consideration is also given to the features of the coolant flow stability in the supercritical water reactor core. In conclusion, the authors note the importance of further computational work using complex models of neutronic thermal-hydraulic stability built on the basis of modern achievements in the field of neutron physics and thermal physics.

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