Modeling aspects in linear stability analysis of a self-pressurized, natural circulation integral reactor

Zanocco, Pablo; Giménez, M.; Delmastro, D.F.

doi:10.1016/j.nucengdes.2004.03.006

Cited by 19 publications

(6 citation statements)

References 19 publications

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“…Currently, a number of (small size) reactors are under development with single phase natural circulation: e.g. the REX-10 (Regional Energy Reactor -10 MW th ) which uses water at 2 MPa, [16]; the CHTR (Compact High Temperature Reactor -100 kW th ) which uses a lead-bismuth eutectic mixture with temperatures up 1000 °C [17] and the CAREM 25 design (100 MW th ) which uses water at 12.25 MPa, [18]. Even though a lot of supercritical technology for the secondary side (such as turbines) already exists because of the fossil fuel based power plants, there still are large uncertainties with regards to corrosion and thermo-hydraulics of supercritical water in these tight lattice bundles; see e.g.…”

Section: Introductionmentioning

confidence: 99%

Experimental study of the coupled thermo-hydraulic–neutronic stability of a natural circulation HPLWR

T’Joen

Rohde

2012

Nuclear Engineering and Design

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The HPLWR (High Performance Light Water Reactor) is the European concept design for a SCWR (SuperCritical Water Reactor). This unique reactor design consists of a three pass core with intermediate mixing plena. As the supercritical water passes through the core, it experiences a significant density reduction. This large change in density could be used as the driving force for natural circulation of the coolant, adding an inherent safety feature to this concept design. The idea of natural circulation has been explored in the past for boiling water reactors (BWR). From those studies, it is known that the different feedback mechanisms can trigger flow instabilities. These can be purely thermo-hydraulic (driven by the friction -mass flow rate or gravity -mass flow rate feedback of the system), or they can be coupled thermo-hydraulic -neutronic (driven by the coupling between friction, mass flow rate and power production). The goal of this study is to explore the stability of a natural circulation HPLWR considering the thermo-hydraulic -neutronic feedback. This was done through a unique experimental facility, DeLight, which is a scaled model of the HPLWR using Freon R23 as a scaling fluid. An artificial neutronic feedback was incorporated into the system based on the average measured density. To model the heat transfer dynamics in the rods, a simple first order model was used with a fixed time constant of 6 seconds. The results include the measurements of the varying decay ratio (DR) and frequency over a wide range of operating conditions. A clear instability zone was found within the stability plane, which seems to be similar to that of a BWR. Experimental data on the stability of a supercritical loop is rare in open literature, and these data could serve as an important benchmark tool for existing codes and models.

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Section: Introductionmentioning

confidence: 99%

Experimental study of the coupled thermo-hydraulic–neutronic stability of a natural circulation HPLWR

T’Joen

Rohde

2012

Nuclear Engineering and Design

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“…The ROM enables a significant gain in CPU time (10 7 ). It would be interesting to develop, build and test ROMs of intermediate complexity between ROM n°1 and ROM n°2 formulations.…”

Section: Discussionmentioning

confidence: 99%

“…These two-phase closed thermosyphons have been studied in many applications such as, solar water heaters [1] [2] [3] [4], telecommunication equipments [5], avionics systems [6], nuclear power plants [7] [8] [9], electronics industry [10].…”

Section: Introductionmentioning

confidence: 99%

Reduced order model of a two-phase loop thermosyphon by modal identification method

Bodjona

Girault

Videcoq

et al. 2018

International Journal of Heat and Mass Transfer

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This study focuses on the model reduction of a two-phase loop thermosyphon. The aim is to propose a nonlinear reduced order model able to mimic the thermo-hydraulic behavior of the loop in order to use it for real-time state feedback control, in future applications. First, the one-dimensional two-phase flow model describing the liquid-gas mixture in both mechanical and thermal equilibrium is recalled. The numerical resolution of this detailed model is carried out using a finite volume approach and a Harten-Lax-van Leer Contact Riemann solver. Then, from this detailed model, a new structure of reduced model is determined via the Galerkin projection method. These reduced models, built by the Modal Identification Method, show a very good agreement between the outputs of the detailed model and those computed by the reduced model,

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“…The time derivative of the fuel temperature is therefore proportional to the difference between the power generated and that exchanged. An axial temperature profile is modelled, neglecting axial conduction within the fuel (see Zanocco et al (2004a) for further details). • It is supposed that the core power has a cosinoidal-type distribution with the maximum moved to the lower part.…”

Section: Modelled Hypothesismentioning

confidence: 99%

“…For this reason an exhaustive analysis regarding the thermal-hydraulic performance (including stability analysis) needs to be performed in order to thoroughly understand the behaviour of such a system. In a previous investigation, Zanocco et al (2004a) presented the stability of CAREM-25 at nominal conditions. From such an investigation it has been found the CAREM-25 stability is strongly influenced by the steam-dome dynamics.…”

Section: Introductionmentioning

confidence: 99%

Stability of self-pressurized, natural circulation, low thermo-dynamic quality, nuclear reactors: The stability performance of the CAREM-25 reactor

Marcel

Acuña

Zanocco

et al. 2013

Nuclear Engineering and Design

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Modeling aspects in linear stability analysis of a self-pressurized, natural circulation integral reactor

Cited by 19 publications

References 19 publications

Experimental study of the coupled thermo-hydraulic–neutronic stability of a natural circulation HPLWR

Experimental study of the coupled thermo-hydraulic–neutronic stability of a natural circulation HPLWR

Reduced order model of a two-phase loop thermosyphon by modal identification method

Stability of self-pressurized, natural circulation, low thermo-dynamic quality, nuclear reactors: The stability performance of the CAREM-25 reactor

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