A whole-core steady-state thermal-hydraulic model for annular fuel type fluoride-salt-cooled reactors

Purpose The objective of the present work is to simulate the nuclear coupled thermal–hydraulic fast transient case studies for a vertically up-flowing supercritical pressure water channel of circular cross section. The emphasis is on analyzing the phenomenon of the deterioration in heat transfer (DHT) inside the channel subjected to sharp pressure variations. Design/methodology/approach The thermal–hydraulic model, THRUST, is integrated with the neutron point kinetic (NPK) solver to account for the non-linear interactions between the thermal–hydraulic and neutronic temperature and density reactivity feedback effects. The model implemented and studied accounts for the time-dependent reactor power and is used to analyze various steady-state and flow-induced transient case studies (time-dependent and step change in exit pressure). Findings There is good agreement in the predicted behavior of the supercritical water pressure system with that of the available experimental data for the steady-state case. The event of DHT in the second transient case (step decrease in exit pressure) is found to be more severe than that of exponential pressure decrease. Originality/value This study evaluated a novel implementation of the thermal–hydraulic model, THRUST, integrated with NPKs applied to supercritical pressure water systems for predicting DHT.

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Development of a Coupled Code for Steady-State Analysis of the Graphite-Moderated Channel Type Molten Salt Reactor

Science and Technology of Nuclear Installations ◽

10.1155/2018/4053254 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Long He ◽

Cheng-Gang Yu ◽

Wei Guo ◽

Ye Dai ◽

Hai-Ling Wang ◽

...

Keyword(s):

Steady State ◽

Density Distribution ◽

Molten Salt ◽

Power Distribution ◽

Three Dimensional ◽

Flow Distribution ◽

Hydraulic Model ◽

Molten Salt Reactor ◽

Fuel Density ◽

Channel Type

The molten salt reactor (MSR) is one of the six advanced reactor concepts selected by Generation IV International Forum (GIF) because of its inherent safety and the promising capabilities of TRU transmutation and Th-U breeding. In this study, a three-dimensional thermal-hydraulic model (3DTH) is developed for evaluating the steady-state performance of the graphite-moderated channel type MSR. The coupled code is developed by exchanging the power distribution, temperature, and fuel density distribution between SCALE and 3DTH. Firstly, the thermal-hydraulic model of the coupled code is validated by RELAP5 code. Then, the mass flow distribution, temperature field, keff, and power density distribution for a conceptual design of the 2MWt experimental molten salt reactor are calculated and analyzed by the coupled code under both normal operating situation and the central fuel assembly partly blocked situation. The simulated results are conductive to facilitate the understanding of the steady behavior of the graphite-moderated channel type MSR.

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