Modeling and simulation of large-scale separated heat pipe with low heat flux for spent fuel pool cooling

A fork-type heat pipe (FHP) is a passive heat-transport and air-cooling device used to remove the decay heat of spent nuclear fuels stored in a liquid pool during a station blackout. FHPs have a unique geometrical design to resolve the significant mismatch between the convective heat transfer coefficients of the evaporator and condenser parts. The evaporator at the bottom is a single heat-exchanger tube, whereas the condenser at the top consists of multiple finned tubes to maximize the heat transfer area. In this study, the heat transfer characteristics and operating limits of an FHP device were investigated experimentally. A laboratory-scale model of an FHP was manufactured, and a series of tests were conducted while the temperature was varied to simulate a spent fuel pool. As an index of the average heat transfer performance, the loop conductance was computed from the measurement data. The results show that the loop conductance of the FHP increased with the heat transfer rate but deteriorated significantly at the operating limit. The maximum attainable heat transfer rate of the unit FHP model was accurately predicted by the existing correlations of the counter-current flow limit for a single-rod-type heat pipe. In addition, the instant heat transfer behaviors of the FHP model under different temperature conditions were examined to interpret the measured loop conductance variation and operating limit.

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The study of passive cooling system assisted with separate heat pipe for decay heat removal in spent fuel pool

Annals of Nuclear Energy ◽

10.1016/j.anucene.2017.08.062 ◽

2018 ◽

Vol 111 ◽

pp. 523-535 ◽

Cited By ~ 4

Author(s):

Kun Lai ◽

Wen Wang ◽

Chongchong Yi ◽

Yiwu Kuang ◽

Cheng Ye

Keyword(s):

Heat Pipe ◽

Cooling System ◽

Heat Removal ◽

Passive Cooling ◽

Spent Fuel ◽

Decay Heat ◽

Spent Fuel Pool ◽

Passive Cooling System

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Safest Roadmap for Corium Experimental Research in Europe

ASCE-ASME J Risk and Uncert in Engrg Sys Part B Mech Engrg ◽

10.1115/1.4037878 ◽

2017 ◽

Vol 4 (3) ◽

Cited By ~ 1

Author(s):

Christophe Journeau ◽

Viviane Bouyer ◽

Nathalie Cassiaut-Louis ◽

Pascal Fouquart ◽

Pascal Piluso ◽

...

Keyword(s):

Experimental Research ◽

Nuclear Power ◽

Large Scale ◽

Reactor Core ◽

Severe Accident ◽

Material System ◽

Stress Tests ◽

Spent Fuel ◽

Fukushima Accident ◽

Spent Fuel Pool

Severe accident facilities for European safety targets (SAFEST) is a European project networking the European experimental laboratories focused on the investigation of a nuclear power plant (NPP) severe accident (SA) with reactor core melting and formation of hazardous material system known as corium. The main objective of the project is to establish coordinated activities, enabling the development of a common vision and severe accident research roadmaps for the next years, and of the management structure to achieve these goals. In this frame, a European roadmap on severe accident experimental research has been developed to define research challenges to contribute to further reinforcement of Gen II and III NPP safety. The roadmap takes into account different SA phenomena and issues identified and prioritized in the analyses of severe accidents at commercial NPPs and in the results of the recent European stress tests carried out after the Fukushima accident. Nineteen relevant issues related to reactor core meltdown accidents have been selected during these efforts. These issues have been compared to a survey of the European SA research experimental facilities and corium analysis laboratories. Finally, the coherence between European infrastructures and R&D needs has been assessed and a table linking issues and infrastructures has been derived. The comparison shows certain important lacks in SA research infrastructures in Europe, especially in the domains of core late reflooding impact on source term, reactor pressure vessel failure and molten core release modes, spent fuel pool (SFP) accidents, as well as the need for a large-scale experimental facility operating with up to 500 kg of chemically prototypic corium melt.

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