Evaluation of a freeze-tolerant decay heat removal system redundancy for fluoride salt-cooled high-temperature reactors (FHR)

A Sodium-cooled Fast Reactor (SFR) has receiving attention as one of the promising next generation nuclear reactors because it can recycle the spent nuclear fuel produced from the current commercial nuclear reactors and accomplish higher thermal efficiency than the current commercial nuclear reactors. However, after shutdown of the nuclear reactor core, the accumulated fission products of the SFR also decay and release heat via radiation within the reactor. To remove this residual heat, a decay heat removal system (DHRS) with supercritical CO2 (S-CO2) as the working fluid is suggested with a turbocharger system which achieves passive operational capability. However, for designing this system an improved S-CO2 turbine design methodology should be suggested because the existing methodology for designing the S-CO2 Brayton cycle has focused only on the compressor design near the critical point. To develop a S-CO2 turbine design methodology, the non-dimensional number based design and the 1D mean line design method were modified and suggested. The design methodology was implemented into the developed code and the code results were compared with existing turbine experimental data. The data were collected under air and S-CO2 environment. The developed code in this research showed a reasonable agreement with the experimental data. Finally using the design code, the turbocharger design for the suggested DHRS and prediction of the off design performance were carried out. As further works, more effort will be put it to expand the S-CO2 turbine test data for validating the design code and methodology.

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Analysis on inadvertent operation of decay heat removal system in NuScale reactor

10.1063/1.5135523 ◽

2019 ◽

Author(s):

Susyadi ◽

Andi S. Ekariansyah ◽

Hendro Tjahjono ◽

D. T. Sony Tjahyani

Keyword(s):

Heat Removal ◽

Decay Heat ◽

Heat Removal System ◽

Removal System

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Fluoride-Salt-Cooled High-Temperature Reactor (FHR) Using British Advanced Gas-Cooled Reactor (AGR) Refueling Technology and Decay Heat Removal Systems That Prevent Salt Freezing

Nuclear Technology ◽

10.1080/00295450.2019.1586372 ◽

2019 ◽

Vol 205 (9) ◽

pp. 1127-1142 ◽

Cited By ~ 2

Author(s):

Charles Forsberg ◽

Dean Wang ◽

Eugene Shwageraus ◽

Brian Mays ◽

Geoff Parks ◽

...

Keyword(s):

High Temperature ◽

Heat Removal ◽

Fluoride Salt ◽

Decay Heat ◽

High Temperature Reactor

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Thermal-hydraulic analysis of an innovative decay heat removal system for lead-cooled fast reactors

Nuclear Engineering and Design ◽

10.1016/j.nucengdes.2016.05.005 ◽

2016 ◽

Vol 305 ◽

pp. 168-178 ◽

Cited By ~ 9

Author(s):

Fabio Giannetti ◽

Damiano Vitale Di Maio ◽

Antonio Naviglio ◽

Gianfranco Caruso

Keyword(s):

Heat Removal ◽

Hydraulic Analysis ◽

Fast Reactors ◽

Decay Heat ◽

Heat Removal System ◽

Thermal Hydraulic Analysis ◽

Removal System

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Feasibility Investigation of the Decay Heat Removal Capability Using the Concept of a Thermosyphon in the Liquid Metal Reactor

10th International Conference on Nuclear Engineering, Volume 2 ◽

10.1115/icone10-22564 ◽

2002 ◽

Author(s):

Yeon-Sik Kim ◽

Yoon-Sub Sim ◽

Eui-Kwang Kim

Keyword(s):

Heat Transfer ◽

Liquid Metal ◽

Heat Removal ◽

Term Operation ◽

Decay Heat ◽

Removal Capacity ◽

Liquid Metal Reactor ◽

Current Design ◽

Heat Removal System ◽

Removal System

A new design concept for a decay heat removal system in a liquid metal reactor is proposed. The new design utilizes a thermosyphon to enhance the heat removal capacity and its heat transfer characteristics are analyzed against the current PSDRS (Passive Safety Decay heat Removal System) in the KALIMER (Korea Advanced LIquid MEtal Reactor) design. The preliminary analysis results show that the new design with a thermosyphon yields substantial increase of 20∼40% in the decay heat removal capacity compared to the current design that do not have the thermosyphon. The new design reduces the temperature rise in the cooling air of the system and helps the surrounding structure in maintaining its mechanical integrity for long term operation at an accident. Also the analysis revealed the characteristics of the interactions among various heat transfer modes in the new design.

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Performance Evaluation of DRACS System for FHTR and Time Assessment of Operation Procedure

Volume 6: Beyond Design Basis Events; Student Paper Competition ◽

10.1115/icone21-16571 ◽

2013 ◽

Cited By ~ 3

Author(s):

Junya Nakata ◽

Mikihiro Wakui ◽

Michitsugu Mori ◽

Hiroto Sakashita ◽

Charles Forsberg

Keyword(s):

Performance Evaluation ◽

High Temperature ◽

Cooling System ◽

Heat Removal ◽

Severe Accident ◽

Air Cooling ◽

Fluoride Salt ◽

Nuclear Power Reactor ◽

Decay Heat ◽

Operation Procedure

The Fluoride-salt-cooled High-temperature Reactor (FHR) is a new concept of nuclear power reactor being investigated mainly in U.S. and China. The coolant is a liquid salt with a melting point of about 460°C and a boiling point of over 1400°C. As the baseline decay heat removal system, a passive Direct Reactor Air Cooling System (DRACS) is utilized. Though DRACS system has been developed in Sodium Fast reactors (SFR), there are some differences between both. For example, the system in FHR must decrease heat removal when temperatures are low to avoid freezing of the salt and blocking the flow of liquid. Therefore, considering its characteristics, a numerical investigation of DRACS system is needed to evaluate whether FHR has proper ability to remove decay heat and to be robust for a long-time cooling operation after even a severe accident. Furthermore, in addition to its performance evaluation, it is required to make up the operation plan of FHR considering features of this system. It is highly important, with the view of avoiding severe accident, to determine by when the system should be started up. In both countries mentioned above, Fluoride-salt-cooled High-temperature Test Reactor (FHTR) is currently in progress to build. Reviewing its design and system is a crucial step needed to develop the FHR technology. In this research, a performance of DRACS system under some thermal-hydraulic basic events was evaluated by numerical simulation. This paper also suggested the adequate operation procedure suitable for FHTR to avoid a severe accident.

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