Thermal Hydraulics Analysis of the Fluoride-Salt-Cooled, High-Temperature Reactor

2017 ◽  
Author(s):  
Yao Fu ◽  
Qiang Sun ◽  
Chong Zhou ◽  
Yang Zou
Keyword(s):  
High Temperature ◽  
Initial Conditions ◽  
Heat Removal ◽  
Forced Flow ◽  
System Component ◽  
Primary System ◽  
Fluoride Salt ◽  
Transient Event ◽  
Coated Particle ◽  
High Temperature Reactor

Fluoride-salt-cooled, high-temperature reactor (FHR) technology combines the robust coated particle fuel of high-temperature, gas-cooled reactors with the single phase, high volumetric heat capacity coolant of molten salt reactors and the low-pressure pool-type reactor configuration of sodium fast reactors. This paper discusses one key technology area required to further define and develop the FHR: the thermal hydraulic performance of the core, primary system and second loop. Shanghai Institute of Applied Physics (SINAP) is leading the China Academy of Science (CAS) FHR program. A TMSR-SF1 reactor with a fluoride cooled pebble bed design has been suggested by SINAP, and the design is currently in progress. For this preliminary thermal hydraulic assessment, a TMSR-SF1 system model was developed using RELAP5. The RELAP5 model was used to help define and size systems such as the intermediate coolant salt selecting. A loss of flow transient was also simulated to evaluate the performance of the reactor during an anticipated transient event. A steady-state calculation was carried out and the calculated initial conditions show the influence of different salt. The loss of forced flow (LOFF) transient simulation results show that the passive residual heat removal system can effectively remove all decay heat from the primary loop under this extreme accident scenario. Some initial recommendations for modifying system component designs, such as heat exchanger with different salt and install place of pump, are also discussed.

Numerical Study of Tritium Mitigation Strategies for Fluoride Salt-Cooled High-Temperature Reactors

2020 ◽  
Author(s):  
Sheng Zhang ◽  
Xiao Wu ◽  
Xiaodong Sun
Keyword(s):  
High Temperature ◽  
Leakage Rate ◽  
System Level ◽  
Transfer Model ◽  
Primary System ◽  
Optimization Approach ◽  
Fluoride Salt ◽  
Large Power ◽  
High Temperature Reactor ◽  
Tritium Release

Abstract Fluoride salt-cooled High-temperature Reactor (FHR) is one of the advanced non-Light Water Reactor (non-LWR) designs, which adopts a low-pressure fluoride salt as the primary coolant, high working temperatures, coated-particle fuel, and a passive safety system for decay heat removal. However, tritium management is perceived as a critical issue for FHRs since tritium is a radiation hazard when inhaled or ingested and its production rate in FHRs is expected to be significantly higher compared to that in LWRs. To reduce FHR tritium release rates into the ambient, two tritium mitigation options, such as using Double-Wall Fluted-Tube Heat eXchangers (DWFT-HXs) with a tritium carrier or Single-Wall Fluted-Tube HXs (SWFT-HXs) with a tritium barrier, are therefore proposed for key HXs in FHRs, which potentially provide major pathways for tritium release due to their elevated temperatures and large surface areas. Tritium carriers investigated include gases, such as helium, and liquids, such as FLiBe, FLiNaK, and KF-ZrF4, while the tritium barrier investigated in this paper is silicon carbide (SiC) due to its low permeability for tritium. These proposed HX designs are then optimized, using a Non-dominated Sorting in Generic Algorithms (NSGA) optimization approach, for the Advanced High-Temperature Reactor (AHTR), one of the FHR designs with a large power output. A system-level mass transfer model is developed to evaluate the tritium transport in the two proposed design options for tritium mitigation in FHRs and quantitively analyze the tritium release/leakage rate from the reactor primary system. Our study shows that both the DWFT-HX design with helium as the tritium carrier and SWFT-HX design with SiC coating as the tritium barrier are able to reduce the total tritium leakage rate in FHRs to the same order of magnitude of the typical average tritium leakage rate in LWRs (1.9 Ci/day).

Investigation of the Modified RELAP5 MOD 3.2 Capability to Simulate the Transients of the Fluoride-Salt High-Temperature Reactors

2016 ◽  
Author(s):  
Limin Liu ◽  
Qiqi Yan ◽  
Dalin Zhang ◽  
Suizheng Qiu ◽  
G. H. Su
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Heat Removal ◽  
Forced Flow ◽  
Fluoride Salt ◽  
High Temperature Reactors ◽  
Temperature Liquid ◽  
Liquid Salts ◽  
Fluoride Salts ◽  
Thermo Physical Properties

Fluoride-salt-cooled high-temperature reactors (FHRs) are a new concept that uses solid fuel and employs high temperature liquid salts as both primary and secondary side working fluids. The thermo-physical properties of the fluoride salts and specific heat transfer correlations have been implemented into the RELAP5-MOD3.2 code to enable the code to simulate the transient thermal-hydraulic response in accidents. The thermo-physical properties calculated by the modified code have been benchmarked versus the experimental data. The results of thermal-hydraulic responses of the PB-AHTR in the steady state and simple loss of forced flow from the publications using the RELAP5-3D are used to verify the ability of the modified RELAP5-MOD3.2 to simulate the transients of the FHRs. The code can predict the variations of the thermal-hydraulic parameters well whereas some results may distinguish from that calculated by the RELAP5-3D. The unprotected loss of flow is analyzed by the modified code, indicating that the passive residual heat removal system can mitigate the consequence of the accidents.

scholarly journals Fluoride-Salt-Cooled High-Temperature Reactor (FHR) for Power and Process Heat

2015 ◽  
Author(s):  
Charles Forsberg ◽  
Lin-wen Hu ◽  
Per Peterson ◽  
Kumar Sridharan
Keyword(s):  
High Temperature ◽  
Fluoride Salt ◽  
High Temperature Reactor ◽  
Process Heat

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

2013 ◽  
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.

An experimental test facility to support development of the fluoride-salt-cooled high-temperature reactor

2014 ◽  
Vol 64 ◽  
pp. 511-517 ◽  
Author(s):  
Graydon L. Yoder ◽  
Adam Aaron ◽  
Burns Cunningham ◽  
David Fugate ◽  
David Holcomb ◽  
...  
Keyword(s):  
High Temperature ◽  
Experimental Test ◽  
Test Facility ◽  
Fluoride Salt ◽  
High Temperature Reactor

Analysis of thorium and uranium based nuclear fuel options in Fluoride salt-cooled High-temperature Reactor

2015 ◽  
Vol 78 ◽  
pp. 285-290 ◽  
Author(s):  
X.X. Li ◽  
X.Z. Cai ◽  
D.Z. Jiang ◽  
Y.W. Ma ◽  
J.F. Huang ◽  
...  
Keyword(s):  
High Temperature ◽  
Nuclear Fuel ◽  
Fluoride Salt ◽  
High Temperature Reactor
Sign in / Sign up

Export Citation Format

Share Document