Experiments on a Water Pool-Type Reactor Cavity Cooling System in a High-Temperature Gas-Cooled Reactor

2007 ◽  
Vol 159 (1) ◽  
pp. 39-58 ◽  
Author(s):  
Hyoung Kyu Cho ◽  
Yun Je Cho ◽  
Moon Oh Kim ◽  
Goon Cherl Park
Keyword(s):  
High Temperature ◽  
Cooling System ◽  
Water Pool ◽  
Type Reactor ◽  
Cavity Cooling ◽  
Pool Type ◽  
High Temperature Gas

Study on the Heat Transfer in the Water Pool Type Reactor Cavity Cooling System of the Very High Temperature Gas Cooled Reactor

2005 ◽  
Author(s):  
H. K. Cho ◽  
D. U. Seo ◽  
M. O. Kim ◽  
G. C. Park
Keyword(s):  
Heat Transfer ◽  
Forced Convection ◽  
Cooling System ◽  
Reactor Vessel ◽  
Water Pool ◽  
Cooling Pipe ◽  
Cavity Cooling ◽  
The Heat Transfer Coefficient ◽  
Pool Type ◽  
High Temperature Gas

In the HTGR (High Temperature Gas Cooled Reactor), the Reactor Cavity Cooling System (RCCS) is equipped to remove the heat transferred from the reactor vessel to the structure of the containment. The function of the RCCS is to dissipate the heat from the reactor cavity during normal operation including shutdown. The system also removes the decay heat during the loss of forced convection (LOFC) accident. A new concept of the water pool type RCCS was proposed at Seoul National University. The system mainly consists of two parts, water pool located between the containment and reactor vessel and five trains of air cooling system installed in the water pool. In normal operations, the heat loss from the reactor vessel is transferred into the water pool via cavity and it is removed by the forced convection of air flowing through the cooling pipes. During the LOFC accident, the after heat is passively removed by the water tank without the forced convection of air and the RCCS water pool is designed to provide sufficient passive cooling capacity of the after heat removal for three days. In the present study, experiments and numerical calculations using CFX5.7 for the water pool and cooling pipe were performed to investigate the heat transfer characteristics and evaluate the heat transfer coefficient model of the MARS-GCR (Multi-dimensional Analysis of Reactor Safety for Gas Cooled Reactor Analysis) which was developed for the safety analysis of the gas cooled reactor. From the results of the experiments and CFX calculations, heat transfer coefficients inside the cooling pipe were calculated and those were used for the assessment for the heat transfer coefficient model of the MARS-GCR.

Simulation of the Operation in Passive Mode of Reactor Cavity Cooling System of High-Temperature Gas-Cooled Reactor

2008 ◽  
Author(s):  
Alex Matev
Keyword(s):  
High Temperature ◽  
Cooling System ◽  
Fission Products ◽  
Computer Code ◽  
Reactor Vessel ◽  
Passive Mode ◽  
Axial Distribution ◽  
Air Ingress ◽  
Cavity Cooling ◽  
High Temperature Gas

The Reactor Cavity Cooling System (RCCS) of a High-Temperature Gas-Cooled Reactor (HTGR) may be required to operate in a “passive” mode when heat is removed from the reactor cavity by letting RCCS water inventory to boil off to atmosphere. Overheating of the reactor cavity concrete walls may lead to a failure of the reactor vessel support structures and its shift off the design position. Dislocation of the massive reactor vessel may cause multiple ruptures of pipes, connected to both the upper and lower vessel heads. Such breaks of the reactor pressure boundary will enable air ingress into the core, fuel oxidation and overheating, and possible release of fission products into the environment. The computer code TINTE [3] was used to simulate a “Depressurized Loss Of Flow Circulation (DLOFC) Without Reactor Scram” accident and determine from its results the magnitude, axial distribution, and time dependence of the heat flux on the RCCS cooling panels. The computer code RELAP [4] was used to model the operation in “passive” mode of one RCCS train, consisting of a tank and four standpipes. This paper describes the application of both RELAP and TINTE for the simulation of RCCS operation in passive mode. The main conclusion from this analysis is that the proposed way of using both codes is suitable to perform scoping studies and design evaluation of RCCS of a pebble-bed HTGR.

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