Han Wang

Experimental investigation on the distribution of spray water in a spent fuel-assembly simulator

Abstract The spent fuel pool cooling system in a nuclear power plant, which is comprised mainly by the cooling pumps and heat exchangers, ensures the safety of the spent fuel assemblies and the integrity of the fuel rods during the period of storage. With the development of the passive cooling technique, a spray cooling system for the spent fuels based on the gravity was designed to further enhance the safety of the spent fuel pool in case of accident conditions. This paper presents an experimental investigation of the validity of the spray-cooling system using two types of tight rod bundles, namely a 5 × 5 heated rod bundle and a 17 × 17 isothermal rod bundle. Results shows that the rod bundle heated with a lower power can be effectively cooled only by air without any spray water. With the increase of the heated power, the rod surface temperature increases gradually and the spray cooling has to be implemented to maintain the wall temperature at a certain level. The effect of flow rate on wall temperature was investigated. For the isothermal rod bundle, main interests were focused on the distribution of the spray water after it flowed along the rods.

Research on thermal-hydraulic behavior in the spent fuel pool using a full-height experimental facility

Abstract During accident scenarios the effective cooling of spent fuel directly affects the safety of nuclear power plants. Two experiments were performed in a full-height facility to study the thermal-hydraulic behavior in spent fuel pool. In spent fuel pool boiling experiment, the heat transfer characteristics are related to the flow patterns. However, the flow pattern in narrow and long channel is different from the traditional flow pattern. In the semi-dry of heated rod, wall temperature oscillation occurs for a long time. In the spent fuel pray experiment, the liquid film thickness varies randomly with time and space. As the spray flow density increase, the maximum wall temperature decrease gradually with a certain linear characteristic.