Study on Temperature Fluctuation Phenomena in Pressurizer Spray Pipe of Pressurized Water Reactor

Abstract

Damage of a pressurizer spray piping in a PWR plant is potentially considered from a safety point of views. Gas-liquid interface is formed in the pressurizer spray pipe of the PWR under a rated power operating condition. Temperature fluctuation may occur if the interface may move periodically. Measurement of inner wall and fluid temperature in the test section simulating the real pressurizer spray pipe was conducted to study mechanism of the temperature fluctuation phenomena. The temperature fluctuations were observed. Visualization experiment was conducted to understand the flow phenomena. It was estimated that Kelvin-Helmholtz instability occurred in the liquid layer in a horizontal pipe in the spray piping.