Experiments on the water leak detection systems in the 50MW steam generator test facility (9); Cold trap efficiency test, hydrogen background concentration test, hydrogen flux through tube test

Kaneko, Yoshihisa*; Nishikimi, Masakazu*; Shirato, Seiichi*; Tsuchiya, Tsuneo

Series of tests on water leak detection system for Monju steam generators have been excuted in the 50MW Steam Generator Test Facility (50MW SGTF). This paper describes the test results about the removal efficiency of hydrogen by the secondary cold trap, the hydrogen background concentration and hydrogen flux through heat transfer tubes to secondary sodium in steam generator (SG) in order to make clear the hydrogen behavior during ordinary plant operation from October in 1976 to July in 1983. Main results from these tests are: (1)The removal efficieney of hydrogen by the cold trap is 7080 percents, but it shows tendency to decrease when difference between hydrogen concentration at cold trap and that in secondary main loop is small. (2)Hydrogen flux through tubes is smaller than the value which is reported in the first report of these series reports. (3)It is found that the hydrogen background concentration in the secondary main loop of 50MW SGTF is thoroughly low. (4)It is estimated that the hydrogen background concentration in the secondary main loop in Monju plant is lower than 169 ppb.