| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for monitoring a hydrogen concentration which can improve the detection accuracy of water leakage.SOLUTION: NaOH generated from moisture entering secondary cooling system piping during the maintenance of a fast breeder reactor plant and Na returned to the piping is resolved by a temperature increase after the start of the plant, and the hydrogen concentration in the Na is increased. The hydrogen concentration in the Na is decreased by cleanup, and a hydrogen concentration peak P is formed. The hydrogen concentration C (characteristic 25) in the normal state of a steam generator at each time after the peak P is obtained beforehand from C=C×exp(-η(F/V)t) using the hydrogen concentration Cat the peak P, the efficiency of the cleanup η, a supply flow rate F of Na to the cleanup, and the inventory V of the secondary system Na and a plant operation time t at the peak P and after. The C during a period tn when the reduction rate of the C is small is defined as a setting hydrogen concentration C. When the hydrogen concentration of Na discharged from the steam generator is not lowered to the C(characteristic 26A or the like) or below, the water leakage arises in the steam generator. |
