Method for the evaluation by simulation of leaks from nuclear reactor vessel cover crossings in operation during a shutdown.

摘要

A mixt. of tracer gases (43) contg. helium is injected into the chamber (7) where any leaks (10) from penetrations through the reactor head would emerge. A mass spectrometer (45) is placed in a double sampling circuit (12-15, 100,16,17) to detect and measure the concn. of the tracer gas in samples extracted from inside the chamber (7) and, as a reference, from inside the reactor building (100). USE/ADVANTAGE - To determine the flow rate inside the chamber (7) and to verify the sampling system, during shutdown. Sensitive measurement since the sample is taken before the tracer gas is diluted by the air flow cooling the control rod drive mechanisms (3).