Fuel Detection Gamma Monitors

The Gamma Monitor System detects fuel element ruptures by continuously monitoring effluent water from each rear cross-header. A gamma sensitive Ion chamber la revolved past the respective continuous streams and measures the magnitude of the gamma emission. Vlstial fluid audible Alarms eumunclate if the trip points are exceeded. radiation profile of the crossheaders Is plotted on multipoint recorders. 

A containment gaseous radiation monitor is provided to measure the gamma radioactivity levels in the containment atmosphere by continuous sampling. Leakage is detected by this method, and to the extent practicable quantified, with a response time dependent on various factors such as the fraction of failed fuel, the fission product inventory in the core, and time of transit from the origin of the leak to the monitor. The activity is indicated in the Control Room by the DPS and averaged hourly. 

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