LEVEL MEASUREMENT BY MEASUREMENT OF GAMMA-COUNT RATES AT THE REACTOR ZLFR

A method for measuring the water level in vessels with internal gamma radiation sources, as they exist in reactors and steam generators of n uclear power plants, is described. The method is based on measurement of the gamma count rate outside the vessel. Two detector arrangements are presented which are suitable for the different measuring condition s at reactors and steam generators, respectively. Relative changes of the gamma count rate are measured in dependence on water level changes . The experimental results confirm that the method is in principle sui table for water level measurement.