Calculation of coolant flow rate by radiation methods and power in first unit of armenian atomic power plant

The present paper discusses the results of measurements of the coolant flow rate in all six of the main circulating loops (ML) and the thermal power of the first unit of the Armenian Power Plant. The coolant flow rate was measured by a method based on the registration of the decay of leN activity with coolant circulating in the ML; the method used to measure the thermal power was based on registration of the neutron flux density under the reactor vessel. For practical implementation of these methods we developed and set up in the first unit of the power plant a flowmeter in the form of a system of 12 experimental channels above the pipes of the primary circuit with sensors installed in them and a power meter was set up under the reactor (Fig. 1). Measuring the Flow Rate of Coolant in the Primary Circuit. High-stability SI-3BG Geiger-Miiller counters were used as sensors. The sensors were installed above the primary-circuit pipes in special collimators to isolate a definite, strictly specified volume of coolant. The first sensor records the intensity of the 16N ~/ rays of the primary-circuit coolant in the segment of the ML at the outlet from the reactor (first detection point DP-1); the second sensor, after the coolant has passed through the steam generator at the inlet of the ML to the reactor (second detection point DP-2). The coolant flow rate G in each ML was found from the ratio of the counting rates N 1 and N 2 of the sensors