| 摘要 |
PURPOSE:To eliminate an error of water level measurement due to a velocity head component by the flow speed, by providing a means for measuring a pressure difference of lower and upper parts of cooling material in BWR vessel and moving flow rate of jet pump and carrying out operational proceessing of both values. CONSTITUTION:An upper side nozzle 12 and a lower side nozzle 13 are attached to the inner part of a pressure vessel of nuclear reactor 1 and a pressure difference DELTAP is obtained by a pressure difference detector 14. Also, a pressure measuring tap 22 is provided to a throat and diffuser parts of a jet pump 6 at lower part of a downcommer part 5 in the vessel 1 and its pressure difference is measured by a detector 23. A relative water level WL is shown by the equation obtained by applying Bernoulli's equation at the part 5 between the surface of the water 11 and the nozzle 13. Accordingly, the pressure difference DELTAP between the nozzles 12 and 13 is found by the detector 14 and moreover, the pressure difference of pressure taps 21, 22 provided to the pump 6 is found by the detector 23. Then, by integrating its output, the water level WL is obtained by finding a flow rate of cooling material W of the nozzle 13. |
