Abstract
Developments on the ultra-sonic flowmeters, which are used widely in the water loop, have been carried out for the application on the sodium loop in fast breeder reactor. This is because of that ultra-sonic flowmeters have several characteristics needed to the large pipe sodium flowmeter, i.e. good linearity, light-weight, leak tight, low cost etc..
After fundamental improvement about the settling method of transducer to high temperature duct and about measurement circuit were developed, in-water tests were conducted and effectiveness of such improvements were confirmed.
So 12B and 24B ultra-sonic flowmeters were made after additions of several improvements to high temperature problems, and tested in the sodium loop, and it is confirmed that the ultra-sonic flowmeters have superior characteristics as the sodium flowmeters. In the sodium temperature (200∼400°C) and flow rate (0∼6m/s), linearity and repeatability were within ±1%. And effect of upper flow straight pipe length to the ultra-sonic flowmeter output was smaller than in water loop tests.
This paper describes mainly the above results of sodium flow tests which showed that ultra-sonic flowmeters are useful as the sodium flowmeter.
