Steam injector development for ALWR's application

Steam Injectors (SI's) can be used in Advanced Light Water Reactors (ALWR's) for high pressure makeup water supply; this solution seems to be very attractive because of the ''passive'' features of SI's, that would take advantage of the available energy from steam without introduction of any rotating machinery. In particular, SI's could be used for high pressure safety injection in BWR's or for emergency feedwater in the secondary side of evolutionary PWR's. An instrumented Steam Injector (SI) prototype, operating at high pressures, has been built and tested. The experimental results confirm the capability of tested SI to operate at constant inlet water pressure (about 0.3 MPa) and inlet water temperature up to 50 deg. C, with steam pressure ranging from 2.5 to 9 MPa (4.5-9 MPa at maximum inlet water temperature). The discharge pressure target (10% higher than steam pressure) was fulfilled in the operating range. It should be noted that the minimum operating limit can be lowered to 1.5 MPa with some modifications. To achieve these results an original double-overflow flowrate-control/startup system, patented by ENEL/CISE in 1993, has been used. (author). 9 refs, 10 figs, 2 tabs