Prediction model development for siphon break phenomena in a research reactor

In a research reactor, the reactor core is cooled by a natural circulation through some opening valves to the reactor pool after the primary cooling pump is turned off. The pool water itself is the ultimate heat sink of the residual heat. Thus, it is very important to guarantee that the pool water level is higher than the minimum level from a nuclear safety point of view. In an open pool-type research reactor, however, a component of the system can be installed below the core level due to the component's purpose. The pool water is then drained below the core by a siphon effect, and the core cannot be cooled by natural circulation when a postulated pipe break occurs below the reactor core position. Therefore, the system should install a siphon breaker to limit the pool water drain during and after all postulated initiating events