The safety related devices in the JRTR were the decay tank and siphon breaker as shown in Figures 1 and 2, respectively.
To investigate the siphon breaker, McDonald and Marten  carried out an experiment in order to confirm the performance of siphon breaking valve as an actively operation type.
Comparing with a 5 MW research reactor, the sizes or numbers of the decay tank and siphon breaker should be increased for a 15 MW research reactor.
This system can perform the three functions of a decay tank, which reduces the radioactivity by delaying the passing time of the coolant in the normal operation of the research reactor; siphon breaker, which prevents coolant loss when a LOCA occurs; and long-term cooling tank, which can remove the decay heat of the core by supplying the coolant to the reactor pool passively.
In addition, we attempted to confirm that the siphon phenomenon was properly cut off when the siphon breaker was operated in a new safety facility.
A new safety system for a research reactor, which integrates the decay tank, siphon breaker, and long-term cooling tank as a single facility, is suggested as shown in Figure 3 to improve the space efficiency and the ease of manufacturing and maintenance.
Siphon Breaker. In the research reactor, the reactor core is cooled by natural circulation through the flap valves to the reactor pool after the primary cooling pump (PCP) is turned off.
In this study, a new type of siphon breaker was suggested.
The rapid loss of coolant from the reactor is stopped by the siphon breaker, as shown in Figure 4(b).