Abstract: Residual Heat Removal System（RRA） can be used to maintain the reactor coolant temperature at cold shutdown conditions to offer the time required for the refueling and maintenance operations. In the maintenance in the cold shutdown condition（with the fuel in the reactor）, this system will keep the reactor coolant temperature less than 60 centigrade for the repairman to get into the manhole of any one of the steam generators and maintain the reactor cooling. In this test, it requires to prove that in this condition the reactor coolant does not enter the steam generator bottom head to result in additional staff radioactive contamination when the primary loop high level alarm occurs. The residual heat removal pump is required to run without cavitation even at its designed maximum flow rate when the primary loop low level alarm occurs. The level of the primary loop should change slowly to avoid the instrument false when the RCP300 MN is put into use during the maintenance cold shutdown condition.