JOYO MK-II power ascension test report; Loss of electric power supply test at 100 MW operation

Takahashi, Hideji*; not registered; not registered; not registered; not registered; not registered

Loss of electric power supply test and manual scram test were conducted as the transient response test on anomaly condition, in 100 MW power ascension test of JOYO MK-II core. The above transient response tests were performed to confirm the following items. (1)The thermal transient characteristics in comparison with the design criteria. (2)Sequential operation of the plant protection system, electric supply system for emergency and other components, and finally the shut down of the reactor in safe. Among the above two transient response tests, this report describes the result of the loss of power test. Main results obtained by the test are as follows. (1) The thermal transient characteristics of each part of main coolant system are within the design criteria. (2) The plant protection system and other components start to operate within the time required by the design. (3) The non-cut-off and the emergency power supply system operate as expected. (4) Both the flow coast down characteristics of the primary main cooling system and the flow rate generated by the pony motors are satisfactory in comparison with the design criteria. (5) The natural circulation of the secondary main loop is observed after the power cut-off. The measured flow rate of the natural circulation is about. 5.7% of the normal flow rate, just after the scram. (6) By the improvement of the secondary loop temperature control system, hunching of the main cooler outlet temperature clarified to be small, enough to satisfy the design criteria.