JOYO MK-III Performance test report; Blower start-up test (PT-303), Power-increase test (PT-301), Rated power operation test (PT-302)

Oyama, Kazuhiro; Kawahara, Hirotaka ; Ishida, Koichi; Ariyoshi, Masahiko; Isozaki, Kazunori ; Sugaya, Kazushi*; Fukami, Akihiro*

In the MK-III performance test, the experimental fast reactor JOYO raised the reactor thermal power gradually with about 20%, 50%, 75%, 90%, and 100% (140MWt), and reached 140MWt which are the full power of a MK-III reactor core on October 28, 2003. Then, continuation operation beyond full power 100 hour was attained. This report summarized the result of power-up test , full power continuation operation test, blower start-up test.The outline is as follows.(1)From the standby state (system temperature of 250degree), the usual power-up operation (an power-up rate ;about 5MWt/20min, a power is held for about 10 minutes every 5MWt) attained the reactor thermal full power (140MWt) gradually on October 28,2004. Moreover, it checked that each part temperature and flow were less than alarm setting values on each power level.(2)The reactor thermal power was made into the parameter, a series of operations about the blower start-up, and the influence which it has on coolant temperature was checked. As a result, the optimal reactor thermal power which starts up the blower from a natural ventilation cooling state was set to about 18 MWt, and the starting procedure was made into the method(order of 1A-2A-1B-2B) which starts four sets of the one blower at a time one by one.(3)It checked that reactor shutdown operation by two control-rod simultaneous insertion at 35MWt, and it could carry out with time margin with a series of sufficient operations of resulting from control rod insertion in the blower shutdown. By adopting this reactor shutdown operation method, operation of an operation stuff was mitigated and it checked that plant characteristics also improved.(4)The reactor full power was reached on November 14. Continuation operation beyond full power 100 hour was attained after that till on November 20, 10:30. The data of each part of a plant was acquired at intervals of 24 hours, and it checked that it was less than an alarm setting value.