JOYO operational experience report results of sampling and analysis of sodium and argon during 75 MW operation

not registered; Odo, Toshihiro; not registered; not registered; not registered; not registered; not registered

In JOYO, coolant sodium and cover gas argon have been sampled and their impurities have been analysed since its initial functional tests. this report describes the results of sampling and analysis during 75 MW operation. The major conclusions are summarized as follows. (1)Impurity concentrations in primary and secondary sodium were within the reference limits of JOYP. (2)analysed oxygen concentrations in both primary and secondary sodium were dispersed and were above the Eichelberger's oxygen solubility curve. On the other hand, hydrogen concentrations showed good consistency with the Visser's solubitity curve. (3)some impurity concentrations in the primary cover gas, such as hydrogen and methane, had been above the reference values. (4)It was confirmed that purity of the primary cover gas could be easily recovered by argon gas purging in the reactor vessel. At the same time, its operational method was established.