Design of mercury cirulation system for J-SNS

Kinoshita, Hidetaka   ; Haga, Katsuhiro  ; Kogawa, Hiroyuki  ; Kaminaga, Masanori  ; Hino, Ryutaro

The JAERI and the KEK are promoting a plan to construct the spallation neutron source at the Tokai Research Establishment, JAERI, under J-PARC project. A mercury circulation system has been designed so as to supply mercury to the target stably. Conceptual design is almost finished. But, it was necessary to confirm a mercury pump performance, and more, to investigate erosion rate under the mercury flow as well as an amount of mercury remained on the surface after drain. The mercury pump performance was tested under the mercury flow conditions by using an experimental gear pump, which had almost the same structure as a practical mercury pump to be expected, and the erosion rates in a mercury pipeline as were investigated. The discharged flow rates of the gear pump increased linearly with the rotation speed. Erosion rates obtained under the mercury velocity less than 1.6 m/s was found to be so small. For the amount of remaining mercury on the pipeline, radioactivity of this remaining mercury volume was found to be three-order lower than that of the target casing.