Data report of tight-lattice rod bundle thermal-hydraulic tests, 3; Rod-bowing effect test using 37-rod bundle simulated water-cooled breeder reactor (Contract research)

Tamai, Hidesada; Kureta, Masatoshi   ; Liu, W.; Sato, Takashi; Nakatsuka, Toru  ; Watanabe, Hironori; Onuki, Akira; Akimoto, Hajime

Japan Atomic Energy Agency has been performing tight-lattice rod bundle thermal-hydraulic tests to realize essential technologies for the technological and engineering feasibility of super high burn-up water-cooled breeder reactor featured by a high breeding ratio and super high burn-up by reducing the core water volume in water-cooled reactor. The tests were performing to make clear the fundamental subjects related to the boiling transition (BT) (Subjects: BT criteria under a highly tight-lattice rod bundle, effects of gap-width between rods and of rod-bowing) using 37-rod bundles (Base case test section (1.3 mm gap-width), Two parameter effect test sections (Gap-width effect one (1.0 mm) and Rod-bowing one)). In the present report, we summarize the test results from the rod-bowing effect test section. The thermal-hydraulic characteristics were obtained for the critical power under the steady-state and transient conditions, the pressure drop and the wall heat transfer within a wide range of pressure, flow rate, etc. including normal operational conditions of the designed reactor. Then the rod-bowing effects were also investigated based on the comparison between the results using the base case test section and the rod-bowing effect one.