Proving test and analyze for critical power performance in the RMWR tight lattice rod bundles under transient condition

Liu, W.; Tamai, Hidesada; Onuki, Akira; Kureta, Masatoshi*; Sato, Takashi; Akimoto, Hajime

A major concern in the design of RMWR is that sufficient cooling capability be provided to keep fuel cladding temperature below specified values, even for a postulated abnormal transient process. In this research, centered the postulated transient cases that may be possibly met in the RMWR running, transient BT tests are performed in 7-rod and 37-rod double-humped tight lattice bundles, under the RMWR nominal operating condition (P = 7.2 MPa, Tin =556 K) for mass velocity G = 300 - 800 kg / (ms). Experiments are analyzed with TRAC code, in which JAERI critical power correlation is implemented for BT judgment. The traditional quasi-steady-state prediction of BT in transient process is confirmed being applicable for the postulated nominal transients in the RMWR cores.