Abstract: To realize long period refueling for Tianwan Nuclear Power Station (TNPS) units 1 and 2, the fuel management scheme on transition to 18 months refueling was worked out. Referring to management experience in Russian nuclear power station, the long period refueling project shall adopt the new type fuel assembly TVS-2M. Before formal transition to long period fuel cycle, the mixed core compatibility was verified by the operation of pilot TVS-2M fuel assemblies. TVS-2M fuel assemblies replaced AFA fuel assemblies in two steps, namely, TVS-2M with blanket was loaded in the first two transition cycles, and TVS-2M without blanket was loaded in the subsequent cycles. The two TNPS units are scheduled to gradually increase operation length and finally reach 480 effective full-power day (EFPD) in four transition fuel cycles. Transition fuel cycles and equilibrium fuel cycles were all designed to adopt the part-low-leakage core fuel loading, which can reduce neutron irradiation to reactor pressure vessel. Fuel management schemes on 18 months refueling for TNPS enhance units capacity factor and economy, and have flexible cycle length.