가압경수로의 초장주기 무붕산 노심 핵설계 = Nuclear Design of the Ultra-Long Cycle, Soluble Boron Free PWR Core

다국어 초록 (Multilingual Abstract)

A feasibility of nuclear design for the ultra-long cycle core with soluble boron free operation option was investigated for both a medium-sized PWR and a small-sized power reactor. For medium-sized reactor loaded with MOX fuel show ed a nuclear design feasibility for 54 months single-batch cycle.
Excess reactivity was compensated by IFBA and WABA BP rods which has enriched B-10 up to 80％.
For improving shutdown margin, B-10 in B4C shutdown rods which has enriched. Ag-In-Cd regulating banks were also used for excess reactivity control throughout the cycle. Axial offset and FQ were found to be kept within the safety limits. Shutdown margin was also preserved at the refueling cold standby condition. Stored energy during a rod ejection accident was far less than the safety limit.
In a small-sized marine power reactor core loaded with U-10Zr metal alloy fuel, Gd203 and Pyrex down margin throughout longer single batch cycle of 12.5 EFP year. All kinds of safety parameters were found to be below their safety limits. With an installation of stainless steel radial reflector, average fuel enrichment level could be decreased by about 2~4w/o.