Determination of the combined effect of boron and gadolinia on the reactivity and safety parameters of (U, Th)O2 fuel. Issue 1 (April 2020)

• Record Type: Journal Article
• Authors: Uguru, E H; Sani, S F A; Khandaker, M U; Rabir, M H; Karim, J A
• Is Part Of: IOP conference series. Volume 785:Issue 1(2020)
• Publication Date: 2020-04
• Subjects: Materials science -- Periodicals; 620.1105
• DOI: 10.1088/1757-899X/785/1/012004
• Languages: English
• ISSNs: 1757-8981

Abstract

Abstract: This study investigated the combined effect of boron in light water moderator and gadolinia in fuel on the neutronic properties of (U, Th)O2 fuel in Westinghouse small modular reactor. The reactivity control of boron and gadolinia, and the potential of gadolinia in increasing thermal conductivity of its mixed fuel pellet motivated this study. Monte Carlo N-particle code integrated with CINDER90 was used for the calculations. Four fuel assemblies were used: one without boron and gadolinia, one with borated water only while the other two contained borated water plus 16 and 24 gadolinia fuel rods in each of the FAs. The BOC safety parameters was calculated at hot zero power (293.6 K) and hot full power (600 K). The results showed that the moderator temperature coefficient of reactivity was highest in FA without boron and gadolinia and smallest in FA containing boron plus 24 gadolinia fuel rods, while a reverse phenomenon was observed for the fuel temperature coefficient of reactivity. The effective delayed neutron fraction was slightly larger in FA without neutron absorber. The results show that boron and gadolinia decreased significantly the MTC but increased FTC slightly in addition to their initial neutron multiplication suppression role.