The development on the 3D kinetics, thermal hydraulics, and plant system transient code sparkle

Mitsubishi Heavy Industries (MHI) has developed the SPARKLE code. This code is dynamic coupling of the three-dimensional neutron kinetic code ANCK (1)(Chao, et al., 1998), the thermal-hydraulics code MIDAC (2)(Akiyama, et al., 1995) and the PWR system transient analysis code MARVEL. The nuclear reactor accident analyses using best estimate codes provides a better understanding of physical phenomena and quantification of conservatism and safety margins in the current safety analysis. Especially, it is useful to apply SPARKLE to the Rod Ejection (R/E) accident and main Steam Line Break (SLB) accident in which power distribution changes significantly during transient. This paper indicates verifications of the SPARKLE using experimental analyses. The result of SPARKLE is shown good agreement with experimental results. And this paper presents calculation results of the R/E and SLB using the safety analysis condition. Analysis results of the R/E and SLB using the SPARKLE can provide more adequate safety margins compared with current licensing method. MHI has a plan to apply the SPARKLE for commercial licensing in the near future. (authors)