Coupled 3D neutron kinetics and thermalhydraulic characteristics of the Canadian supercritical water reactor

Analysis of Shutdown System Effectiveness in the Canadian Super Critical Water Reactor Using Coupled Thermal Hydraulics and Three-Dimensional Neutron Kinetics

“…A core-level coupled model of PT-SCWR thermal-hydraulics and spatial kinetics was previously created to study the transient behavior of the system in the absence of any reactivity control and shutdown systems [4]. This model, with the addition of a fastacting shutdown system, would also serve as the basis for this work.…”

“…Version CATHENA MOD-3.5d/Rev 3, used in this work to model the thermal-hydraulics of the PT-SCWR heat transport system, contains an expanded set of fluid properties for supercritical conditions but no specific heat transfer or friction correlations (standard correlations for subcritical water were used in lieu of dedicated models) [11]. CATHENA MOD-3.5d/Rev 3 has nevertheless been used for much of the safety analysis of the preconceptual PT-SCWR, so its continued use in this study is considered warranted [4,11].…”

“…In fact, lattice-level neutron transport calculations have shown that the reactivity worth of void around the fuel is positive (as high as 10 mk), and only the very large negative reactivity of void within the center flow tube (>40 mk) makes the net effect of voiding both regions negative as required. Previous work demonstrated that this positive reactivity worth leads to brief power excursions in transients with flow reductions (where the coolant density around the fuel decreases before changes propagate to the center flow tube), including loss-of-coolant accidents (LOCAs) and loss-of-flow accidents [4]. A fast-acting shutdown system is potentially necessary to counteract this positive reactivity insertion and mitigate consequences of these design basis accidents.…”

Investigation of Reactor Physics Phenomena in the Canadian Pressure Tube Supercritical-Water Reactor

“…Lattice level calculations have shown that the TCV and ICV have a negative CVR, whereas OCV has a positive CVR. Hence some nonequilibrium cases may result in transients where core power may temporarily increases prior to TCV induced selfshutdown of the reactor [11]. The reactivity and 4 factors for each case (TCV, OCV, and ICV) were investigated at the For personal use only.…”

“…Given the significant differences of the fuel design compared with existing physics code applications, a large number of studies have been performed comparing the 2-dimensional (2-D) lattice level neutronic behavior [6][7][8]. Moreover, research has also been performed on the coupled thermalhydraulic feedback effects in the PT-SCWR [9][10][11]. The key findings of many of these studies show that overall the design has a negative…”