A Coolability Model for Postaccident Nuclear Reactor Debris

Numerical Analysis of Droplet Breakup Behavior using Particle Method

“…The dryout heat flux on particle beds is estimated by Lipinski's model. 1) When the particle diameter is 5 mm, the dryout heat flux is 1 MW/m 2 . If the porosity is assumed to be 40%, the dryout heat flux at the top of the debris bed can cool down 40% of the core.…”

“…If the core is molten, a particulate bed is necessary to form in the pressure vessel or in the containment vessel to cool down in water. Dryout heat flux at the top of the particle bed depends on the diameters of the particles, 1) which have been estimated using the critical Weber number obtained by experiments in simple gasliquid systems.…”

Enhancement of Dryout Heat Flux in a Debris Bed by Forced Coolant Flow From Below

“…Lipinski [12] proposed a one-dimensional model which included the effects of both laminar and turbulent flow, two-phase friction, gravity, and capillary force, and this model is applicable to both uniform and stratified debris as well as debris with liquid entering from the debris bottom. If the bed is uniform and deep enough, i.e., the bed height is greater than the capillary head λc = 6σcosθ (1-ε) ⁄ dε (ρl−ρν)g, the capillary force can be ignored and the Linpinski's formulation of the relation between dryout heat flux (q) and effective saturation (s) appears as follows.…”

“…Analytical models of predicting dryout heat flux in debris beds were proposed by Lipinski [12], Turland and Moore [13], Kim [14], and Burger and Berthoud [15]. Lipinski proposed a one-dimensional model which included the effects of both laminar and turbulent flow, two-phase Tsai & Catton [7] Hu & Theofanous [6] Cha et al [8] Atkhen & Berthoud [9] Schafer et al [5].…”

Boiling Stability in a Porous Medium Heated From Below

“…The interest for this topic is due to various applications in fields of engineering and sciences including drying processes [e.g., high temperature drum drying Rudemiller and Lindsay (1989), vacuum drying Laurent et al (1999); Moyne (1987) or microwave drying Turner and Jolly (1992); Péré and Rodier (2002)], heat pipe and capillary pump loops Faghri (1995); Figus et al (1999), reflooding of debris beds in a damaged nuclear reactor Lipinski (1984); Chawla et al (1985); Stubos and Buchlin (1993), underground high-level radioactive waste repositories Doughty and Pruess (1988); Forsyth (1990), thermally enhanced oil recovery Yortsos and Gavalas (1982), or soil remediation by steam injection Udell (1997), safety evaluation during fire in buildings or tunnels Sahota and Pagni (1979); Schrefler et al (2002), etc. Many other examples can be found from geophysics like hydro-thermal behavior near active volcanoes Hurst et al (1991); Vandemeulebrouck et al (2005), description of geothermal system O' Sullivan et al (2001) or understanding of geyser phenomena Ingebritsen and Rojstaczer (1996).…”