A numerical and experimental study of water ingression phenomena in melt pool coolability

Experimental investigation on melt coolability under bottom flooding with and without decay heat simulation

“…• Subsequently, the heat transfer between melt and water was so rapid and nearly instantaneous. It took only a few minutes to quench the melt to room temperature which otherwise took several hours as compared to top flooding experiments (Nayak et al, 2009). • Fig.…”

“…Most eventual of these is to flood the melt with water from the top (Lomperski and Farmer (2007)). This approach is feasible to execute, however, it may leave the melt in uncooled state due to the formation of thick crust on the top of the melt pool which does not allow water to ingress the melt pool and to cool it, as observed in COMECO tests (Nayak et al, 2005), which hinders further heat transfer. Experiments by Kulkarni et al (2011), Kulkarni and Nayak (2014) has suggested that it took several hours to cool the melt pool with top flooding even when there was no decay heat and the water ingression was limited to only a few millimetres.…”

Experimental investigations on melt coolability with simulated decay heat—The influence of delay time in flooding

“…Nayak et al, 34 Singh et al, 35 and Kulkarni 36 observed that when the strength of the corium concrete mixture decreased, water ingression was enhanced. Similarly, when the thermal expansion coefficient and Young's modulus increase, the stresses in the crust increase, which results in crust break and ultimately causes water ingression.…”

On water-ingression during top-flooding of corium melts

“…Lompersky and Farmer used the Lister-Epstein model in their analysis of SSWICS 1-7 tests [5,6]. However, from our understanding, as will be discussed in next sections, the model includes some technical issues, in particular linked to the the fracture process, previously noted and discussed in [10] and [11]. Also, the model implies numerous highly uncertain physical properties that render it difficult to use.…”

“…Several experiments were performed using simulant materials. Nayak et al [10] performed experiments using a calcium-barium oxide mixture CaO + Ba 2 O 3 (solidus/liquidus temperatures at 1180/1250 K), with an external heating at a level of 1.3M W/m 3 simulating decay heat. In the same facility, Kulkarni [11] later used sodium borosilicate glasses as simulant (melting point at about 900 K from [11]).…”