A Fuel Freezing Model for Liquid-Metal Fast Breeder Reactor Hypothetical Core Disruptive Accidents

About the Nature of the course of BN Reactor beyond Design Accidents under postaccident Core Materials Relocation

“…Профиль поперечного сечения канала для прохода теплоносителя, приходя щегося на один твэл, представляется в виде кольца вокруг твэла, эквивалентного по величине гидравлического диаметра (d г = 2,76 мм) и площади. Значения коэф фициентов формы поперечного сечения центральных каналов треугольной решет ки твэлов в ТВС (ϕ л = 1.47 и ϕ т = 1.07) рассчитаны по зависимостям из [16].…”

Investigation of Passive Safety Methods for Nuclear Reactors

“…This model tended to underpredict the penetration length when compared to experimental results [7]. A model created by Best et al [8] focused on a pressure-driven turbulent pipe flow without considering the effects of gravity. They assumed the pipe wall material would melt as the molten corium was freezing.…”

“…They showed the freezing behavior of corium and determined the penetration distance of corium flowing in a channel. They predicted a loss of thousands of kilograms of corium if the corium escaped the reactor vessel and penetrated empty drainpipes [8]. The Best et al model also included a crust rupture mechanism, which allowed them to predict when and where a crust would form in the flow and then rupture to cause further penetration.…”

“…They assumed the flow to be one-dimensional and incompressible with constant physical properties [8]. The solid-liquid interface temperature was considered to be equal to the material equilibrium solidification temperature, and the liquid injection pressure was sufficiently high to assure turbulent flow.…”

“…All the assumptions listed were used to determine a final penetration distance expression, as shown below in Eq. ( 2) [8].…”