ISSN Online: 2688-7231
ISBN Online: 978-1-56700-524-0
Proceedings of the 26thNational and 4th International ISHMT-ASTFE Heat and Mass Transfer Conference December 17-20, 2021, IIT Madras, Chennai-600036, Tamil Nadu, India
INVESTIGATIONS ON TOTAL INSTANTANEOUS BLOCKAGE IN A FUEL SUBASSEMBLY OF FAST REACTOR USING COUPLED THERMAL HYDRAULIC REACTOR PHYSICS MODEL
Abstract
Total instantaneous blockage (TIB) at the inlet of a sub
assembly (SA) of sodium cooled Fast reactors is a beyond
design basis event that is a theoretical envelope of all small
blockages. The extent of core damage propagation is an
important input for the thermal design of the core catcher,
which is provided for the collection and cooling of molten
core. This study aims to conduct a coupled thermal-hydraulicreactor physics analysis of TIB in a medium sized Sodium cooled Fast Reactor (SFR). Towards this, thermal model is developed by solving heat transfer equations. A reactor
Physics model is developed, which solves point kinetics
equations numerically. The developed model can predict the
temperature distributions of the fuel, clad, coolant and hexcan
during accident conditions upto the start of hexcan melting.
Various reactivity feedbacks and power changes during the
accident are calculated. Time of occurrence of sodium boiling,
clad melting, and fuel melting are obtained. It is found that
TIB is detected earlier than that predicted by previous study
without using coupled analysis.