Analysis of core and core barrel heat-up under conditions simulating severe reactor accidents Academic Article uri icon

abstract

  • This paper reports on the development of a model for estimating the temperature distributions in the reactor core, core barrel, thermal shield and reactor pressure vessel of a pressurized water reactor during an undercooling transient. A number of numerical calculations simulating the core uncovering of the TMI-2 reactor and the subsequent heat-up of the core have been performed. The results of the calculations show that the exothermic heat release due to Zircaloy oxidation contributes to the sharp heat-up of the core. However, the core barrel temperature rise which is driven by the temperature increase of the edge of the core (e.g., the core baffle) is very modest. The maximum temperature of the core barrel never exceeded 610 K (at a system pressure of 68 bar) after 75 min simulation following the start of core uncovering. The results of simulations also show that water make-up flow rate into the core and radioactive heat decay are important model parameters and need to be known accurately for realistic predictions of core and core barrel heat-up. © 1988.

author list (cited authors)

  • Chellaiah, S., Viskanta, R., Ranganathan, P., & Anand, N. K.

citation count

  • 2

publication date

  • January 1988