A Summary of the Uncertainty and Sensitivity Analysis of a Generic CANDU 6 Plant by Means of Severe Accident Codes in the Framework of the IAEA CRP I31033

Abstract

IAEA launched in 2019 the Cooperative Research Project (CRP) I31033 entitled “Advancing the State-of-Practice in Uncertainty and Sensitivity Methodologies for Severe Accident Analysis in Water-Cooled Reactors”, with the main goal to advance the understanding and characterization of sources of uncertainty and investigate their effects on the key figure-of-merits (FOMs) of severe accident code predictions in water cooled reactors (WCRs). The 5-year CRP included participants from 22 organizations representing 18 Member States and generated 5 International Atomic Energy Agency (IAEA) technical documents on uncertainty and sensitivity (U&S) analyses of severe accidents scenarios in different water-cooled reactors (PWR, BWR, CANDU, VVER, and SMR), as well as the QUENCH-06 experiment.

With respect to the CANDU (CANada Deuterium Uranium) pressurized heavy water reactor analyses, three organizations in three Member States (Canada - CNL, South Korea - KAERI, and Romania - UPB) participated in the CRP. Each partner used their own severe accident and uncertainty tools to evaluate relevant input parameters and their impact on common figures of merit (e.g., hydrogen generation, event timing and fission product releases). All three CANDU participants studied a station blackout in a generic CANDU 6 station, with similar analysis assumptions, and used similar plant normal operating conditions.

This paper presents a summary of results of the U&S analyses performed by the CANDU group within the IAEA CRP and discusses all relevant insights and lessons learned in view of the application of the U&S methodologies for severe accident analyses in CANDU.