Decision tree for FSSA rooms in CANDU.

• This paper presents a new methodology for the qualitative screening step for CANDU reactors in Canada for performing Fire PRA. • This qualitative screening step includes a decision tree that screens out fire zones from further analysis according to pre-determined criteria. • This is very important step in any Fire PRA. • It screens out fire zones that do not affect the integrity of Fire Safe Shutdown Analysis (FSSA) cables during worst-case fire scenarios. This paper presents a new decision tree that identifies fire compartments that are screened out from further analysis according to pre-determined criteria. The paper identifies the most common fire zones and uses Computational Fluid Dynamics (CFD) model Fire Dynamics Simulator to calculate the consequences. This is a critical and very significant step in the Fire PRA. It screens out fire zones that do not affect the integrity of Fire Safe Shutdown Analysis (FSSA) cables during worst-case fire scenarios. [ABSTRACT FROM AUTHOR]