NACOM code for analysis of postulated sodium spray fires in LMFBRs

An analysis of potential sodium spills and fires in liquid metal fast breeder reactors has been made to assess the maximum equipment cell loading conditions. A computer code called NACOM (sodium combustion) has been developed at Brookhaven National Laobratory (BNL) to analyze sodium spray fires. This report contains a detailed description of physical models used in this code as well as programming aspects. The single droplet combustion model and the model describing the droplets' motion are verified. Comparisons between NACOM predictions and SPRAY-3A predictions of the Atomics International (AI) LTV Jet Tests are made. Good agreement is found between the NACOM predictions and the experimental data. NACOM predictions of the pressure rise are more accurate than SPRAY-3A predictions for most of the cases studied. The code has been verified for oxygen concentrations ranging from 0 to 21%. NACOM utilizes more realistic single droplet and spray combustion models than SPRAY-3A. Moreover, NACOM does not utilize adjustable parameters for the burning rate equations, contrary to the approach taken with SPRAY-3A. Thus, the NACOM code is a more reliable code for use in the analysis of large-scale sodium spray fires in LMFBR containment cells. 24 refs., 32 figs