MELCOR 1.5 calculations for ABCOVE Aerosol experiments AB5, AB6, and AB7

The MELCOR code was used to simulate the ABCOVE Aerosol experiments AB5, AB6, and AB7. In these tests, a dry sodium aerosol was introduced into an 850 m3 vessel and the aerosol behavior was monitored. Single and double component aerosols were used. Other codes have been used to simulate these tests including the CONTAIN code at Sandia National Laboratories. Results from MELCOR were compared both to the experimental data and to the CONTAIN results. MELCOR results were nearly identical to the CONTAIN results. Code predictions for the suspended mass of aerosol track the experimental data to the end of the experiment to within a factor of two or three. Final predictions of the mass deposited by settling agree within an 11% error for all tests. In AB5, code predictions for the mass of material deposited by plating agree with the experimental data with a 12% error. However, in the other tests, the codes do not give accurate results for the amount of material deposited on the walls at the end of the test. These errors are probably related to the turbulence in the vessel which may cause inertial impaction. Impaction is not modeled in either of the codes