Internal explosion in Ammunition and Explosive (A&E) facility may cause the most dangerous consequences. The blast can spread in all parts of the facility while harming personnel in different levels of severity. High pressure can cause lethality due to lung damage. It may also cause building collapse particularly in structural elements right aside the explosion that may turn into debris and rubbles. Secondary fragments of nearby equipment (connected or unconnected) may fly with high velocity. Shock wave moving through the structure and the ground may cause people to be overturned or fall down with possible injuries or fatalities. Analytical-numerical model for the Israeli Ministry of economy was developed to analyze a typical A&E facility under accidental explosion. Six scenarios were developed and analyzed: Three TNT charges at the weight of 1, 10, and 50 Kgs were detonated, each at two positions: (I) Spherical the charge is at one meter above the floor surface; and (II) Hemispherical charge is on the floor level . The blast waves aroused from explosions were calculated by BLASTX software for a few cases: all openings are closed, all openings are opened, and additional venting opening in the room where the explosion took place. The findings of the analyses were as follows: a one kg explosion caused only minor structural damage. Ten kg explosion caused moderate structural damage, while the fifty kg explosion caused severe structural damage. The blast leakage in all the rooms was calculated for the various cases. In order to supply protection and prevent fatalities in the rooms adjacent to the explosion, a few upgrading protection measures are suggested: addition of steel plate, polymer sheets, or reinforced concrete layer to the existing reinforced concrete (RC) walls that will enhance the flexure and shear capacity of the structure; installing blast doors between the rooms that will be closed when dangerous activities are done, and installation of supplementary venting openings in the dangerous places. A comprehensive risk management model was developed and implemented for the assessment of the economic benefit of the alternative protective solutions. The model incorporates the expectancy of casualty, and the economic loss due to damage to the facility and the loss of the production activities. The economic viability of the proposed solutions was carried out using the Benefit-to-Cost-Ratio (BCR). All the protective solutions were found to be economic as BCR ratios were found to be between 1.25 (1 Kg - opened openings –) and 14.75 (50 Kg – opened openings). The risk analysis reveals that all protective solutions examined are highly effective in terms of expectancy of casualty.
