The gold bars are distributed in 122 compartments not all together in one large room.
Vaporizing the gold inside the vault would not destroy it. Vaporization is not disintegration, the gold does not cease to exist, it is simply a vapor that eventually condenses back to liquid, then cools to a solid. All that would happen is that there would be a layer of gold coating the floors and walls of the vault. it would be a mess, but the gold would still be there.
The shape of the gold bars is incorrect. The bars have a rectangular cross section not the slanted shape shown. In other words, looking end on, they are rectangles not trapezoids.
Supposedly the bomb in the gold vault will generate a temperature of 2,000 degrees which is supposed to vaporize the gold ingots. Gold vaporizes (boils) at 5,378 degrees Fahrenheit over 3,000 degrees hotter.
The bomb in the vault ignites standard size propane tanks. Propane burns at 3,596 degrees Fahrenheit not the 2,000 degrees they say in the show.