Why Beirut Blast was NOT a nuclear explosion

Beware of sensationalism clickbaiting and crazy rumors: Beirut was NOT a nuclear explosion.

However, considering how huge this explosion was, I feel that I ought to post these few reminders:

1. It is quite impossible to conceal the use of a nuclear device, even a low-yield one, in particular in a densely populated area and in a warzone.
2. Most (all?) major explosions produce a “nuclear mushroom” simply because the air rushes back into the place from where it expelled by the explosion.
3. You can clearly see two colors in the explosion, which points to a chemical, not nuclear, event.
4. There is a complete absence of any nuclear flash and fireball.
5. In the case of the Beirut explosion, you can clearly see in the footage that there is/are a (few) primary explosion(s) and a much bigger secondary explosion.  You don’t see that with nukes.  See for yourself: