To give you some meat to chew on regarding the descriptions others have already provided you, check out this paper, specifically section 5.5:

>Annihilation on neutrons
>Antiproton–neutron or antineutron–proton interactions at rest offer additional opportunities to study annihilation dynamics.

You seem to be asking multiple questions. We may have to separate these to provide meaningful answers.

Since both neutrons and antineutrons both have neutral charge, can we distinguish between them?

Yes. The Wikipedia page has details and more in the referenced links. One difference is the magnetic moment.

Can antineutrons exist in the nuclei of regular atoms?

In the most general sense, no. A neutron and an antineutron would annihilate. So you cannot replace them one-by-one.

Could you have anti atoms with antineutrons, antiprotons and positrons?

Sure. Here's a good article on antimatter with some history of such. Trouble is that you have to keep it separated from regular matter which will annihilate it in short order.

> space, which is something

I think this is the root of your trouble.

The easiest answer to your original question, I believe, is simply "no".

A deeper answer would be to redirect you towards learning the nature of EM radiation. Folk here are wrestling with this because it's hard to ascertain adequately the root(s) of your misconceptions.

To me, at least, it seems you're stuck in something akin to where people were more than a century ago where they were convinced light had to be a wave in some sort of medium which they dubbed the ether. You seem to be imagining "EM radiation" as some sort of disturbance in space whereby the space disturbance can be collapsed, ruptured, cavitated (whatever word you want). But our current understanding of EM radiation doesn't work like that... at all.

To better understand destructive interference of electromagnetic waves, you are going to need to fall back to learn about waves, in general. After you get used to constructive and destructive interference in waves of water in a pond, then you should wrestle with the medium-less nature of waves in the electric and magnetic fields.