Military wants to power bases with small nuclear reactors

Surely securing a device such as this wouldn't be the hardest part?

Just dig a really hole in the middle of the base, drop it in there and cover it with either dirt or cememnt, leaving a small shaft for maintanance/access. Then dig it out again at the end?

That would protect it from everything other than the entire base being completely overrun, in which case the enemy has already won right?

I think the main concern here is that these devices won't be made very human-safe since they'll be deployed in warzones where rules don't really apply.

The fact that they leak a bit of nuclear waste and make the land uninhabitable for 1000 years isn't a concern to the US army, as long as it isn't US soil.

NuScale's passively cooled mini reactors might be a good fit here. I think toshiba has something as well, but NuScale is home grown. Are there any other small reactor companies in the us?