Decommissioning can get quite expensive depending on the future use of the land. The technology exists to completely restore the land.

One area I worked at was a toxic waste dump back in the 50s and 60s. The US declared that area as a hazardous site back then and completely restored the area. It's a vast land of trees now. You'd NEVER know it was so polluted.

Decommissioning, though, takes a long time. For nuclear power plants, decommissioning will take decades and billions (USD) to restore to its original site.

Oh yeah, there's definitely a secret stigma to it all as well. Accessing the information isn't common at all even though a lot of it is public. However, like anything else in life, you almost have to be working in the industry to understand the information available.