This was a very fun challenge thanks! I went for a para-dropped rover to minimise time over the reactor, however I was a little low on my approach and clipped the tower (luckily no damage ). My craft is stock + DLC btw.
The reason there are extra batteries on top of my rover was that I couldn't figure out how to stop my plane from charging the rover probe in-flight, so I ejected all unregulated charge before starting clearing the roof.
My rover also has a scoop on the front to aid disposal of graphite, but got blown off while deploying from the pane . This is what it should look like: