We have fixed some misleading level design issues and features:
* The entrance of the cave was blocked at the time you discovered the cavern. Once discovered, the entrance would get cleared out. It was actually there to help you in case you fell into the cavern without a jetpack.
* Now you need to fill your radioactive canister with uranium to fix the generator. :)
V1.3: Fixed misleading LD
Source: Steam Community (opens in a new tab)