The Mass Fusion containment shed is a location in the Commonwealth in 2287.


The Mass Fusion containment shed is a pre-War radioactive containment center, formerly owned by Mass Fusion. The shed was one of several locations under investigation due to formal inquiry into toxic waste dumping at Lake Quannapowitt,[1] instigated shortly after 27 people fell seriously ill or suffered radiation burns at the Lake Quannapowitt Bass Fishing Tournament.

During the investigation, the hazardous materials inspector sent to the site began to strongly suspect that the operation wasn't operating within the law. On the instruction of Mr. Feld, the site supervisor "got rid of him" in a manner that, if discovered, would have incarcerated him for life.[2]


The interior is a warehouse storing many barrels of radioactive material, as such irradiating the entire building. It contains glowing radroaches and feral ghouls. In the top floor room is the supervisors terminal, containing personal entries and the lock control for the security gate at the rear of the ground floor.

A floor hatch is located behind the barrels next to the conveyor belt, directly opposite the generator which leads to the reactor room. In the center of the reactor room, there is a generator with a switch affixed to the farthest side.

Notable lootEdit

  • A fusion core on the generator behind the security gate.
  • A Vault-Tec lunchbox is located in the subterranean area on the desk next to a broken terminal.


The generator in the subterranean chamber is powering the automated radio alarm signal, picked up by radio tower 3SM-U81. Deactivating the generator will stop the signal broadcast.

  • Although the automated radio alarm must be deactivated by the generator at the reactor level, there is a ham radio hidden beyond the wall to the west. It can be seen and used only through console command tcl.


The Mass Fusion containment shed only appears in Fallout 4.

Behind the scenesEdit

It is possible to jump onto the southeast corner of the lower roof (via a large pipe and two air conditioners), where one will find a synth and a human corpse. This seems to be a reference to the final scene of Blade Runner.[1]


  • PCIcon pc Flipping the circuit breaker in the sub-level will sometimes fail to disable the automated radio alarm. A workaround is to return to radio tower 3SM-U81 and re-extend the satellites, then return to the containment shed to flip the breaker again. The warning klaxons in the sub-level can de-sync with the radio signal if the klaxons are turned off before resetting the radio tower.[verified]
  • PCIcon pc Playstation 4Icon ps4 Xbox OneIcon xboxone Both of the ghouls that are hidden in the radioactive waste in the middle of the warehouse can not be looted directly. A workaround is to order one's companion to search the corpses. On PC, one can open the developer's console, click on the ghoul, and enter the command openactorcontainer 1 as another workaround.[verified]



  1. Lake Quannapowitt terminal entries: "Recommend closing the lake to the public and beginning a formal inquiry into the waste management practices of nearby heavy industry (General Atomics, Saugus Ironworks, Corvega)."
  2. Mass Fusion containment shed terminal entries#8/22: "A hazardous material inspector stopped in today unannounced to check out our operation. I started to feel like he was getting suspicious of what has actually been going on around here. I told Mr. Feld and he said if the inspector started catching on we needed to get rid of him, and he didn't mean ask him to go away. Well, he caught on... so we had to get rid of him. If anyone finds out what we did they'll put me away for life..."
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