Powering Up Poseidon

Powering Up Poseidon is an event quest in Fallout 76.

Quick walkthrough
Most of the entrances are locked, needing a level 3 hacking level to get into the reactor. An easy way in is through the cooling towers or, if one goes behind the facility, there is an open door leading inside. If one chooses to go through the cooling towers, this is one of three areas they must fix. Pipes that are emitting smoke are the ones that must be fixed; there are also control panels that can be fixed as well. No materials are required to do so.

Next, through the cooling tower, there should be a door to the generator room. Here many of the consoles are near the yellow generators. Fix those and one can move onto the next stage. Nearby should be the reactor; make the proper repairs (more smokey pipes and consoles). Once that is all completed, one can power up the reactor from the main control room, ending the event.

Detailed walkthrough
The player charcater needs at least the Level 1 Hacker perk to get past the reactor security doors. If they do not have this, they can still get in via the security control room by lifting the reactor and plant lockdowns. The Scorched in the area are usually around level 6 and the rad damage one takes, even with precautions, may make it prohibitively difficult.

The plant is located to the east of the Nuka-Cola plant and just north of the northern edge of Charleston. There is a railroad station nearby to the east with a vendor bot and other vending machines. The cooling towers are visible for a long way while traveling south from Flatwoods.

This quest will usually coincide with the "Take the Yard" quest for the workshop at Poseidon Energy Plant WV-06.

If the player character has no generator plans at all, they will receive them in the following order: Small, medium, wind, large and fusion.

Trigger the event by walking into the area. The event has a timer of one hour. If the timer has already started in the world the player character has joined into, and is below 40 minutes, one may want to consider joining a new instance.

Once the event is triggered, proceed northeast into cooling tower 1 - one will enter it through a ground-level opening on the north side. There one will find a number of low-level Scorched, usually armed with pipe weapons or melee weapons. After killing them, look for the pipes that are emitting steam (they are very loud and obvious). They will have an orange and black banding, and appear cracked when one gets close. Simply walk up to them until the "Repair" prompt triggers, and press the indicated button. Do not forget the control panel in the room at the very top of the catwalks if one wants to get the optional completely repair bonus.

Repeat this for approximately 10 instances of the pipe. One will see the progress bar filling in on the quest tasks in the upper right of the screen. once done in Tower 1, proceed out of Tower 1 the way the player character entered and loop around it a little north to Tower 2. Repeat the exact same procedure (kill the Scorched and find the broken pipes) and also the control panel at the top.

At some point, there will be an audio cue that the "Cooling system functionality is restored."

Once the player character is done, proceed into the generator room, through the door on the catwalks opposite from the way one entered the tower. The player character will find themself in a hallway with a few Scorched. Once they are dispatched, proceed into the generator room. Here there will ve banks of big yellow machinery and some more broken pipes. Find the control panels on each of the generator banks (on each side of the room on the second level, and in the middle at the bottom).

There are a large number of Scorched in this area, as well as defensive turrets and a ton of salvage. Proceed to find and fix broken panels and pipes until the audio cue occurs that "Generator Functionality Restored."

In the southwest corner of the room is an entrance into two areas; one to the left goes downstairs to some crafting resources and there is often a power armor frame present. The other goes straight into another room with a stairway. Climb the stairway and find the terminal to hack into the reactor. If one does not have the perk, they can backtrack to the security room next to the reactor doors at the bottom of this stairway. Follow the wall signs to the reactor.

The reactor room is flooded, filled with radiation and swarmed with Scorched. In a locker room to the left as one enters the reactor area, they will find damaged hazmat suits. The player character will take a high amount of radiation damage in this room, even with Rad-X. Higher-level power armor users need not worry.

In the reactor room, the plan is the same; kill the Scorched, fix the pipes and panels. Again, listen for the audio cue or watch your progress bar. Once the "Reactor functionality restored" cue happens, the quest can be completed.

Take time to lift the lockdowns at the security terminal before finalizing the quest.
 * Reactivate the reactor

Exit the reactor room, turn left and go up the stairs next to security into the main reactor control room. There are a few Scorched and some turrets to deal with, then find the working terminal and select the "Restart Reactor" option. Quest complete, and one should receive a bit of leveled loot, caps and the next in order generator plan they don't have.

If the player character leaves via the cooling towers they came in through, they are now filled with toxic steam and which can be fatal rather quickly. Exit through the transformer yard via the generator room. This will take one back to where the workshop and fusion core processor are located and if they got the fusion generator plans, then one can read the plans and power it on to collect cores.

At the entrance to the plant, "behind" the truck and the gates as one exits, is a uranium deposit. This can be used in the production of the fusion generator.