The Wiki says for the MDPL-13 power station, in part:

If the plant is accessed via the garage door, there will be several lockers and one locked personal footlocker. The door beside the lockers leads you to the large room with the three chimneys. The power substation has ahttp://fallout.wikia.com/wiki/Workbench with ingredients required for a http://fallout.wikia.com/wiki/Nuka-grenade_(Fallout_3) lying around, as well as a http://fallout.wikia.com/wiki/Bottlecap_mine_(Fallout_3). Also on the workbench are a set of http://fallout.wikia.com/wiki/Schematics_-_railway_rifle.

I have been around those chimney bases a number of times and can find no workbench, and there's no door in the wall or on the floor that might lead me to the bench.

Someone? Anyone? I really love those Railway Rifle schematics. Most fun gun in the game (that I've discovered).

Did you find the Fisto on the desk? If not, you may not be in the right place.

There are only two cells in that Interior, one for the Office, one for the Plant. If you don't have both the cells, then leave the power station (note you will be ambushed by Talons near the dumpsters when you leave this place) and save outside the power station. Then exit the game, reboot your system, then load it up again. This may make the cell render correctly.

Oh, the MIRV is the most fun I have had in the game. Just not enough ammo to make that really fun to play with.

You need to go to the substation. As you exit the main plant, kill the Talon's and go to the left. Go past the the electrical equipment and into the garage.

There are two parts to the power station: the building with the three big smokestacks and a storage building behind the main building.

The workbench and schematics are in the storage building. Fisto! is on the second floor of the main building, once you get past all the local residents guarding it.

Thanks, I missed the storage building earlier but got it now. Stupid me. So I have the Railway Rifle in action and the Fisto has already taken out one Talon Merc. Thanks for the help. I'll have to check out the MIRV: don't know what it is.

The most powerful (and impractical) weapon in the game, a Fat Man that fires several mini-nukes at once. One man carpet bombing