With such complex nuclear plant present another tech should be easy thing. 
Nanotech laboratory is a machine to produce and use Nanobots.
I can suggest GUI with three bars, progress indicator and four slots:
1st bar: Energy stored. Has a slot to energy source/accumulator to be used with internal storage.
2nd bar: Row matter stored. Has a slot to any item to be dissolved (with limitations).
3rd bar: Nanobots ready. Has a slot to Nanobot Cell to be filled/used.
Progress indicator: To show progress, made to produce target item. Output slot has faint image of target item.
Work process:
1. Nanolab use incoming energy to fill Energy bar. If it full - recharge accumulator in slot.
2. If Matter bar empty, dissolve item from slot, if no target item, set to dissolved.
3. If Nanobot bar can send Nanobots to cell in slot, send them. If not full, build Nanobots. If Nanobots full and have target item, start replication.
Replication is a process of rebuilding target item from stored raw matter. If it interrupted due to lack of energy/matter/nanobots, result is lost.
Processes of dissolving, Nanobots building and Replication has speed and EU consumption proportional to Nanobots quantity plus one. Both Nanobots in bar and cell counts. Nanolab starts with no Nanobots, so need a lot of time to start working effectively.
When you start Nanolab and feed it with energy and some item to dissolve, it start to slowly dissolve item. When it's Matter bar full, it starts to creating Nanobots. This time speed and power consumption increase rapidly. You can place empty cell to fill it with Nanobots and use in other place, but it will slow process. When Lab full of Nanobots it's time to produce items. Click empty output slot if you do not want this item. It you want to produce some item, you must dissolve it first. Some items are forbidden to dissolve/replication: any items with energy, enchantment, potions, UUMatter... While UUMatter can be used to fill Matter bar instantly without production.
So Nanolab is used in two ways: item duplicator and source of Nanobot Cell. (Cell, filled pink, or purple)
Nanobot Cell can be used in different ways:
Combine with damaged armor/tool in assembly grid to repair keeping enchantment and such.
Combine with different food in assembly grid to get "Nanopotions" ("Pig Speed", "Spider Vision", "Zombie Regen" and such).
When NanoArmor damaged, it can repair itself using NanoCells from inventory...
May be use full NanoCell on a block to "detach" it like a Silk Touch enchantment... for those, who want RedStoneOre floor
And of course all other ways, you want to use it.
Not giving any receipt and value, as it anyway balance matter.