Actually a wrench that at max splits the machines in blocks sounds great. I think it should use a lot of energy and can only be charged in a crystal charger. Something like 4 or 5 uses on it before it depletes, so you actually need to think if you want to move that furnace failsafe and waste something like 10000EU or take the risk of moving it with a normal wrench. Also the high EU consumption is required to balance the item, if it can save you dozens of mass fabricators or crystal chargers it should really cost a bit more than 2 of those machines.
Maybe changing the crafting recipe from the one Dragonmystic suggested to something like that:
U-U
BAB
CB?
U - Uranium Ingot
B - Bronze (maybe something more expensive)
A - Advanced circuit
C - Energy Crystal
? - Something I don't know yet, FreqTrans maybe, just a Diamond, another Advanced circuit, Relay, or a Cable Obscurator to add a use to it apart from making cables pretty, the mutation it generates could lead to a temporary stability in the machine...