All reactor component unstackable, this make reactor crafting slow and painfull with hurge amount of clicks and inventory operations.
Suggestion is simple:
All reactor components initially crafted in deactivated form, nonactive component cannot be used in reactor, but stack up to 64 like all other items.
Activation done with crafting grid without any additional resources (or maybe redstone dust).
Already activated component can be deactivated again (only on full health) in same way.