Nuclear Pasta

If I read the graph correctly, it takes 1200 copper/mn and 40 Smelters to produce 1 Nuclear Pasta / mn (leaving aside the Pressure Conversion Cube for now).

Is that the only way? I didn't find any alt recipe, and I need more than 1 NP / mn.

Even with Mk3 blueprints, the thought of having to put down 40 Smelters for each unit per minute is starting to feel... very tedious and not exciting at all.

Just wondering if I'm missing something simpler.