Design features two prints: the "Head" is placed first and has the fuel inputs and outputs and logic. The "Body" prints are appended as needed. The plant is self-starting, features steam storage and will power off if steam is sufficiently full. It also automatically cuts heat exchanger flow when the reactors are un-fueled to limit warmup time after a sudden power spike. All circuit logic automatically scales as you add more "Body" prints. Just make sure it gets enough water! - Cromptank