The "Head" is placed first and handles logistics & logic. The "Neck" comes second to complete the head. The "Body" prints are appended as needed. The plant is self-starting, has brown-out protection and can start from a complete blackout. It features steam storage and fuel-saving mode. 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 extend it. - Cromptank