The upgrade and retrofit of the old Arc Reactor had initially focused on only two areas: the materials and design used to build the reactor, and the control system. They had not gone straight for the theory or touched the reactor's core components.
Compared with the Arc Reactor completed in 1967, the cutting-edge supporting technologies of that era were now outdated by thirty-six years. They were not obsolete enough to be discarded, but many parts now had better alternatives.
Take the control system upgrade, for example. After preliminary planning, the old and new systems had run in parallel. Control authority had been transferred during off-peak hours for stress testing. Only once everything had proven completely problem-free had control been fully handed over to the more convenient and safer new system.
The replacement and upgrading of construction materials had likewise been handled according to the different components and their varying importance. For instance, where multiple pipelines were available, they had been replaced and upgraded one by one during off-peak periods, when the pressure was lower.
For components that could not be replaced while operating hot, plans had been made to complete them during the Christmas and New Year holiday shutdown and annual maintenance. This was also why ordinary researchers involved in the Arc Reactor upgrade project had been able to help. Tony Stark and the others made the plans, while the people below carried them out.
Tony Stark, Otto Octavius, and Henry had not spent all their time on such trivial matters, either. They had begun sorting through every academic paper related to the Arc Reactor, filling in the missing theory.
They hoped to make the Arc Reactor's cold nuclear fusion theory logically self-sufficient without a key reference point—the Tesseract. At this point, however, no one but Henry knew that.
Generally