 A reactor and separation plant capable of producing enough plutonium for fifteen bombs per year was costed at around £20 million.It fell to the Gen 75 Committee to decide how many reactors should be built at its meeting on 18 December 1945.Considering the demands that reactors would make on scarce skilled labour and materials, the Gen 75 Committee decided to defer a decision on building a second reactor, but to proceed with the first one "with the highest urgency and importance".