Little official information exists about the four Khushab nuclear reactors, which make plutonium for Pakistani nuclear weapons. A key parameter is the power of the reactor, which is directly related to the amount of plutonium the reactors can make. As a result, there have been many estimates of the reactors’ power. The construction of a Thermal Power Plant (TPP) at the nuclear site in Khushab opens a new pathway to estimate the publicly unknown power of the adjacent four nuclear reactors.