In a serious accident, a nuclear power plant%u2019s reactor vessel cracks, and all of the cooling water drains out. Although nuclear fission stops, radioactive decay continues to heat the reactor%u2019s 2.5 X 10^5 kg uranium core at a rate of 120 Mega-Watts. Once the core reaches its melting point, how much energy will it take to melt the core? How long will the melting take?