constants i periodic table a typical nuclear reactor generates 1000 mw (1000 mj/s) of electrical energy in doing so, it produces 2000 mw of waste heat' that must be removed from the reactor to keep it from melting down. many reactors are sited next to large bodies of water so that they can use the water for cooling. consider a reactor where the intake water is at 18 °c. state regulations limit the temperature of the output water to 30°c so as not to harm aquatic organisms