This was a practice problem for a test review.

A nuclear-fueled electric power plant utilizes a so-called “boiling water reactor”. In this type of reactor, nuclear energy causes water under pressure to boil at 283 °C (the temperature of the hot reservoir). After the steam does the work of turning the turbine of an electric generator, the steam is converted back into water in a condenser at 42.0 °C (the temperature of the cold reservoir). To keep the condenser at 42.0 oC, the rejected heat must be carried away by some means – for example, by water from a river. The plant operates at three-fourths of its Carnot efficiency, and the electrical output power of the plant is 1.20 109 watts. A river with a water flow rate of 9.60 104 kg/s is available to remove the rejected heat from the plant. Find the number of degrees in oC by which the temperature of the river rises.