Question

Speculate as to why nuclear power plants are less efficient than fossil-fuel plants based on temperature arguments.

a) Lower operating temperatures
b) Higher operating temperatures
c) Nuclear reactions release less energy
d) Not related to temperature

Answer 1

Nuclear power plants typically have lower efficiency than fossil-fuel plants because they operate at lower temperatures and pressures, thus reducing their ability to convert heat into electrical energy according to the Carnot efficiency principle.

Step-by-step explanation:

You're wondering why nuclear power plants have lower efficiency compared to fossil-fuel plants. The main reason for this is that the operating temperatures and pressures possible in nuclear plants are typically lower than those in fossil-fuel plants.

According to the laws of thermodynamics, specifically the Carnot efficiency principle, the efficiency of a heat engine depends on the temperature difference between the hot and cold reservoirs.

Nuclear power plants operate at lower temperatures because the materials used in the nuclear reactor can't withstand the high temperatures and pressures that fossil-fuel boilers can. As a result, this limits the nuclear plants' efficiency.

Coal, oil, and natural gas plants can reach higher temperatures and pressures, thus allowing them to convert more heat to electricity, leading to efficiencies around 42%. In contrast, a typical nuclear power plant has an efficiency of about 35%,

so there is less electrical energy produced for the same amount of heat transferred into the engine. Furthermore, less efficient energy conversion in nuclear plants means more heat is transferred to the environment for the same electricity output.