Nuclear power plants produce almost 80 percent of the emission-free energy in the nation, and cooling towers—though often misunderstood—are an essential part of what makes that possible.
Despite their being perfectly safe and far removed from anything radioactive, for many people cooling towers conjure up images of toxic waste, environmental contamination, and industrial excess. But, as with most things nuclear, a little education can go a long way.
Many peoples’ worries and fears—What is that coming out of the top? Is it radioactive?—can be put to rest by looking at what cooling towers actually are. They are very similar to cooling towers used at any other industrial facility. The cloud-like vapor coming out the top is nothing more than the condensation of the clean, fresh water taken into the plant from the river.
Other common questions about these often misunderstood towers include:
How do cooling towers work?
In the most basic sense, cooling towers help to cool the water that is heated during the production of electricity in power plants. This includes almost any type of power plant that generates electricity by using steam to spin a turbine.
In a nuclear power plant, nuclear fission is used to heat water. Most nuclear plants are composed of three closed systems of coolants (water):
- The primary coolant that absorbs heat directly from the reactor core,
- The secondary coolant that absorbs heat from the primary to produce steam that is used to spin the turbine, and
- The cooling loop which absorbs heat from the secondary through a condensation process.
This allows the secondary coolant to recycle through the process again. Cooling towers are used at many plants for heat removal from the cooling loop. In the cooling tower, the water either rises to the top and is released as vapor (similar to a cloud), or it falls to the bottom of the tower as water and is put through the process again.
Is the vapor radioactive?
The closed systems in the plant mean that the fresh water used in the cooling towers never touches anything radioactive and is two systems removed from the reactor. The vapor is perfectly clean water and perfectly safe. If it weren’t, “people wouldn’t work here,” says Darlene Viscusie of the TVA Watts Bar Nuclear Station.
How much water is used in a nuclear plant?
There has been some controversy in the past regarding just how much water nuclear power plants actually use.
For example, the Susquehanna plant in Luzerne County, Pennsylvania, uses about 31 million gallons of water per day. To put that into perspective, 27.4 billion gallons of water per day flow from the Susquehanna River into the Chesapeake Bay. This means that the plant uses a whopping 0.07 percent of the water that flows through the river each day.
A typical nuclear plant supplies over 700,000 homes with energy. The plant consumes between 13 and 23 gallons of water per household; the average household uses around 94 gallons of water each day.
What else are cooling towers used for?
Cooling towers are an important part of more than just nuclear plants. They are used in many other industrial capacities. Jim Hopson, nuclear communication consultant for the TVA Watts Bar Nuclear Station, states, “The water that you see coming out of the top of the cooling tower at a nuclear plant is very similar to the water that you would see coming out of any other industrial facility.”
The most common usage of cooling towers, though on a much smaller structural scale, is for heating, ventilation, and air-conditioning systems. Roughly 1,500 industrial plants use cooling towers, including power plants, petroleum refineries, and food processing plants.
Learn more about cooling towers and the important role they play in the new video “What Are Cooling Towers?”. Heritage also explores the science behind nuclear energy and its role in the American energy landscape in the 40-minute film Powering America.
