Nuclear power plants, as currently designed and built, consume prodigious amounts of water for cooling. Compared to combined-cycle gas turbine plants (CCGT), nuclear plants use 4 times as much water for the same output of electricity. Some plants use cooling towers, and others use once-through cooling where the water is pumped through the plant once, then sent off usually into a lake, river, or ocean.
|South Texas Nuclear Plant with Cooling Reservoir|
source: Texas Water Development Board
For this article, the example of the South Texas Nuclear Project is used. This power plant is a twin-reactor, pressurized water reactor design built near the mouth of the Colorado River in Texas, USA. The photo nearby shows the location, just north of the small town of Matagorda, on the Gulf of Mexico. The plant is roughly 50 miles northeast of Corpus Christi, and 100 miles southwest of Houston. The photo shows the nuclear power plant in the middle foreground, the 7,000 acre cooling reservoir at center, and the Gulf of Mexico at the top. The Colorado River can be seen, barely, at the left center.
The plant, known as STNP, is designed to use approximately 50,000 acre-feet (AF) of river water per year for cooling. The reservoir receives water pumped from the nearby Colorado River, plus any rain that happens to fall. Rainfall is important in this case, as it averages 30 inches per year over the long term. Recently the rainfall has been much less due to a prolonged drought. However, in an average year, the rainfall provides approximately 17,000 AF per year for the plant. That then, requires the river to provide 50,000 - 17,000 = 33,000 AF per year.
The water requirements for various types of power plants are shown below, in AF/yr/1000 MW of electrical output. These are based on the design where hot water that is discharged from the plant evaporates in the cooling reservoir to lose its heat.
1. Nuclear power.........................20,300 AF/y/1000 MW
2. Gas powered steam plant......12,700
3. CCGT plant................................5,070
From this, it can be seen that nuclear power requires 4 times as much water (20,300 / 5,070 = 4) compared to a modern CCGT plant. In areas where fresh water is scarce, this is an important consideration when selecting power plant technology.
|Lake Travis and Mansfield Dam, TX|
For some perspective, had a CCGT design been used along with the 7,000 acre reservoir, the plant would be more than self-sufficient in water needs. In fact, a much smaller reservoir could have been constructed, approximately one-third the surface area.
Conclusion: Nuclear power plants consume 4 time as much water for cooling compared to a modern CCGT power plant.
Previous installments in The Truth About Nuclear Power can be found below:
Part One - Nuclear Power Plants Cannot Compete
Part Two - Preposterous Power Pricing if Nuclear Power Proponents Prevail
Part Three - Nuclear Power Plants Cost Far Too Much to Construct
Part Four - This article
Part Five - Cannot Simply Turn Off a Nuclear Power Plant
Part Six – Nuclear Plants are Huge to Reduce Costs
Part Thirteen - Nuclear Plants Are Heavily Subsidized
Part Fourteen - A Few More Reasons Nuclear Cannot Compete
Part Fifteen - Nuclear Safety Compromised by Bending the Rules
Part Sixteen - Near Misses on Meltdowns Occur Every 3 Weeks
Part Seventeen - Storing Spent Fuel is Hazardous for Short or Long Term
Part Twenty - Chernobyl Meltdown and Explosion
Part Twenty One - Three Mile Island Unit 2 Meltdown 1979
Part Twenty Two - Fukushima The Disaster That Could Not Happen
Part Twenty Three - San Onofre Shutdown Saga
Part Twenty Four - St. Lucie Ominous Tube Wear
Roger E. Sowell, Esq.
Marina del Rey, California