Skip to main content

Nuclear Energy, Increased Temperatures and the Truth About the Steam Cycle

Summer is just around the corner, which means that an old anti-nuke talking point that was first used about a year ago is getting trotted out in the press again.

From the International Herald Tribune:
But there is a less well-known side of nuclear power: It requires great amounts of cool water to keep reactors operating at safe temperatures. That is worrying if the rivers and reservoirs which many power plants rely on for water are hot or depleted because of steadily rising air temperatures.

If temperatures soar above average this summer - let alone steadily increase in years to come, as many scientists predict - many nuclear plants could face a dilemma: Either cut output or break environmental rules, in either case hurting their reputation with customers and the public.
For details on why this is not an insurmountable problem, click here and here for posts from our archives. Here's an excerpt from one of those posts by my friend Lisa Stiles:
It doesn't matter if you're burning uranium, coal, oil, or cow dung, anything that uses a steam cycle has the potential problem of exceeding discharge limits if temperatures are excessively warm. Since only about 1/3 of the heat is usable to turn a turbine, the waste heat has to go somewhere. To not have this problem you can:

--Not make the environmental regulations overly conservative
--Build a bigger heat sink
--Build a smaller plant
--Invent a thermodynamic cycle better than the ones the world's best minds have come up with in the past two centuries or so (and be sure to include my name on the patent).
Be sure to read the rest right now.


Rod Adams said…
I agree with Lisa's explanation all the way up to the point where she says "Invent a thermodynamic cycle better than the ones the world's best minds have come up with in the past two centuries or so (and be sure to include my name on the patent)."

Smaller, more distributed plants can help by effectively providing a larger heat sink per unit waste heat produced. Larger heat sinks work, and certainly changing the rules to allow hotter discharges work (it is certainly worth investigating, but there is a real risk to plant and animal life that must be understood.)

With regard to "better" thermodynamic cycles, there are others available that do not have as much of a problem in exceeding discharge limits. Combined cycle gas turbines and cogeneration plants that make better use of their plant's input heat have been around for many years. Since they obtain thermal efficiencies approaching 60% instead of the 33% common to the simple Rankine cycle used by conventional light water reactors, they have less waste to get rid of.

There is a distinct possibility that nuclear combined cycle or cogeneration plants will be available in the not too distant future - the PBMR out of South Africa may be a suitable base plant for such a development.
Anonymous said…
The issue with the French plants is that they use direct cooling with river water. The simple solution to this problem is to use a cooling tower, then there is no limitation from temperature increases to local bodies of water (rivers or lakes). This is the solution that is being implemented for the new ESBWR at North Anna, where there were concerns about too much additional heating of Lake Anna (which is an artificial lake built to cool the original reactors). Heat rejection is no problem if one uses cooling towers.
kconrad said…
Please tell me that the heat emitted from nuclear plants, through the cooling process does not add to the heating of our planet. There must be some way you all can rationalize that away, too.

Popular posts from this blog

A Billion Miles Under Nuclear Energy (Updated)

And the winner is…Cassini-Huygens, in triple overtime.

The spaceship conceived in 1982 and launched fifteen years later, will crash into Saturn on September 15, after a mission of 19 years and 355 days, powered by the audacity and technical prowess of scientists and engineers from 17 different countries, and 72 pounds of plutonium.

The mission was so successful that it was extended three times; it was intended to last only until 2008.

Since April, the ship has been continuing to orbit Saturn, swinging through the 1,500-mile gap between the planet and its rings, an area not previously explored. This is a good maneuver for a spaceship nearing the end of its mission, since colliding with a rock could end things early.

Cassini will dive a little deeper and plunge toward Saturn’s surface, where it will transmit data until it burns up in the planet’s atmosphere. The radio signal will arrive here early Friday morning, Eastern time. A NASA video explains.

In the years since Cassini has launc…

Sneak Peek

There's an invisible force powering and propelling our way of life.
It's all around us. You can't feel it. Smell it. Or taste it.
But it's there all the same. And if you look close enough, you can see all the amazing and wondrous things it does.
It not only powers our cities and towns.
And all the high-tech things we love.
It gives us the power to invent.
To explore.
To discover.
To create advanced technologies.
This invisible force creates jobs out of thin air.
It adds billions to our economy.
It's on even when we're not.
And stays on no matter what Mother Nature throws at it.
This invisible force takes us to the outer reaches of outer space.
And to the very depths of our oceans.
It brings us together. And it makes us better.
And most importantly, it has the power to do all this in our lifetime while barely leaving a trace.
Some people might say it's kind of unbelievable.
They wonder, what is this new power that does all these extraordinary things?

Missing the Point about Pennsylvania’s Nuclear Plants

A group that includes oil and gas companies in Pennsylvania released a study on Monday that argues that twenty years ago, planners underestimated the value of nuclear plants in the electricity market. According to the group, that means the state should now let the plants close.


The question confronting the state now isn’t what the companies that owned the reactors at the time of de-regulation got or didn’t get. It’s not a question of whether they were profitable in the '80s, '90s and '00s. It’s about now. Business works by looking at the present and making projections about the future.

Is losing the nuclear plants what’s best for the state going forward?

Pennsylvania needs clean air. It needs jobs. And it needs protection against over-reliance on a single fuel source.

What the reactors need is recognition of all the value they provide. The electricity market is depressed, and if electricity is treated as a simple commodity, with no regard for its benefit to clean air o…