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.

Comments

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

How Nanomaterials Can Make Nuclear Reactors Safer and More Efficient

The following is a guest post from Matt Wald, senior communications advisor at NEI. Follow Matt on Twitter at @MattLWald.

From the batteries in our cell phones to the clothes on our backs, "nanomaterials" that are designed molecule by molecule are working their way into our economy and our lives. Now there’s some promising work on new materials for nuclear reactors.

Reactors are a tough environment. The sub atomic particles that sustain the chain reaction, neutrons, are great for splitting additional uranium atoms, but not all of them hit a uranium atom; some of them end up in various metal components of the reactor. The metal is usually a crystalline structure, meaning it is as orderly as a ladder or a sheet of graph paper, but the neutrons rearrange the atoms, leaving some infinitesimal voids in the structure and some areas of extra density. The components literally grow, getting longer and thicker. The phenomenon is well understood and designers compensate for it with a …

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.

Huh?

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…

Why Nuclear Plant Closures Are a Crisis for Small Town USA

Nuclear plants occupy an unusual spot in the towns where they operate: integral but so much in the background that they may seem almost invisible. But when they close, it can be like the earth shifting underfoot.

Lohud.com, the Gannett newspaper that covers the Lower Hudson Valley in New York, took a look around at the experience of towns where reactors have closed, because the Indian Point reactors in Buchanan are scheduled to be shut down under an agreement with Gov. Mario Cuomo.


From sea to shining sea, it was dismal. It wasn’t just the plant employees who were hurt. The losses of hundreds of jobs, tens of millions of dollars in payrolls and millions in property taxes depressed whole towns and surrounding areas. For example:

Vernon, Vermont, home to Vermont Yankee for more than 40 years, had to cut its municipal budget in half. The town closed its police department and let the county take over; the youth sports teams lost their volunteer coaches, and Vernon Elementary School lost th…