Skip to comments.Why sweat? Tap nuclear power [for desalination]
Posted on 12/27/2007 7:55:08 PM PST by grundle
State governments looking for ways to cope with severe drought in the Southeast should consider using nuclear power to desalinate seawater. This is a safe and proven technology that the U.S. Navy has been using for more than a half-century to provide drinking water for the crews of its nuclear-powered submarines.
Until a few years ago, the water debate here in Georgia was conducted in an almost surreal atmosphere. We appeared to have sufficient supplies of water to meet our needs, and most of us seemed to feel that this state of affairs would continue indefinitely. By definition, miracles do not often happen, and it is not likely that the water problem will be solved by a miracle. The solution, if there is one, will be found in the development of comprehensive water use plans, strict conservation and technology. No one of these alone will solve our water problems, but all of them together have a good chance of succeeding.
The discrepancy between the need for water and its availability is seen not only in the difficulty of allocating scarce resources for households, industries, farms, electricity production, wildlife and recreation but also sharing common supplies with neighboring states. As our water resources diminish, it is becoming clear that unless we can come up with substitute sources of water, we will simply have less water and a lower standard of living.
Experience shows that nuclear reactors can be used to heat seawater in a process known as "reverse osmosis" to produce large amounts of potable water. The process is already in use in a number of places around the world, from India to Japan and Russia. Eight nuclear reactors coupled to desalination plants are operating in Japan alone.
Seawater desalination raises absolutely no technical problems. The technologies have been used for many years. But most of the world's 12,500 desalination plants use fossil fuels to provide the large amounts of energy needed to desalinate seawater, and that poses economic problems due to the rising cost of oil and natural gas and environmental problems from greenhouse-gas emissions. Nuclear power, on the other hand, is now economically competitive with fossil fuels and produces no greenhouse gases. It is a viable alternative for desalination.
Nuclear reactors could serve a dual purpose, providing both power and fresh water, as they do in nuclear submarines. If anchored a few miles offshore, nuclear desalination plants could be a source of large amounts of potable water transported by pipelines hundreds of miles inland to serve the needs of communities and industries.
A study completed by Argonne National Laboratory determined that dual-purpose reactors called cogeneration plants "could offer a major portion" of the additional water and electricity that municipalities and industry will need for maintaining sustainable development and growth in the years ahead. The study determined that nuclear power would be less costly as a heat source for water desalination than fossil-fuel plants using oil or natural gas. But it said that costs could vary according to the type of reactor used and its specific location, among other factors, requiring further economic analysis.
The next big step needs to be taken by the Department of Energy. It should propose construction of a demonstration reactor for desalination.
Production of large amounts of fresh water would alleviate water shortages in the decades ahead with attendant benefits to homeowners and businesses as well as the environment. Now is the time for the Department of Energy, in concert with Georgia and other states, to determine how best to proceed with nuclear desalination.
NAVSEA techs would show up, have them broken down, put back together, and leave with them still borderline unusable.
Water hours will make anyone appreciate fresh water in a hurry.
I know a few "watermelons" who will cry bloody murder at the mere mention of nuclear or anything remotely related. It is amazing that these people are taken seriously.
Park a few dozen of the luddites on an island with no fresh water and see how long they last. Start with the Algore.
Geez, what do you expect? Technical competence or even awareness on the part of reporters? Sheesh.
Thank you ... I thought I was the only one who saw the author’s mistake on RO.
The greenies will fight any use of technology — including fire or the wheel — for others. Not themselves, you understand. Just the unwashed masses, which will naturally include anyone who is not a greenie.
Reverse osmosis is NOT dependent on the way it is forced through a semipermeable membrane, just that it is. Water pressure, steam, electric pump, water fall, mechanical pump, etc, it does not matter. It is really quite simple.
Just force it through and it works and is filtered. The semipermeable membrane is all that matters. bad stuff on the one side, good stuff on the other. Usually it does not as long as the “good” H2O atoms are one size and go through the “bad” atoms (iron, chlorine, body waste, etc are bigger and do not.
Water powered or steam the force is not what matters. My brother has one on his faucet and it is totally water powered. Just water pressure does it. But it wastes a bunch of water, converting it to steam just makes it more efficient.
From there, the pressure from the column is about 1,000 lbs/square inch and suitable for salt water desalination. What would be required is the ability and electricity, to pump the water to that height.
Some of the required energy could be recovered by placing turbines on the exit of the column and slowing the water flow down to the point it could be discharged directly into the sea or salt water estuary.
Valves could be placed that would shut the flow of water and allow the RO membrane to be replaced as needed or even back flushed to improve the durability of the RO membrane.
While this would be expensive for initial construction, it would seem to have a low operational cost.
nah, just pitch it as a way to combat the rising sea levels caused by global warming along with using the sea salt as a substitute for the salt that’ll no longer have to be mined in order to save a few trees and the spotted owls in them. How can they turn you down?
Those that preach “government knows best” scare Me. Those that believe that the U.N. is our World Government terrify Me.
Conversely, all you need to do is sink such a column into the ocean to that depth. Then you pump it empty from the surface. It will refill with desalinated water forced through the membrane at the bottom of the column. Then you continuously pump the fresh water out of the column to maintain the pressure differential at the bottom. That way you don’t have to worry about disposing of the high-salinity water. The column doesn’t even need to be very big. Just big enough to pump the water out of a much larger surface-area chamber on the sea floor.
Or, you could do it your way on land, but it is only height that matters, and it doesn’t require vertical columns. It could be a pipeline miles long down the slope of a mountain. Pump water to the top of the mountain, and let gravity feed it down through the membrane. It must be much cheaper to build a pipeline along the ground than a supporting tower.
Why is it these articles never give any actual numbers for costs ? What does it currently cost to desalinate seawater ? $100 per acre foot ? $1,000 ? $10,000 ?
I’ve seen numbers anywhere from $600 to $2000 around the world, but those numbers were from ten years ago when energy was much less expensive.
can also make steam for other processes, making electricity & gasification of coal... we can do this, we should have been doing this for decades... but we don’t and probably will not for a long time...
Thanks for the correction, I was working off of very dated knowledge. The company I used to work for had a "dirty water" division and they shared a lab building with the hydraulics group (us). They were working on a portable water treatment plant for the air force. The first contract phase was for gray water, the second phase added sanitary waste. At the time, almost forty years ago, they used aerobic digestion, flocculation & settling, with a RO unit as a final filter for phase two. As I recall it used electrophoresis to move the water through the membrane, hence my assertion that RO involved electric current.
Since we shared the building we all tried the finished product. It tasted flat like distilled water and we recommended that it be aerated before use.
One question for you, since all filters have a pressure drop across the media, what differentiates a RO unit from say a millapore filter with sub-micronic media? Regards,
On the subject of greening the West, I’ve always wondered why we see floods every year. Why haven’t we long since built a system of aquaducts and reservoirs that capture excessive rain when it happens, and pump it to the West ? Or even last month when Washington state had flooding, why wasn’t there a system of aquaducts to capture it and send it down to California or over to Idaho and Nevada ?
It seems like when we have an excess we just dump it out to the ocean rather than try to retain it. I can understand if it is polluted runoff from streets or industrial areas, but flooding is usually when rivers overflow their banks with water that is relatively clean and used all the time for irrigation purposes.