'Hybrid' nuclear plants could make a dent in carbon emissions

Nov 05, 2013 by David L. Chandler
Credit: CHRISTINE DANILOFF

Many efforts to smooth out the variability of renewable energy sources—such as wind and solar power—have focused on batteries, which could fill gaps lasting hours or days.

But MIT's Charles Forsberg has come up with a much more ambitious idea: He proposes marrying a nuclear powerplant with another system, which he argues could add up to much more than the sum of its parts. Forsberg, a research scientist in MIT's Department of Nuclear Science and Engineering, describes the proposals in a paper published in the November issue of the journal Energy Policy.

Now may be just the time for such new approaches, Forsberg says. "As long as you had inexpensive fossil fuels available for electricity demand, there was no reason to think about it," he says. But now, with the need to address climate change, curb , and secure greater energy independence, creative new ideas are at a premium.

While nuclear plants are good at producing steady power at relatively low cost, their output cannot rapidly be ramped up and down. Meanwhile, sources are also good at producing power at low operating cost, but their output is unpredictable. Fossil fuel plants can easily be switched on or off as needed, but have higher operating costs and produce greenhouse gas emissions.

One solution, Forsberg suggests, is to find a way to divert excess power from a , making it a "dispatchable" source of electricity—one that can easily be ramped up and down to balance the disparities between production and demand.

But what to do with that diverted power?

The paper outlines three concepts, which Forsberg says could have potential in the coming decades. They involve pairing a nuclear plant with an artificial geothermal storage system, a hydrogen production plant, or a shale-oil recovery operation.

The last of these ideas would locate a nuclear plant near a deposit of oil shale—a type of deposit, technically known as kerogen, that has not been used to date as a source of petroleum. Heated steam from a nuclear plant, in enclosed pipes, heats the shale; the resulting oil can be pumped out by conventional means.

At first glance, that might sound like a "dirty" solution, enabling the use of more carbon-emitting fuel. But Forsberg suggests that it's quite the opposite: "When you heat it up, it decomposes into a very nice light crude oil, and natural gas, and char," he explains. The char—the tarlike residue that needs to be refined out from heavy crude oils—stays underground, he says.

Today, the heating of the rock is usually accomplished by burning fossil fuels, making the process less efficient. That's where the excess heat from a nuclear plant comes in: By coupling the plant's steam output with a shale-oil well, the oil can be recovered without generating extra emissions. The process also does not need regular heat input: The nuclear plant can operate at a steady rate, providing electricity to the grid when needed, and heating oil shale at times of low . This enables the nuclear plant to replace the burning of in producing electricity, further reducing the release of .

The world's largest -shale deposits are concentrated in the western United States. "We lucked out," Forsberg says. "This has the lowest carbon footprint of any source of liquid fossil fuel."

The resource that could be unlocked is enormous, he says: "Some of these deposits would yield a million barrels per acre. There's no place else on Earth like it."

Steven Aumeier, director of the Center for Advanced Energy Studies at the Idaho National Laboratory, says, "Many times the most formative game-changing approaches are not single new technologies, but rather novel ways of combining technologies. Hybrid energy systems could be a game-changing approach in enabling the cost-effective, secure, and high penetration of low-carbon energy into the economy." Aumeier adds that such systems would "afford a practical and regionally scalable means of using an 'all of the above' approach to energy security."

Funding for the research was provided by the U.S. Department of Energy, the Idaho National Laboratory Institute for Nuclear Energy Science and Technology, and the French nuclear company Areva.

Explore further: Britain, EDF 'strike deal on nuclear project': source

More information: www.sciencedirect.com/science/article/pii/S0301421513007003

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antialias_physorg
4.2 / 5 (6) Nov 05, 2013
At first glance, that might sound like a "dirty" solution, enabling the use of more carbon-emitting fuel. But Forsberg suggests that it's quite the opposite: "When you heat it up, it decomposes into a very nice light crude oil, and natural gas, and char,"

How exacty does that decrease the carbon emissions?

The other two solutions for storage are the same that are needed for alternative power sources - so no advantage there (i.e. nuclear stays as disadvantageous as it was compared to them)
Doug_Huffman
1 / 5 (7) Nov 05, 2013
Char is carbon sequestered.
Eikka
3.2 / 5 (11) Nov 05, 2013
How exacty does that decrease the carbon emissions?


By eliminating fossil fuels as the source of process heat in getting the shale oil and gas to flow out. It says so right in the article.

The EROI of shale oil and gas is pretty low, so there's a significant energy investment going on just to harvest them.

The other two solutions for storage are the same that are needed for alternative power sources - so no advantage there


If you push the output of a wind turbine into geothermal heat or hydrogen, you lose a lot of it trying to get it back. That multiplies the price of energy obtained from the windmill, so it makes sense to use a cheaper source of heat for the stored energy instead and use the renewable power directly as it comes.

Raw thermal energy from a nuclear reactor is many times cheaper than wind or solar power, and nuclear reactors can produce the sort of tempeartures to directly decompose water to hydrogen.
tekram
5 / 5 (2) Nov 05, 2013
Nothing new.
Sep 2005,
Total May Use Atomic Power At Oil-Sand Project (WSJ, behind subscription wall)
PARIS -- French oil giant Total SA, amid rising oil and natural-gas prices, is considering building a nuclear power plant to extract ultraheavy oil from the vast oil-sand fields of western Canada.
Scottingham
5 / 5 (1) Nov 05, 2013
Better utilization of fission's thermal assets is a great idea. If you look at their output, the thermal output is 2-3x than the electrical output. Right now it's typically seen as waste, but if it could go towards desal or this shale oil thing all the better! Co-generation seems to be the way to go.

We are still in dire need of new material sciences though for the next generation of fission reactors to take off. Graphene seems to hold promise for heat-corrosion barriers, but I'm not sure how it holds up to the neutron flux.

I bet we'll end up seeing some awesome meta-material neutron 'cloak' that guides the neutrons away from the reactor walls and into a sacrificial target.
antialias_physorg
3 / 5 (2) Nov 05, 2013
If you push the output of a wind turbine into geothermal heat or hydrogen, you lose a lot of it trying to get it back.

Same with nuclear. So? One has too much variability the other too little. It's the difference between the actual usage and the output that counts.

Erm. No. ALL cost considered nuclear is about 2 dollars per kWh according to some studies (others have it at just 40ct per kWh) whereas wind is between 20 and 5cent per kWh. No contest there.
Osiris1
1.7 / 5 (6) Nov 05, 2013
Arabs are gonna absolutely hate MiT. They see their hold of the world, their way to blackmail the world into Islamic servitude............slipping away and never coming back. We need to make sure so other country tries to control our national asset and/or this great idea from Mass Inst. of Tech.
brt
2.3 / 5 (6) Nov 05, 2013
If you push the output of a wind turbine into geothermal heat or hydrogen, you lose a lot of it trying to get it back.

Same with nuclear. So? One has too much variability the other too little. It's the difference between the actual usage and the output that counts.

Erm. No. ALL cost considered nuclear is about 2 dollars per kWh according to some studies (others have it at just 40ct per kWh) whereas wind is between 20 and 5cent per kWh. No contest there.


that sounds like biased information.
Feldagast
1 / 5 (4) Nov 05, 2013
No contest until you consider when the wind dies for a couple days, nuclear will continue to operate, Solar you have to worry about cloudy days severely reducing power output. I like the thought of a combined effort Solar, Wind, Nuclear with hydrogen production all in one area.
djr
not rated yet Nov 05, 2013
What they don't seem to address is the benefit of releasing this shale oil. There would of course be carbon emmissions associated with burning the oil. What is the EROI - or efficiency of the process of taking the heat from the nuclear plant, and using to release the oil, then processing the oil, then transporting the oil, then burning the oil. I would think it would be more efficient to build a pumped hydro plant next to the nuclear plant - or ans Antialias says - just build out wind and solar - with pumped hydro storage.
Eikka
1.7 / 5 (6) Nov 05, 2013
Same with nuclear. So?


When the energy source is many times cheaper, you can afford to lose much more of it. If you lose 80% of your energy turning wind electricity into hydrogen and back, 5 cents turns to 25 cents per kWh.

Nuclear heat can come as low as 1 c/kWh because the plant design can be much simpler.

ALL cost considered nuclear is about 2 dollars per kWh according to some studies (others have it at just 40ct per kWh)


Extraordinary claims require extraordinary evidence - it can't be 10-50 times more expensive than what we're actually paying for nuclear power right now. That's just ridiculous.

Definitely need a source on that.

just build out wind and solar - with pumped hydro storage.


There's scant little places for pumped hydro storage because of the huge volumes of water required, and the need for high elevation differences, and there's a risk of flooding involved every time you pump water to high reservoirs if your dams break.
Eikka
2.1 / 5 (7) Nov 05, 2013
Better utilization of fission's thermal assets is a great idea. If you look at their output, the thermal output is 2-3x than the electrical output.


In Finland, they're actually trying their hands at growing wine and farming crabs with some of the waste heat from the Olkiluoto 1 and 2 reactors. The seawater comes out of the heat exchangers 13-15 C warmer than it came in, which allows them to extend the growing season by heating the soil.

http://www.bloomb...YbSSOjLc

Their estimate is that the amount of heat given out by the powerplant would be enough to heat 10,000 hectares of land, or 100 square kilometers. The problem is that there's not enough farming land near the powerplant, so the cooling water would have to be pumped further away and then back into the sea.

If the heat was dissapated over land, it would also solve the issue of pumping too much heat to the local sea environment.
djr
not rated yet Nov 05, 2013
"There's scant little places for pumped hydro storage."

That is just one example of the storage systems that are currently in development. The question not being addressed is regarding the eroi of heating, mining, transporting, processing, burning the oil. Surely if the nuclear is 1 cent per Kwh as you say - it would be far better to build massive nuclear plants along the coasts - and pipe the power around the world.
djr
not rated yet Nov 05, 2013
In Finland, they're actually trying their hands at growing wine and farming crabs with some of the waste heat from the Olkiluoto 1 and 2 reactors.

What is the cost per Kwh from these plants?
WillieWard
1 / 5 (5) Nov 05, 2013
Also by increasing thermal to electric conversion efficiency, the carbon emissions can be drastically reduced. http://www.youtub...---y5E2c
Eikka
1.5 / 5 (6) Nov 05, 2013
Surely if the nuclear is 1 cent per Kwh as you say - it would be far better to build massive nuclear plants along the coasts - and pipe the power around the world.


Again, that's a price for high temperature thermal power. For electric power it will be more due to losses.

What is the cost per Kwh from these plants?


The electricity cost from Olkiluoto 1&2 has been roughly 2 c/kWh as far as I can tell. They actually paid themselves back in 1991 and are now just making pure profit for the company, though maintenance and upgrades have cost money along the way. They've increased the reactor power by 100 MW each and modernized the control equipment couple times over from analog to digital tech.

The waste heat used for heating the experimental farms is essentially 0 c/kWh because it would otherwise be pumped straight to the sea. It costs only as much as running the pumps costs.

mfk
not rated yet Nov 05, 2013
There is another hybrid-nuclear approach that is not only more practical, but very competitive as well. In a somewhat simplistic overview, a helium cooled reactor is used to drive the decoupled air compressor of a combustion turbine. Technically, the working fluid and cooling processes of the combustion turbine are separated, allowing optimization of both processes. The reactor is a simplified and readily manufactured version of a high temperature gas reactor.

This US patented approach is a powerful variant of a combined-cycle plant and as such readily supports a wide variety of applications, including coal gasification, energy storage and renewable energy. Process heat (e.g. for heating oil shale) is supplied as steam created by a heat recovery boiler.

This is a new thermodynamic cycle that is a completely new direction for 21st century nuclear power.

The design has been submitted to the DOE as a Small Modular Reactor. Please see hybridpwr.com for additional information.
Egleton
1 / 5 (3) Nov 06, 2013
"Extraordinary claims require extraordinary evidence."
Think about it.
No they don't. They require evidence.
Evidence is evidence-it cannot be dismissed because it is not "extraordinary."
djr
not rated yet Nov 06, 2013
The electricity cost from Olkiluoto 1&2 has been roughly 2 c/kWh as far as I can tell.

I love the caveat "as far as I can tell" Could you give some references to support this number? I am betting there is pretty heavy government support
Bob_Wallace
1 / 5 (3) Nov 09, 2013
The electricity cost from Olkiluoto 1&2 has been roughly 2 c/kWh as far as I can tell.

I love the caveat "as far as I can tell" Could you give some references to support this number? I am betting there is pretty heavy government support


What was it during the payoff period?

Those plants were built over 40 years ago. They paid off many years ago. Trying to use the cost of electricity from paid off plants to predict the price of electricity from a newly built plant makes no sense.
Bob_Wallace
1 / 5 (3) Nov 09, 2013
There's scant little places for pumped hydro storage because of the huge volumes of water required, and the need for high elevation differences, and there's a risk of flooding involved every time you pump water to high reservoirs if your dams break.


There are approximately 80,000 existing dams in the US, we use only 2,500 or so for hydro production. Based on a survey of dams on federal lands at least 10% of the 77,500 existing should be usable for pump-up storage. We're already converting some.

Then there's closed loop hydro. Just need a couple spots with ample elevation change. Not much water is needed since you're only storing for a few days, not months of production.

Germany is working on using abandoned mines for pump-up, the UK is converting an old rock quarry, Canada is converting an open pit mine.
Bob_Wallace
1 / 5 (3) Nov 09, 2013
So this guy is suggesting taking already expensive nuclear energy, storing it at some cost, and using the stored energy to make even more expensive electricity? That sounds like a great idea. With just a little effort we could turn 16c/kWh into 25c/kWh.

And he's suggesting using steam from a nuclear reactor to cook more carbon of out sequestration so that we can increase our CO2 production? Another stellar idea.

BTW, how does he purpose getting that steam from reactor to the various wells that he wants to heat up? By truck? Pipeline? Mount a reactor in a school bus and drive it around?

Geeezzzzeeeeeeeeeee....
Bob_Wallace
1 / 5 (3) Nov 09, 2013
Surely if the nuclear is 1 cent per Kwh as you say - it would be far better to build massive nuclear plants along the coasts - and pipe the power around the world.


The UK has searched for the lowest priced new nuclear-electricity it can find. Turns out it will cost 16c/kWh and the cost will increase with inflation.

Plus the UK has to guarantee to pay for every single kWh the reactor will produce for the next 35 years. Cheaper production will not be allowed to push it aside.

Wind and solar are now around 5c/kWh in the US. One third the price.
TheKnowItAll
1 / 5 (3) Nov 10, 2013
Perhaps it's time to look at other ways to design the reactors themselves so that it don't take days to cool down. Just a thought! hmmm nano sized pellets instead of the 2.5 cm ones?

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