How many nuclear power plants would we need to get us to 100%

[madokie]

We're getting roughly 19.3 percent of our electricity from nuclear now.
Do we have enough fuel for that increased number of NPP?
Considering much of the energy that is used to mine and process the ore now is fossil, how much would there be an increase in the amount of nuclear power plants to do that?
Is it even possible to be at 100% saturation nuclear energy?

With those questions asked wouldn't it be smart to increase our reliance on renewables?

[DetlefK]

1. Renewables can deliver cleaner energy at the same price, but...

there are two problems:
- The power grid would have to be modified from few big power plants to many tiny power plants. (Major overhaul of infrastructure and protests how this ruins the landscape).
- Renewable sources deliver energy in a seasonal way, sometimes too much, sometimes too few. We still need a way to either store the surplus-energy with high efficiency or we have to couple this with a steady source of energy, like a conventional power plant.

[madokie]

2. In a lot of cases solar and wind could be point of use

What would adding several hundred nuclear power plants with the associated mining operations do to the land scape?
I'm not convinced that there would need to be a Total Overhaul of our Grid, additions yes but a total overhaul no.
With the probabilities of a nuclear power plant mishap how would that affect the landscape when the numbers of them are added to get us there be. I'm thinking that we're going to need a shit pot more of them which will also necessitate a reworking of the grid so that argument is mute in this scenario I've put forth in the OP

Where are we going to get the fuel for all those nuclear power plants? Whats the environmental impact of that?

To me it all comes back to the right thing to do is to ramp up our renewables

[DetlefK]

3. The solar roofs of 1000 homes powering a factory?

How are they supposed to get the electric energy to the factory? Just feed it into the electric socket in the wall?

What would be the (virtual) mass of the grid?

What voltage would it run on?

It's not as simple as you think. Instead of balancing the output of 20 or so power plants, you would have to balance the output of millions of power plants.

[madokie]

4. I'm not advocating 100 percent renewables only as much as we can feasibly do which is a lot more

than we have now. I'm suggesting we need to spend our time and efforts, money and all that towards alternates to fossil and nuclear.
The thought that we'd be getting 75% or more of our electricity from nuclear power plants stops me dead in my tracks, when I think about all that would entail. That to me is one scary thought. I shudder just thinking about it

Right now we're having to balance the output of hundreds and I mean hundreds of individual power plants not 20 or so so that argument isn't very strong either

[DetlefK]

5. Whether 20 or 500, it's still practically nothing compared to >50 million.

[madokie]

6. What solar would bring wouldn't require an individual control of each

rather a general which would for the most part act as one. Wind would be a little different but yet it wouldn't be seen as individual producers either, each farm would be but not each turbine.
How many nuclear power plants are we talking about to get there, 4-5 hundred or more? They don't throttle up and down well at all. Gas and Hydro now on the other hand works great in that capacity. Gas and Hydro could be used as they are now just that with increasing solar and wind we could cut down on the numbers of whats referred to as base load generators whether they be coal or nuclear. Either of those two carry a lot more baggage than a grid of renewables with some gas and hydro used a control

[Altair_IV]

16. It depends

The statement was made that nuclear power plants don't throttle up and down well. That statement is not categorically true. It depends on the answer to "how much".

Reactors can throttle up and down with no problem at all. Many universities have small research reactors that can be pulsed and throttle up to extremely high power for a few nanoseconds. The problem is not the reactor, but the thermal inertia of the Rankine steam plant attached; and in that regard, a nuclear power plant is no different than either a coal-fired or gas-fired Rankine steam cycle.

The Rankine steam cycle can certainly throttle up and down extremely quickly for very small changes in load. These plants have to because they have to respond to the changes in load, and match those changes instant to instant. The cycling up and down to match load changes are within the capability of these plants.

The problem is for very large ramp ups or ramp downs that changes the power by a very significant fraction of the plant's current power level. However, good management of the grid makes such demands extremely rare.

Altair_IV

[sabbat hunter]

29. a lot of the fuel

for nuclear power plants can be gained thru reprocessing. It would also reduce the need to store the so called spent fuel at places like the Yucca mountains in Nevada.


Also with modern reactor designs, new ones in planning, they are fairly safe and very reliable. Just don't build them on major known faults like they did in Japan.

[Kolesar]

7. Solar-thermal can bank energy into the wee hours

Solar-thermal should be able to serve the metropolitan areas of Southern California, Arizona, and Texas after the construction of long transmission lines. There are extremely long transmission lines to carry coal fired electricity from Wyoming to Southern California.

[phantom power]

8. I once estimated it would take about 4000 reactors, worldwide

I think that was for producing the energy equivalent of all electricity generation and other energy consumption. Transportation, heating, industrial processes, etc.

[madokie]

9. Choke

That would put the number for us somewhere in the thousand range or 20 or so per state. I know I'm not ready for that.
I don't see a way to fuel that many reactors even if we started reusing the spent fuel as some suggest.

From what I've read there isn't enough known deposits to even get there. I may be wrong.

Where would we get the water to cool them? A nuclear power plant takes more water for cooling than a coal plant does. The generator itself not but the reactor sure will.

I just don't see how we can get there from here using nuclear as our prime mode of making our electricity.
If I'm right Japan is smaller than California in area and they have something like 56 or had something like 56 operating nuclear power plants before fukushima. Man o man.

Thanks

[phantom power]

11. It is achievable...

A thorium based fuel cycle would support that level of output. Earth has a lot of thorium. The water cooling issue is arguably more serious. I've seen designs cooled by passive gas convection. The Palo Verde plant forty miles or so from me is cooled completely by waste water.

Like most human activities, it isn't really an issue of technology. We have the technology. It's a political and social decision involving what kinds of solutions people are comfortable with. Observing the reaction to Fukushima, both here at DU, and out in the world, has convinced me that the world is (mostly) deeply afraid of nukes, and psychologically disposed to reject them.

I personally suspect that's a mistake, but I think that's how it is playing out.

[madokie]

13. Accidents happen

could you imagine if we were to increase the chance of an accident by building more nuke plants. I don't think its a smart way to go, sorry.

Every machine I've ever been around has a chance of screwing up at some point in its lifetime. Machines like at the foundry I worked at for 12 years if a machine went down it pretty much was a hit on the bottom line and that was all but with Nuclear power plants the potential for serious damage is ever present. Look at Chernobyl or Fukushima for an example. We really dodged one with TMI whether the pronuclear crowd wants to admit that or not.

At this point I believe that Thorium has about as many unanswered questions as it has answers so I'm not yet sold on that as viable.

Pripyat Russia. I'm not sure we want to take too many chances of something like that happening around here. I know I sure didn't back in the '70s when we were fighting to stop a nuclear power plant from being built a few miles up wind of where I'm at right now.

[FBaggins]

12. Reconsider E = mc2

From what I've read there isn't enough known deposits to even get there. I may be wrong.

You are (though total electrification powered by nuclear is not a realistic scenario anyway). Remember that only the tiniest proportion of nuclear fuel is actually "burned" / converted to electricity. The reason the fuel needs to be replaced after a few years is that while the fission products are still a small proportion of the total mass, they impair the ongoing nuclear reaction. There's still lots of usable "fuel" in there... it just needs to be separated from the rest. The US doesn't see any need for that now because uranium is so plentiful and cheap... but if you increased the number of reactors tenfold (in a world market that is also many times larger)... then recycling would be prefered (as it is in other countries) to reduce waste (and waste storage) and dependence on foreign uranium supplies.

But as I implied in the earlier reply... fuel supplies in such a scenario really aren't a big concern. While thorium has some rabid fans, it isn't necessary in the current mix, but it certainly could become so if we thought that uranium supplies were in danger even after recycling. Or you could go with something like a traveling wave reactor that's fed with plutonium (recycled from spent nuclear fuel) that breeds depleted uranium into usable fuel. Even if uranium and thorium weren't plentiful... using depleted uranium makes the supply a multiple-century issue (by which time we had better have fusion licked)

Where would we get the water to cool them?

Not all cooling options consume large amounts of water. Proper siting of reactors needs to include water supply concerns. Additionally... I'm a fan of using waste heat from reactors to desalinate sea water. They could even help the water supply concerns.

[madokie]

15. But how do you get sea water all the way to Oklahoma, kansas, North and South Dakota etc. etc.?

How many of these traveling wave reactors are there or is it another of those that sounds good on paper or has been made to kinda work in a lab somewhere? Sounds like its something we don't even want to fuck with let alone use it as an example of what can be done

Kirk Sorensen of Flibe Energy has criticized the TWR as "a particularly difficult implementation" of the fast breeder reactor, which he characterizes as "already hard to build in the first place." As well, he has emphasized the enormous difficulties and risks associated with the eventual nuclear decommissioning of a TWR reactor.[16] Dr. Robert Hargraves, who is on the Flibe Energy Board of Advisors,[17] lauded the goal of addressing energy poverty globally with the TWR, but briefly highlighted that its projected cost of energy production, "competitive with [conventional] nuclear power", wasn't as low as fossil fuels (e.g. coal).[18]

We're talking about a need for a change in the way we're producing our electricity not an experiment that may or may not work. Even with reprocessing there's still that sticky subject of nuclear waste, something that we really don't have any answers for yet. If I remember correctly the waste you finally wind up with after reprocessing has less volume but much longer lived, ie more dangerous to future inhabitants
From wiki

Nuclear reprocessing technology was developed to chemically separate and recover fissionable plutonium from irradiated nuclear fuel.[1] Reprocessing serves multiple purposes, whose relative importance has changed over time. Originally reprocessing was used solely to extract plutonium for producing nuclear weapons. With the commercialization of nuclear power, the reprocessed plutonium was recycled back into MOX nuclear fuel for thermal reactors.[2] The reprocessed uranium, which constitutes the bulk of the spent fuel material, can in principle also be re-used as fuel, but that is only economic when uranium prices are high. Finally, a breeder reactor is not restricted to using recycled plutonium and uranium. It can employ all the actinides, closing the nuclear fuel cycle and potentially multiplying the energy extracted from natural uranium by about 60 times.[3][4]

Nuclear reprocessing reduces the volume of high-level waste, but by itself does not reduce radioactivity or heat generation and therefore does not eliminate the need for a geological waste repository. Reprocessing has been politically controversial because of the potential to contribute to nuclear proliferation, the potential vulnerability to nuclear terrorism, the political challenges of repository siting (a problem that applies equally to direct disposal of spent fuel), and because of its high cost compared to the once-through fuel cycle.[5] In the United States, the Obama administration stepped back from President Bush's plans for commercial-scale reprocessing and reverted to a program focused on reprocessing-related scientific research.[6] Nuclear fuel reprocessing is performed routinely in Europe, Russia and Japan.

I'm not sure you will sell very many on using MOX fueled nuclear power plants

[Altair_IV]

17. Numerous errors and misconceptions..

madokie,

Evidently you don't realize that even if you don't put MOX into a nuclear power plant; about 40% of the energy that one derives comes from fissioning Plutonium that was created "in situ". In other words, if you fuel a plant with MOX, you are just putting back some of the material that you previously took out and you give that material a "second chance" to be burned. Even if you fuel a reactor with Uranium as the only fissile material; the reactor starts making MOX "in situ". So there's really no problem with using MOX in power reactors; they were designed for it, and they make MOX anyway, whether you load it in or not.

You are also in error about the effect of reprocessing on the need for a geologic repository. The need for a geologic repository is mandated by the long half-lives of the actinides, principally the 24,100 year half-life of Plutonium-239. However, if you reprocess; you return all the actinides to the reactor to be burned. Therefore, you don't have actinides in the waste stream. The waste consists *only* of fission products, which are the true nuclear "ash". The lifetimes of fission products are less than a few decades, hence reprocessing obviates the need to store waste for geologic times. The *only* time a geologic repository that can store waste for thousands of years is when a "once through" nuclear waste policy has been mandated. The US Congress mandated a "once through" fuel cycle in a series of Nuclear Waste Policy Acts passed decades ago at the behest of the antinuclear movement.

The above poster made another egregious misstatement above in saying that nuclear power plants required much more water than does a coal or gas-fired power plant. That is just not true. The Rankine steam cycle for nuclear and coal- or gas-fired plants is quite similar; the fossil fuel fired boiler of the fossil fuel plant is simply replaced by a nuclear reactor and nuclear steam supply system. Within the nuclear steam supply system; the coolant water is pumped in a closed loop and isn't "used up".

Compare the following schematics of a nuclear and fossil fueled power plants:

http://www.nrc.gov/reading-rm/basic-ref/students/animated-pwr.html

and

http://ga.water.usgs.gov/edu/wupt-coalplant-diagram.html

The only water that may not recycled in a continuous loop is the water used to cool the condenser; which is exactly the same in the two types of power plant. The condenser coolant can either be cooled by running it to a cooling tower as in the fossil fuel plant diagram. The water is recycled with the addition of make up water to account for the water evaporated from the cooling tower.

The condenser coolant may also be withdrawn from a lake or river, and returned to same lake or river at a somewhat elevated temperature. Either way, water is not "used up". Even the water that is evaporated in cooling towers eventually returns as rain.

Altair_IV

[madokie]

18. Did you just assume another name?

at any rate last summer and a few other summers we've had several nuclear power plants down south that had to throttle back due to the heat and lack of sufficient water for cooling while I don't remember reading one single coal power plant in that area that had that problem. Cooling the core of a nuclear reactor takes a larger amount of cooling than does a coal plant. Thats one reason they're sited near large bodies of water, like large lakes and the Ocean.
Water to air cooling towers are loosing water all the time and that water has to be replaced. All the reading that I've read about nuclear power plants is that the discharge water is hotter than a coal power plant. No I don't have any links handy to show you nor will I go looking for any as I'm working from memory on this.

Where are you and what is your occupation???

Sorry but there seems to be a lot of comparisons to another poster who used to be here in your writings. If I'm wrong mybad but the similarities are there.

[kristopher]

19. Welcome back

Notice the comparative volume of waste:


Cooling:

http://www.ucsusa.org/clean_energy/our-energy-choices/energy-and-water-use/water-energy-electricity-cooling-power-plant.html

A complete introduction to nuclear power plants and the use of water can be found here:
http://www.ucsusa.org/assets/documents/nuclear_power/20071204-ucs-brief-got-water.pdf

Extreme Heat, Drought Show Vulnerability of Nuclear Power Plants
Reactor shutdown in Connecticut is latest sign that nuclear energy would face challenges from climate change.
By Robert Krier, InsideClimate News Aug 15, 2012


Google Earth map of nuclear power plants, via Nature

Will 2012 go down as the year that left the idea of nuclear energy expansion in the hot, dry dust?

Nuclear energy might be an important weapon in the battle against climate change, some scientists have argued, because it doesn't emit greenhouse gases. But separate of all the other issues with nuclear, that big plus would be moot if the plants couldn't operate, or became too inefficient, because of global warming.

In June, InsideClimate News reported on the findings of Dennis Lettenmaier, a researcher at the University of Washington. His study found that nuclear and other power plants will see a 4 to 16 percent drop in production between 2031 and 2060 due to climate change-induced drought and heat.

The U.S. is getting plenty of both this year. Just Sunday, the Millstone nuclear plant in Waterford, Conn., had to shut down one of its two reactors because seawater was too warm to cool it. It was the first time in the plant's 37-year history that the water pulled from the Long Island Sound was too warm to use....

http://insideclimatenews.org/news/20120815/nuclear-power-plants-energy-nrc-drought-weather-heat-water?page=show

[Altair_IV]

22. Not the UCS

kristopher,

In my many years of serving as a Professor of Physics at MIT in Cambridge; I frequently had my opportunities to debate representatives from the Union of Concerned Scientists at many public forums having to do with nuclear power. Despite their name; they most certainly are not scientists. I've know elementary school kids that have a better grasp on the science than the representatives from UCS. They are mostly a bunch of economists. The organization was started by a former colleague of mine; Professor Henry Kendall; but he's about the limit to the scientific expertise that UCS has. So I really don't care to visit any of the propaganda at the UCS website. Perhaps you could get some other substantiation besides those clowns at the UCS.

It's actually quite simple. First, do you know what the composition of spent fuel or nuclear waste is? About 96% of "nuclear waste" is Uranium-238. That Uranium-238 is slightly radioactive; but it is no more radioactive than any other bit of Uranium-238 that is still in the ground, and hasn't been mined yet. Uranium-238 is one of the most uniformly distributed elements in the Earth's crust. You have Uranium-238 in the dirt in your back yard; and if we do a careful analysis of the dirt under your fingernails; we will find Uranium-238.

So Uranium-238 is all around us, and doesn't require the special disposal of a Yucca Mountain. The Uranium-238 from spent reactor fuel could just be put back into the same Uranium mine where we got it in the first place.

So just doing that step "solves" 96% of the nuclear waste problem. The other 4% of the waste requires the Yucca Mountain treatment if we use a "once through" cycle.

Besides, the whole "volume" issue is really a red herring courtesy of the idiots at UCS. In a little over a half-century, the nuclear power program in the USA has resulted in about 77,000 metric tonnes of nuclear waste. Sounds like a lot? However, if we were to place all that nuclear waste in a single location; the volume would be about the same as a high school gymnasium. Volume really isn't the issue.

So many of the antinuclear types forget about how much energy we get per unit mass using nuclear power. Pound for pound, or kilogram for kilogram; we get *millions* of times more energy from nuclear reactions than we do from chemical reactions.

A kindred spirit of mine, another Physics Professor; Richard Muller of the University of California - Berkeley made that point very emphatically in his textbook:

http://muller.lbl.gov/teaching/physics10/PffP_textbook_F08/PffP-01-energy-F08.pdf

Page forward to where he calls out that statement in a little paragraph all its own and suggests that it is so important that the reader should memorize it.

Since we get millions of times more energy per unit mass from nuclear than from other sources; that means for a given amount of energy ( which is what we are interested in ), we need burn a million times *less* of nuclear fuel vis-a-vis some other type of fuel.

So volume really isn't the big issue. The big issue for nuclear waste is longevity. That's where the benefits of reprocessing really shines. If you don't reprocess, your waste stream has nuclides like Plutonium-239 with a half-life of 24,100 years. That means your waste has to stay isolated from the environment for a long time, and that is a challenge to ensure.

However, if you reprocess, you take the Plutonium-239 and the other actinides out of the waste stream; and put them back into the incoming fuel stream, and send them back to the reactor to be burned. In addition to being long lived, *all* the actinides can be fissioned.

So if one reprocesses, the waste stream only contains fission products. Fission products have lifetimes that are at most a few decades. You only have this "tens of thousands of years long" nuclear waste problem if you don't reprocess. If you do reprocess, then the longevity of the waste is thousands of times less. That advantage alone is worth all the expense and effort to reprocess / recycle in my book.

Altair_IV

[kristopher]

26. Too bad you never learned to read a citation PamGreg

Some things never change, you still try to divert, refuse to acknowledge information contrary to your propaganda and mislead about what is before you. misrepresent who you are and reply exclusively on invalid appeals to authority.



Do you see that line at the bottom that says DOE/EIS-0396 GNEP Draft Table 4.8-6 (p.4-139)?

That is where the information comes from, the Draft Global Nuclear Energy Partnership Programmatic Environmental Impact Statement, DOE/EIS-0396 table 4.8-6 chapter 4 page 139.

You've already been banned twice, how many times is it going to take?

[madokie]

21. Yes you have numerous errors

Read this and choke.
You'll have to go to the link to get the full effect

Link: http://large.stanford.edu/courses/2013/ph241/abdul-khabir2/

Nuclear Reactor Water Usage and the Implications of Limited Water Availability
Safiyyah Abdul-Khabir
March 22, 2013
Submitted as coursework for PH241, Stanford University, Winter 2013
Nuclear Reactor Water Usage and Consumption

Nuclear is known as the thirstiest power source. Due to high water withdrawals, nuclear power plants are usually located near lakes, rivers, or the ocean. The vast amounts of water are for cooling purposes typically through the use of a direct cooling or closed cycle cooling system. In a direct cooling system, the steam used to turn the turbines is cooled by water that is pumped through the condensers from an outside source and then discharged back into the environment. This differs from the closed cycle cooling system where the water used for cooling is pumped from the steam condenser to a cooling tower or pond and then recycled back to the condenser. While the direct cooling system has a relatively high amount of water usage from the environment, the closed cycle cooling system has higher amounts of water consumption due to losses from evaporation. [1] In both cases, the water usage and consumption for a conventional nuclear power plant is higher than for the average fossil fuel power plant (Table 1). Nuclear power plants require more cooling water because they operate at thermodynamically lower steam conditions which results in a lower cycle efficiency. Thus a greater steam recirculation rate which contributes to a greater flow of cooling water is needed to produce a given amount of electricity compared to an average fossil fuel plant. [2]
Plant and Cooling System Type Water Usage (gal/MWh) Typical Water Consumption (gal/MWh)
Fossil/biomass/waste-fueled steam, once-through cooling 20,000 to 50,000 ~300
Fossil/biomass/waste-fueled steam, pond cooling 300 to 600 380-480
Fossil/biomass/waste-fueled steam, cooling towers 500 to 600 ~480
Nuclear steam, once-through cooling 25,000 to 60,000 ~400
Nuclear steam, pond cooling 500 to 1100 400-720
Nuclear steam, cooling towers 800 to 1100 ~720
Table 1: Comparison of water requirements for fossil fuel and nuclear power plants. Source: EPRI
Implications of Limited Water Availability

As freshwater resources become scarcer, the nexus between water and energy becomes magnified. Thermoelectric power plants, including nuclear plants, make up 40% of freshwater usage in the US. The high water requirements mean that the operations of these power plants are susceptible to heat waves and droughts. If the temperature of a water body is already high, environmental regulations do not allow for further discharges of high temperature water above a certain threshold. Furthermore, if water levels in a body of water drop too low, the power plant may not be able to intake enough water. [3] In the hot, dry summer of 2006, several nuclear plants across Europe stopped operations due to restricted water availability. [4] In August 2012, a nuclear reactor at Millstone Nuclear Power Station in Connecticut shut down after the seawater used for cooling became too warm. Other nuclear plants, including the Braidwood Generating Station in Chicago, were only able to continue operations with a high temperature cooling water after receiving special permission from the Nuclear Regulatory Commission. [5]

Climate change is predicted to have significant impacts on freshwater river flow levels and temperature. Under future climate scenarios for 2031-2060, nuclear and coal power generating capacities during summers are predicted to decrease by 4.4%-16% in the U.S. and 6.3%-19% in Europe due to a lack of cooling water. [3] To adapt to a warmer climate and scarcer freshwater resources, strategies could focus on siting plants near coasts and increasing the thermal efficiency of power plants.

© Safiyyah Abdul-Khabir. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
References

[1] E. V. Giusti and E.L. Meyer, "Water Consumption by Nuclear Powerplants and Some Hydrological Implications," U.S. Department of the Interior, Geological Survey Circular 745, 1977.

[2] "Water & Sustainability (Volume 3): U.S. Water Consumption for Power Production - The Next Half Century," Electric Power Research Institute, Technical Report 1006786, March 2002.

[3] M. T. H. van Vliet et al. "Vulnerability of US and European Electricity Supply to Climate Change," Nature Climate Change 2, 676 (2012).

[4] J. Jowit and J. Espinoza, "Heatwave Shuts down Nuclear Power Plants," The Guardian, 29 Jul 06.

[5] J. Eaton, "Record Heat, Drought Pose Problems for U.S. Electric Power," National Geographic, 17 Aug 12.


Are you sure you haven't been here before???

[Altair_IV]

23. Students at Stanford?

madokie,

So *students* at Stanford are now considered an authoritative source? Really????

I haven't the time to go through his homework; but if this student says the difference between water requirements of nuclear vs coal power plants is large; I know what his error is.

The student is correct that the steam temperature in nuclear power plants is marginally lower than the steam temperature in coal-fired boilers. Because of the 2nd Law of Thermodynamics; the efficiency of the Rankine steam cycle at the nuclear plant is marginally less efficient than a coal fired plant.That much is true; but it is only marginally so. The common *error* that students make is that when they plug temperatures into the formula for the Carnot Efficiency, they forget to convert the temperature to a temperature on an *absolute* scale. As a Physics Professor, I've seen that mistake many, many times. Students plug the temperatures they are given in degrees Fahrenheit or degrees Celsius into the Carnot Efficiency formula.

The problem is that the zero point on both the Fahrenheit and Celsius scales were arbitrarily chosen and don't correspond to anything that is thermodynamically meaningful. The zero on the Celsius scale is the freezing temperature of water. The zero on the Fahrenheit scale was the temperature on the coldest day of the year plotted by Fahrenheit. In order to get an accurate efficiency difference; the temperature has to be converted to an absolute temperature scale where the zero point corresponds to absolute zero. The Fahrenheit temperature needs to be converted to degrees Rankine, or the Celsius temperature has to be converted to degrees Kelvin. Only by using either a Rankine or Kelvin temperature ( they differ by a multiplicative constant that cancels in the formula ) can one get an accurate efficiency calculation.

So I do agree; the efficiency of the Rankine steam cycle on a nuclear power plant is marginally less than a coal power plant; so the amount of water it uses per Megawatt-hour generated is lower than the coal power plant; but certainly *not* by large factors which is the *erroneous* claim you made.

The lower steam temperature on the nuclear power plant is not an insurmountable problem. The BONUS reactor in Puerto Rico was a reactor that featured nuclear superheating of the steam. The steam from the BONUS reactor was superheated like the steam from a fossil-fueled boiler.

http://en.wikipedia.org/wiki/Boiling_Nuclear_Superheater_%28BONUS%29_Reactor_Facility

The other tack one can take was demonstrated by Consolidated Edison's Indian Point Unit 1 ( now shutdown / decommissioned ). If you look at an aerial view of the Indian Point site, you will see the dome of Unit 1 between the domes of the still operating Units 2 and 3. If you look close, you will also see a tall stack like a fossil fuel plant would have. That's because Indian Point Unit 1 had fossil-fired superheater on it.

So if we choose; and water use per unit energy generated is important enough to us so that we put a premium on that figure of merit; there are ways to get the nuclear plant to perform to levels that rival fossil fuel plants. It doesn't have to be the way it is; marginally inferior that it is.

Altair_IV

[madokie]

24. I suppose a second, possibly third time through

poster on this blog is a more authoritative source then, huh

My Gawd you are easy.

You sure you don't need to come clean

[Altair_IV]

25. ????????

What, pray tell; are you babbling about and what does it have to do with the subject at hand.

Altair_IV

[madokie]

27. I'm making myself very clear

Feign surprise all you want
Lots of things I might do Babbling isn't one of them

[FBaggins]

10. Why would we even try?

France comes the closest (about 95% of consumption) and while they've certainly benefited from it, they still run into problems having too much generation from a single source. If they didn't have fairly significant hydro/fossil (exporting the excess), they would have even more trouble.

Do we have enough fuel for that increased number of NPP?

Absolutely. There are multiple possible fuel cycles and the most likely involve very plentiful resources (uranium and thorium are quite common). The price would certainly have to rise significantly in that demand scenario, but fuel costs are a tiny proportion of the cost of nuclear power.

Considering much of the energy that is used to mine and process the ore now is fossil

That's really not a relevant consideration. You're not properly appreciating how substantial the mass-energy conversion is. The actual carbon emissions related to the mining of nuclear fuel is incredibly tiny on a per kWh basis. All of the major clean generation technologies (hydro/solar/wind/nuclear) involve fossil-powered heavy equipment for steel/concrete/construction/etc... but in all of those cases, the amount is quite comparable (and more importantly, negligible).

Is it even possible to be at 100% saturation nuclear energy?

Not really. And it would be incredibly wasteful. While the newer designs are much more flexible, you would still need to build enough of them to cover peak demand plus a margin to account for refueling and maintenance. A high percentage of the year you would have way too much excess capacity.

But again, why would you even try? For instance... we get 8% of our electricity from hydro power. I can't think of any reason why you would shut those down.

With those questions asked wouldn't it be smart to increase our reliance on renewables?

That's not really logical. First of all... asking questions doesn't imply conclusions. It's the answers to those questions that matter. Second, just from a logical perspective, nuclear and renewables aren't the only alternatives. So saying that you can't see one of them providing 100% of demand doesn't imply that the other necessarily needs to grow. It would be, for instance, much harder for renewables to provide 100% of demand... do you therefore conclude that we need to increase out reliance on nuclear? Of course not.

But the answer is still yes. It would be smart to increase out reliance on renewables. It's also smart to increase our reliance on nuclear power. Because that unmentioned category (coal/gas) is still the 900 lb gorilla that needs to be slain. There's lots of room for growth in both areas before we ever have to choose between one or the other.

[cprise]

14. If you dig back to around 2007

...here in E/E, you'll see discussion where the nuclear industry was (at least tentatively) pitching about a 40X increase in nuclear power to meet all of the world's need (incl. automobiles) for the year 2050.

It seemed absolutely insane at the time. Moreso now.

[kristopher]

20. According to Obama's Science Advisor

Note that this is based solely on nuclear's share of the electric supply. It should be pointed out that nuclear supplies only 1/50th (a 2% share) of the total final global ENERGY consumed. All renewables supplied 16% as of the end of 2012. That means the numbers in this presentation account for only 4% of global final energy use.

Title page

Mitigation of Human-Caused Climate Change
John P. Holdren
Director, The Woods Hole Research Center
Teresa & John Heinz Professor of Environmental Policy, Harvard U President, American Association for the Advancement of Science
A Tutorial at the Learning Centre of
The UN Commission on Sustainable Development
United Nations, New York 5 May 2006

2 pages on nuclear

• If world electricity demand grows 2%/year until 2050 and nuclear share of electricity supply is to rise from 1/6 to 1/3...
– nuclear capacity would have to grow from 350 GWe in 2000 to 1700 GWe in 2050;
– this means 1,700 reactors of 1,000MWe each.

• If these were light-water reactors on the once-through fuel cycle...
– enrichment of their fuel will require ~250 million Separative Work Units (SWU);
– diversion of 0.1% of this enrichment to production of HEU from natural uranium would make ~20 gun-type or ~80 implosion-type bombs.

• If half the reactors were recycling their plutonium...
– the associated flow of separated, directly weapon- usable plutonium would be 170,000 kg per year;
– diversion of 0.1% of this quantity would make ~30 implosion-type bombs.

• Spent-fuel production in the once-through case would be...
– 34,000 tonnes/yr, a Yucca Mountain every two years.

Conclusion: Expanding nuclear enough to take a modest bite out of the climate problem is conceivable, but doing so will depend on greatly increased seriousness in addressing the waste-management & proliferation challenges.

[Altair_IV]

28. That's such a phoney argument

The nuclear proliferation argument is really such a phoney argument when you think about it.

We are considering what the USA should do. Just because the USA can / does do something, that doesn't mean that we have to enable the rest of the world to be able to do the same thing. I know that sounds elitist or hypocritical to some whose mindset doesn't recognize national borders and consider us all one big human community.

We enrich Uranium to 3% to 4% for use in our reactors; that doesn't mean we have to provide enrichment technology to the rest of the world....and we do *not* just because of the proliferation problems. That distinguishes the USA from some other "environmentally sensitive" countries like "go solar" Germany. It was Germany's Siemens Corporation that furnished the enrichment centrifuges to Iran. The real villains in the proliferation problem isn't the US nuclear industry, but the "environmentally sensitive" (choke) Germans.

But I digress. Just as the USA doesn't furnish enrichment technology to less than trustworthy countries, neither does the USA furnish reprocessing technology to other countries. We can keep it for ourselves, and use it ourselves for our own advantages.

So if the USA uses reprocessing technology, is that going to lead to a proliferation problem? That question is so silly, it hardly requires an answer. The only reprocessing plants that are currently in the USA are those that are owned by the US Government for the US nuclear weapon program. In the early days of nuclear power, the Government owns / operated the enrichment plants. Today, the Government *still* owns the enrichment plants; but contracts the operation to a semi-governmental / semi-commercial firm, the US Enrichment Co.

We could do the same with reprocessing. The same Government that we trust to make Plutonium for nuclear weapons without giving it to the North Koreans or the Iranians; that same Government could do the reprocessing for commercial reactors, just as it once did all the enrichment for commercial reactors.

It really is a foolish argument to wave the "proliferation flag" - whether it makes sense or not; but I expect that from Holdren; the man stopped being a real scientist years ago, and is currently no better than any other politician when it comes to telling the truth.

Altair_IV

[madokie]

30. Because he retired he no longer is a Real Scientist

in your last iteration you were a Scientist, now you're telling us you are a Physicist.
Methinks you are lying to us

Your style of writing gives you away 'bro or 'bro'et which ever applies