It is a story about Rankine cycle power plants that throw most of their input fuel energy away in cooling towers.  Coal-fired Rankine cycles (50% of US generation, as compared to ~20% for nuclear) face the same challenge.  Indeed, the only significant generation sources on the grid that don't have this problem are gas turbines where the heat leaves in the exhaust - and cogen plants where the heat rejection is to an industrial process rather than a cooling tower.  (Although those processes may face water limitations of their own if they do not have water recycling in their plant.)

Not quite right to say that nukes and other thermal/ rankine plants face the same issues.  If you turn off the boilers in a coal plant, you can stop cooling it almost immediately.

A power reactor, on the other hand, has decay heat, which tails off gradually from about 7% of full power output (which, on a 4500 MW(thermal) plant is not a trivial heat load) after shutdown.  A big reactor that has been operating for 9-10 months has a huge inventory of decay products that generate a substantial amount of heat, heat that must be removed and sent somewhere.  If your designs have depended on a liquid cooled heat sink, then you have a serious problem when that heat sink evaporates.

The air cooling option means that this is not an insoluble problem for new plants necessarily, but its definitely one that has a significant effect on the cost of the plant and its financing.

Save the world: Reduce greenhouse gas emissions 5% annually.

OK, but that's a transitory issue affecting startup and shutdown.  (And it bears noting that big coal plants cannot be stopped "almost immediately" as they have a huge amount of thermal mass that has to be carefully cooled to prevent stresses in the wrong places... but I take your point.)

At core though, the issue is that if the bulk of your fuel gets thrown away as heat and you do that in a steam cycle, you've got a problem.  You can air-cool, but at the expense of overall plant efficiency (e.g., fewer MW).  If you happen to be next to a river or big body of water, you can heat up the local water rather than draw in freshwater that you then evaporate - but this is geography specific.  (And indeed, part of the reason why this problem is so pronounced in the southwest is because of the aridity of that particular geography.  To wit: there are no Great Lakes in New Mexico.)  So if you're not blessed with an existing cold water source and don't want to limit plant output, you're using a cooling tower.  Unless you decide preferentially to build a more efficient and/or non-thermally based plant.

To get the scale though, steam cycles make up about 70% of all US generation (50% coal, 20% nuke).  Water is going to become a truly massive issue unless we make a comparably massive course correction.

Only wind, solar, and other renewables don't have problems with drought.  They help reverse GHG climate change causing catastrophic drought.

Nuclear, coal, and fuel farming all are dependent on massive quantities of water.  Polluting and contaminating it all the way.  4.5 gallons of water are wasted per gallon of ethanol gas guzzling.

Wind pumped hydro power storage could capture flood waters in wetlands to serve as extra hydro dam power and a backup for river flow levels.  Low levels threaten endangered species, mainly fish, in these river ecosystems.

Extra wetland/resevoirs restore groundwater aquifers, depleted by irrigation and backsup rivers depleted by metroplolitan water use.

Solar power can be used to recycle city water and other water conservation techniques, like drip irrigation and manure/biomass/biogas production save and recycle huge amounts of water while actually increasing agricultural production and quality.

These new, improved nuclear reactors that use no water?  Well, give the nuclear industry time to build a few of these, that also reprocess nuclear waste.  In 10 years rexamine the issue of nuclear power, after the data from these fully functrional experimental reactors is available.

A completey transparent process that the public can trust would be needed.  These must be sabotage and theft (of nuclear materials) proof too.  It's a big design challenge.  I think it is more likely that renewable smart grids, conservation devices, organic farming, and plugin hybrid transportation will beat nuclear in terms of time to deploy, cost, and safety.

And economic revival.  Instead of trillions of dollars to nuclear contractors.  The money would go to local businesses.  The gallon of gas you buy now, from oil company mega multinational taps, replaced by 75 cents worth of electricity bought from a farm down the road, over the smart grid.  Or free from the solar panels on your home.

Anyway, the money would now stay in the local community, instead of in Dubai.  That is anti-globalization.  Relocalization.  It magnifies throughout the local economy, from business to employee to business..  and so forth.

Nuclear and coal power dissappears the cash into shady multinational corporations that bribe local governments to pollute and contaminate at will.  Agribizz mega lobbyistys get the cash from fuel farming.  Destroying conservation carbon sink land to guzzle more gas.  But it's a green gas?  Duuuh..

http://amazngdrx.blogharbor.com/blog

I haven't looked at your numbers in detail, but they appear skewed.  Why report in $/KW?  A 60-year lifespan, constantly producing nuclear KW is a lot different than a variable output solar or wind KW.

JMG wrote: A big reactor that has been operating for 9-10 months has a huge inventory of decay products

Does it have a bigger inventory, after operating 9-10 months, than it did after operating for only an hour?

"Only wind, solar, and other renewables don't have problems with drought." - amazngdrx

But solar has a big problem with night, which comes every day while droughts of such magnitude come to the southeast rarely.  Wind plants do not operate when the wind does not blow, which is 70% to 80% of the time.  

"The air cooling option means that this is not an insoluble problem for new plants necessarily, but its definitely one that has a significant effect on the cost of the plant and its financing." - JMG

Actually gas and air cooled reactors like the PBR and the MSR achieve much higher thermal efficiency than water cooled reactors, cost less to build, and are not effected by drought.

Charles Barton

What I remember from Navy Nuc days is that at right at shutdown, very short-lived fission products would generate almost 7% of the power at the moment of shutdown.  Within 10 seconds, heat energy from the decay of these isotopes would drop to well below 1% of full power.  So overall this "artifact" is trivial in terms of overall energy waste/inefficiency.  
The thing about pressurized water reactors is that you always have to keep the reactor pumps running to circulate the reactor water to keep the heat content of the reactor plant balanced for any short-term (less than a month or so) shutdown.  This alone subsumes any issue/problem with post-shutdown decay heat generation.  
Yes, during shutdown there is heat generation from long-lived fission products and some naturally occuring fission.  But this is more than offset by heat loss to the air surrounding the reactor vessel.  
Non-trivial is the fact that there are energy-using shutdown, and startup, activities which are necessary to control the stresses from heat and pressure differentials, primarily on the reactor vessel.  That would also hold true for a coal-fired steam-driven plant, although not to the extent that is needed in a similar nuclear plant.
The point about Rankine cycle from the initial comment is huge compared to startup/shutdown energy needs.  From my Navy days, steam-driven plants transfer at best 33% of the energy into usable work.  The rest is waste heat.  Regardless of the heat source: nuclear or fossil fuel.  That's the harsh reality of the Mollier diagram.

at a remove

I can't see how they would end up being that different since, wind asside, they are all thermal based power plants.

Lifespan.  It's a bit odd to try and convince us that nuke plants only last 40 years, considering we haven't built one in over 30.

Re: "double or triple" the $/KW cost for solar.  Let's assume the best case:  Solar with sun tracking.  At most you'll get an average of about 60% of the rated power throughout a sunny day (since when the sun is anywhere but overhead you're filtering the light through a long distance of atmosphere).  Cut that in half due to less-than-sunny days.  Cut that in half again because the sun isn't available for half the day.  Where are we at? 15%. So that's 6.7x the cost per KW, without even looking at lifecycle.

One more thing.  I don't mean to pick on you.  I would love it if a renewable source was the cheap way to go.  All of our problems would dissapear, and I'd be against nukes.  But it's just not the case.  

GreyFlcn wrote: Lifespan [...] So is that all you have to fall back on?

Why do you act so hostile toward me? Please stop.

Grey is right on the cost, but the story is more subtle than it looks.  Gas, coal and wind are all - on their face - bad investments, in the sense that all of them require higher prices than you can currently get on the grid to deliver an acceptable return on equity.  That's why all of them require some level of subsidy in order to get built.  (I am ignoring the externality issue here only because it is ignored in current rates - not because I think they shouldn't be factored in.)  What's interesting though is that coal, gas and wind are all about the same price (at current fuel prices and comparable returns on equity): they all need retail rates of about 10 - 12 c/kWh (note that this includes the T&D to connect each to the load) as compared to ~8.5 cent current retail rates.  So absent a 17 - 40% rate increase, you can't get your money out of an investment in any one of those.

But here's the rub: the current retail rate  includes a lot of cheap stuff that's averaged into the mix (hydro, pre-clean air act coal, fully amortized nuke, etc.)  The good news is that this keeps our power price down - but by definition, it's already built and it isn't competing at the margin either.  So there are really two questions:

Q1: What power sources are sufficiently cheap to deliver attractive equity returns and still produce power at less than the prevailing retail rate?  

A1: Energy efficiency, cogen, select opportunity fuels and not much else.  Note that coal, nuclear and gas don't make this list - as evidenced by the fact that no one is actually building them right now (they're just trying to get subsidies to build them).

Q2: What power sources could deliver attractive equity returns if they were allowed to compete against those technologies which are competing to serve new load growth (e.g., coal, gas and to a lesser extent, nuke).

A2: Lots of stuff, including most renewables other than solar PV - plus all the stuff ID'd in A1.  The problem is that in the current regulatory model, getting new expensive stuff built is easy if you have a monopoly and a utility regulator who is willing to declare your investment "prudent".  But if you're just a guy trying to do the right thing, you don't have that luxury - until the expensive stuff gets built and drives up the retail rate.

You can talk about cost per kW/hr and return on investment all you want, but until the mining, transport, use, and storage of nuclear materials can be made as safe as collecting and canning tomatoes, and the waste products can be quickly and efficiently converted into something clean enough to add to the soil in your organic garden, nuclear power will continue to be hazardous, poisonous, and monstrous to the majority of an informed population.

What is our goal- feeding a ravenous economy bent on poisoning the Earth, or creating a healthy, harmonious relationship with our little planet?

a liberal in redsville

Is to get rid of coal - something that is far worse for our environment from the mine to the emissions (including radioactive emissions) to global warming.  If you can convince the world to pay for a switch to solar power* then you will be my hero.  Until then, nuclear is our cleanest large-scale option.

* assuming you can find solar made from tomato-canning-grade materials

Or at least safe enough that you can comfortably offer it to Iran, and countries like it.

You will not convince the world to accept the risk of nuclear holocaust, slow poisoning, or dirty bombs as a trade-off for the (agreeably) devastating effects of burning coal, especially since death by radiation poisoning is much quicker than death by global warming. The false assumption here is that we must continue to use mammoth amounts of energy in order to maintain a healthy, happy lifestyle. We can and must learn to use far less- even if it costs more. I can't convince the world to do this, but I'll bet another Chernobyl might do it.

Our goal should be to convince the world that we can live productive, healthy lives with a small fraction of our current energy use- without fossil fuels or foolish fission.

a liberal in redsville

...Typical windmills will cover the energy costs for their production within 6 months (in other words, within 6 months, they create enough renewable energy to equate to the energy needed to produce, transport, and assemble 'em).

Though nuclear plants create more power, the amount of materials needed to make 'em (particularly concrete ans steel), as well as the energy needed for construction, mean that nuclear plants typically take years to cover the energy used for their production/construction.

...that report ya linked to used relative terms, pertainin' to amount of materials in relationship to the amount of energy produced over the lifetime of the plant.

As you'll note, I said that nuclear power plants produce more power, and they do, in fact last longer, so even though they consume more materials to start with, they'll still produce more energy to offset it over the course of their lifetime.

However, that still doesn't change the fact that windmills will offset the energy used for their production/construction sooner than nuclear plants do.  It still takes nuclear plants years to offset the energy for their construction, they just end up makin' more energy in relation to those materials over the longer lifespan of the nuclear plants.

the Luz II by Bright Source is under review for a a 3,400 acres-of-pristine-wilderness-killing "solar" farm (by that i mean natural gas plant with solar boosting) and will suck 35 million gallons of scarce groundwater/year, produce "salt cakes" and toxic sludge and will only produce 400MW operating at it's top, top capacity.  and they are claiming to be the "good guys!??"  

there was a hearing today at ivanpah.  i hope they send them home ashamed for even applying and we can all enjoy the perfectly balanced ecosystem of the greater Mojave, slap some panels on our roofs and turn off a few danged lights when we leave the room.  

this is seriously ridiculous that in 2008 we are still poisoning, dynamiting, dehydrating, mining, nuking, and paving over wilderness so we can live in McMansions and get even more obese, selfish and boring.  not ridiculous, actually, more like repulsive.

the greenest energy is that which you needn't ever produce.

In what way is Diablo Canyon "eating up" that water?

Meh, you do have a point.

In Gallons per MW, Diablo ain't that bad compared to Moss Landing.

MILLION GALLONS PER MEGAWATT
2.142857143 : Moss Landing
1.157407407 : Diablo Canyon
0.087500000 : Luz II

Is is interesting to note, that apparently Luz uses about 13x less water though.

In what way is Diablo Canyon "eating up" that water?