The Nuclear Power Thread

[russ_watters]

Originally posted by Nereid
... and If PECO (a.k.a. 'the white knight'?) saw it coming, why couldn't the same sort of control systems be installed elsewhere?

I had a conversation with my dad about this last weekend and I wasn't quite right on this. He's a utility cost consultant and just so happened to take a tour of the facility I was talking about. He said it was pretty cool - reminded him of what NORAD is supposed to look like: high security, underground, and set up like a war room with big displays in the front of a theater shaped control room.

The name escapes me right now and I can't find it on Google, but its not just PECO - its a joint effort of a number of power companies in PA - the PA power cooperative or something like that. Basically, it monitors a portion of the grid and allows the companies to transfer energy between them. Supposedly people from other countries (and the DOE) are studying it as a model for how to control a power grid.

In any case, yes, other people could have done the same thing as this control center did and pulled the plug on their sections of the grid. No one wants to do that though - if you're First Energy (the company that started the cascade) and you have a choice between blacking out your part of the grid and trying to get it from the adjacent parts, what are you going to do? It was too late for them either way, but in a failed effort to help themselves (and by others trying to help them), they let the failure spread. So maybe its just a matter of upgrading the decision making process (the people) to deal with that type of situation.

If there's one thing engineers are good at it's solving problems, often very creatively. Russ, do you know if a tiger team of top engineers has been tasked to look at solving the 'grid failure' problem, with broad terms of reference?

Doubt it. Certainly the government is looking at the issue, but we all know how effective they are. The thing in PA exists for economic reasons - it makes it easier for the companies to swap power. Its only a biproduct of that that it is such a good grid control station.

For that phone analogy, its the same and its not. For one thing, the phone system runs at a fraction of its capacity. And when it does get filled, they have the same sort of problems as the power grid has - calls don't go through, systems crash, etc. Usually though, its like wimms said - you just drop a few calls. And think about your cell phone: what kind of absolute reliability do you have, ie how often do you get a dropped call or call that doesn't go through. Imagine if the power grid had the same (lack of) reliability. It would be crippling. Despite things like the NY blackout, the reliability of power grids in the western world is absolutely extrordinary.

 

[wimms]

Originally posted by Nereid
AFAIK, that in IP network systems (e.g. from Cisco) is trivial compared with what's in a modern system from Lucent, MetaSolv,

Trivial isn't necessarily bad/undeveloped. Its a sign that issues to be dealt with are much simpler.

You're right, the answer to unpredictable resource demand in IP networks is massive over-provisioning (how else could it be done, given the wildly unpredictable nature of the traffic?)

Actually this isn't necessary answer. IP traffic can be very well oversubscribed and priotisation of traffic type is easy. Thus in case of network degradation, first to suffer would be least important traffic. Telecoms overprovision just to avoid the hassle, it makes life so much easier. Often, they are forced to due to completely unrelated issues, for eg. you can buy equipment and lines in specific bunches, and you need to make investments so that they can cope with growing traffic in few years aswell. 2 times overcapacity because they plan for loosing half of their capacity in case of major cable failure.

What, essentially, are the key differences between a telecoms network and an electricity grid, in terms of OOM greater difficulty re fault management?

There is one essential key difference that's behind all others. When you switch on consumer device, power starts to flow, and grid has no control over it other than cutting off completely. In telecom, every single node can control exactly how much traffic, what traffic and when does it flow. It throttles back traffic. Thats the main reason why overloads are "soft" in telecom. Nothing really bad happens with overload. With power, every single overload is critical event, because you can't really limit power consumption, you can either attach another power source or shut down the branch (or face physical destruction). One can lead to cascade of overloads as Russ explained, another is basically blackout of area.

So, the only way to deal with overloads in grid is to AVOID the overload. That needs ideally complete knowledge of all main lines and their load, and is quite computationally intensive to make right decisions, that in addition has to be made damn fast. In IP networks, each node is independant and quite safe, capacity steering is merely a quality issue of monthly capacity planning, not critical survival issue.
In IP, you have huge network and rough estimates of capacity planning. In grid, you have even larger network, and requirement for instant and precise decisions.

I'm not sure, but isn't grid actually implemented after successful example of telecom networks?

 

[russ_watters]

Originally posted by wimms
So, the only way to deal with overloads in grid is to AVOID the overload. That needs ideally complete knowledge of all main lines and their load, and is quite computationally intensive to make right decisions, that in addition has to be made damn fast.

Well, either that or what I said before: have enough excess capacity that you don't have to make those decisions and can handle a little hickup without taking any action. The drop in excess capacity is the key difference between the way the grid handles fluctuations today and the way it did 10 years ago. And the solution as I said before is obvious...

...get back to nuclear power!

 

[Nereid]

Please be gentle

Russ, wimms,

Many thanks for your replies to my ignorant posts. I see now that introducing telecoms was, on balance, more of a distraction than a benefit.

Back to my original comment ("A good infrastructure should be able to isolate local failures, irrespective of how heavily loaded it is; it's surely not a very challenging technical problem."), and a (hopefully!) wiser re-casting of it.

this is a 0-th order take; many devils - a.k.a. details - are licking their lips in anticipation of ambushes on the road ahead

Demand varies seasonally (~100 days characteristic time), weekly (~10 days), daily, and hourly. A significant part of this demand is predictable; much detailed historical data is available to characterise variance about (modelled) means within all periods.

Broadly speaking, supply is available to meet all but peak hourly demand. However, there are unplanned supply failures, and the characteristic time for indications of incipient failure ranges from days ("that unit sure has been acting strange!") to milliseconds (or less). Further, a great deal of historical data is available to characterise the root causes, frequency, and 'phenomenology' of all failure modes.

Technology to detect, analyse, and transmit useful information about demand, supply, and failure already exists. As long as the response times are greater than 1 second, 'pre-canned' or algorithmically-based automatic response decisions can be implemented. These automatic decisions can, in principle, be optimised according to a wide range of equipment, supply, demand, down-stream impact, ... conditions. These optimisations can be performed both 'off-line' (independent of the particulars of the event) or 'on-line'.

... and that's as far as technology could take us, in a reactive sense.

Proactively, we could fairly accurately characterise future demand, supply, and improvements in failure detection and remediation capabilities. Through risk analyses (crudely, prioritisation by the 'impact' metric - probability of event x cost of event), main areas to be addressed can be confidently identified (and research investment targeted to improving the probability and cost estimates of the top 3 risks, say). Installing, testing, and refining equipment, maintenance schedules, operations proceedures, etc then follows, using standard QA methodologies.

Finally, the key dimension, economics. Crudely, economics is all about how to better match supply and demand, though price. In the case of grid-supplied electricity, IMHO, there is enormous opportunity for basic economic principles to be better applied. For example, as wimms said "When you switch on consumer device, power starts to flow, and grid has no control over it other than cutting off completely". Yet no (residential) consumer has ever been asked what price they would be prepared to pay for 99% (or four/five/six/seven 9s) availability. With today's technology, I would guess, a multi-tiered set of service contracts could be easily implemented - from 'el-cheapo' electricity (but can have supply cut for up to 10 hours with no notice), to guarranteed 99.9999% availability and 10 seconds restoration in the event of failure (for a VERY large fee).

This is the kind of thing I was referring to when I said "the root cause is bad regulation and wilful ignorance of economics. Behind that there is, without a doubt, the hand of Big Oil [...]
A competitive market should be able to meet demand, unless the regulatory barriers are inefficient."

 

[xeguy]

Interesting thread. I think the Germans are shooting themselves in the foot if they continue with this policy. The nuclear bogeyman looms large over everything thanks to the scaremongers. There's a reason why they dropped the "nuclear" from MRI!

Nuclear power = good. Let it power our space probes and homes.

Fusion will be here...eventually...

It's only a few years overdue. ;-)

 

[wimms]

Nereid,

what you described, looks good on paper, with 15 minutes of thought put into it. After you put about 1000 hours of thought into it, it would look like total nightmare to you. I don't think we can come up with something top people of energetics haven't thought of. Let's mean no disrespect to them. There are soo many things we can't even imagine _needs_ to be thought about.

Reality checks. Technology exists, on paper, but it doesn't think. People do. To program all that people can costs more than its worth. To install all the needed technology is too expensive, and consumer isn't willing to pay for it. Rare epic blackouts cost less. Economics? Case closed.

As to historical data, yeah, there is plenty of it. So plenty, that no blody mortal can make any sense of it anymore. For statistical analysis it isn't precise, structured nor standardised enough. Its best output is a "gut feeling" of experienced dudes.

No residental customer is ever asked because residental customer exists only because of regulation. As always, its business where money is, and it needs all the nines. To install residential cut-off switches is insane, and only adds to costs, because individual households matter nothing in any of the events, and ability to switch off zillions of homes as per individual sla isn't easy nor cheap. The "el-cheapo" electricity would cost more to electric companies than "el-normo" one. Guess why they aren't eager to offer choice?

For a VERY large fee, electricity providers are not needed. There are factories that build their own nuclear plants nearby and sell excess energy to the grid, and use grid as a backup. no ****. They have all the nines, and even get PAYED for it.

Well, yeah, looks like I'm arguing. Infact, basic idea is that the whole thing is too damn complex, that its cheaper to live with it than to fix it. And the cheapest way to fix it is to "take the larger hammer".

 

[Nereid]

Reality bites; devils taste first blood?

Thanks wimms, these kinds of reality checks are very welcome!

No residental customer is ever asked because residental customer exists only because of regulation. [...] To install residential cut-off switches is insane, and only adds to costs, because individual households matter nothing in any of the events, and ability to switch off zillions of homes as per individual sla isn't easy nor cheap. The "el-cheapo" electricity would cost more to electric companies than "el-normo" one.

The sooner we get the regulations changed the better! Let's start charging 'residential' customers a fee that's closer to the marginal cost of producing the electricity they consume, and offer them choices. With the cost of technology decline (courtesy of Moore's law and globalisation), how long before it becomes cost effective? With entrepreneurial suppliers - perhaps 'virtual' - when will biz cases that offer differentiated residential services begin to make sense? With the extraordinary inefficiencies in the industry, re-regulation (soundely based in economics) would surely open a number of juicy niches to creative capitalists?

As always, its business where money is, and it needs all the nines.

Hmm, perhaps they need all the nines because they've never had any real choices? If there were a competitive supply market, with a rich range of nines/time-of-day/etc choices, how many CFOs would start suggesting to their CEOs that they seriously consider re-engineering their processes to take advantage of the cost-saving opportunities that have just opened up? Bet we'll never find out until the possibility becomes real enough

Technology exists, on paper, but it doesn't think. People do. To program all that people can costs more than its worth. To install all the needed technology is too expensive, and consumer isn't willing to pay for it.

Well, it has happened in airline reservations (when's the last time you spoke with a profitable travel agent?), banking, telecoms ( ), quite a lot of B2B commerce, ... what is unique about the energy sector?

Its best output is a "gut feeling" of experienced dudes.

So let's you and I hire them as our technical advisors, once we have the VC funding to start VirtuEnergy

 

[russ_watters]

Originally posted by Nereid
If there were a competitive supply market...

Maybe I'm missing the context here, but in most states now there IS a competitive supply market as a result of "deregulation." I put "deregulation" in quotes because it requires new regulations of course. If done well (Pennsylvania), it leads to a small reduction in energy costs for customers. If done poorly (California) it leads to Enron, doubling of energy prices, and region-wide blackouts. Either way it makes electric power supply a pretty complicated issue for consumers - and that's a pretty lucrative thing for my dad...

 

[wimms]

Originally posted by Nereid
The sooner we get the regulations changed the better! Let's start charging 'residential' customers a fee that's closer to the marginal cost of producing the electricity they consume, and offer them choices.

No problemo. They can offer you electricity closer to the marginal cost of producing it .. AT their plant. You are free to take it somehow and deliver it where you want, the way you want, at costs you want. If it hadn't occurred to you yet, then crucial function of regulation is to force development and maintenance of distribution network, that means wires to your home, your town, your area, country, and protecting you from paying insane money to get your electricity to your home.

when will biz cases that offer differentiated residential services begin to make sense?

When costs begin to relate to differentiated pricing. Already the case. To get the nines, you pay extra. What you have by default, is a free lunch, payed for by someone who needs the nines. No room for whining, be it down for a week if they like. Epic blackouts impact whole economy, that's why they get the front page.

Hmm, perhaps they need all the nines because they've never had any real choices?

Have you ever owned UPS? They need all the nines because downtime costs them money, much more than all the nines they pay for. Please name one crucial business that can run without energy in todays world.

If there were a competitive supply market, with a rich range of nines/time-of-day/etc choices, how many CFOs would start suggesting to their CEOs that they seriously consider re-engineering their processes to take advantage of the cost-saving opportunities that have just opened up? Bet we'll never find out until the possibility becomes real enough

How many CFOs today seriously consider building nuclear plant to SELL electricity instead of buying it? Who cares what it costs if its compensated? The only "CFOs" who will seriously consider re-engineering their processes are residential losers who will take advantage of the cost-saving choices to find more opportunities in whining about the choices. Perhaps also that it has damn rare major blackouts.

And, seems its not obvious to you that "nines" are not function of production of energy, but of reliable distribution of it. By competitive supply market, you are implying alternate distribution network, grid. You are welcome to build your own nationwide grid that's better, cheaper, more flexible. There are thousands of energy suppliers waiting for you.

Well, it has happened in airline reservations (when's the last time you spoke with a profitable travel agent?), banking, telecoms ( ), quite a lot of B2B commerce, ... what is unique about the energy sector?

Nothing has happened there. Planes are crashing, banks are robbed, telecoms have outages. Unique to energy sector is that every damn business stops without energy.

 

[russ_watters]

Nines?

 

[wimms]

99.9999% uptime guarantee - 6 nines

 

[Nereid]

SciAm article

Reading the lead News Scan article in the November 2003 Scientific American, I learned that:

-> a significant contributory factor in the August 14 blackout is likely to be the fact that degulation of the industry left transmission "lagg[ing] behind [generation systems] because of the patchwork of interstate regulations and jurisdictions. Many policy and grid experts say that in the short term, the [FEMC] should enact nationwide policies covering transmission systems operation, capacity and investment."

-> "Once the government decides how the grid should operate, 'we have the technology to implement it almost on the shelf or coming down the pipe,' says Paul Grant, science fellow at [EPRI] ..."

-> technologies mentioned include installation of more heat-resistant lines; better communication systems among power stations (e.g. dedicated fibre optics, and GPS-based time-stamps); faster, smarter switches; a master transmission control computer; and automatic, adaptive 'islanding'.

-> on the über-computer, the article notes "[p]ostmortem studies by the industry suggest that such a global view would have prevented about 95 percent of customers losing power during the 1996 blackouts in the western U.S."

{I wonder who said this:} A good infrastructure should be able to isolate local failures, irrespective of how heavily loaded it is; it's surely not a very challenging technical problem.

A competitive market should be able to meet demand, unless the regulatory barriers are inefficient.

The SciAm article did not mention a need to increase generating capacity.

 

[russ_watters]

Originally posted by Nereid
-> a significant contributory factor in the August 14 blackout is likely to be the fact that degulation of the industry left transmission "lagg[ing] behind [generation systems] because of the patchwork of interstate regulations and jurisdictions. Many policy and grid experts say that in the short term, the [FEMC] should enact nationwide policies covering transmission systems operation, capacity and investment."

The SciAm article did not mention a need to increase generating capacity.

I guess the implicaton there is that regardless of the actual generation capacity, the transmission capacity isn't where it needs to be. So even IF there is enough generation capacity, the lack of adequate transmission capacity will prevent the power from getting where it needs to go.

Sounds like an interesting article - maybe they have it up on their website...

When I was discussing that command center with my dad a month or so ago, we also talked about transmission lines. Near as we can tell there are only 3 lines going from Limerick into Philadelphia and the surrounding counties (I've actually hit one of them several times with a golf ball as its strung over the 5th fairway of a course I frequent). A bad car accident could black out a million people just by knocking down one pole. And a guy with a handful of backpacks of C-4 could take down most of SE PA for a while.

 

[Nereid]

Sounds like an interesting article - maybe they have it up on their website...

try this:
http://www.sciam.com/article.cfm?chanID=sa006&colID=5&articleID=000784B6-E5FB-1F86-9B8C83414B7FFE87

 

[Argentum Vulpes]

I'm slightly disappointed that I did not get on this thread before it turned into a power distribution network debate, so I'll play catch up and address some things that I think need to be added.

First briefly on the subject of coal, there is another reason to not want coal in this day in age. Besides the fact that it pumps CO2, NOx, SO2, and Hg into the atmosphere, one fact that is not discussed is it also puts uranium into the air. Now if we are going to get all huffy about Nuclear power because it uses uranium and might put some extra amount of it into the environment, could we please look at the entire power industry and judge it all by the same standards.

Give me the nuclear plant in my backyard over a coal plant any day.

I totaly agree with this statement

As for all of the talk of Chernobyl there remains a vary important fact about Chernobyl that everyone seems to overlook. This fact is that Chernobyl was a RBMK type of reactor, whos main purpose in life was to create bomb grade Pu. The fact that it produced electric power was a happy side-effect for its main mode of operation. This type of reactor would never be allowed to be open in the US, or for that fact most of the world because of its main purpose and its many deadly design flaws. Two of the flaws are that it operates with a positive void coefficient, and because the fuel needs to be constantly changed there is no secondary containment structure. This info came from www-formal.stanford.edu/jmc/progress/nuclear-faq.html, and this also explains what a positive void coefficient is.

So this is my two cents on this debate. Hopefully if this debate will get back on track of the original post.

 

[i_wish_i_was_smart]

Argentum, i agree with you on everycount, the fact that Chernobyl was poorly maintained and that it used carbonfiber(which can overheat and cause damage and so on) and not HeavyWater as a moderater is a major design flaw, not counting it had no containment structure, he have learned on others mistakes and we have vastly improved the design and operation of Nuclear facilities. If only people weren't so quick to judge half of Canada would be Nuclear powered, Uranium is a source we have plenty of, and we are one of the leaders in nuclear powerplant technology, I'm sure mostly everyone has heard of Candu reactors, and they are currently designing a "next-generation" reactor, many of the Candus were sold all over the world(including *cough*korea*cough*)

but our reactors do produce Trinium, a big part of the hydrogen bomb is made out of trinium (for those reading this that don't know what trinium is, its an isotope of hydrogen) but there is a good side to that, we sell it to you guys for a pretty penny

 

[russ_watters]

Besides all that, there is the fact that as bad as Chernobyl was, it killed only about 40 people, most of them firefighters (that said, we wouldn't want to have to evacuate Pittsburgh).

 

[i_wish_i_was_smart]

which is why, to keep people content, and to keep it on the safe side, we put nuclear reactors in more desolate areas, well i guess the US can't really do that

 

[Morbius]

I'm slightly disappointed that I did not get on this thread before it turned into a power distribution network debate, so I'll play catch up and address some things that I think need to be added.

First briefly on the subject of coal, there is another reason to not want coal in this day in age. Besides the fact that it pumps CO2, NOx, SO2, and Hg into the atmosphere, one fact that is not discussed is it also puts uranium into the air. Now if we are going to get all huffy about Nuclear power because it uses uranium and might put some extra amount of it into the environment, could we please look at the entire power industry and judge it all by the same standards.



I totaly agree with this statement

As for all of the talk of Chernobyl there remains a vary important fact about Chernobyl that everyone seems to overlook. This fact is that Chernobyl was a RBMK type of reactor, whos main purpose in life was to create bomb grade Pu. The fact that it produced electric power was a happy side-effect for its main mode of operation. This type of reactor would never be allowed to be open in the US, or for that fact most of the world because of its main purpose and its many deadly design flaws. Two of the flaws are that it operates with a positive void coefficient, and because the fuel needs to be constantly changed there is no secondary containment structure. This info came from www-formal.stanford.edu/jmc/progress/nuclear-faq.html, and this also explains what a positive void coefficient is.

So this is my two cents on this debate. Hopefully if this debate will get back on track of the original post.

Argentum Vulpe,

I also agree with you - and with enigma about the coal plants. See:

http://www.ornl.gov/info/ornlreview/rev26-34/text/colmain.html

from scientists at the Oak Ridge National Laboratory who state,

"Americans living near coal-fired power plants are exposed to
higher radiation doses than those living near nuclear power plants
that meet government regulations".

and

"The population effective dose equivalent from coal plants is
100 times that from nuclear plants."

The population receives more radiation exposure from coal plants
than nuclear plants because coal contains trace amounts of uranium
and thorium which gets tossed into the atmosphere when the coal is
burned.

Because the USA burns billions of tons of coal per year - the amount of
uranium and thorium tossed into the air amounts to a few thousand tons
per year.

As I stated in another post - the Chernobyl reactor is "over-moderated" -
it has too much moderator. When one removes water - either by heating
it so that it is less dense - or by boiling or "voiding" the water - one is
reducing the amount of moderator. Since the RBMK is over-moderated -
reducing the amount of moderator shifts the amount of moderator
closer to the optimal point - and the reactor GAINS reactivity - which
is the "positive void coefficient" that Argentum Vulpes speaks of.

Yes - many people get "bent out of shape" if someone were to suggest
siting a nuclear power plant next to them - but wouldn't mind a coal
plant as much - all because of a fear of radiation.

They are the ones that need to be informed that they get 100 times as
much radiation exposure from the coal plant than they would from the
nuclear power plant as the scientists from Oak Ridge point out.

Dr. Gregory Greenman
Physicist LLNL

 

[Argentum Vulpes]

Thanks for pointing out the website Morbius. I couldn't find that again when I was typing up my last post (I had used it about ten years ago for a debate on energy production in the US). As for nuclear reactors out in the middle of no where there are plenty of areas in the US that count as that. Montana, The Dakotas, and Wyoming, this I will say for certain as I lived in Montana and traveled across the Dakotas and the north eastern part Wyoming several times.

 

[CharlesP]

A note of caution: Many power plants are situated on rivers to use their water for cooling. Rivers are populated areas. Some site out in the desert will have to use air cooling which is not as efficient-or cheap.

I saw the website of John McCarthy and it looks far fetched. Before the population is allowed to increase further, the rest of the world should be brought up to US living standards. Right now I see a rush to lower the US population to third world conditions.

I had a Motorola pager with six sigma reliability and it kept failing. A contact corrosion/ alignment problem, probably rare. Reliability is proved in the field.

What happened to all that talk about thresholds in radiation hazards below which the hazard was zero?

 

[Morbius]

What happened to all that talk about thresholds in radiation hazards below which the hazard was zero?

Charles,

Using the techniques and results of the Human Genome Project, biologists
at Lawrence Livermore National Laboratory have conclusively
demonstrated the threshold effect.

In fact, they have found that low levels of radiation actually trigger a
cellular response to make the cells resistant to subsequent larger doses of
radiation. In effect, the response of the cell to low levels of radiation is
similar to the response to a vaccine. The vaccine inoculates the cell to
a larger onslaught of a pathogen. Similarly, low doses of radiation
induce a protective response in the cell. One can read about it here:

http://www.llnl.gov/str/JulAug03/Wyrobek.html

Dr. Gregory Greenman
Physicist

 

[CharlesP]

Next question. Has anyone ever studied what happens if one tries to make a nuclear battery by putting a beta source on the head of a pin and surrounding it with a conducting sphere? I expect the current would be small but what mechanisms would prevent a high voltage? I suspect that there is no nice beta emitter that does not also produce gamma?

 

[hitssquad]

Has anyone ever studied what happens if one tries to make a nuclear battery by putting a beta source on the head of a pin and surrounding it with a conducting sphere?

I believe a device like that may have been constructed using tritium as the beta emitter. The engineering/physics article databases should have write-ups of any experiments that have been done along those lines.

I suspect that there is no nice beta emitter that does not also produce gamma?

Tritium does not emit gamma radiation.
http://www.triumf.ca/safety/rpt/rpt_8/node8.html

 

[mohamed helmy]

quate for pof.

dear all. please i need help of expert prof .iam working in industrial dealing with machinery
installed with nucler head to do kind of quality check since 2001, ihave marreid in aprial 2006 idid not get chlidren up to now so my doctor asked me to do sperms analysis for sprems quantity the result was to bad its zero sperms so later i had to do operation to get some sperms to do ivf operation and iam luky because doctor found some sperms so please informe me if the nucler source which iam working with has effect or not in my case.
the source is isolated but i have got the power rate of this source its (843mbq) thanks alot

 

[daveb]

It depends on the source. An 843 MBq (~ 23 mCi) low energy gamma emitter (such as Tc-99m) is nothing compared to a high gamma energy 843 MBq Co-60 source. If it's Tc-99m, the activity is the activity of a standard diagnostic imaging procedure, so I doubt that would be the cause.

 

[katchum]

How much uranium/plutonium is there left in the world? I like nuclear energy, but is it sustainable for 100 years?

 

[Astronuc]

How much uranium/plutonium is there left in the world? I like nuclear energy, but is it sustainable for 100 years?

Certainly 100 yrs. There is limited production of Pu, which essentially absent in nature due to it's relatively short (geologically speaking) half-life.

Nuclear energy is produced primarily from the fission of U-235, with fissioning of some Pu which is produced through transmutation reactions involving U-238 in the UO₂-based fuel. Converting more U-238 to Pu-239/240/241 could extend the U-resources, and then there is Th-232, which can be transmuted to U-233, which is fissionable.

So there is potentially hundreds of years of energy resources based on fission.

One key issue is where to put all the fission products, which must be isolated from the biosphere.

 

[Azael]

For all practical purposes the ammounts of uranium is unlimited.
http://nuclearinfo.net/Nuclearpower/UraniuamDistribution

 

[James Carroll]

The Real Problem

It seems to me that no one on here has really hit the main problem, and that is peak oil. Yes we have coal, yes it is dirty, yes it causes death, yes it releases more radioactive material than does nuclear plants... but what happens when we run out of oil? Of course we won't just run out, but eventually the oil that remains will become more and more difficult to get at, and therefore more and more expensive. People disagree about when this will happen, but it will happen. When it does there will be problems. Infrastructure will have to change to support electric cars, and that will be a nightmare in and of itself unless it happens gradually enough. But then where will all that electricity come from?

You have to realize that electricity demand will increase dramatically in the future, how near is again up for debate, but it is coming.

Now figure that into your discussion and it changes things doesn't it? Can we increase our electric needs sufficiently with coal only? Can we do it without producing enough pollutants that people don't begin to agree that enough is enough?

We will need nuclear. It is inevitable and will happen. One day the environmental wackos will flip on their light switch and nothing will happen... they will try to drive their car, and there will be no electricity and gas will be too expensive. One day. Then they will be yelling at us and asking us why we didn't build all those power plants back before it was too late... and we will look at them and say... THIS IS YOUR FAULT.

My father once did a back of the envilope calculation on solar power, and determined that to supply the US with power BACK IN THE 60'S, even if we could collect solar power 100% efficiently, we would have to turn the state of Arizona into a solar collector. (I would love to see one of you actually crunch those numbers and verify his results, remember that you need to include gas usage, not just electric) It won't work... give it up... Solar isn't the solution, we need Nuclear

On the other hand...

Given that it is inevitable, the question is, what should we do about it? My work is in Decision Theory, and I believe that the probability of a nuclear accident associated with Nuclear power is low... unfortunately the cost is high. Utility is the product of the probability * the cost. There is a good reason to be cautious about Nuclear power. I think that we need a balanced middle of the road approach. The "it's ok, there are no risks" or "the risks are so small" thing is not necessarily the best response. But the argument that the risks are lower than those of coal (as so many of you have nicely made) works better.

Furthermore research is needed to make those risks smaller. Thus it is my belief that research into safer Nuclear energy is the solution. We need to spend the bucks, and get it done. This research needs to focus on making the process safer and on dealing with the waste. We have done a lot on the first one, but can do more.

I truly believe that we can also do much better on the second one. We can find better ways of dealing with the waste that we have. Some have been discussed above but there are others. There is energy in that waste. Decays=energy... perhaps not very much, especially in the stuff that takes forever to decay, but it is in there, and there should be good ways of getting it out and making it useful instead of a scourge. Next we can find better ways of reprocessing (I know proliferation rears its ugly head) but there are ways of reprocessing that can be internationally monitored and where the reprocessed materials can be used immediately... or something... so we aren't stockpiling weapons grade materials. That's the point of research, we don't know what solutions will be found, but we should look for them. Finally we can produce reactors that produce less waste.

These are the research areas. Some solutions already exist in these areas, but we just can't use them for political reasons etc. Some better solutions are in the works, and some even better solutions are sure to come out of some good investments in research.

 

[russ_watters]

My father once did a back of the envilope calculation on solar power, and determined that to supply the US with power BACK IN THE 60'S, even if we could collect solar power 100% efficiently, we would have to turn the state of Arizona into a solar collector. (I would love to see one of you actually crunch those numbers and verify his results, remember that you need to include gas usage, not just electric) It won't work... give it up... Solar isn't the solution, we need Nuclear.

Welcome to PF.

I agree with pretty much everything you said. I believe that nuclear is going to make a dramatic comeback in the next 20 years because there simply is no other option (the fact that it is the best option, unfortunatly, isn't enough for today).

There may be a thread around here somewhere about it, but a few years ago, I did some calculations about solar and concluded that with good solar panels, we'd nee to cover an area of about 300 miles square - similar to your father's calculation of the entire state of Arizona.

Strictly speaking, area isn't the issue - money is. Right now, the per-watt cost of solar is far too high to make it viable. If it can drop by an order of magnitude, then it could be a real solution.

 

[vanesch]

Certainly 100 yrs. There is limited production of Pu, which essentially absent in nature due to it's relatively short (geologically speaking) half-life.

Nuclear energy is produced primarily from the fission of U-235, with fissioning of some Pu which is produced through transmutation reactions involving U-238 in the UO₂-based fuel. Converting more U-238 to Pu-239/240/241 could extend the U-resources, and then there is Th-232, which can be transmuted to U-233, which is fissionable.

So there is potentially hundreds of years of energy resources based on fission.

One key issue is where to put all the fission products, which must be isolated from the biosphere.

I would like to add to this. Current thermal-spectrum reactors use MAINLY U-235 in the power production. U-235 is 0.7% of the natural content of uranium on earth. In fact, at high burnup, SOME U-238 (the 99.3% remaining if we neglect some traces) is converted into Pu-239 and is burned up ; about 30% of the energy that is extracted in a reactor comes from this Pu-burning, and 70% comes from the original U-235 burning.

So that means that currently, we use effectively ONE PERCENT of the energetic content of the uranium that has been extracted.

In a fast reactor, we can use ALL of it, because U-238, through conversion in Pu-239, can become a nuclear fuel. We can use all the U-238 that we already DUG UP, and partially discarded (in the "enrichment" of uranium, which is nothing else but removing 3/4 of the U-238 from the original ore), and MOST of the "burned fuel" which consists mainly of passive U-238.

So, by switching to fast breeders, we can extract in principle ONE HUNDRED TIMES MORE ENERGY from the EXISTING waste than we already extracted. In principle without any more uranium input. Just by using the "waste" correctly.

If some powerplants have been working for 30 years, this means, in principle, that we can extract the same power for another 3000 years, just by using its "waste".

 

[vanesch]

On the other hand...

Given that it is inevitable, the question is, what should we do about it? My work is in Decision Theory, and I believe that the probability of a nuclear accident associated with Nuclear power is low... unfortunately the cost is high. Utility is the product of the probability * the cost. There is a good reason to be cautious about Nuclear power. I think that we need a balanced middle of the road approach. The "it's ok, there are no risks" or "the risks are so small" thing is not necessarily the best response. But the argument that the risks are lower than those of coal (as so many of you have nicely made) works better.

The point really is that the risks ARE already really small in the West. The objective risk (as you point out: risk = probability x cost(lives, land...) ) of nuclear activities is about a million times lower than driving cars, and even lower than making shoes (just by comparing the number of yearly dead). The "maximum disaster" is Chernobyl, which is a serious catastrophe, but much less so than many accidents in other branches of human activity (for instance, the Chernobyl disaster is way less terrible than the Bhopal disaster, and a Chernobyl accident in the west is way way way less likely - for fundamental reasons - than another Bhopal).

Furthermore research is needed to make those risks smaller. Thus it is my belief that research into safer Nuclear energy is the solution. We need to spend the bucks, and get it done. This research needs to focus on making the process safer and on dealing with the waste. We have done a lot on the first one, but can do more.

There are good solutions for the waste. It is not as catastrophic as eco wackos want us to believe. There are in fact 3 timescales in nuclear waste:

- fission products: about harmless after 300 years
- minor actinides: about harmless after 10 000 years
- plutonium: about harmless after 100 000 years.

Now, reprocessing can remove the plutonium (to be re-used as fuel!), and there's a lot of work going on - and prototype processes such as DIAMEX have been set up - to remove also the minor actinides. This leaves us with the main ash from nuclear power: the inevitable fission products. Well, there life time is of the order of 300 years.
That's not the "millions of years" that is usually talked about.

The minor actinides can be considered as waste, but they can also be burned in fast reactors. There are experiments under way to burn them in subcritical accelerator-driven reactors, but I think that this is overkill. Even considering them as waste is not such a problem, because geological storage can be made secure for 10 000 years with high reliability. Also, if there's a leak after, say, 1000 years, that's not a major disaster. There will be a minor polution of a relatively local area, much less of a danger than most waste storages of today.

I truly believe that we can also do much better on the second one. We can find better ways of dealing with the waste that we have. Some have been discussed above but there are others. There is energy in that waste. Decays=energy... perhaps not very much, especially in the stuff that takes forever to decay, but it is in there, and there should be good ways of getting it out and making it useful instead of a scourge. Next we can find better ways of reprocessing (I know proliferation rears its ugly head) but there are ways of reprocessing that can be internationally monitored and where the reprocessed materials can be used immediately... or something... so we aren't stockpiling weapons grade materials. That's the point of research, we don't know what solutions will be found, but we should look for them. Finally we can produce reactors that produce less waste.

Most of this is already well-studied. There have been 18 fast breeder reactors active in the world ; only two of them are still working, most of them were closed down for political reasons. So this is not a dream on paper. Prototypes have been build and made working. One just needs to improve a bit on the engineering to optimise the design. There are no known difficulties of principle. This stuff has been working before.

These are the research areas. Some solutions already exist in these areas, but we just can't use them for political reasons etc. Some better solutions are in the works, and some even better solutions are sure to come out of some good investments in research.

In fact, France has the ambition to put its first Gen-IV reactor, with closed fuel cycle, up and running by about 2020. If the green party didn't ask for drilling a hole in the reactor vessel of super-phenix in 1998 or so, it would probably already be up and running.

 

[Astronuc]

Re: Fast Reactors - this would be of interest.

The status of Fast Reactors programme in France in 2005
http://www-ist.cea.fr/publicea/exl-doc/200600003924.pdf

I attended a lecture by the program manager of the US fast reactor program 25 years ago. At the time, he had just dismissed 300 people from the program! He likened a fast reactor to building a supersonic aircraft out of balsa wood. My colleagues and I were rather shocked at the statement.

Fast reactor technology has been rather problematic, not so much from the standpoint of the nuclear physics and fuel design, but from the aspect of balance of plant and operational issues. FR's are complicated because the fuel handling has to be done under liquid sodium. Traditionally, electrical generation has been accomplished by large steam turbines, but the problem there would be the basic incompatibility of water and sodium.

Superphenix was plagued with problems, and the Japanese MONJU had its own set of problems, including some deficiencies in design.

Perhaps the better alternative is a gas-cooled fast reactor.

I'm not arguing that fast reactor technology is impossible, but rather, it is not so easy.

 

[vanesch]

I attended a lecture by the program manager of the US fast reactor program 25 years ago. At the time, he had just dismissed 300 people from the program! He likened a fast reactor to building a supersonic aircraft out of balsa wood. My colleagues and I were rather shocked at the statement.

This is more kind of emotional rethoric than based upon any technological assessment. I attended a lot of seminars in Karlsruhe a few months ago, and had the opportunity to have a dinner with one of the CEA responsibles for the former Superphenix programme, which seemed to claim exactly the opposite: that liquid sodium cooling is technologically mastered and that the closedown of it was purely political. It is true that Superphenix had a lot of problems in its first years, but in its last years it ran without many troubles, and it was also a prototype: you expect difficulties in a prototype.
Let's not forget that Phenix has been running for over 30 years without problems.
So according to him, one can always improve upon robustness and one can always improve upon engineering, but there wasn't any fundamental objective technological obstacle to building liquid sodium cooled reactors.

Fast reactor technology has been rather problematic, not so much from the standpoint of the nuclear physics and fuel design, but from the aspect of balance of plant and operational issues. FR's are complicated because the fuel handling has to be done under liquid sodium. Traditionally, electrical generation has been accomplished by large steam turbines, but the problem there would be the basic incompatibility of water and sodium.

Nobody will deny that a FR is a bit more complicated than a LWR, but that's more because a LWR is *extremely simple*. The problem with steam turbines - in as much as that is a problem - is the low Carnot efficiency, because you cannot use steam much above 400 degrees Celcius (critical point of water). It would of course be dangerous to have a direct Sodium/water heat exchanger, but nothing stops you from having an intermediate fluid which is compatible with both.

Superphenix was plagued with problems, and the Japanese MONJU had its own set of problems, including some deficiencies in design.

Sure, but these are prototypes, exactly to learn from. If one would have built a few tens of prototypes, the experience gathered would make this technology probably just as robust as LWR are now.

Perhaps the better alternative is a gas-cooled fast reactor.

I'm not arguing that fast reactor technology is impossible, but rather, it is not so easy.

There are essentially 4 types of fast reactors:
- liquid sodium
- liquid lead
- gas
- salt

Sodium makes people nervous because of its reactivity with water, but all the other properties of sodium are OK, which makes it less of a problem than people think. For instance, a liquid sodium reactor is NOT under pressure, which relieves a lot of safety, materials and mechanics issues. In that respect, a liquid sodium reactor is "easier" than a LWR which is under high pressure. Also, one can, as with the IFR, use a "buffer bath" of sodium to make the reactor entirely passively safe. The only true engineering challenge is to keep the water out in all circumstances.

Liquid lead seems to address this, but is actually worse. Yes, liquid lead is less reactive towards water, but: 1) it is very corrosive, which puts a strong materials engineering challenge - which isn't the case for sodium and 2) you generate radioisotopes such as polonium.

Gas cooled reactors seem better in this respect, but, again, they are under pressure, and they are difficult to make passively safe. A loss of pressure for instance means a big challenge to restore the cooling.

Salt cooled reactors seem to address many issues, and are very promising. Only difficulty: almost no experience with it!

So, everything in a row, technologically, sodium cooled reactors are "closest to operational commercially". If we are serious in installing MANY production FR by 2030, we better start with a technology where experience exists.