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The Nuclear Power Thread

by russ_watters
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enigma
#55
Nov21-03, 04:35 PM
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OH NO!!!!!!

You mean they're putting radioactive material into our consumer products!?!?!?!?!

You mean radioactive materials like CARBON-14!?!?!?!?!?!

Damn, that stuff is present in EVERYTHING!!!!!!!!!

Better get started on the regulation of that stuff.

Ignorant knee-jerk reactionary babble is what your links are. Each and every one of them.
enigma
#56
Nov21-03, 04:40 PM
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OHMIGOD, I forgot about that awful radiating sunlight!!!!!!

Sunlight causes more cancer each year than all the pollution ever caused by man. We need to get started with the regulation of that EVIL, EVIL, premeditated-murdering Sun.

If you are exposed to X (plus or minus 1%) amount of background radiation every single day of your life, then increasing that amount by X*10^-6 is not going to make one lick of difference. The definition of 'statistically insignificant'. You should learn some statistics. Seriously.
enigma
#57
Nov21-03, 04:47 PM
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We need to ban Dihydrogen Monoxide!

That stuff is in everything... even our FOOD SUPPLY.

It causes frequent urination. It is a major component in acid rain. It is present in septic systems and they have no problem putting it in baby food.
It's possible to die from it if you are given too much of it.
Massive amounts have even been known to destroy the infrastructure of houses!
Certain isotopes of it are radioactive as well...

Ban Dihydrogen Monoxide!

*sheesh*
theroyprocess
#58
Nov21-03, 05:04 PM
P: 141
Back on topic....is nuclear power more dependable...
not in Japan.

http://www.economist.com/business/di...ory_id=1928646
russ_watters
#59
Nov21-03, 06:31 PM
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Originally posted by RuiMonteiro
The New York blackout happened due to bad managment on the energetic network. The US does not have a good energetic network and a simple failure in a power plant is enought to put milions in the dark.
Thats only the trigger. The root cause is that our power grid is very near maximum capacity. Windstorms and breaking tree branches happen all the time. The cascade failure is a result of one failure leaving the next piece of the grid underpowered. That piece goes offline to keep from damaging the equipment. Then the next piece has to carry the extra load and it goes offline to keep from damaging its equipment. Et cetera, et cetera. What you probably didn't read about unless you live near Philly is that the cascade was stopped by PECO - a control center in Southeastern PA saw the cascade coming and disconnected the umbilicals connecting PECO's section to the rest of the grid. Otherwise the cascade would have continued down the eastern seaboard.

Anyway, an overloaded grid is what keeps a cascade going. Heck, read it in the link theroyprocess just provided about Japan.
The ministry, which oversees the electricity industry, is gearing up for a power shortage that could leave Tokyo facing unprecedented blackouts this summer, when demand for electricity reaches its peak. The reason: Tokyo Electric Power (Tepco), the world's largest private electricity company, had to close its 17 nuclear reactors...
Think its bad now? Its only going to get worse unless we do something about it.

I'll find you the stats, but the demand for electricity virtually everywhere in the western world is growing faster than the generating capacity and has been for some time. The primary cause is the lack of new nuclear power plants.
So, there would be around 250 nuclear plants. So the quantities of radioactive elements released to the environment would increase a lot
Rui, "so small its not detectable above background radiation" - times 2.5 - is still "so small its not detectable above background radiation."
Nereid
#60
Nov22-03, 05:02 AM
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Hey enigma (and theroyprocess, if she's listening),

You should also recommend that folk abandon Denver, ski resorts, and other high places and move into the New York subway (people in England, Paris, Shanghai, etc ... please choose your favourite underground rail system). There will be a reduction in the exposure of humans to ionising radiation - from cosmic rays - many million (billion?) times greater than that which would result from closing all nuclear power plants.
HAVOC451
#61
Nov22-03, 06:40 AM
P: 51
Originally posted by russ_watters
The part of this issue that has me most upset is the 50% of the electricity in the US that comes from COAL. This is the leading cause of air pollution and the leading cause of those 70,000 deaths, not to mention global warming and all the other effects of air pollution.

As far as the Clean Air Act goes, we should immediately do some more sweeping things such as require MASSIVE reductions in emissions by coal plants. Such things are possible, but expensive.
Quite right. This leads directly to why I brought up the Clean Air Act in the first place. The law was changed specifically to exempt those coal burning powerplants from having to install the systems that would make them operate cleanly. Many of the monied interests that lobbied the government for changes in the Clean Air Act are the the very same interests "helping" Dick Cheny write the nations energy policy. Those interests would love to resurect their nuclear power divisions.

Originally posted by enigma
Yes. I'm furious with Bush, and the Clean Air Act is one of the many reasons why.
Kudos, I'm encouraged.

Originally posted by enigma
I didn't know about that issue, but there are major issues with the health of coal miners as well.

However, anecdotal evidence does not prove a case. No data, no case.
I didn't link that anecdote to prove the case, I only note that the case is there.
Coal miners have been taking it in the teeth for a long time. In many ways the only group more marginalised and ignored than coal miners are native americans living down wind/stream from a uranium mine.
Nereid
#62
Nov22-03, 11:05 AM
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HAVOC451 wrote: I didn't link that anecdote to prove the case, I only note that the case is there.
While not exactly a group in the sense of coal miners and native Americans, have you considered those with particularly vulnerable respiratory systems? IIRC, there are a really nasty class of diesel emissions (very fine particulates) that Big Oil is trying to have everyone ignore. It'd be no surprise to learn there is legislation in many countries (not only the US) which exempts Big Oil (and Big Auto) from accepting responsibility for these emissions.
theroyprocess
#63
Nov22-03, 11:14 AM
P: 141
If the Russians were dumping their nuclear waste into commercial
products like industry wants to here in the USA...we would smirk
at them and say "it could never happen here!". BUT IT IS!

Activists Make Nuclear Waste a Russian Election Issue

MOSCOW, Russia, November 18, 2003 (ENS)

http://www.ens-newswire.com/ens/nov2...19.asp#anchor3

[flood deleted]

See also http://nucnews.net - NucNews Links and Archives
HAVOC451
#64
Nov22-03, 11:57 AM
P: 51
Nereid,
I have.
I agree with you on this.
Diesel emissions have been exempted far too long. This is slowly beginning to changs.
RuiMonteiro
#65
Nov22-03, 12:02 PM
P: 30
Originally posted by russ_watters
Thats only the trigger. The root cause is that our power grid is very near maximum capacity. Windstorms and breaking tree branches happen all the time. The cascade failure is a result of one failure leaving the next piece of the grid underpowered. That piece goes offline to keep from damaging the equipment. Then the next piece has to carry the extra load and it goes offline to keep from damaging its equipment. Et cetera, et cetera. What you probably didn't read about unless you live near Philly is that the cascade was stopped by PECO - a control center in Southeastern PA saw the cascade coming and disconnected the umbilicals connecting PECO's section to the rest of the grid. Otherwise the cascade would have continued down the eastern seaboard.

Anyway, an overloaded grid is what keeps a cascade going. Heck, read it in the link theroyprocess just provided about Japan. Think its bad now? Its only going to get worse unless we do something about it.

Exactly because there was a cascade failure it shows that the energetic network supply isnīt very good. When, for some reason, a power plant stops instantanly it should be enough (that is with the proper systems) that there wouldnīt happen a cascade failure. This is possible if a great number of power plants are interconnected in a way to prevent this, there are modern systems that can do this.

And by the way, what you probably didnīt read is that i donīt live near Philly or any other place in the US, i live in Portugal, you probably didnīt even read the entirity of my post...



Rui.
Nereid
#66
Nov22-03, 08:00 PM
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IMHO, the root cause is bad regulation and wilful ignorance of economics. Behind that there is, without a doubt, the hand of Big Oil.

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.
russ_watters
#67
Nov22-03, 11:44 PM
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Originally posted by Nereid
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.
The power grid actually presents an enormously complicated technical problem. There are a hundred or so suppliers, a thousand or so power plants, and around a billion services (est). And the resilience of the grid is directly related to the excess capacity.

Think about it - if you have a 96% load factor and 10 power plants of equal size, what happens if you lose a plant? Now you are 6% over capacity. The grid is designed so in this situation, you pull the extra power for the adjacent sections of the grid. But what happens if THEY are at 96% capacity? Now they don't have enough power either.

Thats a very conservative illustration of how our power grid works. The load factor is roughly correct, but the power plants - well, there are more of them, but the few nuclear power plants are what produce the vast majority of the power (in the northeast anyway). Trip a single line coming off of one plant and you're screwed. The grid will try to adjust and fail because it can't adjust fast enough. The laws of physics are against it - once you have detected the spike, its too late.

That said, there is a design issue there: when there is enough spare capacity, a grid system is a good thing - you CAN get power from elsewhere to cover your failure. Thats what its designed for. And thats the reason why major blackouts are so rare in the US. But load the grid to its limits and the grid works against itself - it causes the cascade failures we have seen recently and makes the rare power failure epic in scale.
Nereid
#68
Nov28-03, 08:07 PM
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Originally posted by russ_watters
The power grid actually presents an enormously complicated technical problem. There are a hundred or so suppliers, a thousand or so power plants, and around a billion services (est). And the resilience of the grid is directly related to the excess capacity.

Think about it - if you have a 96% load factor and 10 power plants of equal size, what happens if you lose a plant? Now you are 6% over capacity. The grid is designed so in this situation, you pull the extra power for the adjacent sections of the grid. But what happens if THEY are at 96% capacity? Now they don't have enough power either.

Thats a very conservative illustration of how our power grid works. The load factor is roughly correct, but the power plants - well, there are more of them, but the few nuclear power plants are what produce the vast majority of the power (in the northeast anyway). Trip a single line coming off of one plant and you're screwed. The grid will try to adjust and fail because it can't adjust fast enough. The laws of physics are against it - once you have detected the spike, its too late.

That said, there is a design issue there: when there is enough spare capacity, a grid system is a good thing - you CAN get power from elsewhere to cover your failure. Thats what its designed for. And thats the reason why major blackouts are so rare in the US. But load the grid to its limits and the grid works against itself - it causes the cascade failures we have seen recently and makes the rare power failure epic in scale.
Been thinking about this a bit. A telecoms network is considerably more complex than a power grid, and subject to all kinds of nasty shocks. Yet a great deal has been done to make them very resilient. Of course, the analogy is quite imperfect at the direct-comparison level (there's no equivalent to IP in power grids, for example), but perhaps at a meta-level some lessons could be learned?

For example, to what extent are the key generators and main parts of the grid under constant surveillance by AI/neural network-based systems looking for incipient failure? IIRC, some US airline maintenance department built such a system for detecting failures in jet engines. After some time, they not only substantially reduced the amount of maintenance that needed to be done, but were able to turn the service into a profit centre, by offering it to other airlines.

Presumably planned shutdowns would cause considerably less disruption than unplanned ones; a good grid-wide fault management system may result in more planned shutdowns, but that'd be a small price to pay for avoidance of the kind of east coast disruption earlier this year. Indeed windstorms and tree branches are somewhat unpredictable, but if they constitute the majority of root causes, then remedial action (and proactive reduction of future likelihood) is pretty easy to characterise. After all, it's not as if we don't know where trees grow, or the seasonal distribution of wind strength (including variance), or the short-term (hours, minutes) likelihood of windstorms.

once you have detected the spike, its too late
and
What you probably didn't read about unless you live near Philly is that the cascade was stopped by PECO - a control center in Southeastern PA saw the cascade coming and disconnected the umbilicals connecting PECO's section to the rest of the grid. Otherwise the cascade would have continued down the eastern seaboard.
If PECO (a.k.a. 'the white knight'?) saw it coming, why couldn't the same sort of control systems be installed elsewhere? How about building a more distributed type of control system, better able to make local disconnections?

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?
wimms
#69
Nov29-03, 10:09 AM
P: 473
Telecoms network is not comparison at all. It doesn't fail when there is lack of capacity, it just slows down. With overload, it just drops some of calls. With energy this doesn't work, some things just physically blow up if overloaded, and no way to selectively drop few electrons, if it goes, so goes whole branch.

And, telecoms solved their quality issues very straightforward - they design in at least 2 times overcapacity.

Actually, being somewhat from telecom industry (networking) and having seen issues that grids have to face, i can say that telecoms networks are completely piece of cake compared to issues grids have to face. It is SO much easier to deal with issues in telecom.
Nereid
#70
Nov29-03, 06:16 PM
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I did say: Of course, the analogy is quite imperfect at the direct-comparison level (there's no equivalent to IP in power grids, for example), but perhaps at a meta-level some lessons could be learned?
Just an example: what use of AI/neural networks is there in the fault/performance/assignment/configuration components of the grid companies' network management systems? AFAIK, that in IP network systems (e.g. from Cisco) is trivial compared with what's in a modern system from Lucent, MetaSolv, Telcordia ... even TTI, which were developed in an era of scarce resourses and much higher cost of failure than today's IP-based data networks.

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?), and graceful degredation, with some serious work going into SLAs and contracts.

What, essentially, are the key differences between a telecoms network and an electricity grid, in terms of OOM greater difficulty re fault management?
russ_watters
#71
Nov29-03, 08:28 PM
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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
#72
Nov30-03, 11:58 AM
P: 473
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 thats 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?


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