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The Daring Dufas wrote: ...

That particular work wasn't terribly related to each other -- the pressure vessel samples are chunks of the reactor vessel material that are placed in special specimen holders designed into the vessels on initial installation and then removed after a specified set of intervals and tested. The primary test for these samples is for ductility (testing against radiation-induced embrittlement) to, as you inferred correctly, determine that the vessel and other high pressure components have not undergone excessive degradation so as to still be capable of withstanding operating pressures and temperatures.
The accelerometer measurements in piping I referred to earlier were for the pulverized coal flow distribution pipes in coal-fired boilers, not nuclear plants. These are fairly low pressure but high air flow volume pipes and the air is both for coal transport and is also a major fraction of combustion air. Since it isn't liquid fluid flow and is blown not pumped, cavitation isn't an issue there. The turbulence noise here is simply a byproduct of the transport system that we were using w/ the characteristics that fluid transport/flow isn't stochastic but chaotic to find information regarding coal and air flow rates buried in that ultrasonic signal we could pick up via the accelerometer. It had the major advantage of being non-invasive as coal dust is extremely abrasive so it's a major hassle to try to keep instrumentation alive that can survive inside a pipe. Being as how there is no free lunch, the counter problem was that the processing was quite intensive.
Back to your question regarding flow noise and measurements in nuclear plants -- in general, the answer is "yes, stuff like that is done" and is done routinely as you're familiar with for preventive maintenance and other various mechanical systems. If you've worked in the area much at all you've probably come across my last employer that I mentioned above, CSI (Computational Systems, Inc) in Knoxville, TN, now a subsidiary of Emerson Electric in the Rosemount catalog of instrumentation.
As for other similar measurements in reactors, the secondary piping and so on wasn't particularly my area of expertise. I'll note, however, though, that other than the reactor itself, the rest of the plant is really no different than are the other large generation plants in pressures and/or flow; in fact, super-critical fossil boilers run at much higher pressures and temperatures than do pressurized water reactors. The containment of such fluids was pretty much routine long before commercial nuclear power came along.
There is routine monitoring of primary reactor coolant pumps for such problems as you would expect. As a complete sidelight, interestingly, the reason the TMI accident progressed to the point it did was that the operators misinterpreted some pressure/temperature data and fearing cavitation in the RCPs turned them off, thus cutting off forced circulation in the core for several hours. The accident sequence was brought under control and began to be stabilized when the SRO of the subsequent shift recognized the issue and had the pumps restarted as well as the HPI (high pressure injection) system and recovered the core and reestablished core cooling. If the first crew had simply kept their hands in their pockets and let the safety systems and control systems "do their thing" there would have been no event other than a reactor trip and a manual reset of the PORVs and the plant would have gone back to normal operation in a week or so after some routine maintenance. A case where an event can be turned into a major one by a combination of mistakes after a mechanical failure (which wasn't terribly uncommon nor is unexpected, particularly, for a PORV to not automatically reclose which not being manually closed after it failed to reseat and not being recognized was open was the source of the primary coolant loss).
Some of the things that are unique to nuclear units that are done to monitor for early signs of failure or mechanical problems in the reactor include "loose parts monitors" and "neutron noise analysis". The first of these uses a group of accelerometers mounted in various places on the reactor vessel and primary coolant piping and "listen" for impact noises that could be the result of some reactor internals failure or similar. They are tied into systems that use a triangulation method on time of arrival for impacts to try to localize where within the plant any particular noise might actually be coming from. Did do the software for a prototype one of these systems for TVA way back when, too...just after the REMOTEC work. Unfortunately, then was about the time TVA was pulling back so only the one prototype was ever finished and by the time things picked up again, technology (and I) had moved on...
"Neutron noise" is a very interesting and intellectually and computationally challenging area -- it uses the small fluctuations in the signal of the excore neutron detectors and signal processing to infer things about reactor internals such as the movement of the core inner liner or fuel assembly vibrations. As the inner barrel moves slightly (on order of tens of mils), the change in water density owing the that slight change in thickness is discernible in a very small fluctuation in the neutron flux at the detector. By monitoring this in time, if something were to happen to one of the studs that holds the barrel in place, one could detect a larger amplitude of barrel motion (this has happened at at least on reactor I'm aware of). By knowing this before either the next outage or larger damage became apparent, one can monitor the situation and determine when or if an early shutdown would be required.
There are any number of other monitoring systems and instrumentation besides for almost all systems and certainly for those that are directly safety related.
Again, undoubtedly, far more than one might care about in ahr... :)
--
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On 1/1/2011 4:38 PM, dpb wrote:

I think I understand about the pulverized coal. Ultrasonic transducers are used to measure the flow of material through the pipes because a paddle wheel would quickly disintegrate? Rereading what you wrote it seems that you were listening for a specific resonance or you were trying to separate the sound of the airflow from the noise of the flow of the pulverized coal mixed with it. Is that what all the processing power is required for? It kind of reminds me of what modern military sonar systems do. Heck, I find everything interesting, back in the last century BI, "Before Internet", I spent a lot of time in libraries reading every sort of engineering, scientific or medical journal I could get my hands on. Years ago, there was a Star Trek convention in Huntsville, Alabama hosted by NASA engineers and instead of looking for Mr. Spock, I was hanging out with the engineers looking at and discussing all the neat stuff they had on display like cross sections of the Space Shuttle fuel tank showing the different layers in its construction. Don't worry about the subject matter, I find it all interesting, besides, it will make me go searching The Web for more information. :-)
TDD
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The Daring Dufas wrote: ...

Anything like a paddle wheel wouldn't make it 5 minutes. :)
In an early stage of the work, I tried a hardened steel drill rod as a sounding rod in one small-scale test facility. The test duration was only for a couple of days and it came out oval in cross-section in even that short a time frame with a good third of the frontal surface gone. The utilities are very reluctant to insert stuff into the coal pipes that could fail and either block the flow in a pipe w/ a resultant high pressure event back at the pulverizer or block a burner nozzle in the furnace and cause an event there. The air:fuel mixture is right at the limits and so it's a real danger of fire or explosion if something goes wrong outside the boiler or in a coal pipe. Needless to say, an open 14" pipe w/ a burn out isn't a desirable event... :) In at least few cases where they have happened the flame has actually melted the side of a boiler containment and ended up w/ an entire boiler open. That wreaks havoc in a plant _very_ quickly. :(
As far as more explanation of exactly what the computations are, unfortunately, the actual technique is proprietary but it does not look at the signal in a conventional sense at all; it is not, as I've stated, based on frequency components per se, but on the fact that turbulent flow is chaotic, not random. It doesn't repeat exactly, but there are certain patterns and we have identified some 30 scale-invariant measures that can be calculated from the broadband ultrasonic signal as picked up by a passive accelerometer as minute vibrations transmitted through the pipe wall. We do not introduce any additional energy into the pipe at all as does a classic ultrasonic detector.
There were some other research teams looking at other techniques such as microwave and/or more approximating conventional ultrasonics but our technique was/is unique.
--


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On 1/1/2011 8:30 PM, dpb wrote:

In other words your sensors were passive listening devices not active like the ultrasonic flow sensors I'm familiar with? I'm guessing you were looking for a semblance of a pattern in the white noise of the chaos. Am I getting warmer? :-)
TDD
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The Daring Dufas wrote: ...

Yes, as I said they were/are simply high frequency (>75 kHz resonance) commercially available accelerometers...

Except white noise implies a stochastic process whereas a chaotic process, while not strictly repeatable, is not stochastic. Hence, typical statistical measures used for such processes are not effective and the measures used in the analysis are, as mentioned, nonlinear and then combined in other nonlinear ways for prediction. (I know, that's a lot of mumbo-jumbo unless one already knows the answer, but as I say, the specifics are proprietary so can't really reveal much more about the details).
Suffice it to say that there is information buried in the audible and supersonic noise of the flow and that can be related to the actual air and coal flow rates in a given pipe over a range of operating conditions and air:fuel ratios and flow rates by a set of specific operations on the recorded waveform. One important feature of these computations is that they all produce quantities that are independent of the actual magnitude of the signal itself (iow, they're self-normalizing). This is a key feature in that it means that simply a level change from a location difference doesn't affect a given signature. It also means, of course, that simple measures such as the mean aren't what is giving the actual correlations. :) But, from those correlations a prediction of flow is possible for a given new set of measures computed for the same pipe from any set of operating conditions and this has been shown to be valid over a range of operating conditions and at various power plants of differing sizes and styles and manufacturer (albeit the correlations are at least to this point plant-specific, the measures used in those are for the most part the same ones of of the total set of those identified as candidates).
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On 1/1/2011 11:26 PM, dpb wrote:

The only problem I'm having is grokking the difference between stochastic and chaotic. I suppose there must be a enough difference between random and disorderly for your system to work. I love this kind of stuff. :-)
TDD
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The Daring Dufas wrote: ...

Indeed, there is a fundamental difference.
The beginning of the following link is on the line of the way I used to try present it to the bleary-eyed utility guys who really only wanted to know enough as to whether they thought it (the R&D project; EPRI is a utility self-funded research organization so we had to have buy-in from the member utilities to continue to have the resources to support the effort) made enough sense to continue or not and like you, wanted at least a grasp of the concept.
<http://www.math.tamu.edu/~mpilant/math614/chaos_vs_random.pdf
I'd not read the Wikipedia entry on chaos; so often they're not of much help so did--it's not terrible reading.
<http://en.wikipedia.org/wiki/Chaos_theory>
For a non-technical read if you're interested in such things, I'd recommend
_Chaos: Making a New Science_ by James Gleick
It's the best written of several of the popular expositions imo for a general overview of chaotic systems in natural processes.
For more esoteric approach, Benoit Mandelbrot is a stretch but two of his at least summarized rather than actual papers include _The_Fractal_Geometry_of_Nature_ and _Fractals_and_Chaos:_The_Mandelbrot_Set_ and_Beyond_
Of course, there's an almost unlimited literature on turbulent flow but other than how it's touched upon in some of the above as a field I don't know of any popularization of the subject itself. The pneumatic transport of solids is, of course, a subset within it with another whole literature/history...
None of those will explain the processing we're doing; but they are an interesting introduction into a whole (relatively) new way of looking at much of the physical world.
--
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On 1/2/2011 9:23 AM, dpb wrote:

Thanks for the links, I may comprehend it yet. :-)
TDD
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The Daring Dufas wrote:

But the validity of the processing inherently requires that the underlying process be chaotic, not stochastic; it (the method) is simply a way of making approximating functions that are indirectly related to things like the Lyapanov numbers, etc., that can be measured and computed in sufficient quantity and speed to be the basis of an instrument.

It is indeed a fascinating field w/ almost as many bizarre features as string theory and higher dimensions.
Enjoy... :)
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?

Well, thanks for nothing. At the New Years party last night I was discussing that with a couple of ladies and I promised to get back to them with some reports. My chances of getting laid just went down now thanks for you. They were really excited too when I talked about differing containment materials. .
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Ed Pawlowski wrote:

Chuckle, snicker...it's a bummer, ain't it? :)
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On Thu, 30 Dec 2010 16:06:21 -0600, Vic Smith

A lot of the programs the major insurance companies run on - particularly the actuarial stuff in the life insurance business is STILL Fortran. Same programs developped in the '60s, still running with modification after modification.
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On Thu, 30 Dec 2010 19:47:49 -0500, snipped-for-privacy@snyder.on.ca wrote:

Maybe so. But I spent years at Allstate and CNA insurance and knew State Farm and Farmers Group employees and talked shop with them. Those are major insurance companies. It was 90% COBOL and assembler. That covers a gamut of the usual insurance company processing, and I worked in the major insurance processing areas - premiums, claims, accounting, investments. Did payroll elsewhere, all COBOL. Never saw a Fortran app anywhere, and I got around to most areas. Doubt there was any tucked away either, unless somebody was running Fortran from a PC. I had access to the system libraries and would have seen it. Pretty much knew all the programming tools where I worked. Might have been tucked away somewhere. I never say never. And though casualty isn't life, most insurance processing is as i said. You run into "scientist" users who prefer a language, but they are a small part of business processing. I had a client at McDonalds corporate marketing who liked using SAS for some day-part analysis. He got no help from me. Marketing staff there were still using Macs and they got just a little help. But that's not why I was there. McDonalds actually did analysis on what was sold at different hours of the day. Massive amounts of data coming in from POS terminals. First time I heard the term "terrabyte" but I left before they got the IBM drives in. Boucoup expensive. Now anybody can get multiple terrabytes cheap at Best Buy. Reminds me of the data management boss there. First day there I grabbed maybe 100 cylinders of disk to run something. That was no big deal in my previous shop, and about the same bytes as what I had on my big PC hard drive at home. I get a call from data management a few minutes later asking what's up. I told them what's up, and that was that. They asked me to call first next time I want that much space. Later that day I'm out front for a smoke and I get introduced to the data management boss. "Vic? Rings a bell. You the guy who hammered my space?" "C'mon," I said. I got that much on my PC hard drive at home. "Bring it in." he says. Not much for words, but I liked him and we got along fine. Closest to actuarial I got was working for an epidemiologist at International Mineral and Chemical. Similar mortality study to actuary I think. He loved me, because I built a huge table and report process for him for a study he was doing. Used COBOL. At that time COBOL - ANSI 74 I think - had a 32k max for indexed table size. I needed to store and access about a dozen times that. About 18,000 deceased employee vitals, work site and job position. Mostly Florida phosphate workers. I started a Rube Goldberg of multiple tables to handle it, mentioned my predicament it to an "old-timer" who was really sharp, and he showed me how to trick COBOL by defining filler area beyond the allowed table size in working storage and subscripting into it. Slower than the binary search on the search end, but it ran fine. Never met another programmer who knew that one. It was a good start to my IT first job, and I won't forget Mike. Lots of ggod guys I learned from, and I tried to pass it all on. God dammit! Gimme another beer and a hanky!
--Vic
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On 12/30/2010 05:06 PM, Vic Smith wrote:

That's not exactly what I said, it was that a ME professor who assigned a program in Fortran for homework, and was incredulous that nobody could complete it. Still a sign of a disconnect with reality IMHO :)
nate
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replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
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snipped-for-privacy@att.bizzzzzzzzzzzz wrote:

COBOL "still used"?
There are more lines of COBOL code in production than any other language. Most financial back-room stuff is in COBOL. For example, almost the entire Social Security System EDP is in COBOL. There are many production programs, written back in the 60's, that are still running in production every day.
These examples may say more about the unchangeability of the financial system than the COBOL language, but they're interesting nevertheless.
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what is your opinion of EE or Civil as a viable degree?
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On Thu, 30 Dec 2010 19:14:03 -0600, snipped-for-privacy@privacy.net wrote:

both are "viable" If you are not looking for a lifetime job guarantee. Civil engineering is harder than some jobs to send off-shore, and EVENTUALLY there will need to be electrical engineering done in north america. Might be a good idea to studi Punjabi , Sanskrit, Mandarin, and a few other eastern languages along with the engineeing if you expect to be very valuable in the future though.
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On Thu, 30 Dec 2010 19:14:03 -0600, snipped-for-privacy@privacy.net wrote:

There is nothing wrong with either but don't expect any guarantees. Don't go deep into debt to get the paper.
I'm an EE and have had no problem finding a job, but I have a lot of experience and history. I'm sure it would be a lot more difficult to break in now, even though the mid-'70s were no picnic either. I did get in at the tail end of the "lifetime employment" era. As Clare says, don't expect anything of the kind, but there are also some amazing opportunities for the right sort of person.
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wrote:

OK so what abt health care?
Such as a biochemistry degree.... or pharmacy degree?
Something for a 40 something to switch careers to?
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?

Pharmacy is something like 5 years. Pays well though, seems steady as we get older.
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