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Post by cyrilr on May 16, 2019 15:52:30 GMT 9.5
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Post by Roger Clifton on May 17, 2019 16:55:11 GMT 9.5
The document appears to have been written for "the intelligent layman", somebody with an interest in science and in this case, in nuclear reactors. It is refreshing to see hard facts being used when our opponents can only speak in qualitative terms. However the frequent use of numbers does overwhelm.
Such a person knows the International System of units from school and because he (or she) is interested, in his subsequent reading. This will help you reduce the excessive occurrence of "millions" (44 of) and "billions" (also 44 of) and "000" (53 of), by replacing many of them with the correct prefix. The change will require more than a search-and-replace, because an intelligent laymen would require the correct spelling of "gigawatts" and "zettabecquerels" etc.
The SI unit, watt appears (incorrectly) capitalised at many places in the document. Do a search-and-replace. The name of the element, uranium also appears capitalised, four times on page 56.
On page 9 one statement is out of date. "Continued use will lead to dangerous levels of climate change." I suggest that be changed to read, "Use of coal has already led to dangerous levels of climate change. Continued burning of coal will continue to worsen the problem."
The word "gasses" is a verb, you want the noun, "gases".
There is too much underlining, so it no longer emphasises, just clutters the reading. I recommend removing all underlining except when something may be difficult to understand.
To assert virtue in this statement, "The byproduct, called fission products are the "ash" and the "smoke" of a nuclear reactor; but they do not go out the chimney, they stay contained..." could read, "Nuclear power stations have no chimneys because they do not emit greenhouse gases, smoke or ash. Even the fission products stay contained…"
The topic, "Is nuclear energy natural?" drifts off into natural radioactivity, which deserves separate treatment. "The Oklo natural nuclear reactors are only an extreme example of natural radiation" should read – "The nuclear reactors at Oklo are the only ones known to occur naturally, but there must have been many more in the previous three billion years, when U235 was more prevalent."
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Post by David B. Benson on May 17, 2019 17:19:37 GMT 9.5
"must have been" This expresses a certainty that geologists are not prepared to defend. Try "may have been".
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Post by Roger Clifton on May 17, 2019 21:07:24 GMT 9.5
"must have been" This expresses a certainty that geologists are not prepared to defend. Try "may have been". Perhaps you're right. I will leave the decision to CyrilR. However I do have history on this question. In about 1987, I discussed the possibility of earlier reactors forming during the days of higher U235, with a physicist who had worked on the isotopes from Oklo. After all, the deposit was rather unremarkable (deposition in an alkaline mud) yet reactors had started in 16 of the similar deposits in the area. He said that there was no evidence for other reactors in the isotopes of other uranium deposits elsewhere. However I figured that earlier reactors would have had even higher proportions of U235 and thus been more vigorous and more able to recirculate their uranium into the free water above before being buried as deeply as at Oklo. Further, minerals deposited by water are repeatedly reworked by subsequent infusions of water. Either way, the remains of these earlier natural reactors are not so likely to have survived. As a curiosity, I remember that he had said that the inference that most of the fissions had been Pu239 rather than U235 was preferred by the isotopic evidence. I think that would be implied by a higher proportion of fission products with atomic weights 103-106 relative to ~90.
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Post by cyrilr on May 17, 2019 23:32:40 GMT 9.5
Thanks for the comments! Will take a look at them for the next version.
Lets not get bogged down too much in the details of writing style and syntax. It is more important that there aren't any incorrect numbers and such in the doc. That would hurt the credibility.
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Post by cyrilr on May 17, 2019 23:44:35 GMT 9.5
""Nuclear power stations have no chimneys because they do not emit greenhouse gases, smoke or ash. Even the fission products stay contained…"
Technically they do have chimneys - usually called a stack. To dilute any ventilation or other activity. Pretty trivial source, but regulations require as-low-as-unreasonably-achievable so nuclear plants are built with an enormously tall stack.
I've always thought this is a mistake, since the stack isn't needed, and only gives the impression that something nasty is being vented and that somehow it is an enormous amount of nasty-ness. Why else would they build a 200 meter plus tall stack? Is the general impression. And so people's fear is further increased... not decreased because nuclear plants do ALARA.
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Post by cyrilr on May 17, 2019 23:46:22 GMT 9.5
Regarding Watts versus watts. Pretty sure it is spelled Watt. Like Becquerel is spelled with a capital too, since it is based on a historic figure.
If people are going to make that sort of comment I can only assume that the document must be pretty good and that reviewers have reverted to nitpicking. Good.
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Post by engineerpoet on May 17, 2019 23:57:23 GMT 9.5
You still haven't posted a single change log, so every time you post a new version I have to start over from scratch. This is not conducive to prompt or accurate review.
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Post by cyrilr on May 18, 2019 0:36:20 GMT 9.5
You still haven't posted a single change log, so every time you post a new version I have to start over from scratch. This is not conducive to prompt or accurate review. Now you're starting to sound like the regulator. You gonna charge me $290/h too with no end in sight for a license? If you've got comments on a previous version please send them to me, I will take care of change control stuff.
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Post by engineerpoet on May 18, 2019 0:43:00 GMT 9.5
I had some notes but I lost them when Windows 10 closed all my apps and rebooted against my explicit demand to do so LATER.
Have I mentioned today just how much I hate Microsoft? (And now also Dell, which has Linux for the computer I'm using but won't let me have it?!)
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Post by David B. Benson on May 18, 2019 9:06:46 GMT 9.5
Check the SI rules on units. The name is Watt so the unit, to be unique, is watt. Similarly for all the other units named for a person, such as kelvin and becquerel.
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Post by Roger Clifton on May 18, 2019 10:50:32 GMT 9.5
""Nuclear power stations have no chimneys because they do not emit greenhouse gases, smoke or ash. Even the fission products stay contained…" Technically they do have chimneys... Perhaps the same message could be rendered as – "Nuclear power stations don't really need chimneys because they do not emit…" Or – "For example, nuclear powered ships don't have smokestacks because they do not emit…" Well, that's almost correct. The symbol of a unit should be upper case if it is named after a real person, such as W, Bq, K, but the full name of the unit should always be in lowercase, such as watt, becquerel, kelvin. I can't point to a single website that comprehensively and correctly renders the modern version of the SI. The International Standards Organisation is of course the authority, but every webpage they put up, such as ISO 80000, promptly gets modified with a new webpage somewhere else and without an up-to-date digest. (Anyone who knows one, please tell us all.) The most prolific versions of the modern metric system are written in America, and in my experience, universally wrong. (Anyone, please prove me wrong(*).) However, the Wikipedia version is probably kept up-to-date. (*) PS: The authoritative guide to the American usage of the SI is available on the web as the NIST Guide for the Use of the International System of Units (SI). It is comprehensive, rather than the subset used by technical people, but it includes an excellent guide for authors.
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Post by Roger Clifton on May 20, 2019 9:55:21 GMT 9.5
The document does provide something of a self-defence manual for defenders of nuclear electricity. The questions are loaded with the myths that the answers are designed to dispel. To that extent, they are useful as a look-up table when we are attacked in public debate. However, they should not be offered to the public for perusal. Rather than give credence to the myth by reiterating the question in the presence of relatively impartial listeners, I am inclined to rephrase the question so that it is loaded with the answer rather than the myth. For example, the question: "Aren’t nuclear powerplants expensive?" Should receive the initial reply, "Are nuclear power plants cost-effective?" Then anybody whose attention span is only a couple of seconds will have received the answer, whether his loyalties lie in that direction or not. Questions structured "what about X?" invoke preconceptions without exposing content we could address. There is an exchange in an old Peter Sellers movie, where a spokesman for a mob of inarticulate workers gives the catch cry, "What about the workers?!". Although an idiot, the management spokesman aptly defuses the loading of the question by asking for more content. "Indeed sir, what about the workers?"
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Post by cyrilr on May 21, 2019 0:23:10 GMT 9.5
The document does provide something of a self-defence manual for defenders of nuclear electricity. The questions are loaded with the myths that the answers are designed to dispel. To that extent, they are useful as a look-up table when we are attacked in public debate. However, they should not be offered to the public for perusal. Rather than give credence to the myth by reiterating the question in the presence of relatively impartial listeners, I am inclined to rephrase the question so that it is loaded with the answer rather than the myth. For example, the question: "Aren’t nuclear powerplants expensive?" Should receive the initial reply, "Are nuclear power plants cost-effective?" Then anybody whose attention span is only a couple of seconds will have received the answer, whether his loyalties lie in that direction or not. Questions structured "what about X?" invoke preconceptions without exposing content we could address. There is an exchange in an old Peter Sellers movie, where a spokesman for a mob of inarticulate workers gives the catch cry, "What about the workers?!". Although an idiot, the management spokesman aptly defuses the loading of the question by asking for more content. "Indeed sir, what about the workers?" Well, the document structure is fairly simple and the idea behind it is deliberate. First, most people don't understand how fission works, and you can't explain why something is a good idea if people don't know how it works. So the first part of the doc starts off with that. Pretty logical I think. The form chosen is a FAQ - so it starts with a logical first question and then follows from there. Next is why this whole nuclear thing is a good idea. This isn't obvious to many people for some reason so that section goes on about that a while. When viewed in isolation, it may appear we shouldn't bother with nuclear. After all it makes nuclear waste and it might be hazardous. Similarly, we shouldn't do solar because solar is unreliable, not there most of the time and solar panels are toxic. Similarly we shouldn't do fossil fuels because of climate change and waste problems. When viewed in isolation, a case can be made against any energy source. When viewed as anything else in life - a CHOICE - it is much more clear-cut why nuclear is a good idea, because it is a better idea than all the other energy sources. So that section goes on about that. Then we get into the controversial part: the myths. Most of the arguments brought up against nuclear are myths - they are fabrications, lies, half-truths. Fake news. This is a key take-away-point from the document. If people take just one point away and it is that, the document is hugely succesful. It isn't possible to discuss the myths without mentioning the myths. The general narrative is usually the same - the question is posed as a bias, as a myth. Then there is a narrative, a story, that rather clearly shows that the story is a myth. That is then re-iterated and concluded at the end. Not all sections follow this narrative because I thought it would be boring so added a bit of journalistic diversification. It is not possible to say that all the downsides of nuclear are all made up without pointing a finger of blame. People will say "ok so if nuclear is so good why aren't we doing this more". So this is where the organized opposition part comes in. I kind of like the FAQ narrative because it starts with the myth and then delves into the truth and facts. Of course if you prefer a different narrative you can try yourself. This is my attempt and while it needs some polishing here and there, it is about the best I can do for now.
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Post by cyrilr on May 21, 2019 0:28:55 GMT 9.5
I had some notes but I lost them when Windows 10 closed all my apps and rebooted against my explicit demand to do so LATER. Have I mentioned today just how much I hate Microsoft? (And now also Dell, which has Linux for the computer I'm using but won't let me have it?!)Oh man yeah, that sucks, very familiar problem. I just got a message from Microsoft saying it WILL START UP MY COMPUTER IN 5 MINUTES!. Ransomware, but from the OS. All I can say is: don't use Microsoft OS for your nuclear plant! It might decide to shut itself down and update the firmware during a fire or earthquake. I gotta go, my computer is about to restart. Nothing I can do.
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Post by engineerpoet on May 22, 2019 2:06:35 GMT 9.5
Okay, I'm approaching 1/4 of the way through the latest posted rev. Here's what I have so far:
p. 8: "Some reactors cool the metal tubes directly by using water and letting it boil in the reactor vessel, the boiling water reactor (BWR)."
The sentence fragment after the comma should be a separate sentence or follow a colon.
p. 8: "The most common reactor type today is the pressurized water reactor, (PWR) which keep the coolant pressure higher"
"keeps", not "keep".
p. 8: "Instead the coolant is pumped to another heat exchanger, that exchanges the heat from the heated reactor coolant to a water-steam side."
Awkward repetition of "exchange". Suggest "transfers" and replace "heated" with "hot".
p. 8: "These rods are filled with material that absorbs a lot of neutrons but doesn’t fission."
The reaction 11-B + n -> 3 α IS a fission reaction. It's just not one that generates neutrons.
p. 9: "And the higher everyone’s standard of living becomes, the more energy we require."
Strike "and" or use a comma splice.
p. 10: "Splitting an atom of uranium (in nuclear fuel) releases 50 million times more energy"
This "times more" construct is ambiguous and mis-used. "One times more" could be taken to mean 100% more (2 times), or no increase at all. I suggest a search for the phrase "times more" and replacing it with "times as much" wherever appropriate. Saying "50 million times as much" is not ambiguous.
Also, the factor of 50 million is by atom, not by weight. Uranium is about 20 times as massive as carbon, reducing the advantage to ~2.5 million by weight. It gets even weirder if you go by volume, but I think the public would grasp things better if you used a gram-to-gram comparison.
p. 10: "50 million times fewer atoms of uranium have to be mined"
"times fewer" has the same ambiguity problem as "times more", only worse. 50 million times fewer is arguably -49,999,999 times the original quantity, 8 orders of magnitude GREATER in magnitude but the opposite sign. Replace with "one 50-millionth as much", adjusted for mass vs. moles as appropriate.
p. 10: "The current commercial power reactors run on the U235 isotope."
Suggest "Current commercial power reactors run mainly on the U235 isotope" instead.
p. 10: "occurs only as 0.7% of the mined uranium" Suggest "natural uranium".
p. 11: "removing it from the ground will not rob animals or plants from any resources."
Awkward, and I think "rob" is too strong a word here. I'd write "does not compete with plants and animals for any resources." You might also add that uranium is present as a contaminant in most phosphate deposits, so it can be recovered as a byproduct of the production of phosphate which plants require.
p. 12: "the earth’s crust contains about 40 trillion tons of natural uranium."
A brief note about how many years of human energy consumption this represents would be helpful in bringing the issue home to the lay reader.
p. 13: A graph with no visible bar looks like a mistake. Try log scale?
p. 15: Ditto on the graph. Adding numbers to all the bars would help.
===================================================
And breaking here to post what I've got. I'll pick up again as I have time.
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Post by cyrilr on May 22, 2019 3:59:34 GMT 9.5
Thanks E-P. I'm very lucky to have you as my English spell checker!
The 11-B reaction isn't terribly relevant, it is the (n,a) reaction on 10-B that we're after with absorbers. 11-B is actually a pretty decent moderator like graphite.
I suppose you could think of the 10-B neutron-alpha reaction as fission, since the ejected alpha particle is so big relative to the lithium core left behind. I would consider it fission, but this might be confusing to the reader. Nuclear community usually considers it a (n,a) reaction not (n,f) so there's the consensus view. "doesn't fission" seems to work for intent, though perhaps "doesn't emit neutrons" is more scientifically pleasing. Please keep in mind my objective is not to please nuclear scientists.
40 trillion tons - that'd be what, 600 million years worth of today's consumption? I sort of go into nuclear fuel resources later so don't want to create contradictions here (I talk about 100 ppm being a reasonable minimum for LWRs, so "only" 2.2 billion tons).
Log scale - people don't seem to understand log scale. I sort of like the graph where there is a bar and one other smaller than a pixel so doesn't compute.
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Post by engineerpoet on May 22, 2019 6:13:03 GMT 9.5
The 11-B reaction isn't terribly relevant, it is the (n,a) reaction on 10-B that we're after with absorbers. 11-B is actually a pretty decent moderator like graphite. Still a fission reaction! 10-B (n,α) 7-Li is fission, just aneutronic. It's the absence of neutrons in the product which prevents both a chain reaction and neutron activation. I find that Google Translate is inadequate to reliably translate "you're welcome, friend" into Russian. The closest it comes is пожалуйста, друг which doesn't translate back to anything close to the original.
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Post by cyrilr on May 22, 2019 18:03:10 GMT 9.5
The problem about saying that 10-B (n,a) is fission is that it really disorients the reader. If alpha emission is fission, then why is uranium natural decay by alpha emission not fission? This is much too confusing to the reader. It would also go against much of the convention in cross section databases that list it as (n,a).
This is a very interesting subject, as is the helium pressure generated in the control rod tubes, but way too much detail for a public information doc. Probably I will write something like, "a material that absorbs but does not generate new neutrons". ? If people are interested enough to read more about this then the information document has done a swell job.
Russian is a fun language. Their word for feedwater (as in boiler feedwater) is nutritious water. Very funny. But I'm not Russian. Try Dutch. Next time you're in Amsterdam let me know, I'll buy you a couple beers!
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Post by engineerpoet on May 22, 2019 22:31:05 GMT 9.5
Travel to the low countries is not on my bucket list and I've had to give up beer for the sake of my waistline, but thanks for the offer.
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