Today I Learned

  • Thread starter Thread starter Greg Bernhardt
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Today I learned that cleaning a white hat can be done with bleach cleaner, but it’s important to rinse it before wearing it again. I also discovered that "oyster veneering," a woodworking technique from the late 1600s, is experiencing a minor revival despite its labor-intensive nature. Additionally, I learned that the factorial of 23 (23!) equals 25,852,016,738,884,976,640,000, which interestingly has 23 digits, a unique coincidence among factorials. I found out that medical specialists often spend less than 10 minutes with patients, and that watching TV can contribute to weight gain. Other insights included the fact that a kiss can transfer around 80 million microbes, and that bureaucracy can sometimes hinder employment opportunities. The discussion also touched on various trivia, such as the emotional sensitivity of barn owls and the complexities of gravitational lensing around black holes.
  • #931
Every time a man puts a new idea across he finds ten men who thought of it before he did -- but they only thought of it.
-- Anon.

it's men of action who make the world go...
 
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  • #932
jim hardy said:
it's men of action who make the world go...
The odds of fundraising and/or political connections might play a role as well.
 
  • #933
edward said:
Today I learned that a medical specialist will spend less than 10 minutes in the examination room with me. I also learned that after three minutes they start typing on the computer even if I am still talking. I did not learn if they can actually multitask.
Love the multi tasking observation, as in can they or not. Hilarious!
 
  • #934
Every time a man puts a new idea across he finds ten men who thought of it before he did -- but they only thought of it.
-- Anon.
Yeah, I was saying this exact same thing years before Anon was born.
 
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  • #935
Today I learned that the accident at Three Mile Island was due, in part, to a valve that was stuck open. The operators had no idea it was stuck open because they had an indicator light that they believed told them when it was open or closed. In fact, the indicator light only registered whether there was current or not to the solenoid that operated the valve. It did not occur to anyone until the next shift came on, that the solenoid could be energized without the valve having been closed by it, which, unfortunately, is exactly what had happened.

It was already known that these valves could get stuck open:
The Government Affairs Vice President confirmed that the Metropolitan Edison Company, which operated the company, had shortly before received a warning from the Nuclear Regulatory Commission (NRC) that Babcock & Wilcox reactor valves were vulnerable to failure under certain conditions. He said he had sent it on to the Vice President of Engineering, who confirmed that he had read it. Shortly after that, the two men met at the water cooler where the Government Affairs VP asked the Engineering VP a question. The Government Affairs VP remembered the question as "Is there a problem here?" The Engineering VP thought the question was "Have you solved the problem?" Both VPs agreed that the answer was "no." One walked away believing that the problem was solved. The other believed that he had informed his bosses that there was a problem.
-Wiki


 
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  • #936
zoobyshoe said:
The operators had no idea it was stuck open because they had an indicator light that they believed told them when it was open or closed.


I remember that morning well - it was really unnerving to hear of a plant in such trouble...
Soooo many confusing symptoms for those guys...
There's a temperature sensor downstream of that valve whose purpose is to detect hot fluid leaking past the valve.

The operators had not been trained to understand the ambiguous nature of the pilot-operated relief valve indicator and to look for alternative confirmation that the main relief valve was closed. There was a temperature indicator downstream of the pilot-operated relief valve in the tail pipe between the pilot-operated relief valve and the pressurizer that could have told them the valve was stuck open, by showing that the temperature in the tail pipe remained higher than it should have been had the pilot-operated relief valve been shut. This temperature indicator, however, was not part of the "safety grade" suite of indicators designed to be used after an incident, and the operators had not been trained to use it. Its location on the back of the desk also meant that it was effectively out of sight of the operators.
https://en.wikipedia.org/wiki/Three_Mile_Island_accident

You'd think, releasing 2250 psi/650 degree steam through the valve, it'd get pretty hot in the tailpipe downstream of the valve.
But steam cools when it throttles.
So with tailpipe temperature gauge showing not very hot it looked as if there wasn't flow,

which agreed with the valve's indicator light !


That's because of the the enthalpy curve for steam...
http://www.engineeringtoolbox.com/saturated-steam-properties-d_273.html
at 2250psi/650 degrees it's ~1114
at 15psi/250 degrees it's more , ~1164
so throttling 2250psi/650 degF steam to 15 psi you get a steam-water mix at ~250 degf

That modest temperature in the tailpipe wasn't thought unusual.

http://www.osti.gov/scitech/servlets/purl/5982361
upload_2016-1-17_5-37-49.png


Soooo many lessons were learned from that accident.
 
  • #937
So - communication failure by the VPs, failure to understand that the downstream sensor wouldn't respond as strongly to a valve failure as expected, a valve failure, user interface design failure and operator failure to put the signs together until shift change. Murphy was on top of his game that day, wasn't he?
 
  • #938
Ibix said:
Murphy was on top of his game that day, wasn't he?

There's a fascinating book i read over fifty years ago "Fate is the Hunter" by Ernest Gann.
He was a legendary airline pilot. The book is autobiographical . His investigations of airplane crashes point out that disasters always result from little insignificant things lining up like dominoes until some little something sets off a chain reaction. I believe that's how the small things of the Earth confound the mighty...

Murphy is an optimist. That's why a nuke plant is a good career for an OCD perfectionist .

https://en.wikipedia.org/wiki/Fate_Is_the_Hunter
it's still a good read
 
  • #939
Ibix said:
So - communication failure by the VPs, failure to understand that the downstream sensor wouldn't respond as strongly to a valve failure as expected, a valve failure, user interface design failure and operator failure to put the signs together until shift change. Murphy was on top of his game that day, wasn't he?
If one of those components would have been missing, we wouldn't have heard of it.

Anyway, 14 µSv additional dose on average - about the natural radiation everyone receives in two days, or the additional dose received from one hour of airplane flight.
Even if you add Chernobyl and Fukushima accidents and the normal operation, nuclear power leads to lower radiation doses released than coal power plants during normal operation.
 
  • #940
zoobyshoe said:
Today I learned that the accident at Three Mile Island ...
Shortly after I've seen a graffiti in a subway station here: "Chernobyl - Harrisburg 1:1"
 
  • #941
mfb said:
If one of those components would have been missing, we wouldn't have heard of it.
Indeed. I wasn't being down on them for failing to catch it (well, maybe the hidden warning light deserves a bit of a facepalm). One can always go back over any chain of events and find a point when someone could have averted the end, and I cannot claim any moral high ground here. :wink: It's just how bad their luck had to be to have so many opportunities go the wrong way.

It'd be interesting to know how many times they've added a page to The Book because of a situation like this that they caught versus the number of times they didn't catch it.
 
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  • #942
Ibix said:
Indeed. I wasn't being down on them for failing to catch it (well, maybe the hidden warning light deserves a bit of a facepalm). One can always go back over any chain of events and find a point when someone could have averted the end, and I cannot claim any moral high ground here. :wink: It's just how bad their luck had to be to have so many opportunities go the wrong way.

It'd be interesting to know how many times they've added a page to The Book because of a situation like this that they caught versus the number of times they didn't catch it.
In the section called "lessons learned" they introduce Charles Perrows concept of Normal Accident Theory. Clicking on that leads to an article entitled System Accident:

In a December 2012 article in a popular magazine, Charles Perrow writes, "A normal accident is where everyone tries very hard to play safe, but unexpected interaction of two or more failures (because of interactive complexity), causes a cascade of failures (because of tight coupling)."[3]

There is an aspect of an animal devouring its own tail, in that more formality and effort to get it exactly right can make the situation worse.[4] For example, the more organizational rigmarole involved in adjusting to changing conditions, the more employees will delay in reporting the changing conditions, and the more emphasis on formality, the less likely employees and managers will engage in real communication. New rules can actually make the situation worse, both by adding a new additional layer of complexity and by reminding employees yet again that they are not to think but are just to follow the rules.
Indeed, the trigger of the accident at Chernobyl was a scheduled test to determine if a safety feature was working.
 
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  • #943
jim hardy said:
Soooo many lessons were learned from that accident.
I'm sure. The problem is that the next big accident, Chernobyl, arose from a completely different "perfect storm" of minor glitches, and Fukushima was triggered by forces completely out of human hands.

Nuclear power plants are just one example of a complex system that's vulnerable to it's own complexity. The example that's really through the roof is the DoD budget:
https://www.physicsforums.com/threads/the-pentagons-doctored-ledgers-conceal-epic-waste.727651/
If you read the (unfortunately very long) article Greg linked to, you may come to the conclusion I did, which is that the problem there is completely unfixable.
 
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  • #944
What makes me angry about nuclear power plants is, that if you start to completely calculate total costs, i.e. costs for their wastes included, they immediately stop to deliver cheap energy. It's somehow unfair that profits go to the share holders and costs to the community. Am I the only one who sees this?
 
  • #945
mfb said:
Even if you add Chernobyl and Fukushima accidents and the normal operation, nuclear power leads to lower radiation doses released than coal power plants during normal operation.
I've never looked into radiation released by coal power plants, but, correct me if I'm wrong, I would assume the radiation they release is very much more spread out, and that the problem with nuclear accidents is how concentrated the released radiation is.
 
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  • #946
fresh_42 said:
What makes me angry about nuclear power plants is, that if you start to completely calculate total costs, i.e. costs for their wastes included, they immediately stop to deliver cheap energy. It's somehow unfair that profits go to the share holders and costs to the community. Am I the only one who sees this?
I haven't even looked into it. But on that subject, a nuclear accident must be astronomically expensive. You lose all the money put into building the affected reactor, you lose the revenue from the power it would have generated, and then you have to pour vast amounts into clean up and lawsuits. That has to affect the profitability of all the remaining nuclear power plants that didn't have big accidents. The radiation at Chernobyl is so bad they had to abandon the other three operational reactors there and stop work on the two more they had planned.
 
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  • #947
Yep. Uninsurable.
 
  • #948
fresh_42 said:
What makes me angry about nuclear power plants is, that if you start to completely calculate total costs, i.e. costs for their wastes included, they immediately stop to deliver cheap energy. It's somehow unfair that profits go to the share holders and costs to the community. Am I the only one who sees this?
Where are those costs not included? Every opponent of nuclear power makes sure they get overestimated as much as possible.
zoobyshoe said:
I've never looked into radiation released by coal power plants, but, correct me if I'm wrong, I would assume the radiation they release is very much more spread out, and that the problem with nuclear accidents is how concentrated the released radiation is.
There were two accidents where the radiation levels exceeded those from typical coal power plants. None of them were at a level where direct consequences (radiation sickness and similar) would be a problem for the population. That leaves the low-radiation dose effects, which are expected to be linear with dose. "Expected" because their effects are too small to be significantly notable in scientific studies.
The concentration makes bad PR, but it is actually helpful: in the extremely rare cases of accidents, you can move away. You cannot move away from coal power plants.

zoobyshoe said:
But on that subject, a nuclear accident must be astronomically expensive.
So are the total expenses coming from coal power plants. The costs are just more hidden. There are various estimates on lifes saved from using nuclear power instead of coal, but they are all in the range of millions (e.g. 1.8 millions here, http://pubs.giss.nasa.gov/docs/2013/2013_Kharecha_Hansen_1.pdf[/URL] and so on). There are attempts to put a [url=http://www.theglobalist.com/the-cost-of-a-human-life-statistically-speaking/]monetary value on human lifes[/url], typically around 5 millions. Multiply both together and nuclear power saved ten trillions, potentially tens of trillions, just based on the waste coal power plants that got avoided - several billions per operational power plant. That is not even including the CO2 emitted and its consequences!
Coal is by far the most expensive reliable source of power we have, if you include all the effects. But coal is the alternative to nuclear power today - shut down nuclear power plants and coal power plants appear.
 
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  • #949
mfb said:
There were two accidents where the radiation levels exceeded those from typical coal power plants. None of them were at a level where direct consequences (radiation sickness and similar) would be a problem for the population.
You mean Chernobyl and Fukushima?
That leaves the low-radiation dose effects, which are expected to be linear with dose. "Expected" because their effects are too small to be significantly notable in scientific studies.
The concentration makes bad PR, but it is actually helpful: in the extremely rare cases of accidents, you can move away. You cannot move away from coal power plants.
Why can't you move away from a coal plant?
So are the total expenses coming from coal power plants. The costs are just more hidden. There are various estimates on lifes saved from using nuclear power instead of coal, but they are all in the range of millions (e.g. 1.8 millions here, http://pubs.giss.nasa.gov/docs/2013/2013_Kharecha_Hansen_1.pdf[/URL] and so on). There are attempts to put a [URL='http://www.theglobalist.com/the-cost-of-a-human-life-statistically-speaking/']monetary value on human lifes[/URL], typically around 5 millions. Multiply both together and nuclear power saved ten trillions, potentially tens of trillions, just based on the waste coal power plants that got avoided - several billions per operational power plant. That is not even including the CO2 emitted and its consequences!
Coal is by far the most expensive reliable source of power we have, if you include all the effects. But coal is the alternative to nuclear power today - shut down nuclear power plants and coal power plants appear.[/QUOTE]
That pretty much supports what I was saying: a nuclear accident must be astronomically expensive. Your information makes it more so, since it means resorting to more expensive coal plants.
 
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  • #950
mfb said:
Where are those costs not included? Every opponent of nuclear power makes sure they get overestimated as much as possible.
You can't believe this. This is simply not true, and I wondered if you would not know. May I ask whether you receive money for making those funny statements? *)

Nobody on this planet can afford to a) build thousands of safe places for nuclear waste over and over again and b) guarantee to safely guard it for the next 40 billion years.
Nobody can afford to insure the risk of a major accident as it happened already twice in about 50 years since we started to use fission.
If you really price in these two factors of costs nuclear energy couldn't be afforded by anyone. These costs are simply spread over the entire community and over the forthcoming 50 billion years.

*) Arguments only hold in characteristic zero case with prime field ℚ.
 
  • #951
fresh_42 said:
Where are those costs not included? Every opponent of nuclear power makes sure they get overestimated as much as possible.
This is simply not true
Well, "every" is an exaggeration. Apart from that, it is true.
A typical example from Germany: We have a "Brennelementesteuer", a special tax specifically for fuel of nuclear power plants. This tax is included in the costs of nuclear power, although it is just a redistribution of money from the companies to the public. But it gets worse: some argue that the Brennelementesteuer could be higher, and then claim it would be a subsidy that the tax rate is not higher. This made-up subsidy is then also counted as cost of nuclear power.
Germany heavily subsidizes wind and solar power. Does this increase the cost of nuclear power? Obviously not, but someone found an argument for it: Mining and processing uranium and operating various systems in a nuclear power plant costs electricity, and those costs are taken from the German electricity mix, which includes wind and solar power. It also includes coal, which is then counted as CO2 emission from nuclear power.

If there is any possibility to add any amount of money to the cost of nuclear power, someone did that.
fresh_42 said:
Nobody on this planet can afford to a) build thousands of safe places for nuclear waste over and over again and b) guarantee to safely guard it for the next 40 billion years.
There is no need for either of them. Oh by the way, the Earth did a pretty good job of storing uranium for billions of years. Doing it even better than that is quite a high standard.
fresh_42 said:
Nobody can afford to insure the risk of a major accident as it happened already twice in about 50 years since we started to use fission.
This is not a problem of cost, it is a problem of scale and the unclear way to quantify a possible damage in money.
fresh_42 said:
If you really price in these two factors of costs nuclear energy couldn't be afforded by anyone.
Nuclear power saves lifes and health compared to fossile fuels. The cost is negative.
 
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  • #952
mfb said:
There were two accidents where the radiation levels exceeded those from typical coal power plants. None of them were at a level where direct consequences (radiation sickness and similar) would be a problem for the population.
I'd still like to know which two accidents you're referring to here.
 
  • #953
Sorry, missed your post. Chernobyl and Fukushima, sure.
zoobyshoe said:
Why can't you move away from a coal plant?
Take a map, draw 100 km circles around each coal power plant, and see what is left. Then draw 200 km circles and see what is left. Finally take the CO2, where the circle is the whole surface of Earth. You can move away from the direct neighborhood where you can paint your house every year, but the dirt of coal power plants gets spread over a large area.
 
  • #954
mfb said:
There were two accidents where the radiation levels exceeded those from typical coal power plants. None of them were at a level where direct consequences (radiation sickness and similar) would be a problem for the population.
mfb said:
Sorry, missed your post. Chernobyl and Fukushima, sure.
If you are saying that no one in the population around the plants died within a couple weeks like the nuclear workers did, then, yes. But since so many birth defects and cancers were directly caused by those accidents, it is not accurate to suggest they were consequence-free for the people in the vicinities. Those sites are poisoned in complex configurations, which is why they have to permanently evacuate large numbers of people. Simply being evacuated is a traumatic experience.

I'm getting my info from the wiki articles. Since this is such a controversial subject, I'm making the assumption that what's there has been batted back and forth enough times by editors on both sides of the issue that it's the safest to use as a reference.
 
  • #955
One of the most unusual, and rather ugly nuclear power reactor accidents I've read about... The SL-1.

A later investigation concluded that the 26,000-pound (12,000 kg) vessel had jumped 9 feet 1 inch (2.77 m) and the upper control rod drive mechanisms had struck the ceiling of the reactor building prior to settling back into its original location. The spray of water and steam knocked two operators onto the floor, killing one and severely injuring another. One of the shield plugs on top of the reactor vessel impaled the third man through his groin and exited his shoulder, pinning him to the ceiling.
 
  • #956
zoobyshoe said:
If you are saying that no one in the population around the plants died within a couple weeks like the nuclear workers did, then, yes. But since so many birth defects and cancers were directly caused by those accidents, it is not accurate to suggest they were consequence-free for the people in the vicinities. Those sites are poisoned in complex configurations, which is why they have to permanently evacuate large numbers of people. Simply being evacuated is a traumatic experience.
I did not say consequence-free. I said: at radiation levels where radiation influences are coming from low radiation doses, i. e. mainly a higher risk of cancer. Which makes it comparable to the effect of radiation from coal power plants (and radiation is by far not the worst product of coal power plants - but still more than from nuclear power).
 
  • #957
mfb said:
I did not say consequence-free. I said: at radiation levels where radiation influences are coming from low radiation doses, i. e. mainly a higher risk of cancer. Which makes it comparable to the effect of radiation from coal power plants (and radiation is by far not the worst product of coal power plants - but still more than from nuclear power).
Are you saying it was unnecessary to evacuate them?
 
  • #958
It was certainly necessary to do evacuations. I don't get it, what is your point with those questions?
 
  • #959
mfb said:
It was certainly necessary to do evacuations. I don't get it, what is your point with those questions?
You seem to be saying that, despite nuclear disasters, nuclear is overall safer than coal in terms of radiation. What's missing from that, in my understanding of the situation, is the fact that the after effects of nuclear disasters are mitigated by evacuating huge numbers of people, while no one gets evacuated from the vicinity of coal plants. In other words, it is not that radiation from nuclear disasters are slightly less bad than coal radiation, it is the fact special measures are taken after nuclear disasters that aren't taken with the much less concentrated ongoing coal radiation that skews the statistics. Local poisoning from radiation was much worse at Chernobyl and Fukushima than what those places received from coal radiation, therefore, evacuation was in order. Evacuation took place, and the natural consequences of the concentrated radiation was avoided.

Not that I'm a fan of coal at all. Coal is so bad for so many reasons it hardly constitutes a viable alternative to nuclear.
 
  • #960
Today I learned a huge difference between Russian and Hispanic cultures. In Russia, apparently, the expression, "Eff your mother!" is not an insult to the listening party, but an expression of general exasperation or surprise:

"Ivan Ivanovitch just found 4 bottles of vodka he forgot he had!"

"Eff your mother! Let's go visit him."

Or:

"Pavel Pavlovitch got fired!"

"Eff your mother! He owes me 30 rubles!"
 

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