Emergency Core Cooling of PWR

  • Thread starter Muti
  • Start date
  • #26
Hiddencamper, thanks for such detailed information.
 
  • Like
Likes Hiddencamper
  • #27
1,753
819
Just to amplify HiddenCamper's "wall of text" here's an estimate of 35 million dollars per unit:
http://[url [Broken][/url]

That's alot of money, I try to think of the customers scraping together their electric bill every month. Now imagine you spend that and then the regulator says "nice try but not exactly what we had in mind..."

In a rational world, the plant owners would figure out what needs to be done to prevent their plant from being destroyed like F-D and then they would do that, in their own self-interest if nothing else. But the world isn't entirely rational, it's regulated and that doesn't always lead to the optimum approach.
 
Last edited by a moderator:
  • Like
Likes QuantumPion
  • #28
In a rational world, the plant owners would figure out what needs to be done to prevent their plant from being destroyed like F-D and then they would do that, in their own self-interest if nothing else.
We now have empirical evidence that they won't do that: when disaster is (or perceived to be) very rare, managers tend to just hope it won't hit *them*.

In more details: managers who bug their superiors with suggestions a-la "let's spend $10 million implementing such and such safety measure, I think it's worth it" get sidelined by managers who don't commit the ultimate crime of hurting the bottom line. So the second type rises on the ladder faster.

Then, BOOM.
 
  • #29
jim hardy
Science Advisor
Gold Member
2019 Award
Dearly Missed
9,839
4,875
It is a social problem, as you say.

I have more faith in executives. Their problem is all the management apples in the bowl turn their bright side up, so from above it's hard to tell them apart.
The game is played thus : One group's job is to play "What If" and the other's job is to find a scientific basis to dismiss the "What If"'s. They exchange memos endlessly.
If after enough memos it can't be dismissed it gets acted on.
Mother Nature doesn't read their memos.

I reiterate my opinion - had some lowly workingman presented TEPCO's CEO with the fact that geologists found historical evidence of "recent" tidal waves way bigger than design basis, said CEO would have got somebody working on it.
 
  • #30
etudiant
Gold Member
1,197
114
The problem is that within the Japanese culture, the opportunity for a 'lowly workingman' to actually make a presentation to the CEO was and is nil.
We have the same weakness here, just consider the recent financial meltdown. Lots of people knew, none were able to reach decision makers and persuade them to act.
 
  • #31
mheslep
Gold Member
311
728
In a rational world, the plant owners would figure out what needs to be done to prevent their plant from being destroyed like F-D and then they would do that, in their own self-interest if nothing else.
If you mean only a rational economic choice, plant owners with ~ten years of life left (over the NRC's ten year decision to implement flex) might do an actuarial analysis of the risk of an F-D event versus the cost of the upgrade and simply ride out the last ten years.
 
  • #32
1,753
819
If you mean only a rational economic choice, plant owners with ~ten years of life left (over the NRC's ten year decision to implement flex) might do an actuarial analysis of the risk of an F-D event versus the cost of the upgrade and simply ride out the last ten years.
Maybe. Do you see that as inappropriate? Do you think the 35 million dollars is well-spent if the plant is closing in 10 years? How about 5 years? Next summer? Next month? Tomorrow? Somewhere along that spectrum the answer is clearly that the money is better spent on other endeavors. So I dont see anything wrong with the concept.

My point was really that the delay in implementing the "fixes" is due to the need for NRC review & approval; or more accurately, it is due to the unwillingness of the licensees to shoulder the financial risk that the NRC might ultimately not approve any fixes implemented prior to approval. That's a learned behavior, something the licensees have learned over the past 50 years of regulation.

Finally, don't forget that the FLEX approach was developed and proposed by the licensees/NEI, it was not the NRC's idea. The plant owners thought it would be more timely & less uncertain if they went ahead and proposed an approach, rather than waiting for the NRC to put forth new requirements (as happened following TMI). Anyone who thinks 3 1/2 years is too long should consider how much longer it could have been had the licensees simply sat back and waited for new rules. I was working on resolution of NUREG-0737 items throughout the 1980s, that's up to ten years after TMI. Though most of the plant modifications were done in 1985 - 1987, that is still 7 years.
 
Last edited:
  • #33
I reiterate my opinion - had some lowly workingman presented TEPCO's CEO with the fact that geologists found historical evidence of "recent" tidal waves way bigger than design basis, said CEO would have got somebody working on it.
I don't think so. Why? Because any Japanese CEO himself should feel that "max tsunami height is below 6 meters" has to be a lie.

Even a cursory read of the tsunami history of Japan shows that 10 meter tsunamis are not unusual, 20 and even 30 meter ones happened about once in a century. Granted, *I* did not know this before Fukushima, but I don't live in Japan.

I cannot imagine that an educated Japanese wouldn't know how high tsunamis in Japan can reasonably be.
 
  • #34
Maybe. Do you see that as inappropriate? Do you think the 35 million dollars is well-spent if the plant is closing in 10 years?
The plant makes something like one billion dollars per year. So, yes, spending ~4% of that sum is okay.

My point was really that the delay in implementing the "fixes" is due to the need for NRC review & approval
Can NRC at least try to move faster than glacial speed? (Cynic in me says "no, it can't. It's a bureaucracy").
 
  • #35
1,753
819
The plant makes something like one billion dollars per year.
Where did you get that idea? I don't know what the long-term contract cost of a MW-hr is but I would guess that $30 is about right. At 9 million MW-hr per year, and say $30 per MW-hr the revenue is one-quarter of that.

By the way, I too believe that the FLEX fixes are justified for a plant with ten years of life left. On the other hand, I would not think the same for a plant with a few months left. The point is, there is a rationale for doing a risk-based analysis before spending the resources on fixes.

Can NRC at least try to move faster than glacial speed? (Cynic in me says "no, it can't. It's a bureaucracy").
Here's where we agree: it would be better (much better) if they could move faster. But I dont think they can. See Hiddencamper's post above. Read through some of the stuff churned out by the NRC. Hundreds of pages of mind-numbing development of "frameworks" for further study.
 
  • #36
jim hardy
Science Advisor
Gold Member
2019 Award
Dearly Missed
9,839
4,875
Granted, *I* did not know this before Fukushima, but I don't live in Japan.
Well you made me think with that one.
I didn't know it either.
And i never considered that somebody living there might be better aware of local natural history than i.

[PLAIN said:
http://carnegieendowment.org/files/fukushima.pdf][/PLAIN] [Broken]
First, there appears to have been insufficient attention given by TEPCO and
NISA to historical evidence of large earthquakes and tsunamis. Best practice, as
promulgated by the IAEA, requires the collection of data on prehistorical and
historical earthquakes and tsunamis in the region of a nuclear power plant in
order to protect the plant against rare extreme seismic events that may occur
only once every ten thousand years.
36
Historical data was used in assessing plant
safety. The original design-basis tsunami for Fukushima Daiichi of 3.1 meters
was chosen because a 1960 earthquake off the coast of Chile created a tsunami
of that height on the Fukushima coast.
37
However, greater attention should have
been paid to evidence from further back in history. Over the last decade or so,

12
|
Why Fukushima Was Preventable

Historical data was used in assessing plant
safety. The original design-basis tsunami for Fukushima Daiichi of 3.1 meters
was chosen because a 1960 earthquake off the coast of Chile created a tsunami
of that height on the Fukushima coast. 37 However, greater attention should have
been paid to evidence from further back in history. Over the last decade or so,
evidence of much larger tsunamis in and around Miyagi has emerged. Japanese
researchers have discovered layers of sediment that appear to have been depos-
ited by tsunamis and have concluded that the region had been inundated by
massive tsunamis about once every one thousand years. 38
They have attributed
the most recent of these events—in 869 AD—to a magnitude 8.3 earthquake.
More generally, given the historical record of tsunamis in Japan, TEPCO and
NISA should have been much more conservative in defining the design-basis
tsunami. For instance, one compilation of historical tsunamis in and around
Japan lists twelve events since 1498 having a maximum amplitude of more than
10 meters, six of which had a maximum amplitude of over 20 meters. 39

Of course, such “red flags” are much easier to spot with the benefit of hind-
sight than they are ahead of a disaster. The challenge of sifting through and
evaluating the stream of potentially relevant geophysical studies to extract
data important to nuclear power plant safety should not be underestimated.
Perhaps not surprisingly, there has been a fairly bitter debate within Japan
about whether academia did not provide suitable warnings or whether it did
and industry and regulators ignored them.
Nonetheless, Japan has a historical
legacy of severe tsunamis; it does appear that heeding this record, especially
as it relates to the area around the plant, would have led to an upward revision
of the design basis
for Fukushima Daiichi Nuclear Power Station and perhaps
consequently to infrastructural improvements to better defend the installation.
As i said, such things are debated within the bureaucracy by endless memos ( See Parkinson's "Law of Delay", chapter "The Paper Blob").
You blame the executives, i blame the bureaucrats.

I say "to-may-to", you say "to-mah-to" ? :)

old jim
 
Last edited by a moderator:
  • #38
Where did you get that idea? I don't know what the long-term contract cost of a MW-hr is but I would guess that $30 is about right. At 9 million MW-hr per year, and say $30 per MW-hr the revenue is one-quarter of that.
So the four-unit station makes about one billion $.

Regarding revenue-versus-profit:

IIRC for nuclear stations, fuel and maintenance are relatively small fraction (10-20%) of their revenue - the biggest expenses are in initial planning and construction stages. Please correct me if I'm wrong.
 
  • #39
jim hardy
Science Advisor
Gold Member
2019 Award
Dearly Missed
9,839
4,875
Interest is a lot of that cost.

Way back when, my old plant that cost only $120 million to build could produce power for two-ish cents a KWH , half what a billion dollar plant of similar capacity could do just a few years later .
Back then a kwh was only a nickel retail .
By contrast - my Father-in-law's refractory plant in Niagara Falls was buying that wonderful hydro power for 1/10 cent per kwh, around half our nuclear fuel cost at the time.
Nothing beats hydro. Its advantage over wind is it's concentrated.
US side of Niagara Falls is about 2.4 gigawatts . see http://www.nypa.gov/facilities/niagara.htm
That's equivalent to thousands of windmills and it's way more reliable. Cost per kw to build wind is , well, beyond reason IMHO. The industry exists because of tax credits.
But , every KWH that's made by a windmill is one pound of coal that doesn't have to be dug out of the ground. (For a realistic peek into a coal mine see movie "October Sky" * .


In mid 70's when the low grade fuel oil that our fossil plants burned went from $4 to $12 a barrel the fuel cost differential suddenly became substantial. .
Energy companies then got into the uranium business. We had some Exxon fuel assemblies.
[PLAIN said:
http://www.nytimes.com/1986/12/24/business/company-news-exxon-plans-sale-of-nuclear-unit.html]Exxon[/PLAIN] [Broken] Nuclear, founded by the world's largest oil company in 1969, designs, manufactures and markets pressurized and boiling-water reactor fuels and provides related services for electric utilities.
At today's oil prices we can thank the Lord for natural gas. It burns a lot cleaner, too. Much as i dislike coal fuel I'd hate to see it go away - we just dont have a viable replacement for it. Just the electricity to heat a hundred million twenty gallon hot showers in the morning amounts to miles of coal cars..... i once calculated how many but have since forgot. Try it - 100 tons of coal in a car, 10,000 BTU's per pound of coal, 40% efficient power plant, shower water gets40 degree rise ...


Nuke fuel will continue be priced just enough below fossil to keep both viable.
http://www.world-nuclear-news.org/ee-double_nuclear_by_2040_says_exxon-1309138.html
Exxon Mobil's figures spurred a lively and wide-ranging debate amongst Khemakhem's fellow speakers in a panel discussion on energy and nuclear power. Ron Cameron, head of nuclear development at the OECD Nuclear Energy Agency (NEA), led a call for greater transparency over prices across the energy sector. Growth in renewables of the scale seen in recent years had been made possible through subsidies, but the way subsidies had been handled in some countries had been an "economic disaster", he said. Consumers were effectively being asked to pay for the transition into renewables, he said, pleading for the hidden costs of renewables to be made clear, with no disconnect between wholesale cost of electricity and the price. "Affordability is an issue," he remarked.

Nuclear should be seen as complementary to rather than in competition with renewables, the panellists felt. Nuclear could play a vital role in providing affordable baseload power to support the intermittent nature of many renewables,
Sorry - i got off topic.

old jim

* re October Sky - The movie is interesting, suitable for kids., Chris Cooper and Laura Dern deliver their usual great performances, and best of all it shows up in Walmart's $5 pile.

Coal railcar metrics here http://www.bnsf.com/customers/equipment/coal-cars/
 
Last edited by a moderator:
  • #40
55
7
Interest is a lot of that cost.

Way back when, my old plant that cost only $120 million to build could produce power for two-ish cents a KWH , half what a billion dollar plant of similar capacity could do just a few years later .
Well the topic moved to another dimension but I too have my point of view about this. Soon after F-D accident we heard term like "stress test" and most plants spared a group of their manpower for strengthening some post Fukushima weaknesses in their plants. I found most of their recommendations something like "last deperate efforts after some unforeseen accident" (maybe these peoples have refined now...). Do some other person too feel like this? or these things are helpful?
 
  • #41
Astronuc
Staff Emeritus
Science Advisor
18,821
2,009
Well the topic moved to another dimension but I too have my point of view about this. Soon after F-D accident we heard term like "stress test" and most plants spared a group of their manpower for strengthening some post Fukushima weaknesses in their plants. I found most of their recommendations something like "last deperate efforts after some unforeseen accident" (maybe these peoples have refined now...). Do some other person too feel like this? or these things are helpful?
NPPs have routine testing procedures. Following an event like the failure at FD, testing may be revised, and "stress tests" may be devised to discover deficiencies in the design or operation. Severe accident mitigation guidelines may be found to be satisfactory, or maybe found to be deficient. Ostensibly, deficiencies are corrected through new infrastructure and/or operating procedures.

Clearly, FD was not prepared for the magnitude of the tsunami that took out the emergency equipment (DGs and buses). In fact, much of the coastline was not prepared based on the videos of whole villages and towns being overwhelmed. Very little of the coastline was protected, but clearly some places were. It's certainly tragic the FD was not better protected.
 

Related Threads on Emergency Core Cooling of PWR

Replies
8
Views
2K
  • Last Post
Replies
2
Views
2K
Replies
0
Views
867
Replies
2
Views
1K
  • Last Post
Replies
2
Views
3K
Replies
3
Views
2K
  • Last Post
Replies
4
Views
4K
Replies
5
Views
5K
  • Last Post
Replies
4
Views
4K
Replies
3
Views
947
Top