Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[KateB]

Cooling by latent heat of evaporating water is not a long term solution as
the steam has to go somewhere. If the reactors where running 80% capacity
at the time of the accident then the heat generated by the decay of the
fission products would be 3.9MW for unit 1 and 3.9MW for units 2 and 3 today
and reducing to 0.7 and 1.2MW in half a years time. External cooling by circulation
and heat exchanger is the only solution, and with all that salt ...

Post #1084 talks of the Marines having flat hoses/pumps that can collect freshwater from nearby lakes, would it also be plausible to use said pumps to get the water cycled in, out? In order to restore function to the cooling system(if repairable at all)? IF they could get enough pumps and hoses, could they conceivably pump water from the lakes in and pump the cycled water out, as a short term solution(or long term depending on the repairability of the cooling system) though awful in the long term, thinking of all that material hitting the sea...But the alternative is...
Also, would there be a way to cycle in boron through the hoses?

 

[AntonL]

ADDITIONAL INFORMATION ABOUT CONTAMINATED BASEMENT FLOODING

Source: http://www.world-nuclear-news.org/RS_Fukushima_Daiichi_two_weeks_on_2503111.html

QUOTING, IN PART:

"Investigations are now underway into the unexpectedly high level of contamination in the water, particularly as the basement of the turbine building is not a recognised radiation area. One theory is that there is a leak from the reactor circuit, but pressures in the reactor vessel indicate this must be elsewhere in the loop."

Added emphasis is my own. Elsewhere in the loop, indeed.

Basically if things go wrong in BWR NPP the complete site becomes a radiation site. you have pipes leading from the reactor carrying steam and returning water into the turbine building, scrubbers and heat exchangers. In a partially molten core and sea water coolant any breach of a pipe in the turbine building is a breach of the the reactor vessel to the outside. This is a big flaw in BWR design and after this accident all BWR in operation should be shut down.. Pressurized Water reactors have addressed this problem.

 

[|Fred]

Reactor 1's turbine building basement just got flooded with highly radioactive water just like n°3 did yesterday..
reported at 00:30 (Japan Standard Time) on the 26th of April

 

[AntonL]

Post #1084 talks of the Marines having flat hoses/pumps that can collect freshwater from nearby lakes, would it also be plausible to use said pumps to get the water cycled in, out? In order to restore function to the cooling system(if repairable at all)? IF they could get enough pumps and hoses, could they conceivably pump water from the lakes in and pump the cycled water out, as a short term solution(or long term depending on the repairability of the cooling system) though awful in the long term, thinking of all that material hitting the sea...But the alternative is...
Also, would there be a way to cycle in boron through the hoses?

Rethink your post http://www.nrc.gov/reading-rm/basic-ref/teachers/03.pdf" all the water that has been pumped into the reactors for the last 14 days has been boilded away, partly released to atmospher intentionally, partly unintenyionally and some condensed in the dry well and torus.

 

[Joe Neubarth]

Today is day 14 since the accident.

Google "Nuclear experts specialist fly to Japan" and nothing of relevance is returned.
Why has a international nuclear expert community not arrived in Japan, helping TEPCO
to analyze the data and brainstorm best actions.

I personally feel that Tepco engineers are overextended, paralyzed and firefighting,
instead of having a set clear path of action with small deviations to solve the problem.
The question now arises if nuclear reactor accidents should be co-managed internationally,
an new task for the United Nations as they are the only body to enforce this.

This accident will pose many questions. Such as why was the sea water injection allowed to
continue so long? To keep the reactors at constant temperature by latent heat of
evaporating water, would have by now consumed 7100m3 this is on average two 10T tanker
trucks every hour over the period - that is manageable. Now about 210 tonnes of salt is
distributed in 3 reactors.

This picture tells everything: Overwhelmed Tokyo Electric Power Company Managing Director
Akio Komiri cries as he leaves after a press conference in Fukushima (18/3/2011),
(and Japanese usually do not show emotion publically)

American nuclear experts were there on day three of the crisis. The news reports said that they were receiving regular briefings. That to me says they were being informed as to what the Japanese wanted them to know, BUT that their expertise was not being solicited or appreciated at that time. A couple of days later there was a news release showing that the Americans were working with the Japanese. What Japanese we do not know. Hopefully their contribution was not going for naught.

 

[Joe Neubarth]

Rethink your post http://www.nrc.gov/reading-rm/basic-ref/teachers/03.pdf" all the water that has been pumped into the reactors for the last 14 days has been boilded away, partly released to atmospher intentionally, partly unintenyionally and some condensed in the dry well and torus.

If the primary coolant loop is not leaking the only radioactive alternative is the condensation of radioactive steam. I think they have a primary leak and are not telling us all of the truth.

 

[TCups]

Breaking news: Reactor 1's turbine building basement just got flooded with highly radioactive water just like n°3 did yesterday..
reported at 00:30 (Japan Standard Time) on the 26th of April

Fred:

You left out Unit 2. See post #1176 and shadowncs's post a few earlier than that. I am glad to see I am not the only one having trouble keeping up

OOPS! Sorry Fred, post #1175 is the correct reference ()

 

[AntonL]

Breaking news: Reactor 1's turbine building basement just got flooded with highly radioactive water just like n°3 did yesterday..
reported at 00:30 (Japan Standard Time) on the 26th of April

Kyodo news article

http://english.kyodonews.jp/news/2011/03/81133.html"

does not make good reading

 

[Astronuc]

From what I understand, after the Spent rods are exposed and begin heating again, the addition of water could, in theory, instigate a recriticality. But it is a catch-22, because if you don't introduce water, then you could have an uncontrolled criticality/heating, that unchecked could become another source of worry, i.e. corium. It worried me that the water that was dumped from the Chinook obviously was sans Boron, as with it, the water is less a modulator and more a coolant. Correct me if I am wrong. Thanks for the great information, everyone.

Spent fuel generates heat from the decay of fission products. Some radionuclides decay in seconds, minutes, hours, days, . . . , but as time goes on the shorter half-life nuclides decay away rapidly leaving the longer half-life nuclides which decay more slowly. The decay process is ongoing, unlike the fission process, which can be 'shutoff' by making a system subcritical.

Water is a good conductor of heat, unlike steam or air which has low heat capacity (and low density) as well as low thermal conductivity.

Criticality is unlikely in the core assuming the control rods remain intact. The fuel could be damaged, but as long as the control rods remain inserted between the fuel assemblies, the core remains subcritical. Also, without water, the core would remain subcritical, since there is no moderation. Similarly, the SFPs should remain subcritical, by design, as long as the neutron absorbing material in the walls of the racks remains intact.

Dumping water from the air was pretty much ineffective. I think most of the water did not get to the SFPs, but rather sprayed onto the structures or otherwise outside of containment. It seems to me that the pilots did not understand the significance of what they were trying to accomplish. It's not like dropping water on a forest fire. The target of the water drop was very specific and very localized.

For a BWR SFP, boron in the water should not be necessary to achieve criticality. Unlike a PWR, BWRs do not use boron in the coolant because boiling normally occurs in the core, and the deposition of boron compounds on the fuel would be problematic from a reactivity control (power distribution) aspect.


Meanwhile - http://news.yahoo.com/s/ap/20110325/ap_on_bi_ge/as_japan_earthquake

The contaminated water outside of containment could be coming through the recirculation or feedwater system. The system normally collects water from the condenser, which comes after the turbine, or the reheaters which bleed off condensed steam (water) from the turbines, and pumps the water back to the reactor vessel.

The fuel does not have to melt for there to be fuel released from the cladding. An open crack can allow fuel particles to be collected in the coolant, which can there makes its way to any connected pipe, possibly into the feedwater system, which includes condensate polishers (filters).

The corrosion products, including Co, would indicate that water from the primary system is leaking outside of containment, possibly through the feedwater system or other ancillary systems.

 

[Borek]

Google "Nuclear experts specialist fly to Japan" and nothing of relevance is returned.

Try "Nuclear experts sent to Japan" then.

 

[TCups]

If the primary coolant loop is not leaking the only radioactive alternative is the condensation of radioactive steam. I think they have a primary leak and are not telling us all of the truth.

"They"? Most of us think "they" have a breech in containment. High level waste in the basements of Turbine Buildings doesn't happen normally. Do you mean, by "primary leak", a leak in the reactor vessel (RV) or a leak in the Primary (Drywall) containment, or both?

I think the information is fragmented, and understandably so, given the situation on the ground. This isn't TMI where there was only one reactor at risk, where reporters were camped out 24/7, where the surrounding infrastructure wasn't devastated, and where there wasn't a surrounding catastrophe of Biblical proportions surrounding the event, and completely independent of any reactor accident(s).

source: https://www.physicsforums.com/private.php?do=showpm&pmid=312554

A situation summary from the World Health Organisation put the death toll from the 11 March earthquake and tsunami at over 8800 confirmed dead with more than 12,600 still missing. More recent reports now put the cost at over 10,000 lives.

In total almost 320,000 people have been evacuated, with over 130,000 of these from Fukushima prefecture for reasons of both the tsunami and the nuclear emergency.

Over 220,000 homes are still without access to electricity, notwithstanding the non-operation of nuclear and fossil power plants. Gas supplies are disrupted to almost 440,000 homes. Some 1700 roads are damaged with many of these closed. More than 50 bridges are down.

There is a lot going on that "they" might not have told us yet, it is true. Concentrate on what we do know and let's not ascribe some malicious intent to any lack of information we on the net haven't been made privy to just yet.

 

[AntonL]

For a BWR SFP, boron in the water should not be necessary to achieve criticality. Unlike a PWR, BWRs do not use boron in the coolant because boiling normally occurs in the core, and the deposition of boron compounds on the fuel would be problematic from a reactivity control (power distribution) aspect.

For emergency Boron is injected into the BWR reactor, http://www.nrc.gov/reading-rm/basic-ref/teachers/03.pdf"

 

[Astronuc]

For emergency Boron is injected into the BWR reactor, http://www.nrc.gov/reading-rm/basic-ref/teachers/03.pdf"

Yes - only in an emergency! If the reactor was returned to operation, the entire primary system would have to be flushed.

Boron is not normally introduced into the primary coolant system, for the reason I stated above. Injecting borated coolant is extraordinary, and indicates a serious matter.

Injecting seawater and boron into the core, especially for days or weeks, pretty much means those units will never operate again - unless essentially the entire primary system is replaced.

 

[Gilles]

Gentlemen, I read that on a French forum

Regardez la video au dessus du reacteur N° 3 . A 0:30 secondes faites un arret sur image et vous verrez une lueur orange/rouge dans le tas de beton.
C'est le coeur du reacteur qui est à l'air libre et en fusion (Temp: à partir de 3000° et ça ne va pas refroidir avant des mois ou des années...)
Ces matieres en fusion (Corium) ont sans doute deja percé l'enceinte d'acier puisqu'on les voit et sont en train de percer la dalle beton de 6 ou 8 metres d'épaisseur.
Si jamais cette masse en fusion rencontre de l'eau = explosion (Craking de l'eau) et liberation de tres grosses quantités de matieres...
Donc on en est au meme stade tres grave qu'a Tchernobyl. Sauf que les charges radioactives de ces reacteurs là sont beaucoup plus
dangereuses et puissantes avec en plus du plutonium...et il y a 3 reacteurs HS au lieu d'1.
Bref, c'est pas fini cette histoire et je suis pessimiste pour l'avenir dans ce pays qui est minuscule...et tres peuplé. Pauvres gens et peut etre pauvres de nous...
J'espere me tromper mais cette lueur orange est edifiante...d'autant plus que les fumées viennent de là...

and now the translation (sorry for the possible broken English)

look at the video above the Reactor Nb 3. At 30 sec make a pause and you'll see an orange glow among the concrete heap.
It's the glowing core of the reactor, in free air and in fusion. (Temp> 3000 °C and it won't cool before months and years). This molten material (corium) has already come through the steel vessel since we can see it and is being piercing the 6-8 meters thick concrete slab. If this molten mass meets water - explosion (water cracking) and emission of large amounts of [radioactive] material.

So we're at the same very ominous stage as in Tchernobyl - except the RA loads are much more dangerous and powerful, with a lot of Pu , and with 3 reactors out of order instead of 1.
So this story is far from being over, and I am very pessimistic about the future of this tiny and overpopulated country. Poor people, and maybe poor us ...

I hope being wrong but this orange glow is telling .. and the smoke is coming from there..

and the screen shot

[PLAIN]http://www-laog.obs.ujf-grenoble.fr/~henri/Fukushima.gif

what's your opinion?

 

[AntonL]

Try "Nuclear experts sent to Japan" then.

I did and found this - US deploys two nuclear experts to Japan - You need a team, each assigned to subtasks, reactors, cooling, SFP, data collection etc etc

All I want to say is that nuclear accident management need to be rethought and taken out of the control of the operator. It would be of interest if the big nuclear nation have a national emergency manual that structures the accident management that takes immediate effect with military like precision.

 

[83729780]

for perspective: some good news:

Japanese authorities have informed the IAEA that on March 24, examinations of the thyroid glands in 66 children (14 of which are infants) were conducted near the evacuation area around the Fukushima nuclear plant. The exams were conducted at the Kawamata Town Health Center (40-50 kilometres from Fukushima Daiichi NPP) and Kawamata Town Yamakiya Branch Office (30-40 kilometres from Fukushima Daiichi NPP).

According to a 25 March 2011 Nuclear and Industrial Safety Agency press release, the results of the examinations indicated that the dose rate "of all the 66 children including 14 infants from 1 to 6 years old had no big difference from the level of background and was at the level of no problem in light of the view of Nuclear Safety Commission."

http://www.iaea.org/newscenter/news/tsunamiupdate01.html

Kawamata is about 40 km NW of the Daiichi plant.

These exams are done peripherally right? No direct examination of tissue?

 

[AntonL]

what's your opinion?

repeating what has been discussed her a week ago. old video

 

[Borek]

what's your opinion?

I see many other orange spots in the video.

 

[AntonL]

Yes - only in an emergency! If the reactor was returned to operation, the entire primary system would have to be flushed.

Boron is not normally introduced into the primary coolant system, for the reason I stated above. Injecting borated coolant is extraordinary, and indicates a serious matter.

Sorry - I misread you original mail

 

[Borek]

I did and found this - US deploys two nuclear experts to Japan - You need a team, each assigned to subtasks, reactors, cooling, SFP, data collection etc etc

Plus Russian, Korean, Ukrainian, EU and UN experts, check following pages.

But it is obvious that while these experts can try to help, locals have the best knowledge about the system and situation.

 

[TCups]

Gentlemen, I read that on a French forum



and now the translation (sorry for the possible broken English)


and the screen shot

[PLAIN]http://www-laog.obs.ujf-grenoble.fr/~henri/Fukushima.gif

what's your opinion?

How do you say "I very much doubt it." in French?

 

[|Fred]

"information irrationnelle délibérément mise en avant pour modeler une audience réceptive" ... Just an educated guess

 

[Joe Neubarth]

"They"? Most of us think "they" have a breech in containment. High level waste in the basements of Turbine Buildings doesn't happen normally. Do you mean, by "primary leak", a leak in the reactor vessel (RV) or a leak in the Primary (Drywall) containment, or both?

.

When I referred to PRIMARY COOLANT, I was writing about primary coolant which is a common term when referring to the coolant that passes through the reactor and is used as steam in the Boiling Water Reactor. Sorry if there was any misunderstanding. I have a tendency to use terms that originated with the pressurized water reactors that use a Steam Generator to create steam. That Loop of hot water, steam and condensate is usually referred to as the Secondary. I have heard technicians use PRIMARY for the water in the reactor loop even when it is a BWR. Perhaps another term is better?

 

[TCups]

"information irrationnelle délibérément mise en avant pour modeler une audience réceptive" ... Just an educated guess

The original video was over 9 minutes long and I have been through it almost frame by frame. I will have to look back when I have more time. The glowing red stuff did not appear to be in the region of the reactor. One new observation, though. Take a look at the long, rectangular box-like structures with rods sticking out the end . . .

hmmmm. . .

 

[Joe Neubarth]

how do you say "i very much doubt it." in french?

Oh Sheeeeeeet! What I see is a GLOW without smoke. How do you get a glow like that without smoke? I know that Blast Furnaces can get molten metal red hot, but that was not a blast furnace. How do we explain the red hot glow?

Fuel Rods can glow if they heat up enough, expecially if they are not sitting in a pool of water.

 

[TCups]

When I referred to PRIMARY COOLANT, I was writing about primary coolant which is a common term when referring to the coolant that passes through the reactor and is used as steam in the Boiling Water Reactor. Sorry if there was any misunderstanding. I have a tendency to use terms that originated with the pressurized water reactors that use a Steam Generator to create steam. That Loop of hot water, steam and condensate is usually referred to as the Secondary. I have heard technicians use PRIMARY for the water in the reactor loop even when it is a BWR. Perhaps another term is better?

Then, I, too believe there was a steam-like continuous leak of primary coolant from near the top of the primary (dry wall) containment going on for hours before the darker smoke started appearing. And this screen shot is taken near the top of the reactor containment atop Bldg 3.

If so, it does not necessarily mean a complete melt down of the core with breech of the reactor vessel (at least at the time of the photo), and does not preclude leakage of highly contaminated water from the plumbing circulating in the basement of Turbine Bldg 3, either.

 

[Astronuc]

I did and found this - US deploys two nuclear experts to Japan - You need a team, each assigned to subtasks, reactors, cooling, SFP, data collection etc etc

All I want to say is that nuclear accident management need to be rethought and taken out of the control of the operator. It would be of interest if the big nuclear nation have a national emergency manual that structures the accident management that takes immediate effect with military like precision.

Yes - there needs to be a team of experts, but considering that this event is unprecedented, at least by scale, for an LWR, there will be no experts with direct experience. The event is well beyond design basis, so there could be no plan.

One outcome of the Fukushima accident will be a re-assessment of how a utility responds to such an event (multiple failures), particularly at multi-site plants.

US utilities (especially those with BWRs with Mk I containment) began reviews of their plant designs and emergency operating procedures (EOPs), within a couple of days of the event. They did not wait to be told by the NRC or INPO.


It is worrisome that the utility had to resort to water canons and air drops (mostly ineffective) to ensure water in the SFPs. The reactor damage is much more complicated, because most of the potential damage is inaccessible within containment, especially when they have core damage and contamination of the containment systems.

 

[AntonL]

Kyodo news article

http://english.kyodonews.jp/news/2011/03/81133.html"

does not make good reading

However, water is found in the basements of all 4 reactors, if the basement are linked via cable tunnels then it could be a common source of water.

 

[jensjakob]

Reactor 1's turbine building basement just got flooded with highly radioactive water just like n°3 did yesterday..
reported at 00:30 (Japan Standard Time) on the 26th of April

Source? Link? Please add verifiable source on all such statements,

 

[M. Bachmeier]

Oh Sheeeeeeet! What I see is a GLOW without smoke. How do you get a glow like that without smoke. I know that Blast Furnaces can get molten metal red hot, but that was not a blast furnace. How do we explain the red hot glow?

Please note Joe your post was different "Oh Sheeeeet " only when I choose to quote it.

If I didn't think it would upset a lot of people right now, I would crack a joke because many of us are getting more serious and agitated then we should be. Newcomers aren't the only one's that are starting to jump at ghosts.

It seems to me that speculation is starting to be speculated upon and that media information(re: speculation) (even from credible sources) is being re-posted as if it is current information.

My suggestion is that when posting information or a link to that information you include a date when that information was made available to the public. I've encountered a number of posts that imply new information that is in fact dated.

Given the size of this particular thread people are unlikely to attempt to read all previous posts.