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Japan Earthquake: nuclear plants

by gmax137
Tags: earthquake, japan, nuclear
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rhody
#1981
Mar29-11, 07:40 PM
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Quote Quote by Astronuc View Post
About 15 years ago, I met one to two guys who experienced glove box explosions while working with Pu. The accidents has happened in the 70's, and he was still doing well in the 90's. He had had glass and Pu solution embedded in his face, neck and chest. As far as I know he's still alive, but I'll have to check.
Astronuc,

If someone suspects they have inhaled plutonium, are there medical or radiological tests to confirm it ?

Rhody...
AtomicWombat
#1982
Mar29-11, 07:53 PM
P: 150
Michio Kaku trying to calm fears and reassure people:

http://www.youtube.com/watch?v=qdq4l...yer_detailpage
rhody
#1983
Mar29-11, 08:13 PM
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Quote Quote by AtomicWombat View Post
Michio Kaku trying to calm fears and reassure people:

http://www.youtube.com/watch?v=qdq4l...yer_detailpage
AW,

He stirs the masses and at the same time putting himself front and center... Wait, did I just say that !!! Doesn't he have a new book out as well, Wait, did I say that too !!!

Rhody...
Astronuc
#1984
Mar29-11, 08:33 PM
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Quote Quote by AtomicWombat View Post
Michio Kaku trying to calm fears and reassure people:

http://www.youtube.com/watch?v=qdq4l...yer_detailpage
If they abandon ship?!!! Free fall?!!!!

Um - we don't do that.


Incidentally from JNES BWR_Safety_Design
AntonL
#1985
Mar29-11, 09:29 PM
P: 521
KYODO 11:04 30 March
NEWS ADVISORY: Radioactive iodine 3,355 times legal limit found in seawater near plant

So the trenches are overflowing

for the past detailed seawater analysis up to 28 march can be found in this 15MB pdf file

and here are the latest results supporting the news advisory

and again Tc-99m 6 hour half life is detected - I hope measuring error
ailog
#1986
Mar29-11, 09:37 PM
P: 9
Any news on the fresh water that the US navy is/has barged to the site? Is it being put to use? I havn't seen anything about it recently.
Astronuc
#1987
Mar29-11, 09:48 PM
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From World Nuclear News:

A good description of the Fukushima event - http://www.world-nuclear.org/info/fu...nt_inf129.html

I've been wondering about the ground motion and accelerations. Apparently not all the data are collected and/or processed, but from WNN,

http://www.world-nuclear-news.org/RS...i_2303113.html
More detailed data of the ground acceleration rates caused by the magnitude 9.0 earthquake have also been made available by Tepco. Although not all the data has yet been collected, they record very powerful tremors that exceed the design basis in one dimension.

At Daiichi there is still no data for units 1, 2 and 5, but available figures put the maximum acceleration as 507 gal from east to west at unit 3. The design basis for this was 441 gal. Other readings were below design basis, although east-west readings at unit 6 of 431 gal approached the design basis of 448 gal.

At the Daini plant, ground accelerations ranged from 186 gal in the vertical plane at unit 1 to 277 gal from north to south at unit 3, as recorded by sensors in the reactor building foundation. The range of design basis figures is a spread from 415 gal to 512 gal.
No mention of unit 4.

From - http://www.world-nuclear.org/info/inf18.html
Japan's Nuclear & Industrial Safety Agency eventually declared the accident as Level 5 on INES scale - an accident with wider consequences, the same level as Three Mile Island in 1979. The design basis acceleration for both Fukushima plants had been upgraded in 2008, and is now quoted at horizontal 441-489 Gal for Daiichi and 415-434 Gal for Daini. The recorded data for Daiichi are still being analysed, but it appears that 507 Gal was the maximum for it, and 251 Gal for Daini. (Ground acceleration was around 2000 Gal a few kilometres north, on sediments.)
AntonL
#1988
Mar29-11, 11:35 PM
P: 521
New idea - wrap the structures in special cloth to filter radio-activity

I suppose Christo and Jeanne-Claude will be asked to help with the design - nobody more experienced.

From below info graphic:
But more important the highly radio-active water unit 2 to be shipped off-site - and then?



Quote Quote by www.asahi.com/special/10005/TKY201103290495.html (machine translated)
 Fukushima Daiichi nuclear power plant at TEPCO, 1,3,4 a rocket blew the building, Kan, the Cabinet is considering measures to prevent radioactive material dispersal of a special cloth to cover it. To ensure that working conditions for recovery and stable power supply to cool the reactors. Water pollution measures, including high levels of radioactivity leaking into the turbine building basement, is also out with a plan to collect contaminated water tankers. TEPCO has struggled to win work, they need to recognize more ambitious plans.
Yes a neat "out of the box idea" as an example of ambitious plan
Reno Deano
#1989
Mar29-11, 11:40 PM
P: 128
BWRs have an astounding number of penetrations (CRDMs and reactor instrumentation) coming through the bottom of the reactor vessel. A CRDM ejection is a remote possibility. But if the CRDM seismic supports failed, that could be the breach.
razzz
#1990
Mar30-11, 12:38 AM
P: 205
Quote Quote by Reno Deano View Post
BWRs have an astounding number of penetrations (CRDMs and reactor instrumentation) coming through the bottom of the reactor vessel. A CRDM ejection is a remote possibility. But if the CRDM seismic supports failed, that could be the breach.
Apparently a 'leaky loop' is acceptable in this design since avenues are built-in. Maybe the graphite rod don't morph into rough diamonds due to heat but their seals sure can fail.

Too bad now that it is a problem just trying to keep the working environment safe. The contaminated cooling water or seawater is of secondary importance whether it discharged into the Pacific or tanker ship, as trying to keep the hot spots cool and keep the cool spots from becoming hot spot is of utmost importance. Even if they can keep the situation static, it's a waiting game.

I'd probably be unloading the (slightly) off site major spent fuel pond and then unload unit 5&6 ponds getting ready for the day that unit 4 pond can be unloaded...I don't even know if these things are possible.
NUCENG
#1991
Mar30-11, 01:02 AM
Sci Advisor
P: 916
[QUOTE=|Fred;3218037]Thank you Nuceng and Cire for those anwsers, you mention that the drywell (primary containment in concrete if I'm not mistaken) Has been flooded. I've seen this "idea" on the paper writen by or for Areva.
But I haven't seen any statement , indications or explanation by the Japanese authorities or tepco that they did so ...
Is is a standard procedure ? how did they get some water there and when..


Early on TEPCO reports indicated that they were injecting seawater into the reactor pressure vessel. My Bad. I misremembered reading that they had been performing containment flood. However looking at the TEPCO updates since 11 March, I cannot confirm that. So my speculation of a steam explosion was invalid. However if melt-throu does occur, the interaction with containment concrete will be revealed by the activation and release of concrete materials.

I will do better job of checking my WAGs.
Gilles
#1992
Mar30-11, 01:53 AM
P: 30
Sorry, I come here only from time to time (plus jet lag ..) and I may have missed part of the discussion, but it seems that interesting observations can be done on these graphs

http://www.ic.unicamp.br/~stolfi/EXP...s/v8/Main.html

Obviously explosions happened after the sudden decrease of pressure in React 2 and 3, and most likely 1, probably to the voluntary depressurizing to allow water to flow in the reactor - releasing a huge amount of steam and hydrogen that had been produced very early after the failure of cooling systems. Then in R1 and 3, temperature remained very high (300 or 400 C) whereas the pressure was only a few bars -indicating that places where temperatures were measured were out of water, and overheated by fuel rods much hotter than the boiling point at this pressure. Probable oxidation and maybe fusion have occurred continuously then. Can it be that the vessels were totally dry at this time ? R2 was steadily around atmospheric pressure and 100 C - probably boiling water covering the fuel. Around the 20th of March a significative decrease of temperature occured. Is it due to the arrival of fresh water in the vessel - although no variation of water level was recorded, but may be they're measured in the confinement around the vessel - or may be to the melting of upper parts of fuel rods that gathered in the liquid phase, solidifying here ? A new rise of temperature in R2 these last days is worrying - does it mean that water is again very low ?
rmattila
#1993
Mar30-11, 01:57 AM
P: 242
[QUOTE=NUCENG;3218594]
Quote Quote by |Fred View Post
Thank you Nuceng and Cire for those anwsers, you mention that the drywell (primary containment in concrete if I'm not mistaken) Has been flooded. I've seen this "idea" on the paper writen by or for Areva.
But I haven't seen any statement , indications or explanation by the Japanese authorities or tepco that they did so ...
Is is a standard procedure ? how did they get some water there and when..


Early on TEPCO reports indicated that they were injecting seawater into the reactor pressure vessel. My Bad. I misremembered reading that they had been performing containment flood. However looking at the TEPCO updates since 11 March, I cannot confirm that. So my speculation of a steam explosion was invalid. However if melt-throu does occur, the interaction with containment concrete will be revealed by the activation and release of concrete materials.

I will do better job of checking my WAGs.
As far as I have followed the situation, in the early JAIF raports it was mentioned that water injection to core at all units was continuing, water injection to unit 1 containment vessel was "done", and to units 2-3 "to be decided".

In later JAIF reports, up until March 21, water injection to containment vessels 1 and 3 was reported to be "continuing (Seawater)", and for unit 2 "to be decided". On March 22, they changed the status to "confirming" on units 1 and 3 and "to be decided (Seawater)" on unit 2. On the latest releases, the status on units 1 and 3 containment vessel is stated as "to be confirmed".

Based on that mixed information, I'm not sure if anyone outside Tepco has an accurate idea whether water has so far been injected to any of the containment vessels on purpose. It seems that there has been a constant confusion of the terms "reactor pressure vessel" and "containment", with different combinations such as "core containment vessel" etc. being seen in different reports.
AntonL
#1994
Mar30-11, 02:31 AM
P: 521
Quote Quote by rmattila View Post
Based on that mixed information, I'm not sure if anyone outside Tepco has an accurate idea whether water has so far been injected to any of the containment vessels on purpose. It seems that there has been a constant confusion of the terms "reactor pressure vessel" and "containment", with different combinations such as "core containment vessel" etc. being seen in different reports.
Assuming that heat generated in reactor is only from residual heat from the decay of the isotopes, I have observed that water volume injected is 200% to 400% of water required to boil that heat away.

This leads me to conclude that the indicated flow rates are the combination of
1) Water injection into reactor vessel
2) Water spray in PCV to condense some of the steam generated

that could explain the huge amount of water now being leaked/released into the basements.

According to pressure readings released
reactor vessel: Unit 1 OK as >.3MPa_g high pressure Unit 2 & 3 breached zero and even negative

Primary Containment Vessel - all units OK as high pressure

leads me to believe a controlled discharge of water from PCV into the basement area - naughty naughty especially with below report from two days ago:
Quote Quote by AntonL View Post
Quote Quote by Originally Posted by //www3.nhk.or.jp/daily/english/28_19.html
Edano said he has received a report that the radioactive substances are assumed to be either condensed steam from the reactor containment vessel or radioactive substances diluted by the water released into those facilities as part of cooling efforts
"released into those facilities as part of cooling effort"
What does that mean !!
Surely they know the consequences !!
|Fred
#1995
Mar30-11, 03:06 AM
P: 312
You are in deed right "Water injection to Containment Vessel" is mentioned on the JAIF reports
http://www.jaif.or.jp/english/news_index.php

What is a bit misleading is that the status change from "done" to "confirm" to "to de decided" to "confirming" to "to be confirmed" etc.. in a confusing order as the status is present without logical link to past action like "to be confirmed" rather than "resuming to be confirmed"
|Fred
#1996
Mar30-11, 03:26 AM
P: 312
Analyse of the day
http://www.meti.go.jp/press/20110330...10330002-5.pdf
http://www.meti.go.jp/press/20110330...10330002-4.pdf

140La 8.1 10^-2 Bq/cm^3 .. 1.6 days half life ..
132Te 1.8 Bq/cm^3 ...
129Te 21 Bq/cm^3
129mTe 4.1Bq/cm^3
110mAg 3.6 10^-2 BQ/cm^3 They specify a half life of 250 days for this element , what deos "m" stand for Silver 110 half life is suppose to be a few seconds?
havemercy
#1997
Mar30-11, 03:36 AM
P: 21
According to french IRSN yesterday' release, the people in charge have put sand bags and concrete to prevent the water to flow from the Trench to the ocean :


http://www.irsn.fr/FR/Actualites_pre...032011-12h.pdf
AntonL
#1998
Mar30-11, 03:38 AM
P: 521
Quote Quote by |Fred View Post
Analyse of the day
http://www.meti.go.jp/press/20110330...10330002-5.pdf
http://www.meti.go.jp/press/20110330...10330002-4.pdf

140La 8.1 10^-2 Bq/cm^3 .. 1.6 days half life ..
132Te 1.8 Bq/cm^3 ...
129Te 21 Bq/cm^3
129?Te 4.1Bq/cm^3
As asked earlier:
Tc-99m 6 hour half life -


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