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Japan Earthquake: nuclear plants

by gmax137
Tags: earthquake, japan, nuclear
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Astronuc
#3205
Apr7-11, 10:15 AM
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Quote Quote by WhoWee View Post
Has the required (replacement) flow rate of water been posted?
Not that I'm aware of.


Regarding the Mag 7.1 (revised down from 7.4) which just happened of the coast near Sendai, there is concern about additional damage to FK units.
rasherz
#3206
Apr7-11, 10:27 AM
P: 8
TEPCO has stated that there has been no additional damage, sorry no link, it was just on Japanese TV. Still waiting to see if there is a tsunami though.
jensjakob
#3207
Apr7-11, 10:33 AM
P: 123
<sarcasm>Wouldnt TEPCO report that?</sarcasm>

Seriously - TEPCO has no possible way to state anything about the effect of the quake, since they dont have access to large parts of the plant due to radiation.

They can claim "Not identified any immediate damage in the areas that we can monitor".

But it is not valid to say "no additional damage", sorry
StrangeBeauty
#3208
Apr7-11, 10:34 AM
P: 61
USGS has it as a 7.1 so far (this can change as they get more data)
http://earthquake.usgs.gov/earthquak...usc0002ksa.php

Depth was 30 mi. which is deeper than the 9.0 quake (19.9 mi).

Tsunami warning center here:
http://ptwc.weather.gov/ptwc/?region...1.04.07.143955
Taxidermista
#3209
Apr7-11, 10:34 AM
P: 3
This last 7.1 quake happened only 12 miles away from Onagawa nuclear plant.

7.1 2011/04/07 14:32:42 38.253 141.640 49.0 NEAR THE EAST COAST OF HONSHU, JAPAN

NISA: Onagawa Nuclear Power Plant started emergency power generator, 1 external power-line left, so continue to cooling the fuel rod down
tsutsuji
#3210
Apr7-11, 10:43 AM
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Quote Quote by TCups View Post
Hope someone can find the live Fukushima video of the current 7.4 quake and tsunami expected to hit about now.
If such a video exists, it must be quite dark, because it is in the middle of the night.

Quote Quote by Taxidermista View Post
This last 7.1 quake happened only 12 miles away from Onagawa nuclear plant.

7.1 2011/04/07 14:32:42 38.253 141.640 49.0 NEAR THE EAST COAST OF HONSHU, JAPAN

NISA: Onagawa Nuclear Power Plant started emergency power generator, 1 external power-line left, so continue to cooling the fuel rod down
The radioactivity monitoring at http://www.tohoku-epco.co.jp/electr/...nagawa/mp.html seems to be OK by now.
Jorge Stolfi
#3211
Apr7-11, 11:28 AM
P: 279
Quote Quote by artax View Post
good work
Beware that there is an artificial earth bank (and possibly some low hills) just west of the plant. Depending on the viewpoint, the bank will hide the lower half of the reactor buildings.
ivars
#3212
Apr7-11, 11:33 AM
P: 16
I predicted such larger late aftershocks may come here, on March 27th:

Potential late 7-8,5 aftershocks to 9.0 Quake

And this may be not the last, but first, and not the biggest one.
Jorge Stolfi
#3213
Apr7-11, 11:43 AM
P: 279
Quote Quote by NUCENG View Post
Your scenario has three complications.
I have been almost entirely convinced that those straight tubes are not fuel rods.

Wiring or fluid ducts seem unlikely: ripping them off the walls/ceiling should have bent them at the attachment points. (As for loose spare ducts, why keep them on the working floor?)

Someone claimed they look like neutron-measuring instrumentation tubes; I suppose that is it.
Joe Neubarth
#3214
Apr7-11, 11:47 AM
P: 238
Quote Quote by Taxidermista View Post
This last 7.1 quake happened only 12 miles away from Onagawa nuclear plant.

7.1 2011/04/07 14:32:42 38.253 141.640 49.0 NEAR THE EAST COAST OF HONSHU, JAPAN

NISA: Onagawa Nuclear Power Plant started emergency power generator, 1 external power-line left, so continue to cooling the fuel rod down
41 miles out to sea from Sendai.
Joe Neubarth
#3215
Apr7-11, 11:52 AM
P: 238
Quote Quote by jensjakob View Post
<sarcasm>Wouldnt TEPCO report that?</sarcasm>

Seriously - TEPCO has no possible way to state anything about the effect of the quake, since they dont have access to large parts of the plant due to radiation.

They can claim "Not identified any immediate damage in the areas that we can monitor".

But it is not valid to say "no additional damage", sorry
It was 40 miles closer than the 9.0 quake. Allowing for attenuation of the shockwaves from the epicenter, it should not have done much damage to intact structures. The non-intact structures are what we need to worry about if we are prone to worry.
flyingblind
#3216
Apr7-11, 12:53 PM
P: 7
Quote Quote by georgiworld View Post
Thank you for the great, well-organized site. Are you the author?
Author No.
shogun338
#3217
Apr7-11, 01:31 PM
P: 133
Thats the last thing they need is for another plant to have cooling failure . Two out of three external power lines to the Onagawa nuclear power plant, 75 miles northeast of Fukushima and near the epicenter of Thursday's temblor, have been damaged, causing power loss. The plant, operated by Tohoku Electric Power, has been shut down since the March 11 quake and has been relying on external power to cool the reactors. Japanís Atomic Energy Agency said the two lost power lines were not being used for cooling when tonightís earthquake hit.
http://www.csmonitor.com/World/Asia-...hima-evacuated
shogun338
#3218
Apr7-11, 01:35 PM
P: 133
Toshiba Corp submitted a proposal to Tokyo Electric Power Co and the Ministry of Economy, Trade and Industry to dismantle the damaged Fukushima Daiichi nuclear power plant by 2020 http://www.reuters.com/article/2011/...7F73E720110407
Sirius (b)
#3219
Apr7-11, 01:49 PM
P: 13
Greetings everyone.

Here's the EQ information: http://quakes.globalincidentmap.com/; http://earthquake.usgs.gov/earthquak...uakes_all.html & http://geofon.gfz-potsdam.de/eqinfo/list.php

And this is a result of a FOIA to NRC: http://fukushimafaq.wikispaces.com/f...+26march11.pdf

This report was quoted in the NYT article, but we have more details now,

On Unit 3:
Primary Containment
Damage suspected (NISA, TEPCO) "Not damaged" (JAIF 10:003/25); Fuel pool is heating up but is adequately cooled, and fuel may have been ejected from the pool
(based on information from TEPCO of neutron sources found up to 1 mile from the units, and
very high dose rate material that had to be bulldozed over between Units 3 and 4. It is also
possible the material could have come from Unit 4);


ASSUMPTIONS: Rad Levels: DW 5100 R/hr, torus 150 R/hr (Industry); 100 R/hr debris outside Rx
building (covered).
SNF pool in number 3 is not the only worry that should captivate you, there's been a steam/thermal explosion in RPV, top of PCV breach with some of the debris landing SW of Unit 3-4 - where 3 out of 5 soil samples had been taken, contained pu- isotopes - http://www.tepco.co.jp/cc/press/betu...es/110328n.pdf



Added: Unit 3 thermal imagery, March 20th, 2011, looking West:
ivars
#3220
Apr7-11, 01:53 PM
P: 16
Many nuclear facilities have lost onsite or off-site power.

Consequences of 7.1. quake-IAEA

Onagawa Nuclear Power Plant:

NISA has confirmed that two out of the three lines supplying off-site power to the site were lost following the 7 April earthquake. Off-site power continues to be supplied through the third line.

Cooling of the spent fuel pool was temporarily lost, but has subsequently been restored.

Higashidori Nuclear Power Plant

NISA has confirmed that the Higashidori NPP was shutdown and in a maintenance outage at the time of the 7 April earthquake. Off-site power has been lost. Emergency power supply to the site is operating.

Rokkasho Reprocessing Plant

NISA confirms that Rokkasho Reprocessing Plant and uranium enrichment facility lost off-site power. Emergency power supply to the site is operating.

Now all what is needed is another aftershock of size >M7 to knock emergency power supply out.
rmattila
#3221
Apr7-11, 01:54 PM
P: 242
Not being familiar with the GE ECCS & MCP design, I have some worries about the status of the core cooling:

if the route through which water is being injected to the core is such that the flow either goes entirely through the feedwater nozzles or is divided between the core spray and the feedwater route, then it might be possible that
  • the core spray nozzles have been clogged due to prolonged use of seawater (impurities, salt deposits)
  • the water goes mainly or entirely to the downcomer, not on top of the core
  • furthermore, if the main circulation loops have developed leaks, water will escape from the bottom of the downcomer to the recirculation loops and then to the leak

Adding to this the (i presume by now ascertained) fact that the level measurement monitors the level in the downcomer, not in the core, and the possibility that at least the upper temperature measurement monitors the temperature of the core vessel close to the feedwater inlet (=area affected by the inflow through feedwater lines), this currently leaves us very little on which to base estimates on the state of the cores. As I see it, it could be that only a little part (if any) of the water injected in the reactor vessel actually ends up cooling the core.

Based on the above guesses (I repeat that I really don't know the design details of the GE BWR:s very well), I think that the water samples collected from different parts of the plant could currently provide very important information regarding the degree of core damages. However, some of the nuclides that could be used to indicate high core temperatures (such as Sr-90) require rather sophisticated methodology to be identified, and I'm not sure the analysis methods currently used provide very good information regarding the important indicator nuclides.

Would somebody have better information on the core injection routes used at the Fukushima Dai-ichi plants? Is there some way to ascertain that the water injected in the reactor vessel actually reaches the core?
Idaho_246
#3222
Apr7-11, 02:04 PM
P: 2
Quote Quote by Jakeh View Post
If that's the case (and it may be), it is not a bit surprising that (a) the sound effects person added in all the rumbling noises as well as the dramatic bangs and (b) counterintuitively chose to add 3 bangs rather 1 or perhaps 2.

The sound may have been travelling a much more direct route to the mike than you experienced in those London bombs. Unless you were on top of Hampstead Heath or Crystal Palace (or the like) at the time, there would have been a lot more reflection/muffling etc from buildings between the explosions and your ears.

Someone earlier cited the timing as proof the sound was artificial. That isn't exactly proof - if the timing is off, the soundtrack may just have been shifted in time against the video so the sound was a closer match to the picture for TV purposes.
Is it possible that the soundtrack is from the reactor 2 explosions.


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