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JustGuessing
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Has anyone seen the stills lifted from this video that seems to show the top of a reactor vessel sitting at a 45 degree angle?
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each day - from bad to worseenglish.kyodonews.jp/news/2011/04/82390.html said:Groundwater at nuclear plant 'highly' radiation-contaminated: TEPCO
TOKYO, April 1, Kyodo
More signs of serious radiation contamination in and near the Fukushima Daiichi nuclear power
plant were detected Thursday, with the latest data finding groundwater containing radioactive
iodine 10,000 times the legal threshold and the concentration of radioactive iodine-131 in
nearby seawater rising to the highest level yet.
Radioactive material was confirmed from groundwater for the first time since the March 11 quake
and tsunami hit the nuclear power plant on the Pacific coast, knocking out the reactors' key cooling
functions. An official of the plant operator Tokyo Electric Power Co. said, ''We're aware this is an
extremely high figure.''
The contaminated groundwater was found from around the No. 1 reactor's turbine building, although
the radiation level of groundwater is usually so low that it cannot be measured.
Japanese authorities were also urged to consider taking action over radioactive contamination outside
the 20-kilometer evacuation zone around the plant, as the International Atomic Energy Agency said
readings from soil samples collected in the village of Iitate, about 40 km from the plant,
exceeded its criteria for evacuation.
The authorities denied that the seawater and soil contamination posed an immediate threat to human
health, but the government said it plans to enhance radiation data monitoring around the plant on the
Pacific coast, about 220 km northeast of Tokyo.
According to the government's nuclear safety agency, the radioactive iodine-131 at a concentration
of 4,385 times the maximum level permitted under law has been detected in a seawater sample
collected Wednesday afternoon near the plant, exceeding the previous high recorded the day before.
In Tuesday's sample, the concentration level was 3,355 times the maximum legal limit.
Hidehiko Nishiyama, a spokesman for the Nuclear and Industrial Safety Agency, acknowledged there
is a possibility that radiation is continuing to leak into the sea, adding, ''We must check that (possibility) well.''
He reiterated that there are no immediate health concerns as fishing is not being conducted in the
designated evacuation zone stretching 20 km from the plant and radioactive materials will be
diluted by the time seafood is consumed by people.
Still, the nuclear regulatory body said it has decided to add another three areas located 15 km offshore for monitoring.
Tokyo Electric said it is likely that the high level of contamination in seawater has been caused by water
that has been in contact with nuclear fuel or reactors, but how it flowed to the sea remains unknown.
The No. 1, No. 2 and No. 3 reactors at the plant are believed to have suffered damage to their cores,
possibly releasing radioactive substances, while the fuel rods of the No. 4 reactor kept in a spent fuel pool
are also believed to have been exposed at one point, as the reactors lost cooling functions after the March 11 quake and tsunami.
In Vienna on Wednesday, Denis Flory, IAEA deputy director general and head of the agency's nuclear safety
and security department, said readings from soil samples collected in Iitate between March 18 and March 26
''indicate that one of the IAEA operational criteria for evacuation is exceeded (there).''
In response to the IAEA, Japan's Chief Cabinet Secretary Yukio Edano said Thursday the government may
implement measures, if necessary, such as urging people living in the area to evacuate, if it is found that
the contaminated soil will have a long-term effect on human health.
Nishiyama said at a press conference in the afternoon that the agency's rough estimates have shown
there is no need for people in Iitate to evacuate immediately under criteria set by the Nuclear Safety Commission of Japan.
''The radiation dose of a person who was indoors for 16 hours and outdoors for eight hours (
and continued such a lifestyle) would be about 25 millisieverts, which is about half the level
which requires evacuation based on the commission's criteria,'' he said.
The commission explained that domestic criteria are based on measurements at radiation in the air, and not the soil.
In another effort to prevent radioactive dust from being dispersed from the plant, where masses of
debris are strewn as a result of explosions, Tokyo Electric initially planned to conduct a test
spraying of a water-soluble resin on Thursday, but postponed the plan due to rain.
An official said rain would have slowed down the work and made it difficult to gauge the effects of the resin spraying.
The utility firm known as TEPCO is considering when to conduct the work, at the south and west sides
of the No. 4 reactor. A total of 60,000 liters will be sprayed over a period of two weeks.
TEPCO also tried to remove contaminated water filling up some of the reactors' turbine buildings and
tunnel-like trenches connected to them. But given the large amount of water, authorities
are having difficulty finding places to store it.
TEPCO has been pouring massive amounts of water into the reactors and spent nuclear
fuel pools at the plant as a stopgap measure to cool them down, because serious damage
to fuel rods from overheating could lead to the release of enormous amounts of
radioactive materials into the environment.
However, the measure is believed to be linked to the possible leak of radiation-contaminated
water from the reactors, where fuel rods have partially melted.
Removal of the water at the turbine buildings is believed to be essential to restoring the
vital functions to stably cool down the reactors and the spent nuclear fuel pools.
On Thursday afternoon, a ship provided by U.S. forces carrying fresh water to cool
down the reactors docked on the coast of the plant site to help the mission of water injection.
==Kyodo
rmattila said:We've been taking some air samples here in Finland, with
I wonder if anybody else is doing anything similar, and if someone would have better information on the fuel/reload strategy used in the accident reactors.
JustGuessing said:Has anyone seen the stills lifted from this video that seems to show the top of a reactor vessel sitting at a 45 degree angle?
TCups said:It was not the overhead crane that fell in the SFP3, it was the fuel handling equipment.
JustGuessing said:It is this grab with the time code 10:12:11 I'm interested in.
jlduh said:TCUPS I try to reload the picture showing the "something like a cover pressure vessel in reactor 3" through the insert image function of the forum, maybe it's better for you?
TCups said:All:
The overhead crane was reported to have fallen through the north side of the top of Bldg 3 and then down, crushing the adjacent building below.
The "stuff" in the SFP3 may be the fuel handling equipment on top of the rods.
http://english.kyodonews.jp/news/2011/04/82390.html said:groundwater containing radioactive iodine 10,000 times the legal threshold . . . The contaminated groundwater was found from around the No. 1 reactor's turbine building
According to the government's nuclear safety agency, the radioactive iodine-131 at a concentration
of 4,385 times the maximum level permitted under law has been detected in a seawater sample
collected Wednesday afternoon near the plant, exceeding the previous high recorded the day before.
Based on the attached and assuming 1/4-core reload for unit 1, it has 4 batches with 148 days of operation since 15-Oct-2010. The batch size could be more like 104 up to 120 or so. If it was 1/3 core reload, the batch size would be about 132 assemblies. But they have a low duty and CF. Outage was 25-Mar to 15-Oct.rmattila said:We've been taking some air samples here in Finland, with preliminary results suggesting Cs-134/137 activity ratios of the order of 1,05. Having no idea of what kind of core design they are using at Fukushima, we made some rough calculations of isotopic concentrations of "typical" BWR assembly at different void histories (see example below).
What we're hoping is to try to see, if it would be possible to estimate the extent of core damage based on isotopic ratios of nuclides from different samples. Like, if it would seem that the measured isotopic ratios correspond to the void history in the top of the core rather than the core average, or the burnup in the most powerful assemblies vs. core average etc.
I wonder if anybody else is doing anything similar, and if someone would have better information on the fuel/reload strategy used in the accident reactors.
jlduh said:TCUPS:
Do you talk about what I identify on what looks like the cover of the pressure vessel?
To Justguessing: based on the position where it is on the picture, it cannot be -for sure- the part where there are "rings on the vessel". Because it would mean the vessel is heavily tilted towards the external wall, which i don't foresee based on the layout of the building...
http://www.netimago.com/image_184761.html
JustGuessing said:The top right corner of the 10:12:11 image look like the rings of the vessel to me.
It's possible some of the core(s) found a way route to bedrock or their contamination did besides following the overflow channels leading to the sea.83729780 said:how can the levels in the open ocean be almost half as much as the levels in a puddle?
artax said:No Idea, How much has the pressure increased or how quickly is it rising, and where are they measuring it... the last I heard (Wiki) they thought 1,2 and 3 had cracks in the containment, or was it the pressure vessel I just read.
Anyone know how high the reactor buildings are...(were!) I want to work out how high that concrete went in the blast at number 3.
The reactor pressure vessel (RPV) normally operates at an internal pressure of 1055 psia (7274 kPa) with 101 kPa outside! The containment is design to hold about 400 kPa, but should be capable of more.DSamsom said:Here's the graph of reactor-parameters of Unit 1: http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/plots/v3/plot-un1-full.png
Core pressure is now at its highest point since March 11th, >600 kPa. Not a level that a BWR pressure vessel is very used to.
razzz said:I come up with a minimum of 350 tons of uranium needed to load these 4 reactors not counting extra or excess rod assemblies in various states (new and/or used) stored in proximity i.e. Unit 1,2 and 3 spent fuel ponds or whatever other basement broom closets they might be stored in.
How much potential heat in 350 tons of uranium?
The design pressure for the RPV is about 8.9 MPa = 8900 kPa, and the hydrostatic test pressure is about 1.3 times design or about 11.6 MPa (11600 kPa).
Astronuc said:Based on the attached and assuming 1/4-core reload for unit 1, it has 4 batches with 148 days of operation since 15-Oct-2010...
AntonL said:here some basic facts to the cooling problem and amount of fuel on site
Unit 1
design 460 MWelect 1380MWtherm
400 Fuel elements in core and 292 in SFP
rest heat day 17 - 2.66MW reactor and about 60kW for pool
Unit 2
design 784 MWelect 2381MWtherm
548 Fuel elements in core and 587 in SFP
rest heat day 17 - 4.59MW reactor and about 400kW for pool
Unit 3
design 784 MWelect 2381MWtherm
548 Fuel elements in core (6% MOX since August 2010) and 541 in SFP (?% MOX)
rest heat day 17 - 4.59MW reactor and about 200kW for pool
Unit 4
design 784 MWelect 2381MWtherm
0 Fuel elements in core and 1331spent +200unused in SFP
rest heat day 17 - 0MW reactor and about 2000kW for pool
Total 14.5MW of cooling required
rest heat assuming 100% load at time of accident
in about 2 months the rest heat would be 50% of above
1MW will boil away 1.41 m3/h of water at temperature of 30 degree
Total 14.5MW of cooling required that is 20.5 m3/hour without overflow and spillage--------------------------------------
under control
Unit 5
design 784 MWelect 2381MWtherm
548 Fuel elements in core and 946 in SFP
rest heat day 17 - 4.59MW reactor and about 700kW for pool
Unit 6
design 1100 MWelect 3293MWtherm
764 Fuel elements in core and 876 in SFP
rest heat day 17 - 6.35MW reactor and about 600kW for pool
razzz said:Your pic with totals seems high. Do they really have that much stored in spent fuel ponds? Did Unit 4 actually have those amount of assemblies already loaded?...At least as far as you know.