2 Japanese nuclear reactors may be in meltdown

[CraigS]

Originally Posted by CraigS

I read somewhere (in all of these links) that one of them was due for decommissioning, which might explain why there were fresh rods in the pool. (?)

Just found a reputable site … the IAEA (International Atomic Energy Agency)

As an independent international organization related to the United Nations system, the IAEA´s relationship with the UN is regulated by special agreement. In terms of its Statute, the IAEA reports annually to the UN General Assembly and, when appropriate, to the Security Council regarding non-compliance by States with their safeguards obligations as well as on matters relating to international peace and security.
…
It was set up as the world´s "Atoms for Peace" organization in 1957 within the United Nations family.
…
The Agency is led by Director General Yukiya Amano and six Deputy Directors General who head the major departments.

This is the guy who flew into Tokyo a couple of days ago and has been talking with the TEPC Vice President and the Japanese PM.

and they say ..
Japan Earthquake Update (19 March 2011, 4:30 UTC)

Unit 4:
All fuel had been removed from the reactor core for routine maintenance before the earthquake and placed into the spent fuel pool.

The give a daily site-by-site status update on the developing situation.

… A reputable site for updates, I would think …

Cheers

[Sylvain (Jon)]

I recommend following the BBC live coverage of the events unfolding in Japan. Very informative and updates come on in all the time.
Focus on the updates on the left hand side of the page.
The videos on the right are good too, but the same videos are being played over and over again.

http://www.bbc.co.uk/news/world-middle-east-12307698

Cheers

[gary]

Originally Posted by CraigS

and they say ..
Japan Earthquake Update (19 March 2011, 4:30 UTC)
The give a daily site-by-site status update on the developing situation.

Hi Craig,

Thanks for the link to the IAEA Fukushima status page.

The confirmation that, for Unit 4, "All fuel had been removed from the reactor core for
routine maintenance before the earthquake and placed into the spent fuel pool",
and that "a portion of the building's outer shell was damaged" is consistent with the US
NRC reporting and a set of facts of considerable concern.

That unit had a output capacity of 1100 MW of power. The source of that power
was purely from its fuel rods when in a controlled fission state. Now those fuel
rods, the potential source of all that energy, are inconveniently sitting outside
the primary containment vessel effectively out in the open. Separated by space gaps,
they currently do not form a critical assembly, but they are rising in temperature
hour by hour. If they should catch fire and melt (and they eventually will if they cannot be cooled),
they may form a conglomerated mass and a fission reaction will begin again releasing
even more energy. So there is a real race against time here probably over the next few weeks.

The pool structures are said to be made of concrete lined with "a thin
stainless steel liner". One concern from TEPCO has been that the concrete on
Unit 4's pool has partially fallen away leaving only the stainless steel liner.

It would be interesting to learn of a link to an authoritative source as to whether it is
believed the thin stainless steel liner of the cooling pool will be sufficient or not
to hold the rods in the spent pool, should the worse occur and the rods melt.

One can only hope that Unit 4's pool is watertight and that, if it is not too late,
water can be added to it. Should a cladding fire occur, water is not the
correct material to pour on it. In that eventuality, they may have to start dropping
large amounts of sand on it, possibly mixed with boron, which acts as a neutron
poison. Hopefully this will not occur, but suffice to say, it would be an act of
desperation.

Yesterday, France flew out 95 tonnes of boron destined for Japan.
See http://www.straitstimes.com/Breaking...ry_646202.html

[Sylvain (Jon)]

Some things are just ridiculous:

"Mr Besson said that France had offered the boron on Saturday, the day after Japan's biggest earthquake on record struck but 'either they didn't think it was useful or they didn't have the time to reply.'"


"0409: The Yomiuri Shimbun claims the Japanese government did turn down a US offer of technical help to cool the overheating nuclear reactors, soon after the earthquake. The paper, citing an anonymous senior member of the Democratic Party, said the offer was refused because it was felt to be "premature". Last week Tokyo denied turning down an American offer of help."

-_-'

[CraigS]

Gary;

I wonder the melting point of the Stainless Steel would be relative to the rod encasement ?

I think type 304 stainless has a melting point of around 1400 - 1450 degrees C.

I'm sure the composition of the tank would have been carefully selected for other properties, as well, though.

I suppose it doesn't really matter if the rod encasement decides to light up !

[CraigS]

Originally Posted by Sylvain

Some things are just ridiculous:

"Mr Besson said that France had offered the boron on Saturday, the day after Japan's biggest earthquake on record struck but 'either they didn't think it was useful or they didn't have the time to reply.'"


"0409: The Yomiuri Shimbun claims the Japanese government did turn down a US offer of technical help to cool the overheating nuclear reactors, soon after the earthquake. The paper, citing an anonymous senior member of the Democratic Party, said the offer was refused because it was felt to be "premature". Last week Tokyo denied turning down an American offer of help."

-_-'

Sylvain;

There are heaps of reasons this may have occurred.
Eg: Perhaps they didn't know the exact status of anything at that stage. (I mean, a tsunami had just hit following massive damage everywhere)..

If someone asks do you need help immediately after a catastrophe, more often than not, its difficult to answer definitively. Straight after the offer, the next question is likely to be .. 'what kind of help do you need ?'

How do you answer that if you don't know exactly what's happening ?

Its easy to have opinions after the fact .. but consider what these people have just gone through … and, they've been running these reactors for forty years !

They have the expertise and nuclear resources !

[Sylvain (Jon)]

I guess all I am trying to say is that no chances should have been taken. It's better to have too much help than not enough.

I am not making any judgement, in fact I don't think other countries would be any better at handling the situation.
I just hope they somehow manage to cool the reactors down, but it's looking too optimistic at this stage.

[Sylvain (Jon)]

Apologies if I am sounding a bit harsh, but it's just that I have loved ones in the vicinity and I'm worried.

[multiweb (Marc)]

Originally Posted by CraigS

Its easy to have opinions after the fact .. but consider what these people have just gone through …

I think this statement is spot on. We're all looking from a distance in the comfort of our living room watching TV and saying what were/are they thinking. But the fact is that those guys have been hit repeatidly by a series of unprecedented events. There is a massive psychological effect to the whole story too. They have to cope with it all on ground zero. It's so overwhelming they probably don't know where to start. I'd say give them a break. They're doing a grand job so far.

[CraigS]

Here's a photo of a fuel storage pool. The caption reads:

A fuel storage pool in the Fukushima plant reactor building. Surrounding this and reactors like it is a containment vessel, the last line of defense if cooling fails.

(from NY Times).

[gary]

Originally Posted by CraigS

Here's a photo of a fuel storage pool. The caption reads:

"A fuel storage pool in the Fukushima plant reactor building. Surrounding this and reactors like it is a containment vessel, the last line of defense if cooling fails."
(from NY Times).

Hi Craig,

Thanks for the photo. Alas the pool is outside the primary containment area
and only in the secondary area, which is the outer building which has been damaged.
This New York Times short video shows their location graphically -
http://www.nytimes.com/2011/03/19/wo...9japan.html?hp

New York Times also has this excellent interactive step-by-step graphic showing
more detail of the pools under the heading "Hazards of Storing Spent Fuel"
http://www.nytimes.com/interactive/2....html?ref=asia

Here is a link to a PDF of a PowerPoint presentation dated 16 Nov 2010
by Yumiko Kumano of the Tokyo Electric Power Company entitled
"Integrity Inspection of Dry Storage Casks and Spent Fuels at Fukushima Daiichi
Nuclear Power Station".
http://www.nirs.org/reactorwatch/acc...powerpoint.pdf

[CraigS]

Thanks Gary;

Excellent interactive and info ... makes it all look pristine, shiny and new .. pity the one that matters looks nothing like this !

Rgds

[gary]

According to today's New York Times, unfortunately the Japanese Government
has detected "abnormal levels" of radiation in spinach and milk in Fukushima and
Ibaraki prefectures.

Originally Posted by New York Times

Yukio Edano, the chief cabinet secretary, said that the radioactivity contained in the average amount of spinach and milk consumed during an entire year would be equal to the amount received in a single CAT scan.

Originally Posted by New York Times

The government has not banned shipments of milk or spinach from the affected areas, but it would further study the issue, Mr. Edano said. The milk that contained higher levels of radioactive material was tested at farms about 19 miles from the hobbled nuclear plants in Fukushima Prefecture. The spinach was found in Ibaraki Prefecture farther south.

“These levels do not pose an immediate threat to your health,” Mr. Edano said, adding that the Health, Labor and Welfare Ministry would provide additional details. “Please stay calm.”

Story here -
http://www.nytimes.com/2011/03/20/wo...0japan.html?hp

[CraigS]

Oh brother .. those words … 'please say calm' !

Mind you, the levels could've been at those levels before the accident too, maybe ?

[Sylvain (Jon)]

"0907: Despite encouraging reports about progressing reconnecting power to cooling systems at the Fukushima plant, the BBC's Tim Willcox cautions that they are still nowhere near the process of restarting the pumps as it is unclear whether - given quake and tsunami damage - they even still work. Even if they do initially work, they could quickly short out."

(From the BBC news update link I gave before).
It would be good if the Japanese government would let us know what the hell is going on down there.

[Sylvain (Jon)]

Some hope:

"1200: Power lines have been connected to the Fukushima nuclear plant's reactor 2 but electricity has not been restored yet, a spokesman for Japan's nuclear safety agency has said according to AFP. "If the power is turned on without checks it may malfunction. They are checking the facility now. If no problem is found at the facility today, the power will resume as early as tomorrow [Sunday].""

Fingers crossed.

[Sylvain (Jon)]

Another update from the IAEA:

"1543: The IAEA is giving a press conference on the situation at the Fukushima Daiichi nuclear power plant. It hopes that power will be restored to reactor 2 today, which will then act as a hub to restore power to reactor 1. However it is not clear if water pumps have been damaged and if they will even work once power has been restored."

[CraigS]

So, from this morning's news, looks like Nos 5 and 6 are being cooled by two emergency diesels. As per Sylvain's posts, power lines have been run into No 2, but they have not yet succeeded in reconnecting power (just yet - a few minor problems by the sound of it - they had to run the lines in darkness). Once they get power to No 2 it will act as a hub for No 1 as well.

Nos 3 and 4 would then seem to be the biggest problems. From the Washington Post:

Chief Cabinet Secretary Yukio Edano said the renewed attempts to regain control of Fukushima Daiichi had shown signs of success at the plant’s No. 3 nuclear reactor, the highest priority for officials aiming to cool spent fuel rods that have begun spewing radioactive material into the atmosphere. But he acknowledged that the gains could be temporary.

“As of now, we cannot say anything definite, but we think we have succeeded in putting a certain level of water in Unit 3, and we think that it is in a certain stable situation,” Edano said at a news conference. “We have been able to prevent the situation from worsening . . . but I believe we are reaching a big turning point.”

It seems as though they don't have reliable info on the water and temperature levels at Nos 3 or 4.

From the SMH:

Prime Minister Naoto Kan said the situation remained ''very grave'' as forecasts indicated changing winds could blow radioactive material closer to Tokyo by tonight.

Radiation levels (from IAEA):

The Japanese Ministry of Health, Labour and Welfare informed the Agency that radiation levels exceeding legal limits had been detected in milk produced in the Fukushima area and in certain vegetables in Ibaraki. The Ministry has requested an investigation into the possible stop of sales of food products from the Fukushima Prefecture.

I wouldn't be drinking milk for a while. Spinach is also off the menu.

Rgds

[Sylvain (Jon)]

Thanks for the update Craig.
I read that traces of radioactive iodine where detected into tap water in Tokyo and other cities. They say it is not harmful to human health but also said there is normally no traces whatsoever.

Reactors 3 & 4 definitely remain the main concern. Let's hope they get the cooling pumps to work again.

[gary]

Hi Craig, Hi Sylvain,

Thank you both very much for the synopsis of the situation as it stands this Sunday
morning.

A picture appears in the Sydney Morning Herald today of what the caption says to be
the green crane for the spent rod pool for No. 4. It can be seen through a gaping hole
in the side of the damaged secondary containment building.
See http://www.smh.com.au/environment/po...319-1c1cu.html

The caption also reads the storage pond is just out of sight in the shot and that it
has "boiled dry".

One would hope that the hole in the side of the wall allows them the opportunity to
get a remote camera in there by one way or another.

It is clear that an important piece of information will be the status of the mechanical
integrity of the pool itself.

If it can still hold water, it will undoubtedly give them one option which they will
be deliberating over, which is whether to try and get water back into it. Depending
upon the integrity of the rods, half of which are "fresh", they may be weighing up
whether the risks, both short and long term, of the initial steam cloud of radiation
that will be emitted is less than those from taking some other action, such as
attempting to entomb it, first with sand and boron and later with concrete.

The lack of time, the prevailing winds, the fact that it is probably easier to fire
water through the hole in the wall than try to get sand in there, the risk of a meltdown,
etc. must all be featuring as bullet points on white boards up there.

But if Unit 4's pool can't hold water, or if it is deemed too much of a radiation
risk to douse them now, then the alternative remedies would create new
challenges.

At present, the fact that No. 4's roof, though damaged, still provides some
covering may help prevent steam and radioactivity from rising higher into the air
if they should douse the pool. If the prevailing winds allowed the steam to go offshore
out into the Pacific, it may help curtail more damaging contamination on the
Japanese mainland. However, that same roof covering would not make it easy to
try and get material such as sand dropped in from the top in which case they
might have to convey it through the hole in the side.