Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[bytepirate]

An interesting question, indeed. Posited another way: If the emergency efforts to cool the reactor cores are (and it would seem, can only be) a temporary solution as long as the coolant (water) is not contained in a closed system,

Then only three alternatives exist:

1) Continue to spill contaminated water and slowly (relatively) contaminate the ground water and ocean while temporizing. (possibly, to allow time to deal with the spent fuel in the SFPs?), or

2) Somehow devise a stable, permanent system to contain, decontaminate and if possible, recirculate the water being used for cooling the cores (unlikely), or

3) Prepare to let the cores melt and deal with the consequences.

Is there another option I am missing? If not, then option (3), it seems, is most likely the "not if, but when" final event in the Fukushima disaster sequence.

Which begs the question: What might be done while temporizing with the current efforts to cool the cores to mitigate the ultimate consequences of one or more melted reactor cores with loss of the primary containment? If the answer to that question is "nothing effective", then, is option (1) with ongoing contamination by un-contained, highly contaminated water for as long as humanly possible worse than option (3)?

I don't know.

maybe they need a feynman (or any other brilliant mind, preferred alive) to come up with an unexpected fourth solution.
something like:
fill up the RPV with copper pellets, then pour in some radiator sealant (i have heard pepper and eggs are working), then cool the thing from the outside.

this is not a serious suggestion, but maybe the final solution will be something like that: unexpected, ridiculous - and working.

 

[83729780]

Is there another option I am missing?

I honestly think they're still considering the giant cloth. It's been mentioned twice in Kyodo news reports.

 

[Borek]

Considering that at d + almost 30 , they aren't any closer to restore cooling , if anything situation is worse , containment is not really containing , what option do they have ? They can't let it bleed out for ever ...

Amount of heat evolving should be getting down, even if there are short criticalities. Once the power gets down they can stop cooling. But I doubt there is much that can be done earlier.

 

[StrangeBeauty]

Pardon if this is a repost: They've issued corrections to a number of released readings/info including pressure readings for RPVs #1 and #3:

http://www.nisa.meti.go.jp/english/files/en20110411-3.pdf

[Edit]: There appears to be some new data for #3

 

[shogun338]

A fire broke out at Japan's crippled Fukushima Daiichi nuclear power plant, operator Tokyo Electric and Power (TEPCO) said on Tuesday, although flames and smoke were no longer visible. http://www.reuters.com/article/2011/04/11/idUSL3E7FB1YD20110411

 

[shogun338]

Magnitude 6.6 - EASTERN HONSHU, JAPAN
2011 April 11 08:16:13 UTC http://earthquake.usgs.gov/earthquakes/eqinthenews/2011/usc0002n9v/

 

[Astronuc]

They just had a mag 6.2 down near the Tokai plant.
http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/usc0002nzx.php
Date-Time:
Monday, April 11, 2011 at 23:08:16 UTC
Tuesday, April 12, 2011 at 08:08:16 AM at epicenter

Location: 35.406°N, 140.542°E
Depth: 13.1 km (8.1 miles)

Distances:
77 km (47 miles) ESE of TOKYO, Japan
82 km (50 miles) E of Yokohama, Honshu, Japan
106 km (65 miles) S of Mito, Honshu, Japan
140 km (86 miles) SSE of Utsunomiya, Honshu, Japan

 

[shogun338]

RPV temperatures remain above cold shutdown conditions in all Units, (typically less than 95 °C). In Unit 1 temperature at the feed water nozzle of the RPV is 228 °C and at the bottom of the RPV is 121 °C. In Unit 2 the temperature at the feed water nozzle of the RPV is 149 °C. The temperature at the bottom of the RPV was not reported. In Unit 3 the temperature at the feed water nozzle of the RPV is 92 °C and at the bottom of the RPV is 111 °C. With the temperature being over 428 degrees Fahrenheit at the feed nozzle does this indicate that fission is still occurring inside Unit 1 ? http://www.iaea.org/newscenter/news/tsunamiupdate01.html

 

[SredniVashtar]

They have raised the level to 7
http://www.bbc.co.uk/news/world-asia-pacific-1304534

Japanese authorities have raised the measure of severity of their nuclear crisis to the highest level, officials say.
The decision was taken due to radiation measured at the damaged Fukushima Daiichi power plant, NHK reported.
"This is a preliminary assessment, and is subject to finalisation by the International Atomic Energy Agency," said an official at the Nuclear and Industrial Safety Agency (NISA)
The decision to raise the threat level was made after radiation of 10,000 terabequerels per hour had been estimated at the stricken plant for several hours.​

 

[Astronuc]

RPV temperatures remain above cold shutdown conditions in all Units, (typically less than 95 °C). In Unit 1 temperature at the feed water nozzle of the RPV is 228 °C and at the bottom of the RPV is 121 °C. In Unit 2 the temperature at the feed water nozzle of the RPV is 149 °C. The temperature at the bottom of the RPV was not reported. In Unit 3 the temperature at the feed water nozzle of the RPV is 92 °C and at the bottom of the RPV is 111 °C. With the temperature being over 428 degrees Fahrenheit at the feed nozzle does this indicate that fission is still occurring inside Unit 1 ? http://www.iaea.org/newscenter/news/tsunamiupdate01.html

The temperatures on Unit 1 are puzzling, and the Unit 3 temperatures are problematic.

 

[I_P]

An interesting article providing some details of the first two days of the accident:

http://www.yomiuri.co.jp/dy/national/T110411004567.htm"

 

[Bodge]

Confusion reigns in Japan:

11:14 NEWS ADVISORY: Radioactive materials from Fukushima plant 10% of amount from Chernobyl

11:39 NEWS ADVISORY: Fukushima different from Chernobyl, without massive radiation leak: agency

12:09 NEWS ADVISORY: Radiation leak may exceed amount in Chernobyl accident: TEPCO

http://english.kyodonews.jp/news/"

 

[JustGuessing]

The temperatures on Unit 1 are puzzling, and the Unit 3 temperatures are problematic.

Astronuc,

Thank you so much for all the information you have supplied during this past month.

This forum has been invaluable as I struggle to understand what all the data, and corrected data, and crazy theories, mean to everyone living near the nuclear plants -- and the future of nuclear power.

Your insights are great. And now I must also thank you for saying when the data points are simply puzzling. Sometimes the explanation is not clear...hopefully we'll get more data soon that will help us understand the situation on the ground better.

-- JustGuessing

P.S. A month in, how do you think they are doing? What are you most concerned about? C an you start to image the cleanup?

 

[liamdavis]

With respect to this the information contained in this report.

"

http://www.f.waseda.jp/okay/news_en...ower_Plants_suffered_big_eart_quake110331.pdf

Pg5
Emergency DGs started at the earthquake. But Tsunami damaged ultimate heat sinks (sea water pumping and cooling system) of units 1F1-4. caused common cause failure
•Without ultimate heat sink, Emergency DG (need to remove its generated heat for operation) and spent fuel pool cooling do not work.

Pg6
2:46pm: The earthquake happened. Plants automatically shut down. Offsite power lost. Emergency DG started up.
•3:42pm Emergency DG(diesel generator) stopped due to loss of equipment cooling water. (Tsunami was bigger than expected.) All AC power was lost for 1F1-4 and consequential isolation from UHS(ultimate heat sink), except for IC (isolation cooling system) in 1F1. RCIC(reactor core isolation cooling system) in 1F 2 Blackout + (mostly) loss of UHS"

When I worked on the construction of Pilgrim 1 in 1970 the diesel generators were radiator cooled, each had six starters, each starter had its own energy source and on site was a minimum of six months of fuel. In other words it was independently self sufficient, as an emergency system should be.

The system described in the publication above sounds like back up power for convenience. It was dependent upon, and assumed the the continued operation of, systems external to itself "sea water pumping and cooling system" for any operation.

I can understand a sea water-to-coolant heat exchanger in addition to a water-to-air heat exchanger, but not instead of it. I am,of course, assuming that the design purpose is the protection of human life.

I maintain commercial aircraft and I would not want to be responsible for maintaining anything designed by people who thought out the emergency(?) power system at Daiichi.

 

[shogun338]

Emergency Preparedness and Response to Radiation . What Preparations Can I Make for a Radiation Emergency
Your community should have a plan in place in case of a radiation emergency. Check with community leaders to learn more about the plan and possible evacuation routes. http://www.bt.cdc.gov/radiation/emergencyfaq.asp

 

[shogun338]

How close are you to a nuclear plant ? Are you in the 50-mile exclusion zone ? This map will show you how close you are in case of an accident . http://d3fjco7hozu03c.cloudfront.net/index.html

 

[AntonL]

Confusion reigns in Japan:

11:14 NEWS ADVISORY: Radioactive materials from Fukushima plant 10% of amount from Chernobyl

11:39 NEWS ADVISORY: Fukushima different from Chernobyl, without massive radiation leak: agency

12:09 NEWS ADVISORY: Radiation leak may exceed amount in Chernobyl accident: TEPCO

http://english.kyodonews.jp/news/"

Confusion reigns in Kyodo,

http://english.kyodonews.jp/news/2011/04/84828.html"

''The radiation leak has not stopped completely and our concern is that the amount of leakage could eventually reach that of Chernobyl or exceed it,'' an official from the Tokyo Electric Power Co. said ... however, that the amount of radioactive materials released from the nuke plant is estimated to be about 10 percent of the amount released in the Chernobyl accident.

 

[Cire]

RPV temperatures remain above cold shutdown conditions in all Units, (typically less than 95 °C). In Unit 1 temperature at the feed water nozzle of the RPV is 228 °C and at the bottom of the RPV is 121 °C. In Unit 2 the temperature at the feed water nozzle of the RPV is 149 °C. The temperature at the bottom of the RPV was not reported. In Unit 3 the temperature at the feed water nozzle of the RPV is 92 °C and at the bottom of the RPV is 111 °C. With the temperature being over 428 degrees Fahrenheit at the feed nozzle does this indicate that fission is still occurring inside Unit 1 ? http://www.iaea.org/newscenter/news/tsunamiupdate01.html

All these temperature sensors where cooked (ie. Damaged). They greatly exceeded their operating temperature. I don't believe these numbers are accurate. The feed nozzle is the point where the cold water is being injected and has probably the highest temperature drop because of the flow rate and temperature difference.

If these temperatures where accurate we'd be seeing the steam equivalent of 8 cubic meters of water per hour pouring out the reactor somewhere. Not cold water leaking into trenches and pouring into the ocean.

The feedwater temperatures being reported are very close to what you see when the reactor is running. You can read more about these measurements and how you can get gradients in the plumbing here: http://www.google.com/url?sa=t&sour...tn6DA&usg=AFQjCNH_z5TkAmOzCywqIAMaB7-JoVijFQ"

 

[Cire]

How close are you to a nuclear plant ? Are you in the 50-mile exclusion zone ? This map will show you how close you are in case of an accident . http://d3fjco7hozu03c.cloudfront.net/index.html

I'm about 12 miles from a plant. I get a free packet of Potassium Iodide in the mail each year. I also keep my dosimeter and Geiger counter running

I'm glad the plant is there, even knowing the risks.

 

[sp2]

P.S. One more question:

I've been asking this of various people in various places for a couple of weeks now, and I've yet to hear a convincing answer: If the reactors shut down on March 11, and the half-life of I-131 is 8 days, and we were assured, therefore, by every Pompous Nuclear Pundit from Day 1 that the Iodine was a transient problem that would disappear in a jiffy... why is it that we're still seeing so damn much I-131, everywhere we look, what, FOUR half-lives out, now??

What gives? How many half-lives do we have to go, before someone starts to wonder what the hell is going on?

Forgive me if there's an obvious explanation for this, but I'm really having a hard time seeing it.
(If it *is* just a case of normal decay of the initial products, then what the heck does that say about the quantities that were originally released? They'd have to be pretty huge, no?)

Thanks again.

 

[shogun338]

Map of Radiation Measurements by Greenpeace team http://maps.google.com/maps/ms?ie=U...581055&spn=0.761327,1.647949&z=9&source=embed

 

[shogun338]

I'm about 12 miles from a plant. I get a free packet of Potassium Iodide in the mail each year. I also keep my dosimeter and Geiger counter running

I'm glad the plant is there, even knowing the risks.

I'm 20 miles from Plant Hatch in Georgia and receive no Potassium Iodide and no alert radio . My relatives that live closer to the plant receive all that . I think they should expand the zone considering the event in Japan . There are dozens of towns in this area that would be affected in a accident at the plant such as a fire in the spent fuel pool . I have a lot of friends that work in the plant that are glad its there too. I know we need nuclear energy but we all need to ensure it it made safer .

 

[Bodge]

After 2 weeks without a report, the sensor at the bottom of reactor 2's RPV is showing 208.1C

http://www.meti.go.jp/press/2011/04/20110412002/20110412002-3.pdf

http://atmc.jp/plant/temperature/?n=2

This is the highest reported temp at that location.

Also, possible context via Kyodo, 12:22 12 April

"BREAKING NEWS: Released radioactivity comes mostly from No. 2 reactor blast March 15"​

Discuss!

 

[AntonL]

A fire broke out at Japan's crippled Fukushima Daiichi nuclear power plant, operator Tokyo Electric and Power (TEPCO) said on Tuesday, although flames and smoke were no longer visible. http://www.reuters.com/article/2011/04/11/idUSL3E7FB1YD20110411

http://www.tepco.co.jp/en/press/corp-com/release/11041202-e.html

At approximately 6:38 AM, April 12th, fire has been found at the
distribution switchboard containing batteries located in the sampling
equipment switchbox situated close to the south water discharge channel
for Units 1-4

 

[shogun338]

After 2 weeks without a report, the sensor at the bottom of reactor 2's RPV is showing 208.1C

http://www.meti.go.jp/press/2011/04/20110412002/20110412002-3.pdf

http://atmc.jp/plant/temperature/?n=2

This is the highest reported temp at that location.

Also, possible context via Kyodo, 12:22 12 April

"BREAKING NEWS: Released radioactivity comes mostly from No. 2 reactor blast March 15"​

Discuss!

I don't see in the link where the sensor for bottom of RPV is showing readings in Unit 2 after 3-30-11 .

 

[NUCENG]

P.S. One more question:

I've been asking this of various people in various places for a couple of weeks now, and I've yet to hear a convincing answer: If the reactors shut down on March 11, and the half-life of I-131 is 8 days, and we were assured, therefore, by every Pompous Nuclear Pundit from Day 1 that the Iodine was a transient problem that would disappear in a jiffy... why is it that we're still seeing so damn much I-131, everywhere we look, what, FOUR half-lives out, now??

What gives? How many half-lives do we have to go, before someone starts to wonder what the hell is going on?

Forgive me if there's an obvious explanation for this, but I'm really having a hard time seeing it.
(If it *is* just a case of normal decay of the initial products, then what the heck does that say about the quantities that were originally released? They'd have to be pretty huge, no?)

Thanks again.

After 4 half lives 1/16 of the I-131 is still there. Based on an initial source term of about 75 MILLION Curies there are still 4.7 million Ci on site or somewhere down wind that haven'r decayed yet. Half of a big number is still a big number.

 

[hbjon]

I'm pondering what you're pondering sp2. I've only had a sunday supplement course on all this jazz, but maybe that I-131 is the reason for the heightened alert. Atomic Mass of 131 doesn't seem like a natural decay atom of U-238. And again, I am no authority on the subject. But, when you have high energy particles flying around, I speculate that quite a bit of artificial transmutation will cause the formation of that particular radioisotope.

 

[AntonL]

At 14:07 another 6.0 aftershock strikes at 14km distance from yesterdays 6.6 and 52km from Fukushima I

Workers ordered once again to evacuate the stricken plant

 

[shogun338]

Just watched TEPCO new drone video and was going to post it but quality is so bad its worthless ! Pics to show bad quality ! I hope they have better shots that there not releasing . It does show steam still coming from Unit 3 spent fuel pool and reactor location . Looks like even more . Unit 4 steam or smoke coming from turbine facing side out of blowout in wall if you look close .

 

[shogun338]

Pic of the tsunami in the plant . Before and after .