Nuclear accident follows Japanese earthqauke

2 As and a B · Post by **2 As and a B** » 13 Mar 2011, 11:16

biffvernon wrote:That's funny - all the nukes are on the coast. Isn't 'tsumani' a Japanese word?

Their nuclear power plants are built on concrete platforms, probably with lines of weakness between them.

I guess that's what this shows:

Earthquake damages nuclear power station in Japan, July 2007

They also design tsunami defences around the plants. Obviously can't cope with all eventualities though.

UndercoverElephant · Post by **UndercoverElephant** » 13 Mar 2011, 12:26

http://www.bbc.co.uk/news/world-asia-pacific-12726297

Speaking after Mr Kan, government spokesman Yukio Edano said that although seawater was being injected into reactor 3 at the Fukushima plant, gauges were not showing the water levels rising.

"We do not know what to make of this," he said.

WTF???

Sounds like the reason we aren't getting much in the way of detailed information is that they haven't got much clue what they are doing.

Ippoippo · Post by **Ippoippo** » 13 Mar 2011, 12:58

biffvernon wrote:That's funny - all the nukes are on the coast. Isn't 'tsumani' a Japanese word?

There isn't anywhere else in Japan to build them. The country is basically mountainainous (steep and covered with forest), with small coastal plains where all the farmland, housing areas, and industry are crammed in. It would be pretty difficult to build any kind of power station (nuclear, or fossil fuelled) in land.
Anyway, in-land, you get landslides and volcano's instead

2 As and a B · Post by **2 As and a B** » 13 Mar 2011, 13:02

UndercoverElephant wrote:http://www.bbc.co.uk/news/world-asia-pacific-12726297

Speaking after Mr Kan, government spokesman Yukio Edano said that although seawater was being injected into reactor 3 at the Fukushima plant, gauges were not showing the water levels rising.

"We do not know what to make of this," he said.
WTF???

Sounds like the reason we aren't getting much in the way of detailed information is that they haven't got much clue what they are doing.

I heard that the gauges are not working.

marknorthfield · Post by **marknorthfield** » 13 Mar 2011, 13:47

A bit more detailed analysis of the technical side etc. Have only skimmed so far, but it looks interesting.

http://theautomaticearth.blogspot.com/2 ... anese.html

biffvernon · Post by **biffvernon** » 13 Mar 2011, 14:25

That's a very good piece from Stoneleigh.

madibe · Post by **madibe** » 13 Mar 2011, 14:45

Injecting Sea Water is a terminal process - this news just on the BBC from expert. I am suprised that the corrosion would take hold so fast, but apparently so.

These plants will need to be de-commissioned.

What impact this has on the Japanese grid is the worry, since over 1/3rd of their power is from nuclear.

2 As and a B · Post by **2 As and a B** » 13 Mar 2011, 15:34

I heard 30%, from 55 reactors.

The NY Times has been carrying some informative articles.

Partial Meltdowns Presumed at Crippled Reactors

Danger Posed by Radioactivity in Japan Hard to Assess (what radioactive elements have been created/released and how toxic they are)

Crisis Underscores Fears About Safety of Nuclear Energy (Japan's nuclear safety/secrecy record)

Ippoippo · Post by **Ippoippo** » 13 Mar 2011, 16:03

maudibe wrote:Injecting Sea Water is a terminal process - this news just on the BBC from expert. I am suprised that the corrosion would take hold so fast, but apparently so.

These plants will need to be de-commissioned.

What impact this has on the Japanese grid is the worry, since over 1/3rd of their power is from nuclear.

If I recall, some of the Fukushima reactors were due to be decommissioned anyway in the next few years.

I then recalled another issue they'll have, regarding the grid. Japan doesn't actually have a single grid as such, there are two! There's the East Grid which covers Tokyo and 'the North' (so pretty much the affected areas). Then you've got the 'West' which covers places like Osaka and Kyoto all the way down to Hiroshima and the southern islands.
The East grid runs at 50Hz, whereas West is 60Hz.
http://en.wikipedia.org/wiki/File:Power ... _Japan.PNG
I'm not sure how much juice they can pump through the interconnects?

Aurora · Post by **Aurora** » 13 Mar 2011, 17:01

Latest from The Guardian - 13/03/11

Japan's nuclear crisis: the causes and the risks

Article continues ...

raspberry-blower · Post by **raspberry-blower** » 13 Mar 2011, 20:11

NHK is the Japanese news service.

They are reporting a build up of Hydrogen in reactor no. 3. Worryingly coolant levels are down at reactor no. 2 as well.

Also evacuation advice for 80,000 near the plant. Apparently over 60,000 have already been evacuated...

Post by **clv101** » 13 Mar 2011, 21:38

The reactors had the control rod inserted okay (apparently) so the normal fission process is pretty much stopped. The continued production of heat is from decay of radioactive fission products. Someone at TOD said this was around 7% of reactor power declining over time.

Just thinking off the top of my head here. So Fukushima I – 1 has an electric output of 430 MW, call it a round 1000 MW thermal (I guess it's a bit more than that). With the full insertion of control rods, there remains 7% or ~70 MW of heat to dissipate. The latent heat of vaporization of water is 2.5 MJ/kg (ignoring energy to boil), so we get through 28 kg of water per second, or 100 tonnes an hour!

Seawater is around 3.5% salt, so using seawater is going to deposit 3.5 tonnes of salt per hour. Wow, is this even remotely right?

Edit: Okay, so I read the Wikipeda page on decay heat now. The ~7% is the instantaneous rate. After a day it's more like 0.4%, so leaving 4 MW to cool, leaving behind around 200 kg of salt per hour.

Aurora · Post by **Aurora** » 14 Mar 2011, 06:07

BBC News - 14/03/11

A second explosion has hit the nuclear plant in Japan that was damaged in Friday's earthquake, but officials said it had resisted the blast.

TV footage showed smoke rising from Fukushima plant's reactor 3, a day after an explosion hit reactor 1.

Japan's nuclear safety agency said the blast was believed to have been caused by the build-up of hydrogen.

Government officials said the reactor core was still intact as they tried allay fears of a radioactive leak.

Article continues ...

biffvernon · Post by **biffvernon** » 14 Mar 2011, 06:52

Film of #3 reactor blowing up http://www.youtube.com/watch?v=yucakonW6gM

~45 seconds in

"To lose one reactor, Mr. Worthing, may be regarded as a misfortune; to lose both looks like carelessness."

2 As and a B · Post by **2 As and a B** » 14 Mar 2011, 08:31

Some apt comments on that video. I particularly like this one:

jhsu889 wrote:I believe it is only fair for top government officials and their families to live next to the nuclear power plant.