Emergency declared at second quake-wracked Japanese nuke plant - coolant temp. >100o C

[jpak]

http://www.theregister.co.uk/2011/03/12/second_nuke_plant_emergency/

The Japanese government has declared an emergency at a second Japanese nuclear plant: Fukushima No. 2, seven miles away from Fukushima No. 1, which lost cooling after Friday's devastating megaquake in northeastern Japan.

Japan's Kyodo News reports that on Saturday morning, Tokyo Electric Power Company (TEPCO) released news that the cooling systems had failed in three reactors in the Fukushima No. 2 nuclear power plant.

TEPCO, said Kyodo News, "notified the industry ministry that the failsafe system at the No. 2 plant stopped functioning as the temperature of coolant water has topped 100 C." A TEPCO spokesperson told Fox News that pressure was stable in the reactors, but rising in their containment vessels.

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[xchrom]

1. Recommend

[somone]

2. And the reactors at Fukushima No. 2 are newer

[Sirveri]

3. Reactor coolant water normally is above 100C...

Not really sure why they're pimping a normal that is within normal operating temperatures.

[jpak]

4. When they are operating normally - not not after a scram

n/t

[FBaggins]

5. Just means that the water is boiling.

Where did everyone think the extra pressure was coming from?

I think that a number of their reactors are at this point now.

It's important to keep in mind that the amount of energy being added to that pool is going down and down as the hours go by. Simply reachign the boiling point isn't the departure into the danger zone.

[jpak]

7. "the failsafe system at the No. 2 plant stopped functioning"

n/t

[FBaggins]

8. Ok. And?

That's not the only safety system.

They're still a LONG way from a major disaster.

[jpak]

9. It is

I'm sorry to say

[FBaggins]

10. "It is" what?

Their only safety system?

Give me a break. That's not even CLOSE to accurate.

[Sirveri]

6. Yes, even after a scram, you can't drop coolant temperature that quickly.

You'll hit thermal limits for the core and risk brittle fracture if you do that. Plus there is the issue of how much heat you can dump from the volume of water in the coolant system, which is probably like 20k gallons. Also you've got about 1.5% of power still being put into the coolant system due to decay heat.