TEPCO to inject nitrogen gas into No. 1 reactor containment vessel tonight due to fear of explosion

[Viva_La_Revolution]

Source: Daily Yomiuri

DailyYomiuri The Daily Yomiuri
by BreakingNews
BREAKING NEWS: TEPCO to inject nitrogen gas into No. 1 reactor containment vessel tonight due to fear of explosion from hydrogen buildup.
1 minute ago

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[maddogesq]

1. I guess they need to come up with a 10 on that 1-7 scale.

This is getting way beyond Chernobyl. Ladies and gentlemen, we're talking the health of the Pacific, much less the futrue of a nation that has been around for a long time.

[benh57]

15. Um, no.

Hardly. You have no clue about Chernobyl if you think this is anywhere close.

[DeSwiss]

18. Not everyone agrees.

While there are several dozen substances that can be of concern in a nuclear accident, this analysis will focus on cesium-134 and cesium-137. Cesium has a long half-life, is easily incorporated into living organisms, and results in full body radiation exposure. It has been the major legacy of contamination from Chernobyl, and is the basis for the exclusion zones enforced in Eastern European countries today and for the foreseeable future.

Cesium is a fission product, produced by the splitting or decay of larger atoms of uranium (or plutonium, whether from MOX fuel blending or from plutonium produced in normal nuclear fuel reactions). Together with strontium, cesium produces most of the decay heat over a long period after a core is shut down.

Oak Ridge National Laboratory analyzed the core constituents at the Brown's Ferry nuclear plant as a 'reference unit' for boiling water reactors. In a 1,065 MW core, cesium was estimated at 429 kg given an extended period of fuel irradiation. For the slightly smaller 1,000 MW Chernobyl core the comparable figure would be 402 kg if the fuel was fully irradiated, but Chernobyl Unit 4 was only three years old. For the Fukushima Daiichi Units 2, 3 and 4 rated at 784 MW, 315 kg of cesium should be present in each core load of fuel. For the 460 MW Unit 1 185 kg of cesium would be present.

Thus, in the cores of Units 1-4, some 1,130 kg of cesium was in place when the accident occurred. Adding the spent fuel pools (net of the offloaded Unit 4 core) gives an additional 1,245 kg for a total of 2,375 kg of cesium in the damaged buildings

Fraction Of On-Site Material Emitted Into the Atmosphere

According to the UN, only 22 kg of cesium was released into the atmosphere as a result of the Chernobyl accident. The amount of cesium at the Fukushima Daiichi site, then, represents over 100 Chernobyl releases. The next question is, what fraction of the total cesium may be released into the atmosphere from Fukushima Daiichi?

http://oilgeology.blogspot.com/2011/04/jim-in-mn-analyses-radioactive.html

[flyingfysh]

2. There is another suggestion that should be tried

Bob Park of the University of Maryland has this suggestion for *all* nuclear reactors:

I have repeatedly urged that a tuft of "platinum wool" always be attached at the high points of nuclear containment buildings where hydrogen bubbles would be expected to collect. The platinum would catalyze the oxidation of
hydrogen back to water before the mixture reaches an explosive level. The one-time cost would be trivial.

[Mika]

5. Stockholders wouldn't hear of it .....

http://www.kitco.com/charts/liveplatinum.html

$1794/ounce tonight.

[caseymoz]

11. You talk about theft in a bad economy.

You might as well say "fill it with gold coins."

Nitrogen is a great idea. Really, they should look into gas cooling now that water-cooling has proved to have too many drawbacks.

[Webster Green]

3. Hydrogen would be from deteriorating zirconium cladding on rods, I think.

That doesn't sound good.

[caseymoz]

13. Actually, that story is about ten days old.

The worrisome thing is that they haven't made any progress in bringing this under control.

However, I do believe that problem was in reactors 3 & 4. This is reactor 1!

[Webster Green]

17. Yeah, I thought #3 was the worst problem. n/t

[50000feet]

4. The key phrase is

"fear of explosion." I suspect they don't know how much hydrogen, if any, has built up in any of the containment structures. Injecting nitrogen gas would preempt a possible build-up. This NYT article gives some explanation:

http://www.nytimes.com/2011/04/06/world/asia/06nuclear.html?pagewanted=1&_r=1&hp

[jimlup]

6. Wow they can't seem to find an euilibrium!

We are still going down here...

[Electric Monk]

7. WSJ link

APRIL 5, 2011, 10:37 P.M. ET
Tepco: May Pump Nitrogen Into No.1 Reactor Due To Possible Hydrogen Build-Up

http://online.wsj.com/article/BT-CO-20110405-714963.html

TOKYO (Dow Jones)--Tokyo Electric Power Co. (9501.TO) said Wednesday it may inject nitrogen gas into the No. 1 Reactor at its crippled Fukushima Daiichi nuclear plant to prevent a possible explosion due to a buildup of hydrogen.

"We are thinking of putting in nitrogen gas to prevent a hydrogen explosion, to reduce such a risk," a Tokyo Electric ("Tepco") spokesman told Dow Jones Newswires, adding that there was a possibility that hydrogen gas may be accumulating in the No.1 reactor.

He added that this would be the first time to use such a measure to tackle the ongoing crisis at the plant.

Separately, a Yomiuri Shimbun report on the same day said that Tepco is also considering pumping nitrogen into the No. 2 and No. 3 reactors.

[jwirr]

8. If one explodes will it cause a chain reaction in the others and I would

like to know what the comparison between a reactor like this exploding and a bomb exploding are? In other words - how close to a nuclear winter are we? I know nothing about these things so enlighten me.

[caseymoz]

10. It won't cause a chain reaction.

Not in terms of a nuclear chain reaction, anyway. A nuclear bomb is very complex and precise thing, because it takes a lot of fine tuning to make an explosion like that. You can't just do it accidentally.

No, it's not going to be like a nuclear bomb. It will be like a big, rather conventional, but dirty, bomb. The explosion will be caused by heat and chemical reactions not direct nuclear ones.

What it will do is, it will scatter radioactive material far and wide. Not in the form of a cloud but in the form of fallout. Most of the damage and death will be from this fallout and resulting radiation, not from explosion. And reactor might burn and smolder for weeks releasing fallout. It will be impossible to get near them due to the high radiation. However, there won't be nearly enough dust from four reactors to create a nuclear winter. No, Sagan was speaking of nuclear war-- many, many nuclear bombs.

But the radiation will be a big problem. It could make northern Japan uninhabitable and cancer deaths due to fallout could effect any country in the pacific rim.

[jwirr]

12. Thank you. That gives me a much clearer picture of what could happen. nt

[caseymoz]

9. Nitrogen sounds excellent, at least they're thinking outside the box.

And they need that here.

They might also try liquid sodium. which will be a liquid anyway if it's close to that heat. It's used as nuclear coolant, second only to water, or maybe even superior to water.

But I guess it's not chemically neutral enough when it's uncontained, especially in the presence of hydrogen and oxygen, but then you can inject nitrogen in too to keep it neutral.

Or how about a neutral cooling gas like helium or argon? I mean, if water's causing too much trouble, and it is then you have to try a different coolant. Good thing about helium or argon is, no radioactive materials will dissolve in it like water.

Of course, those gases are hard to get in the quantities needed, but they have to do something.

[MilesColtrane]

14. So that's going to do what?

...turn the gas inside the reactors into ammonia?

And, doesn't ammonia explode at high temperatures too?

(Go easy on me. The only chemistry class I ever took was over thirty years ago.)

[truthisfreedom]

16. My guess is it's supposed to displace the oxygen so the hydrogen can't explode

The idea is similar to a CO2 fire extinguisher... it displaces oxygen too, eliminating oxygen necessary for the fire to burn.

An attempt to "smother" the hydrogen.