8.9 earthquake in Japan: tsunami warnings

hypatia

And now a explosion at the damaged plant..this just keeps getting worse.

DevilsAvocado

Too small:

Massive Explosion at Fukushima I Nuclear Power Plant

Astronuc

There are conflicting reports:

Explosion did not occur at reactor: Japan spokesman
http://mdn.mainichi.jp/mdnnews/news/...dm073000c.html

vs

Explosion Destroys Walls of Japanese Nuclear Reactor Building, NHK Reports
http://www.bloomberg.com/news/2011-0...k-reports.html


http://www.world-nuclear-news.org/RS...s_1203111.html

It is certainly a very serious, even grave, situation. However, it is difficult, even impossible to give a reliable assessment based on the sketchy information available.

Lacy33

Hi Astro,
So we are wondering here really, is it possible that it will be a Chernobyl type situation or as my husband thinks and hopes they build these plants differently now.
I think I understand him to say that. He worked on building one.
What I am asking specifically is it possible that we could have an event that big again?
And are any professionals going there to help keep Japan it safe?
And Astro why are you not over there now helping? Thank you

nismaratwork

It really does sound like it was a hydrogen explosion... the images show smoke rising, but mostly dirty steam. I'm... unclear that this is anything as serious as an exposed or melting core. Chan Dallas is reporting, "620 mREMS/Hour", which I certainly don't want a part of, but it's hardly going to make you... poop... the bed.

I'm buying 'hydrogen blast' without the fuel becoming exposed.

nismaratwork

Oh, and 9,500 missing in Miyagi prefecture alone (CNN)

Astronuc

I don't see this being the same as Chernobyl, but there is a concern that if the cladding oxidizes/corrodes that fisson products would be released into the coolant. Fissions gases, radioisotopes of Xe and Kr, and volatiles like I, could be released into the atmosphere, but one would expect, the Iodine would be trapped in filters. Other soluble nuclides would be in the cooling water.

Japan has a large population of professionals, and the USNRC and other organizations are ready to step in and provide support and assistance.

There will be repercussions due to the poor performance, really failure, of the safety systems. I imagine that unit 1 at FK Daiichi will be permanently shutdown, especially if they use seawater directly in the core.

The industry will do yet another reassessment of the preparedness for such an event.

I would certainly go if asked. I would like to be there in person to see what is actually going on, but I'd be in the way. They need personnel with direct plant operating experience with that particular plant design.

nismaratwork

Do you think there's any way to turn this event into a drive to actually BUILD newer generation reactors, replacing older models, rather than the usual anti-nuclear hysteria?

DevilsAvocado

Thanks Astronuc. Yes, it seems hard to get coherent and reliable info. The question is why?

Of course it’s a very 'confusing' situation with quakes and tsunamis, but personally I don’t like when things are obvious 'downsized' from the company in charge:
Every amateur on the planet can watch the videos and see the explosion with own eyes...

We, and probably every Japanese are asking the same question – What is really going on??


Note: I’m not a fundamentalist "anti-nuke", that’s stupid. My opinion is that being a fundamentalist "pro-nuke" could be 'problematic' as well... (no offence). My opinion is pragmatic; we should go for the safest, environmental and most productive solution...

Astronuc

There was definitely an explosion at the plant. It's not clear from the media what building did explode. Edano is stressing that folks stop propagating rumors.

http://news.yahoo.com/s/ap/20110312/...pan_earthquake

I have no idea how information flows from the plant to officials or the media. I am too far removed from the situation.

Certainly the US NRC will lean on the suppliers of nuclear technology and the utility operators to make sure that such failures do not occur in the future. However, to make any meaningful assessment, we need accurate information about what actually happened and is happening.

As I mentioned elsewhere, it looked like the explosion occurred away from the troubled unit 1. But I'd have to find a site map to determine the orientation of units 1-4 in order to figure out which building was damaged in the explosion.

Edit: If unit 1 is the northernmost of the 4 units, then it is unit 1 where the explosion occured.

Units 1-5 apparently have Mark I containment.
http://www.ucsusa.org/nuclear_power/...elying-on.html


Most plants of that type have metal building (shells) surrounding the reinforced concrete containment. If the outer metal structure is damaged, there is still the inner reinforced concrete containment system.

Here is a basic schematic of a BWR unit.
http://www.nrc.gov/reactors/bwrs.html

The problem is to get cooling water through the emergency cooling system to the core inside the pressure vessel.

According to this article - Japan has informed IAEA about explosion: watchdog
http://www.channelnewsasia.com/stori...116088/1/.html

nismaratwork

I think that nuclear power is, as you say, just one of the newest tools in the arsenal of energy production. It has its ups, and its downss... anyone who says anything else is selling you a spent Uranium mine.

Still... why the reliable info gap? Fear... media echo chamber... distrust... and the reality that radiation is not something most people understand at the 'gut' level. Hearing 620mREM/hour is alarming in one sense, but in a practical sense it's not... I'd worry if we're in the REM/hour range, which is going to do some ugly things to you if you stick around.

Still, how many people in the world bother to study radiation exposure, which isotopes decay at what rate... they'll fear mystical fallout, and inhale radioactive I without a blink. People are fundamentally terrified of things that can kill them, without being seen.

nismaratwork

One thing that isn't up for grabs: 4 people have been (at least) injured in that explosion, so I'm guessing the info-flow is not exactly smooth from on-site, to staging area, to central command post.

Oh, and there was just a 6.4 aftershock... sheesh.

DevilsAvocado

Watch it! I was on the edge digging up that disgusting Lame Joke!

True. No one is winning the "media war" acting like "Baghdad Bob", "Tahrir Mubarak" or "Tripoli Crazy Horse"...

Well, we actually got some of the 'stuff' from Chernobyl here on the ground in Sweden... and I can tell you it’s not fun to wonder if those delicious Mööse-meatballs are radioactive or not! ()

nismaratwork

Of course they're radioactive, they would be anyway... the trick is HOW radioactive, and is it a strong alpha emitter?

Remember, Chernobyl was a meltdown and a fire... a complete disaster and failure of containment and cooling of the fuel. At worst, and please correct me if I'm wrong here Atronuc, I think this could be a 3-mile Island... at the worst. I don't see a burning core in the future of this plant, but I can understand why you'd be concerned.

Hell, if we weren't looking at coal as the main alternative, it wouldn't be so attractive, but theonly way to look at nuclear power is in the context of its alternatives.

DevilsAvocado

True, and the truth is that the levels in Sweden was not lethal. And yes, there are no working alternatives, yet.

(Astronuc could you pleeeeaaaase fix that Cold Fusion Beta 1.0 NOW!! )

rhody

If I may, first, thanks Astronuc for providing such honest and accurate assessment as possible given the situation. Stepping back for a moment, and on a brighter note (no, nismara, no pun intended, hehe), a few years back I watched a Frontline or PBS or 60 Minutes segment I can't remember which on the making the uranium fuel rods safe. I won't go in great detail, but the essence of the presentation was:

Make the rods in small segments with (combined with other elements, boron perhaps) if the rods heat to a critical, but not super critical state (due to the loss of cooling water), they are designed to give off "slag", that was the term used in the segment, and this would build up around the perimeter of the rod, slowing the reaction to a safe level. Lastly, these rods would be arranged in the core in such a way that if the cooling water were removed, they would not explode. I believe the they said that this technology has been available since the mid 1980's, and I am not sure if any of our plants use this fuel rod configuration or technology. I am sure their are efficiency issues as to how much heat is really produced using this type and configuration of fuel rod assemblies, but that is not the point here.

Would you care to comment on this, for the benefit of us all ?

Thanks...

Rhody...

P.S. I added overhead view of plant, see thumbnail...It appears from the thumbnail that is from 1975, it is just Fukushima I NPP, there are four more near the site, so I am not sure this is really of that much value, but I thought I would give it a shot, see wiki. From the video it appears to occur in the third plant (separated by towers) from the right, however, if that is helpful. Wow, the wiki is up to date, and fairly accurate, kudos... to who ever is keeping it updated. I am impressed, for once...

Astronuc

It's apparently more like TMI-2 core damage than Chernobyl.

Picture shows the loss of upper containment, the metal part of the building that covers the inner concrete containment.
http://d.yimg.com/a/p/ap/20110312/ca...cVI7tak6ppOw--

The explosion could have been from hydrogen which is generated from the oxidation/corrosion of the Zircaloy (Zr alloy) cladding of the fuel and the channels surrounding each assembly with the steam at high temperature. The hydrogen then escaped from the primary system into containment and the resulting explosion blew off the metal sheeting.

It would appear that Unit 1 is history.

Let's not bring cold fusion into this.