Nuclear plants in Japan risk meltdown

[Cookie]

None are safe. My husband worked on one of the three back then in Taiwan, I think, after his death they added a fourth. They get some pretty fierce typhoons & earthquakes. He worked on Unit 1 & 2 in Shippingport and he had to quit because the rads he was getting was comparable to those my mom got getting rads for health reasons. I would shut off the lights to see who glowed more. I still wouldn't live near Three Mile Island for no money in this world. Depending on how the wind blows I would reckon, everyone is going to glow alittle from Japan's meltdown. And, it is going to be around a long, long time; and, cause alot of stomach problems.

[ballvalve]

The British are on the way.

http://www.bbc.co.uk/news/uk-12721827

Not sitting on their hands like the Americans.

And remember this is not a pot stirrer!.... And from his cousin:

You may find it interesting that us dumb Americans have also built atomic power plants in seismic active areas...
Here in the US we have the San Onofre and Diablo Canyon Reactors with similar seismic exposure...

Diablo is not in the ring of fire, and its not in a position for backup power to be flooded [DUH! in japanese] And Diablo was stopped for 3 years for the most intensive seismic upgrades ever made.

If you can make a power plant that operates on a ship in a typhoon, you can make the same model for use on land

And if anyone had a brain 40 years ago, and I believe a few did, all the plants would operate in FAIL SAFE mode with passive cooling, irregardless of a power supply or a drunken operator.

But then the pump makers would'nt have made much money on the plants construction.

Funny how every city in America has a water tower up 100 feet in the air with a few hundred thousand gallons of water in it for relatively non-safety related issues. But the Japanese couldnt afford to put a few next to each reactor?

HEY! Just in from Japanese news central: "We discova Dodge floor mat got stuck under the nuclear accelerator pedal!!" And "we no design-a the hokey pokey electronics! .... Amelican General Electric designer told us put genalator on beach!!! So we had to put old fuel lods ona roof, shaking building apart in earthquake - plobably cause by Amelican drill rigs in Alaska. "

And all horseplay aside, no humans should face this three punch knockout they have suffered. If these plants melt down, japan will lose about half of its real estate. At least we have places to move people to.

[Redwood]

Here ya go BallValve! Have a go at it!
http://esa21.kennesaw.edu/activities...nergy/nuke.htm

[ballvalve]

Take the pumps OUT and have a go at the game ! The reactor always wins.

Think of todays nuclear power as every house on pumped sewage and septic.

Gravity rules. Like a Tsunami.

[Cookie]

I feel bad for those people in Japan. So many are missing. I read an article where a woman was looking for her missing husband and it made me think so much of my life. So many people told me to just get over my husband's loss, to move on, like I could just go out and replace him. I was infact, treated badly. So many people just want to ignore you when something bad happens, and they want you to ignore it, too. But you can't. I feel bad for these people's suffering and I hope others will treat them much more kindly than I have been with my loss in life. They will suffer with PTSD, just like I do.

[nukeman]

ballvalve: there are some designs out there that are based on passive cooling. One design does use the "water tower" concept by placing a large tank of water above the core inside of the containment (reactor) building. Although gravity always works, there are challenges with this too. Remember that a plant during normal operation will be at 2200 psia or so (for PWR reactors)..the GE is a BWR and typically runs around 1000 psia. You get about 0.5 psi for every foot of head, so to be able to inject under high pressures, this water tower would have to be close to 0.5 - 1 mile high (not practical). The other issue is the amount of water needed. Not only do you need enough water to fill the reactor vessel to the top of the core, but you really need enough to flood the entire reactor building to the level. If there is a break in the piping, the water that you put in just goes back out and onto the floor. If your containment is intact, you just flood the thing to the top of the core level and go into "boiling pot" mode. This might require 500,000 to 1,000,000 gallons of water or more. The other issue is that this tower and piping would need to be "safety-grade" meaning that it could withstand earthquakes, tornados, huricanes, etc. The other issue is that the containment outer shell is the last line of defense with regards to a fission product barrier (I'm talking about typical PWR reactors here). This means that you don't want penetrations through this wall to the outside.

In the current designs that use a water tank above the core for passive cooling, they need to get the system pressure down to were the head from the tank can overcome the system pressure in order to inject. They use 4 valves that are about 14" in diameter that pop open and release to the containment. If your containment has failed, then this would be released to the environment.

These are the reasons why active systems are typically used.

In the design of the reactors where this event is going on (BWRs), the building that was damaged is not designed to be a real barrier. The real containment barrier is inside the building. On typical PWR (usually plants where you see a dome), the outer wall is typically 4' thick concrete, heavy rebar, plus a steel liner. Some newer designs even use a double containment ( two shells, each 4' thick, with a gap between them).

The other aspect to this is to what levels do you design to? Typically, we will look at historical information and design for the worst + additional margin. Now say you build somewhere that has never recorded a quake bigger than 2.0. What do you design for? Do you design for a 4.0...but then maybe a 5.0 will hit? Maybe you design for 8.0 and an 8.9 hits??? Each point you go up on the scale is 10x the magnitude, so building to withstand an 8.0/9.0 in an area that has never seen over 2.0 is not very practical. Nature typically doesn't give us an upper bound for disasters. All you can do is look at the historical information and do your best to design based on that information. There is always some chance that something will happen that is worst than anything ever recorded (like this event).

[Redwood]

It looks like the #3 reactor has now had an explosion.



Nukeman, Be prepared for a never ending argument that defies all logic and common sense...
Bear in mind you are talking to an engineer....

One whose never-ending passion for pressure relieving ballcocks and relief valves vs. expansion tanks has been opposed by every plumber on the forum...

Good Luck with that!

[Cookie]

Hey hey Red, my beloved was an engineer! And, the nicest guy you would ever had met. He never let on how smart he was even though like I told him, I had a higher IQ, lol. I was smart enough to marry him.

I got a solution for the reactor problem, build less! The world will survive loads better with less, "less is more."

I am sure, they will rebuild another and another and another.

[Cookie]

I almost forgot this. I had someone tell me, that bad things happen ( storms etc) in our country, this person was from Japan by the way, because of our sins. Hmmm.

[jimbo]

No easy answer here. An accident or natural catastrophe involving a reactor is a big thing, but rare. How many people over 100 years have developed cancer from the exhaust of fossile fuel and coal plants? What about the pending disasters at many coal sluge 'lakes' which are starting to leak?

There is no free lunch. And Darwn always wins.

[ballvalve]

One whose never-ending passion for pressure relieving ballcocks and relief valves vs. expansion tanks has been opposed by every plumber on the forum...

Seems the japanese agree with pressure relief valves - to vent Hydrogen that blows up on bad days. But plumbers and their design knowledge, and ability to think beyond grandpa's ideas [just a bit over roofers on the scale of clear thought] Would have used a few expansion tanks for the reactors core. And they would have put them out front on the ocean side.

If it wasn't for the engineers you'd be out threading iron pipe day in and day out. And if it was not for plumbers unions, we would have had PEX 30 years ago.

Nukeman, Be prepared for a never ending argument that defies all logic and common sense...
Bear in mind you are talking to an engineer....

Placing backup power on the beach, is what defies logic. If the highest predicted wave was 25 feet, then a few more sticks of iron would raise that genset to 50'.

Pretty elementary, Watson. And today, one of the plants ran out of fuel for the gensets. I guess there is a shortage on diesel tanks to place around power plants.

There are some engineers with dirty hands, JB weld and a few excavators that were raised with common sense, who think outside the box. But most of the plumbers, roofers and painters I have used had, at best, just dirty hands.

You are correct in that at least 80% of engineers can't tie their shoes, and have never driven a screw, drilled a hole or set a big valve....

[Ian Gills]

Stop this talk of Darwin all the time!

Just because he wins does not mean he is right.

The problem with evolution is that it is too short-term.

In other words a species that will thrive later can be completely wiped out by a simple short-term event, like a radiation leak or global warming.

American values seem to be based on natural selection. And in this sense are also too short-sighted.

Some of those you discredit and choose not to help today, may be the ones you need tomorrow.

[ballvalve]

Nukeman, my wine cellar has a domed 6 to 12" thick high strength concrete roof, with at least as much steel as the average Nuke dome. Now if I can afford that, and the existing plants are at 4", we have a pack of dopes building them.

The passive nuclear plant designs exist, and will continue to be improved upon:

http://en.wikipedia.org/wiki/ESBWR

The operator can sleep for 3 days and it won't blow.

GRAVITY! a CONSTANT.... PUMPS - a problem. Valves - problematic, but redundancy helps.

That is just one of them, and an example what an engineering team with some common sense and an angry public can inspire.

Natural selection is as constant as gravity, and will always prevail over social 'programs'. Just turn off the power in Japan -entirely- for a month and assume the red cross and the supply chain is otherwise engaged. That would make a fine horror film.

Under such conditions, those you helped yesterday, may be roasting you on a spit tomorrow.

[Redwood]

If it wasn't for the engineers you'd be out threading iron pipe day in and day out. And if it was not for plumbers unions, we would have had PEX 30 years ago.

Yea...
30 years ago the engineers gave us Polybutylene with Acetal fittings...
Can you blame us for being a tad bit reluctant to jump up and down with joy eagerly accepting the next generation of plastic miracle pipe?
When the plumbers were left holding such a large liability on a defective product...

Especially when the lawsuits started up with Kitec http://www.plumbingdefect.com/index.html, Zurn, Rehau, and DuraPex....
And many of those same companies that made the polybutylene are doing the same thing over again...
The plumbers are going out of business and the manufacturer says "There isn't anything wrong with our product but we are going to stop selling it."

Nukeman, my wine cellar has a domed 6 to 12" thick high strength concrete roof, with at least as much steel as the average Nuke dome. Now if I can afford that, and the existing plants are at 4", we have a pack of dopes building them.

Ummm Ballvalve....
I'm seeing some sloppy engineering here...
Attention to detail is very important in engineering especially when life safety is involved.
Nukeman said 4' thick.... the difference between 4' and 4" is 44" which is a fairly large error when you are designing a nuke reactor containment dome...

Please whatever your area of engineering excellence is please go there and stick with it....

This Jack of All... Master of None... is getting a little scary....
You are clearly out of your league both in Plumbing and Nuke Design...

There are some engineers with dirty hands, JB weld and a few excavators that were raised with common sense, who think outside the box. But most of the plumbers, roofers and painters I have used had, at best, just dirty hands.

You are correct in that at least 80% of engineers can't tie their shoes, and have never driven a screw, drilled a hole or set a big valve....

Clearly you aren't saying that you as an engineer would be using JB Weld on a Plumbing or, Nuke Build....
That is not thinking outside the box or, with common sense! That is just plain Hackery!

I'm beginning to think that I have met an engineer that hacks his way along using JB Weld to cover his mistakes, Ties his shoes with a granny knot, puts in screws and forgets to tighten them, drills crooked holes, & we can only hope hasn't set a big valve where life safety might be an issue....

[nukeman]

BV: I think we have a problem with units here. A typical containment is 4' (FEET) thick. It looks something like this:



On the plants that are having problems, the building that was destroyed is nothing but a roof for the building for the most part. The actual containment is intact, which is pretty impressive given what it has endured.

I'm fully aware of passive plant (Didn't I already say that?). I have even worked on some of them. What you have to understand is that even passive plants do require some active systems to get the job done. For instance, if you want to inject water using gravity, you 1st need to drop the system pressure. This means opening some large valves and dumping to containment. When you do, steam/coolant/contamination goes out with it. If your containment had failed, this gets released to the public. So to get the water into the system, you may have to have a significant release to the public. In addition, if multiple valves fail to open, the pressure won't drop fast enough to get the water in there before the core melts. Like anything, there are advantages and disadvantages to any design.