If my fragile and incomplete mental picture of the reactor challenges in Japan is accurate, the most pressing need is to get water to the reactors to cool things down into controllable temperature zones and to keep various hot bits covered.

Discussing this on ETS will not physically solve this problem, but perhaps we can use the story to exercise the brain trust in suggesting ways of that could work. It feels a bit like helping which I like better than the helpless alternative, and who knows what we might come up with?

So:

1. How much water do they need?

2. If that amount of water was delivered to the site, are there systems that would let them easily use it?

3. Is there infrastructure in place that could be used to deliver enough water to the site, even if it means converting it from its different intended use?

4. Is there new infrastructure that could be put in place quickly enough to get the needed water to the site?

5. Do we know how far the site is from big enough water sources like the ocean, big lakes, and rivers?

6. Is container delivery of water a viable solution?

7. Is onsite generation by water-from-air technology a viable solution?

And then there are the smart questions that those who understand the reality better than I can suggest!

What I don't understand: if the nuclear plant was flooded once, why can't they do it again?

Taking the plant to the water instead of water to the plant, so to speak.

Jim- Can *you* generate a 40 foot wall of water from the ocean when you need one?

Dweste- While these might seem sensible questions it feels to me like it's the same kind of thing as asking about why a platoon leader doesn't have his men shoot just a little further to the left or wondering why they don't get out the grenade launcher while he's engaged in combat.

We don't know. We aren't there. Our discussion won't help them solve the problem.

Make a donation to disaster relief headed for Japan if you want to help. (we already have)

Fugushima's right next to the pacific ocean..

Well, isn't there a way to transport the fuel rods and dump them into the sea? That will keep them cooled right?

http://theconservativetreehouse.files.wo...w=640&h=445

This photo gives a better understanding of the scale of the problem.

If you take into consideration the physical size of the building then even the Japanese Authorities stating that they jury rigged a series of water pipes from the ocean to then run sea water into the burnt out reactor buildings is once again getting more and more difficult to believe.

The latest news media reports of the use of Riot control vehicles with water cannon to pump water into the reactors is once again a red herring.

Right next to the ocean when there's been a 9.0 earthquake and there's no electricity means the ocean is a long ways away.
Bucket brigade might be a solution.

The fuel rods are probably (a) hard to find (b) too radioactive to handle (c) heavy (d) impeded by minor obstacles such as reactor vessels, containment vessels and explosion debris.

If a virtually unlimited supply of water will not solve the problem, or get it into the solvable range, then - never mind!

My questions do assume the opposite, and then ask for thoughts on how to get the water to the reactor site.

As I updated my post in the other thread, it seems that they will be restoring grid power soon. If successful, then it sounds like they can restart the normal cooling systems instead of doing whatever jury rigged system they're using right now.

http://www.youtube.com/watch?v=6JrIYR8jArk

Sounds like this is what happens if you get all those 'nuclear experts' currently doing the rounds on the news media and put them in a room.

If the piping is intact.
If the pumps will run.
If the valves will open/close.
If the electrical power to the pumps is intact.
If the controllers for the pumps are intact.
If the intake supply to the pumps is/are intact.
If the operators can get to the manual valve handles.

There are probably a half-dozen more IFs involved.


Don't forget, there was a 9.0 earthquake followed by a 40' wall of water and several explosions and lots of water and debris getting kicked around. Some damage may have occurred.

Still, it might help. I'm sure it will, eventually.

I hope they are successful in restoring grid power, especially if that is all it will take to get things under control. So one answer to the "get the water there" question would be to get enough power there to allow the in-place infrastructure to "get the water there."

If true, then the question might be more usefully transformed, or at least become a companion to the original questions, into how to "get and keep the power there." Then some questions would be:

1. How much power do they need?

2. Is there a practical way to generate enough power onsite with generators?

3. If onsite generation is not practical, then what offsite power sources are close enough, or can be moved close enough, to provide the needed power?

Yep.

Even with grid power available, restarting the normal cooling systems presumes that the normal cooling systems are intact. Considering the fires and explosions in the Fukushima reactors, grid power may not be enough.

They really needed those back-up diesel systems to function as designed. Back-up systems don't need to be efficient, but they do need to be reliable under the most adverse conditions.

Eventally they are going to have to remove the fuel rods, or what's left of them. The problem is at the moment those rods are too hot and too damaged to move. Also, if transported unshielded, they will administer a lethal dose of radiation to anybody in the area within 18 minutes. For reference; A dose of 6-10 Sieverts (Sv) is fatal even with treatment, and Chernobyl (which had exposed rods) was pumping out 20 Sv/hour.

I did a little more reading on BWRs.

Rod groups of 75 to 100 rods per bundle.
About 800 rod bundles per reactor.

That's a lot of rods. 140 tons or so.



Easier to bring the ocean to the rods. (even if it isn't very easy)

Each of the ideas you have is noble and well intentioned, and if they could be done, they would be done.
No expense is being spared here - they have already deliberately destroyed $26 billion dollar reactors in an effort to control the reaction, there's no lack of willingness or ability to try ANYTHING to cool the systems. The reality is that the scope of destruction is so incredibly vast and the most basic assumptions we have (Get a crane! Get a fire boat!) are crippled by a lack of roads, fuel, debris in the ocean, on the land, everywhere. Roads completely gone. No food, no water, it's snowing.

This is, in every definition an apocalyptic disaster.

Y'all do realize the steam from the hot radioactive rods is radioactive. And when the rods are uncovered they get hotter, so when water is introduced, they make steam.

The problem is getting water to the plant, then somehow containing the steam which if left unfettered will contaminate a large area. Think of steam heat in a house; the steam has to go someplace to condense, and in this case, it must be a closed protected system.

Next problem is that workers just can't be in there. They have to be in suits, and work in rather short shifts, or they get dead pretty quick.

So you have a plant that's basically in pieces, contaminated by radioactivity, and it can possibly blow up at any moment.

And not to mention that somehow the water was being split into component parts and that is an explosive risk - hydrogen and oxygen in an area makes a boom with a small spark capable of igniting it.

I know I wouldn't want the job of fixing this mess.

Some additional perspective on the size of the problem.

A typical house faucet moves 2.5 gallons per minute. A firetruck can pump around 1,500 gallons per minute. One of the pumps used in a BWR can move over 100,000 gallons per minute.

That means that it would take a whole lot of firetrucks to equal just one of the normal pumps.

Another way to look at it. The electrical generating capacity of unit #1 is around 460MW. The actual thermal capacity is much higher due to inefficiencies in converting heat to electricity. The notional thermal capacity of a shut down reactor is approx. 5% of operational load. Ignoring the inefficiencies that makes the shut down reactor core the equivalent of at least a 23MW heater that needs to be kept cool. I can't recall the loss rates for steam turbines and generators at the moment but I would suspect we could easily double that to 43MW and still be low. Multiply by 3.4 to get rough BTUs.

That is a lot of heat to transfer.

- Eric

Is there a straightforward answer to the question: will getting a lot of water to the reactor site help?

Only those on scene could actually answer the question. For those of us in the bleacher seats there is no simple straight forward answer. Generally more water is a goodness but there are all sorts of exceptions and complications that vary by circumstances and we just don't know enough to reliably make the call.

Edit/Add - a lot of water is a variable quantity, if you only have enough capacity to turn a lot of water into steam without getting everything covered again that may be worse than leaving things uncovered. When talking megawatts of heat generating capacity the definition of a lot grows very quickly.

-Eric

If this aerial photo is accurate, then the reactor complex is directly adjacent to the Pacific Ocean - for all practical purposes an infinite supply of seawater.

http://www.imgstant.com/-open-channel-blog-2007-japan-quake-was-wake-up-call-on-nuclear-safety-474x500/msnbcmedia2.msn.com%7Ci%7CMSNBC%7CComponents%7CInteractives%7C_swf%7CNews%7Cjapan_quake_2011%7CFukushima-Daiichi-Nuclear-Power-Station2.jpg/

Problems of lack of water must be very local lack of means to pump enough water to the places where it would do the most good.

If the proximity of the ocean is a given, I would have thought ship based pump and power systems would have been deployed. I can only guess the magnitude of the need exceded such straightforward solutions. [Shudder.]

Some problems with just adding water when the temperatures are too high:

Steam explosions. Happens if you heat water very rapidly in an enclosed cavity. Water and very hot metal is a very volatile mix if the rapid expansion of steam has nowhere to go. (I remember that one liter of water would turn into 1200 liters of steam in an instant if you put it in direct contact with molten metal).


Steam will have to be vented to the outside air. Hopefully, the steam itself won't bee too radioactive (at least not for too long) and hopefully it won't drag highly radioactive aerosols (particles small enough to be airborne) with it


Chemical reactions between the water and components in the reactor control rods and/or fuel rods that leads to formation of hydrogen. Mixed with oxygen it is very explosive. There has already been several hydrogen explosions, if I am not mistaken.

Complex Systems (hopefully) fail in complex ways.

There's a LOT of problems with adding water to fuel rods that are already very hot. It will definitely cause oxidation reactions with both the zirconium and uranium (the casing and fuel in the rods). These generate further heat. It could also cause some formation of hydrogen, which causes subsequent explosions. That has already happened several times. And if the rods get VERY hot, the process of hitting them with cold water might even crack the outside casings - releasing pellets of uranium (which would tend to settle by sinking to a lower level).

These are not my thoughts - they came from a buddy at work who was in the nuclear industry. I just talked to him this morning.

BUT with all that being said ... my friend still thinks the best thing is to flood the exposed rods with lots of seawater. And i assume that the Japanese are still working on this option. The trouble is - they are facing one of the biggest challenges in Engineering Emergency Operations in the last decade. Let's see how they handle it.

other Pete

As I understand they are very close to having a line which will provide electric power to the main pumps. This is the only long term solution in my opinion (which means darn little). The main pumps will get the water moving where it needs to be.