Japan crisis - the worlds economic outlook?

Really2

michaels wrote: »

As I understand it the fissionis going on, earthquake happens and control rods are inserted which stops fission from increasing (more particles are absorbed than emmited so gradually fission rate declines presumably towards the natural decay rate of each fuel rod.

Has anyone read anything about how long this is likely to take for the rods to reach a level of activity at which they no longer require water cooling and thus could be moved?

I am fairly sure I read they can be removed after 2-3 months after cold shut down and cooling.
Could be wrong ( most probably I am) but I believe that was the case with one of the reactors (possibly 4?), it's fuel had recently be moved to a communal pool for servicing.

hardass_ets

All this time its releasing harmful radiation, this is going on far longer than Chernobyl

1984ReturnsForReal_2

Really2 wrote: »

Cooling it is the first priority

Cooling it is the only priority.

After that they need to stabilise the buildings. Some on the verge of collapse. Then they can work out what to do with the fuel.

Its going to be many months before things are "contained"

ronny_todgers

Gorjao wrote: »

What does that mean stabilise the reactor?

One idea would be to make a big platform of about 2m of solid lead because radiation can not get through that much lead. Then on top of that a high melting point containment material. Then use machines to put all the reactors in the containment material then pour another 2M lead on top and then about 30 ft of concrete on top just like Chernobyl.

The problem is if they just cover the top then radiation goes down and get into the water supply.

What about under the reactor?

Sorry you are a bit misinformed about chernobyl! no 2m of lead there and the concrete containment is now full of holes and is only a few feet thick!

It is however a completely different situation as others have said - in Chernobyl the core was made of massive lumps of graphite which burned away pumping vast amounts of fuel and waste products into the atmosphere for days after the initial explosion.

In Japan I don't think they have had any leaks of fuel itself - most of the radiation released has been from radioactive Iodine which has a half life of 8 days and genuinely poses very little if any risk to those not working at the site. They need to collect the store the more contaminated water which they are doing now but there is no prospect of needing to entomb the whole site unless they get fuel escaping from one of the reactors in significant quantities. - Fingers crossed we are passed the risk for that.

SilverStandard

They were talking about building a big containment thing around each reactor.

But the problem is to stop radiation going down and then yes getting into the water.

pwllbwdr

Radiation going down is not a problem. Leakage of radioactive isotopes to the ground below and the water table would be a problem.

Really2

hardass_ets wrote: »

All this time its releasing harmful radiation, this is going on far longer than Chernobyl

are you sure about that? We did not know about chernobyl for days it took a fair time to get it sorted as far as I can remember.

SilverStandard

The Northern Hemisphere now has higher radioactive levels than the South because of Chernobyl, after this it will be even higher.

Really2

SilverStandard wrote: »

The Northern Hemisphere now has higher radioactive levels than the South because of Chernobyl, after this it will be even higher.

Even higher than when? 6 days after Chernobyl, 6 months after Chernobyl? or higher than 10 years ago or higher than 2 months ago?

So even higher is a bit of a red herring it is unlikely to go higher than the aftermath of Chernobyl for any country except Japan.

SilverStandard

Obviously since Chernobyl