Tuesday, March 15, 2011

Japan U-235

As most of the faithful readers here know, I’m not much good at prayer and mumbo-jumbo. I take great comfort in knowing the facts. Yep, there is nothing like having a solid grip on reality for me. So, I keep hearing about this nuclear cloud coming to our shores from Japan’s failed nuclear power plants. Not being very reassured by the governmental agencies reassurance that “everything is okay folks”. I decided to look into a few things myself. Of course, I only looked into the things that are so real that you could hit them with a hammer.

It seems that at least two of the power plants are under control because they are keeping them cool by pumping seawater into the reactor core. There is this little thing called “critical mass” that can cause uranium 235 fuel rods to burn ferociously when allowed to become too close together. They can keep the critical mass from being reached by keeping the fuel rods separated by “heavy water”. If anything happens to allow the rods to interact with each other and start ”reacting” they will melt down, hit the bottom of the reactor vessel, where they will start reacting uncontrollably. The Uraniun 235 reaction isn’t in danger of exploding because it isn’t contained tightly enough. (layman terms) It starts to heat up and burn uncontrollably, and melt through the bottom of the vessel. When that happens, the hot melting uranium will melt through the rock underneath and keep boring it’s way toward the center of the earth. Uranium 235 is heavier than the surrounding rock , so it will have a tendency to stay together and keep boring.

Eventually, the uranium will become diluted and lose it’s critical mass and stop heating. Unfortunately, while it is boring beneath the reactor vessel it will be spewing great masses of radioactive steam and other radioactive particles, that are very, very dangerous to breathe. Some people think that Iodine tablets may save them, but it’s not a very good cure for radioactive poisoning, in fact, there is speculation that it only works for children.

While it is comforting to know that the seawater that they are pumping will keep the reaction under control, it occurs to me to wonder what the next step will be. Those that think the problem will eventually go away are right, but the half life of uranium 235 is 700 million years! So, 700 million years from now, the uranium will be half gone. Sadly, the way half lives works, is that it will take another 700 million years to get rid of HALF the remaining u-235. That’s a long wait folks. I wonder how many times that they will be pumping the worlds supply of seawater past the reactor cores. Not a very comforting thought. Now I know why people just pray for miracles. It’s easier, and much more productive.

10 comments:

Anonymous said...

I've heard that the Uranium 235 burns at 3000° C and the containment at the site is rated up 5000° C. If it does burn through the containment we better Pray.

Oregon

charlie two crows said...

Ernie......Two of the four reactors in Japan,
afew years ago decided to mix plutonium rods in with the U 235 rods. The plutonium if confined enough will explode not burn. Years ago I attended a PGE open house at the eureka nuke plant. They said in a case of melt down the lock down would leave the controllers confined to the control room! Doors locked. Even though the humboldt plant is decommissioned. The spent rods are still on the property outside the containment vessel. Just like the plants in japan. A tsunami at the humboldt site could damage the spent rods in water bath that are on the site.

Ernie Branscomb said...

Three Mile Island accident

Ernie Branscomb said...

Charlie
The radiation has to be either contained or cooled to take the heat away. Either way, I think that they are screwed.

I think the thing that bothers me the most, is that we have the technology to make nuclear reactors safe enough to root up and roll down the road. Greedy investors keep us away from doing so. A perfect example of greed is the Gulf oil spill. They bypassed numerous safety measures that could have made the well perfectly safe. I.E. Using heavier drill pipe, redundant automatic surface-level shut-off valves and using regular drilling mud instead of just seawater. All of these things were done against the screams of the drill platform workers that it was unsafe.

The weak link in humanity is becoming more and more apparent that it's Greed". Technology doesn’t fail us, greed does.

Bunny said...

I'm glad we're getting older Ernie. It's not going to be a pretty sight. What the hell happened to the conscientious of mankind? And I feel like it all happened in our exact lifetime. damn.

charlie two crows said...

Ernie........Read the book (We almost lost Detroit) The true events reported in the book are relevant this very minute!!!!

I've said here before; look at the picture of destruction, look way in the back round. You will see GREED walking away unhurt. In this case the figure walking away is GE!!!!!

charlie two crows said...

Ernie.......you mentioned Three Mile Island. The six reactors in Japan are light Water Reactors. Three Mile Island was and its sister reactor is a BREEDER REACTOR. Ernie look that up. It will scare the hell out of you!

Anonymous said...

Looks like the Mayans had their stuff together.

Oregon

Anonymous said...

Ernie, reactor 3 was powered partially with plutonium. The hald-life of that is far far longer than if it were a uranium reactor. If the winds blow it over here, there will be problems. There will be problems regardless.

When they cool with seawater, seawater has all kinds of particles and minerals. Those become radioactive just from being near the rods. While not as bad as plutonium in the atmosphere, it will enter the food chain.

charlie two crows said...

The first nuclear accident on american soil (with casualties) occurred at SL-1 reactor in Idaho falls. All three operators were killed. One was found stuck to the ceiling, Impaled by one of the U-235 rods. There is a tall fence around the site,no admittance EVER. The Government and the manufacturer(GE) covered the accident up for years. So that other sites wouldn't loose their startup licensing(Humboldt PGE nuclear) ,do to public outcry. Even now its hard to get the truth about this nuclear disaster. Greed wins again!