Japanese Nuclear Watch Update – One Meltdown, Another Probable, Large Evacuations Ordered - FDL

[WillyT]

Japanese Nuclear Watch Update – One Meltdown, Another Probable, Large Evacuations Ordered
By: Bill Egnor
Sunday March 13, 2011 6:54 am


This cutaway diagram shows the central
reactor vessel and thick concrete containment
in a typical boiling water reactor of the
same era as Fukushima Daiichi 1
(image: www.world-nuclear-news.org)


<snip>

Disaster is not too strong a word for what has happened to Japan in the last three days. The biggest earthquake recorded, the subsequent massive tsunami and now the follow-on of at least two partial meltdowns of nuclear reactors at Fukushima and the critical status of three more there, and others in the nation.

Let’s start with a little vocabulary so things are as clear as they can be in this confusing situation. When I talk about the “Reactor Vessel,” I am talking about the stainless steel bottle where the fuel and control rods are housed. This also includes the entire pressurized system for generation of electricity as it is a closed single loop system.

When I talk about the “Reactor Building,” that is a concrete structure primarily designed to keep the weather off of the reactor and generator equipment. It was not designed to be another sealed radiation containment building like AT some of the plants elsewhere the in the world.

That said, let’s talk about what we do know. Reports vary but between 200,000 and 450,000 people have been ordered evacuated from the area around the Daiichi and Daini power stations. The Daiichi complex is the older of the two with 6 reactors built in the 1970’s and Daini has 4 reactors built in the 1980’s

It is the Daiichi Unit Number 1 that has experienced the explosion (more on that shortly) and has been the focus of an attempt to cool the reactor core with seawater. Reports have come in that Unit Number 3 there has also had a complete failure of the emergency cooling system and rods are exposed to a level of three meters. (more after the jump)

This is a very dire situation as some percentage of the rods (it is unclear how many) have been loaded with Plutonium instead of Uranium235. Plutonium is not only radioactive for a much longer time (a half life of 24,100 years) than uranium but is directly toxic to humans in small doses. If this reactor completely melts down and ruptures its containment vessel exposure to the resulting fallout pollution would be devastating.

<snip>

More: http://my.firedoglake.com/somethingthedogsaid/2011/03/13/japanese-nuclear-watch-update-one-meltdown-another-probable-large-evacuations-ordered/

:evilfrown:

:kick:

[Iwasthere]

1. Why Plutonium

How much additional power does Plutonium give a plant? Is it cheaper? Not worth the risk, obviously. Uranium is bad enough. JESUS FUCKING CHRIST!

[Tesha]

4. There's lots of plutonium around from various countries' nuclear weapons efforts.

It's also a waste product derived from reprocessing
spent low-enriched uranium-based nuclear fuel from
commercial nuclear power plants.

It represents a substantial source of "stored energy"
and a nuclear weapons proliferation hazard so one of
the better ways of getting rid of it is to "burn" it
as "mixed oxide" nuclear reactor fuel.

This is one of the many ways in which the nuclear
weapons and nuclear power establishment represent
"the gift that keeps on giving".

Tesha

[snagglepuss]

6. Good explanation at the link

http://www.nirs.org/factsheets/basicmoxinfo.htm

[meow mix]

2. "no immediate danger" indeed

[roamer65]

3. I have always been against loading MOX fuel into commercial reactors.

It is bad enough that we use the Light Water Reactors (LWR's) as they require enriched uranium, MOX fuel means you're "tickling the tail of the dragon" even further.

If we must utilize nuclear power, I am much more a fan of CANDU reactors (Canada - Atomic Energy of Canada Ltd). They are heavy water (Deuterium Oxide) modulated reactors that can run on unenriched uranium and can even run on spent fuel from LWR's.

[snagglepuss]

5. what are LWRs