Skip to main content

Disclaimer: I haven't operated a nuclear reactor since 1984 and I have not kept up with it closely.  But I do know some basics and have written a short note.  I warmly welcome correction or elaboration from those who know more.

The Fukushima nuclear power station has 6 so-called "boiling water reactors"

In these type of reactors, water is sent through the core, boils and turns into steam which in turn spins the blades of a power generating turbine.  The steam is then condensed back into water and goes through the core again.  This steam/water is radioactive.

The reactors have been shut down; the control rods (which absorb neutrons which cause the fissions) are down.  But, a significant amount of heat comes from the radioactive decay of the fission products; this is called "decay heat":

when a uranium atom splits, there are two new atoms formed.  These atoms are unstable and will decay and release gamma radiation (very strong rays caused by a change of energy states; these similar to x-rays but stronger).    This gamma decay generates a significant amount of heat; depending on reactor design this can account for more than 10 percent of a reactors power.  I don't know what percentage of power that decay heat accounts for in the Fukushima design.

Hence the core has to be cooled even if the reactor has been shut down; heat is still being generated and the core has to remain covered.

We have radioactive steam problems (hence the pressure build up), escape of gasses in the water, and of course, some potential for the overheated fuel pellets to melt.

I do not know what the odds are in this situation.

This will NOT be a Chernobyl situation as there was a graphite fire in Chernobyl and this reactor has no graphite; also Chernobyl didn't have a containment building.   This is more similar to the Three Mile Island situation.

Bottom line: they need to get some water circulation in the primary system (the water system that runs through the core) to keep the core cool.

The explosion:  could have been many things, including many non-nuclear things.

Your Email has been sent.
You must add at least one tag to this diary before publishing it.

Add keywords that describe this diary. Separate multiple keywords with commas.
Tagging tips - Search For Tags - Browse For Tags


More Tagging tips:

A tag is a way to search for this diary. If someone is searching for "Barack Obama," is this a diary they'd be trying to find?

Use a person's full name, without any title. Senator Obama may become President Obama, and Michelle Obama might run for office.

If your diary covers an election or elected official, use election tags, which are generally the state abbreviation followed by the office. CA-01 is the first district House seat. CA-Sen covers both senate races. NY-GOV covers the New York governor's race.

Tags do not compound: that is, "education reform" is a completely different tag from "education". A tag like "reform" alone is probably not meaningful.

Consider if one or more of these tags fits your diary: Civil Rights, Community, Congress, Culture, Economy, Education, Elections, Energy, Environment, Health Care, International, Labor, Law, Media, Meta, National Security, Science, Transportation, or White House. If your diary is specific to a state, consider adding the state (California, Texas, etc). Keep in mind, though, that there are many wonderful and important diaries that don't fit in any of these tags. Don't worry if yours doesn't.

You can add a private note to this diary when hotlisting it:
Are you sure you want to remove this diary from your hotlist?
Are you sure you want to remove your recommendation? You can only recommend a diary once, so you will not be able to re-recommend it afterwards.
Rescue this diary, and add a note:
Are you sure you want to remove this diary from Rescue?
Choose where to republish this diary. The diary will be added to the queue for that group. Publish it from the queue to make it appear.

You must be a member of a group to use this feature.

Add a quick update to your diary without changing the diary itself:
Are you sure you want to remove this diary?
(The diary will be removed from the site and returned to your drafts for further editing.)
(The diary will be removed.)
Are you sure you want to save these changes to the published diary?

Comment Preferences

Subscribe or Donate to support Daily Kos.

Click here for the mobile view of the site