• Blog Stats

    • 82,799 hits
  • Archives

  • Enter your email address to subscribe to this blog and receive notifications of new posts by email.

    Join 158 other followers

  • Copyright notice

    This blog entry and all other text on this blog is copyrighted, you are free to read it, discuss it with friends, co-workers and anyone else who will pay attention.

    If you want to cite this blog article or quote from it in a not for profit website or blog then please feel free to do so as long as you provide a link back to this blog article.

    If as a school teacher or university teacher you wish to use content from my blog for the education of students then you may do so as long as the teaching materials produced from my blogged writings are not distributed for profit to others. Also at University level I ask that you provide a link to my blog to the students.

    If you want to quote from this blog in an academic paper published in an academic journal then please contact me before you submit your paper to enable us to discuss the matter.

    If you wish to reuse my text in a way where you will be making a profit (however small) please contact me before you do so, and we can discuss the licensing of the content.

    If you want to contact me then please do so by e-mailing me at Chalmers University of Technology, I am quite easy to find there as I am the only person with the surname “foreman” working at Chalmers. An alternative method of contacting me is to leave a comment on a blog article. If you do not know which one to comment on then just pick one at random, please include your email in the comment so I can contact you.

  • Advertisements

The degree of core damage in the Japanese nuclear reactors

Dear Reader,

I hold the view that the way in which nuclear fuel behaves during an accident is not simple, and it has a great effect on the way in which an accident progresses (or does not progress).

In the ideal world the radioactivity inside a nuclear fuel will stay locked inside the fuel like a dangerous criminal locked in their cell. Sadly during an accident some effects can liberate the radioactivity from its prison cell.

One reaction which I consider to be important is the reaction of zirconium (the tubing used for covering most reactor fuel) with water, this is a reaction where the water oxidises the zirconium to form zirconium dioxide and hydrogen. Under normal aqueous oxidising conditions titanium and zirconium are passive because they have an oxide layer which prevents any further reaction. But at high temperatures steam, oxygen and hydrogen can react with zirconium alloys. For details please see the following documents.



Another important reaction is the thermite like reaction between uranium dioxide and zirconium tubing, this reaction was observed at Chernobyl. In a paper by B.E. Burakov, E.B. Anderson, B.Y. Galkin, E.M. Pazukhin, and S.I. Shabalev, Radiochimica Acta, 1994, volume 65, pages 199-202 they use the evidence created by this reaction (uranium zirconium oxide) that shows that the fuel at Chernobyl reached 2500 to 2600 degrees centigrade.

These reactions damage the zirconium alloy tubing and in the latter case it helps the melting process.

The IAEA have stated that in unit one that TEPCO now think that 55 % of the fuel has been damaged, in unit two 35 % of the fuel has been damaged while in unit three 30 % of the fuel has been damaged. I sadly do not know what they mean by “damaged fuel”, it is not clear what the dividing line is between damaged and undamaged fuel is.


I hope to be able to post my views on some of the other reactions which are likely to occur during an accident another day.


Go on, Have your say !

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: