Re: CANDU Reactors

[Rodney Bauman <rodney_bauman@wssrap-host.wssrap.com>]

Kent, Michael wrote:  

>Just a quick question.  

>I'm not an expert, but doesn't CANDU reactors use U-238?
>I believe if they do use U-238 to generate electricity,


Answer:  No.  The CANDU reactors use U-235, just at its natural abundance.  The
trick is to employ a moderator that doesn't absorb valuable thermal neutrons as
effectively as light water - i.e., deuterium oxide (heavy water).  With heavy
water as the moderator, the thermal neutron absorption is reduced by a factor of
~ 630 compared to ordinary water.  Subsequently, enough thermal neutrons will
survive in the core to maintain criticality with natural uranium as the fuel.

Rodney Bauman, CHP, RRPT
rodney_bauman@wssrap-host.wssrap.com



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