Subject: Use of heavy water in nuclear weapons

From what little I know on the matter, it sounds like heavy water is used to 
slow reactions in a nuclear reactor, as opposed to the reactions in a nuclear 
weapon.  Yet I've heard that heavy water could be used in the creation of 
nuclear weapons.  Is this true?  In what way is, or has, heavy water been used 
in nuclear weapons?

I've searched the archives to find answers to this question, but I haven't 
found anything regarding the use of heavy water in nuclear weapons.

Re: Use of heavy water in nuclear weapons