What is the different between a light water and a heavy water nuclear reactor?

Question

Seem Canada is using heavy water reactor and the US is using light water. what is the different between them in the following area?

1. construction cost
2. running cost
3. maturity of the technology
4. safety
5. effiecncy
6. any other...

Answer 1

As they say in the South Park movie "Blame it on Canada". Heavy water is a stronger absorber of neutrons than is light water. So the heavy water reactor would use less material than the light water reactor, and might initially cost less to build. Then there is a tradeoff in the cost of providing heavy water vs light water (nearly free). The technology are both mature; in fact, the realization that the Nazis were interested in nuclear bombs was due to their activity at a heavy water plant in Norway, which was subseqently destroyed.

Answer 2

light water or standard pure water was Chemically = H20.
Heavy water chemically was = H202.
(All the "2"s should be written as subscripts, slightly below the base line.) (Two parts of Hydrogen, and two parts of Oxygen for heavy water).