This is from the CANDU plant near my house "Total capital costs including interest were $14.319 billion CAD (about US$11.9 billion) with the heavy water accoun

This is from the CANDU plant near my house "Total capital costs including interest were $14.319 billion CAD (about US$11.9 billion) with the heavy water accounting for $1.528 billion, or 11%, of this. " $1.5 billion (CAD) for heavy water seems like a LOT of money??