It's hard for us to determine exactly what the source of the difference is because we don't have a very clear window as to how DND determined its cost estimate. The most recent one that it released publicly is a couple of years old, so it's very difficult to determine why DND's cost estimate is so much lower than ours. Time is an important factor, contributing to the difference. Besides that, DND is in a good position to determine what's different between its cost estimate and ours, because our methodology is very well known to DND. It's pretty open and transparent, but we don't have the same window into DND's methodology.
On October 31st, 2022. See this statement in context.