They started building the new airport in 2006, and it took 5 years. The new and improved runway is on the site of a previous smaller runway that was used occasionally for medivac flights and maybe other small charter planes.
The former regular airport was around 30 km away, close to the old mine and townsite of Nanisivik. Weather at the old airport was frequently a problem so flights would often be cancelled- I have heard it's much better now that the new airport is open. As well, if the taxi forgot you on it's way to the old airport (happened to me once!), it was a very big deal to try to get a ride out there before the plane left without you (if it landed at all... weather!)