The INL were the folks that made the reactor used in Camp Century. I think it was serial #6 (which would imply that there were at least 6 made).
Just read your Greenland story, but couldn’t stop until I had read the whole page. Great anecdotes! I was in the Air Force ‘61 through ‘65, and 5 months of that was Ernest Harmon AFB in Newfoundland in the winter. I was always thankful I didn’t get sent to Thule.