“You can see the main tunnels, pieces of debris down to about the size of a vehicle, maybe even a fuel drum.
“Our preliminary estimate is that we think the debris field is about 55 acres in size, or 100 football fields and we think it contains just over 9,000 metric tonnes of debris.
“We are very interested in how deep everything goes and where it is so that when we go to do our simulations of how much meltwater there might be at the site over the next century.
“There are concerns that if meltwater starts interacting with the debris field, it could mobilise some contaminants.
“In the Sixties, the building codes were a little different, we know, for example, that the materials they were using at Camp Century were rich in PCBs and other types of persistent contaminants and they still come out of the ground kicking, they don’t deteriorate at all.”