The Canadian Nuclear Safety Commission's on-site inspector has confirmed that all four canisters carrying hazardous material that fell while being moved off a cargo ship in Halifax are intact.

The CNSC expert arrived from Ontario Friday evening. He confirmed none of the containers leaked after falling from a height of six metres.

"Canadians should be reassured that Canada only allows shipments of uranium material for peaceful purposes in accordance with its international non-proliferation commitments on the peaceful use of nuclear substances," the CNSC said in a news release.

Halifax Regional Fire and Emergency said a large container was being moved just before 10 p.m. AT at the north-end dock when the bottom released, dropping up to four canisters filled with uranium hexafluoride.

Uranium hexaflouride, considered a "class seven" dangerous material, is a chemical compound used in the gas centrifuge process to enrich uranium, that is then used as reactor fuel or to arm nuclear missiles.

The CNSC confirmed that radiation levels at the site were "extremely low."

"The transport package used for the shipment ensures that levels pose a very low risk to the health and safety of Canadians and the environment. In fact, standing [six metres] from the containers for a period of 10 consecutive hours would result in a dose comparable to taking a cross-Canada flight," the commission stated in a release.

Calvin Whidden, senior vice-president of Cerescorp, the company that operates the terminal, said though dangerous goods are shipped through the Ceres terminal in Halifax all the time, they've never had anything like this happen before.

“We ship everything imaginable through the port. There are nine classes of dangerous material — they’re all handled, but to comfort anybody and everyone they're very stringently regulated," he said.

“We’ve never had any experience with a class seven, with this kind of catastrophic fall. We have had incidents before, of course, we handle over a million containers here … they're mechanical machines and humans operating them, so there’s human errors, there’s mechanical failures.”

Whidden said people in Halifax should be confident what's coming through the port is safe, saying this incident was a worst-case scenario.

“I think they should be very confident … it does show that it’s properly packaged, it does show it can withstand a fall. So the absolute worse thing that could have happened to a class seven radioactive box — and it survived. So I think it shows confidence in how it’s packaged and how it’s handled,” he said.

There was little movement Friday at the usually bustling Ceres terminal in north-end Halifax. Cranes are halted and trucks are parked.

Whidden said crews are expected to be back on the job Saturday at 8 a.m. AT.

Investigators with the Canadian Transport Emergency Centre will be coming to ensure there is no leak. They'll also figure out the best way to safely remove the material that fell.

Upon arriving at the scene, members of the Halifax fire department found levels four times higher than background levels. In other words, the levels were higher than the base level humans are exposed to daily, but it was still a low reading.

“There’s radiation everywhere all the time. It was just an indication it was higher than normal,” said Phil McNulty, a spokesman for Halifax Regional Fire and Emergency.

McNulty said the public isn't at risk.

“The experts have told us we should have a 50-foot area around it,” he said. “So that's a very small evacuation zone.”

The call was made to evacuate the area. A further inspection showed there was no actual leak.

“We believe the risk to the people here in Halifax is absolutely zero," said Whidden. "We don't believe we have any breach of the product at all. We don't believe we have any radiation coming out.”

But Whidden said they weren't taking any chances.

Workers tested

“So we shut the terminal completely down and sent everybody home until the experts get here with the proper equipment to determine whether there is actually a leak or not,” he said.

Employees were tested for radiation exposure, but McNulty said no one tested positive.

Not much moving in and out of the Ceres terminal in Haliax Friday morning. (Angela MacIvor/CBC)

The crew of the Atlantic Companion, the ship carrying the four containers, were taken to a local hotel.

Two evacuated crew members, who didn't want to be identified for fear of losing their jobs, said the ship encountered two bad storms on the crossing over from the last port call in Liverpool, England. They said there were about 29 crew members on board.

Whidden estimates between eight to 10 containers carrying radioactive material are transported through the terminal every month.

He said the containers were encased in concrete and then metal to protect the hazardous material inside.

“Very, very seldom do they drop,” he said. “It’s a mechanical failure of some kind, and it actually could be the box itself that has failed.”

Whidden said it's rare and happens maybe once every "200,000 lifts."

Containers guarded

About half a dozen firefighters roamed the scene Friday morning, the CBC's Craig Paisley reported. The containers are cordoned off.

McNulty said his team executed a "picture-perfect" response.​

The Canadian Nuclear Safety Commission said it was aware of the incident.

The shipment was bound for South Carolina.

Atlantic Companion is a Swedish-built ship owned by Atlantic Container Line.