North Sea radioactive cargo sinking

Although no radioactive material was released into the environment from the cargo carried by the Mont Louis when it sank in the North Sea, the incident brought international attention to the dangers of transporting such material.

THE EVENT: Sinking of a ship carrying a cargo of hundreds of tons of radioactive material

DATE: August 25, 1984

Uranium hexafluoride is a radioactive material created in the process of refining uranium. Naturally occurring uranium consists of two isotopes: uranium 235 and uranium 238. Only uranium 235 can be split apart in a to produce energy. In the process used to separate the two isotopes, the uranium is converted to uranium hexafluoride and passed through a gaseous facility.

On the night of August 25, 1984, the small French ship Mont Louis was running eastward in the North Sea, parallel to the coast of Belgium. It carried a cargo of thirty containers holding 225 tons of uranium hexafluoride. At the same time the Mont Louis was passing, the West German vessel Olau Britannia departed from Flushing, Holland, bound for Sheerness, England. In this situation, the Olau Britannia had the right-of-way, but there was heavy fog, and the sailor who should have been the Mont Louis lookout had been assigned other duties. The Olau Britannia struck the Mont Louis in the starboard, or right, side. The two ships remained locked together until they were pulled apart by tugs, at which point the Mont Louis capsized and sank in 14 meters (45 feet) of water. Although five members of the ship’s crew fell into the sea, they were quickly rescued, and no one on the Olau Britannia was seriously injured. Some of the fuel aboard the Mont Louis leaked into the sea and fouled a Belgian beach near Ostend.

The uranium hexafluoride on the Mont Louis had been created in France, and it had been en route to a gaseous diffusion facility in Riga, Latvia. Most of the uranium hexafluoride had been made from freshly mined uranium, but a small amount had been made from used reactor fuel. While uranium itself is mildly radioactive, uranium hexafluoride made from used reactor fuel is contaminated with highly radioactive materials produced in the reactor.

The Mont Louis lay with its starboard side above the water and the containers of uranium hexafluoride still in its hold. Smit Tak International, a salvage company, was hired to recover the uranium hexafluoride and then raise the sunken ship. The salvage workers cut a large hole in the exposed side of the ship and used a floating crane to lift out the containers of uranium hexafluoride. Throughout this process, which took weeks, detectors were used, but no significant radioactivity was found. The last container of uranium hexafluoride was recovered on October 4, 1984. The wrecked ship was raised on September 29, 1985. The estimated cost of the salvage operation was $4.6 million.

Rules published by the International Maritime Organization state that ships larger than a certain size are requested, but not required, to notify authorities in those nations whose coasts they pass if they carry dangerous cargo. Because the Mont Louis was under the size limit, its owners were not obligated to follow this recommendation. The crew had received no special training in handling radioactive cargo; they may not even have known that the ship carried such cargo. It was fortunate that no uranium hexafluoride was released into the in this incident. If a had occurred, it would have posed a danger to personnel near the scene but not to people onshore.

Bibliography

Angler, Natalle. “A Shipwreck Sends a Warning.” Time, September 10, 1984, p. 33.

Business Week. “An Accident at Sea Raises Nuclear Alarms.” September 10, 1984, p. 58.

Makhijani, Arjun, Howard Hu, and Katherine Yih, eds. Nuclear Wastelands: A Global Guide to Nuclear Weapons Production and Its Health and Environmental Effects. 1995. Reprint. MIT Press, 2000.

"1984 – Mont Louis." Maritime Integrated Decision Support Information System Transport of Chemical Substances, 18 Aug. 2021, midsis.rempec.org/en/incidents/1984-mont-louis. Accessed 22 July 2024.