‘Largest-ever’ 165-ton spent nuclear fuel flask to be carried by modified diesel ship
The Pacific Grebe has completed technical modifications to carry the TN Eagle, a new type of transport flask for used mixed oxide fuel. This vessel is the first in the Pacific Nuclear Transport Limited (PNTL) fleet to undergo these changes.
Following initial trials at the Barrow Marine Terminal in the United Kingdom, the ship moved to Cherbourg, France, for a series of full-scale test fittings.
Engineers confirmed the flask was compatible with several different holds to ensure that the ship’s infrastructure could accommodate the equipment.
PNTL, the operator of the vessel, is primarily owned by Nuclear Transport Solutions (NTS), a subsidiary of the United Kingdom’s Nuclear Decommissioning Authority. Other shareholders include the French company Orano and a group of Japanese utility companies.
“Nuclear Transport Solutions (NTS), the world’s leading nuclear transport specialists, has successfully evolved its shipping capability to transport a new nuclear flask, ensuring the safe and secure transportation of spent Mixed Oxide (MOX) fuel,” said NTS in a press release.
Already received orders for several flasks
The organization has moved more than 2,000 nuclear casks over a distance of approximately 5 million miles. Its operations serve several countries, including Japan, the United States, France, Germany, Finland, and Sweden.
The fleet currently consists of three diesel-powered ships: the Pacific Heron, the Pacific Egret, and the Pacific Grebe.
The decision to update these vessels follows the development of the TN Eagle flask by Orano. This flask measures 5 meters in length and 3 meters in diameter, with a total weight of 150 tonnes (165.3 tons), as reported by World Nuclear News.
The design received regulatory approval from the French Nuclear Safety Authority in 2020 and from the US Nuclear Regulatory Commission in November 2023.
Orano has already received orders for several dozen of these flasks from various international customers. Because of the size and weight of the TN Eagle, specific engineering was required to integrate it into the PNTL vessels.
NTS engineers and transport specialists developed an adapter plate to secure the flask within the ship’s hold. This component was manufactured with millimetre precision to provide a stable fit.
“The 150-tonne flask was successfully placed in the ship’s various holds to check compatibility, and the exercise proved an outstanding success,” added NTS.
Creation of a specialized tool
The project also involved the creation of a specialized tool designed to align the ship’s removable decks with the flask during loading and unloading. These modifications were necessary because the TN Eagle is the largest package that NTS has managed in its transport history.
According to NTS Director of Shipping Conner Love, the trials in France precede a series of spent-fuel movements the company will conduct globally. The organization plans to adapt the Pacific Egret in the near future to ensure it can also accommodate the TN Eagle design.
These updates are intended to maintain the company’s capacity to transport nuclear materials in accordance with current regulatory and technical requirements.
“We are proud to have worked on the successful completion of this project, but this is just the beginning as we embark on a series of vital spent fuel movements around the globe,” concluded Love.