KUA nuclear flask Profile and Models

KUA nuclear flask

37423 hauls two Nuclear Flask wagons to Devonport in May 2014. ©Clagmaster

The fleet of two KUA Nuclear flask carrier wagons were produced for the Ministry of Defence in the Late 1990s for the transport of spent nuclear fuel. Primarily these wagons are seen carrying used fuel from Royal Navy nuclear submarines at Devonport and Rosyth for disposal at Sellafield. They are also known for using the Far North line to access the Nuclear Research Centre at Dounreay. These imposing vehicles are some of the largest wagons in use in the UK, and each weigh 150 tonnes when loaded. Typically these wagons are double-headed with a pair of diesel locomotives and are sometimes escorted by specially adapted support coaches, with military personnel on-board for security.

Type of Vehicle

Nuclear Flask Carrying Wagon


Bombardier/ Prorail, Wakefield

Build Dates


Total Built


Wheel Configuration

Articulated - Four Bogies

Operated By

Direct Rail Services

Main Duties

Nuclear Waste Disposal

In Service Until


Surviving Examples

Both in service