The UK is shipping plutonium dioxide from Sellafield, Cumbria, to France this week using a converted roll-on, roll-off ferry .
The powder will be driven in French lorries from Sellafield to a local dock and then aboard the ship. The vessel will carry security staff from the Civil Nuclear Constabulary. The cruise is being organised by the UK's Nuclear Decommissioning Authority
The Atlantic Osprey is a single-engined ship and will travel with an armed escort.
The exact date is being kept secret on security grounds, but is expected in the next few days. Spokesmen for both Lib Dems and Tories expressed concern at the shipments. Anyone who's taken a look out of the window today at the gale-lashed UK will also be pretty concerned about the prospect.
Protest group Cumbrians Opposed to a Radioactive Environment (CORE) warned that the cargo was an attractive target for terrorists.
Core spokesman Martin Forwood said: "The shipment from Sellafield will contain enough plutonium to make a large number of such devices and it is plain stupid that, given this and other warnings in recent years, the Government and industry are still prepared to put us at risk with their cavalier attitude to security and public safety."
The group warned that previous shipments of plutonium powder had full military escorts.
The ship in question is rated INF 2 - the second of three possible classifications.
Core can be found here. ®