Two armed ships set off from the northwest of England this week to sail round the world to Japan on a secretive and controversial mission to collect a consignment of plutonium and transport it to the US.
The cargo of plutonium, once the most sought-after and valuable substance in the world, is one of a number of ever-growing stockpiles that are becoming an increasing financial and security embarrassment to the countries that own them.
So far, there is no commercially viable use for this toxic metal, and there is increasing fear that plutonium could fall into the hands of terrorists, or that governments could be tempted to use it to join the nuclear arms race.
All the plans to use plutonium for peaceful purposes in fast breeder and commercial reactors have so far failed to keep pace with the amounts of this highly-dangerous radioactive metal being produced by the countries that run nuclear power stations.
The small amounts of plutonium that have been used in conventional and fast breeder reactors have produced very little electricity − at startlingly high costs.