In the 1940s and 1950s, its scientists and engineers played a significant part in the development of the main production techniques (reactors, reprocessing and enrichment); British companies have been prominent since the outset in uranium mining and processing; since 1958, Britain and the US have engaged in a unique and highly secretive military trade in plutonium, HEU and tritium; through its heavy investment in Magnox reactors and its construction of large-scale reprocessing plants, Britain was the world's largest separator of civil plutonium (domestic and foreign) before being overtaken by France in the mid-1990s; Britain probably has the widest experience of any country of decommissioning reactors and fuel-cycle facilities; it has contributed in important ways to the development of safeguards and physical protection techniques; and among the nuclear weapon states (NWS), Britain has gone to the greatest lengths to submit its civil nuclear activities to international safeguards. .
This history gives Britain significant influence over policies towards fissile materials and, thereby, over the development of arms control and fuel-cycle strategies. But it also presents the new British government with a series of issues that need to be addressed with some urgency. .
The first concerns the future status and regulation of fissile material production, stocks and infrastructures in the UK, the other four NWS (Russia, the US, China and France) and the three de facto nuclear weapon states (India, Israel and Pakistan). The importance of increasing transparency and bringing their various nuclear assets under more extensive multilateral control is widely acknowledged, and necessary measures have been identified, the most prominent being the Fissile Material Cut-Off Treaty (FMCT) and the verification of warhead dismantlement envisaged in START III. However, most diplomatic initiatives in this field are currently in the doldrums.
