§ Llew Smith
To ask the Secretary of State for Trade and Industry which international agreements cover the arrangements permitting the swapping of plutonium batches between that material owned by British Nuclear Fuels, British Energy or the United Kingdom Atomic Energy Authority and that owned by foreign customers as held at Sellafield. 
§ Mr. Wilson
In the European Union, the ownership of nuclear materials is governed by the Euratom provisions that deal with the supply of nuclear materials (essentially Chapter 6 of the Euratom Treaty). These provide that exchanges of material—which are basically a commercial matter for the companies concerned—require the approval of the Euratom Supply Agency on a case-by-case basis.
External obligations, for example limiting the use of such material to peaceful, non-explosive purposes are, however, a feature of some international nuclear co-operation agreements, such as those between, Euratom and the United States, Euratom and Australia and Euratom and Canada. In some cases where there are no Euratom agreements in place, there are bilateral agreements which contain comparable provisions. The owners of nuclear material can request that external obligations attached to one batch of material can be exchanged or swapped for different obligations on another equivalent batch of material. Each such request for a swap involving material that is subject to Euratom co-operation agreements must be approved by the Services of the European Commission, whose assessment takes account of the characteristics of the nuclear material concerned, (i.e. to ensure that the swap would not diminish the obligations involved) and the reasoning behind the request.