§ Lord Jenkins of Putneyasked Her Majesty's Government:.
Whether, given that it would be difficult but technically possible to use plutonium arising from reprocessing at Sellafield "to produce a reliable weapon giving a predictable yield" (WA 184, 24 July 1997), they will confirm that building a crude nuclear bomb with an unpredictable yield from reactor grade plutonium would be no more difficult than building a more reliable bomb from weapons-grade plutonium.
§ The Minister of State, Ministry of Defence (Lord Gilbert)It is our considered view that it would be more difficult to build a nuclear weapon, even with unpredictable yield, using reactor grade rather than weapons grade plutonium. A number of factors, including increased radiological hazards, would lead to additional design and manufacturing complexities. However, a sufficiently determined group or state with nuclear aspirations might be able to overcome these difficulties and produce such a device using reactor grade plutonium. It is because of this that civil reactor grade plutonium held in this country is subject to the most rigorous physical protection measures and to stringent nuclear materials control and accountancy procedures. Such material is also subject to EURATOM safeguards and may also be inspected by the IAEA.