Seeking clarification on the Environment Agency’s statement to Sellafield’s local stakeholder group (WCSSG) meeting on 9th June that, with ONR, it has been asked by the NDA to review the option of immobilising plutonium, CORE received the following response from the NDA:
“Research work on the immobilisation of plutonium is being carried out to find out if the process can be “industrialised” so that it could be used to treat material that is unsuitable for reuse or for disposition of the entire stockpile if Government decided not to pursue re-use.”
Since the Government declared in 2011 that its preferred management option for the UK’s stockpile of separated plutonium (c120 tonnes) was its re-use as MOX fuel, this review of immobilisation suggests that, having specifically ruled out immobilisation as an option for the plutonium stockpile (apart from the handful of tonnes of the material too contaminated for re-use), the NDA is having second thoughts.
This, together with the merest hint that Government might back-track on its preferred option, adds to the lingering doubts on the official commitment to plutonium re-use. The doubts first surfaced in 2012, just months after the Government’s preferred option announcement, when the NDA invited third parties to submit ‘additional alternatives’ to the re-use as MOX option. Whilst this resulted in proposals being submitted by GE Hitachi (PRISM fast reactor) and Candu Energy Inc – both of which continue to be assessed today – the need to issue the invitation in the first place suggested at the time that NDA confidence in the re-use as MOX option was less than convincing. Since then, the painful progress (delays and cost-overruns) of the construction of the Savannah River MOX plant in the US – closely watched by the NDA – will have added further to the Authority’s doubts.
The immobilisation option currently being funded and researched by the NDA and the National Nuclear Laboratory for the plutonium that cannot be re-used is the Hot Isostatic Press (HIP) system which, under high pressure and temperature, converts the plutonium into a ceramic waste form suitable for long-term storage and ultimate disposal.