SPP1 handover: accelerating the Sellafield clean-up?
The ageing facility presents a significant decommissioning challenge with programme timescales stretching out for more than 100 years. But the recent completion and handover of a new £240m Sludge Packaging Plant (SPP1) is being described as a major milestone.
The SPP1 has been built to receive historic radioactive waste from Sellafield’s First Generation Magnox Storage Pond (FGMSP), which in its lifetime handled 27,000 tonnes of nuclear fuel and is now an urgent decommissioning priority. It is estimated there is up to 1,500 cubic metres of radioactive sludge left in the 60-year old nuclear pond which will be pumped into the new SPP1 towards the end of 2014.
The emptying and decommissioning of FMGSP presents a host of technical and safety challenges. For a start, the structure has no roof and sits open to the elements, meaning that the radioactive sludge that has accumulated over the years lies up to one metre deep in places. Until now, the removal of the sludge from the bottom of the pond has proved impossible, as Martin Leafe, Head of FGMSP at Sellafield, explains: “We simply didn’t have the means to deal with it. [Now, with the arrival of SPP1], we can make significant progress in decommissioning part of the UK’s historic nuclear legacy.”
The FMGSP is one of four high-hazard facilities at Sellafield – two fuel storage ponds and two waste silos dating back to the Cold War defence programme and nuclear civil engineering industry of the 1950s and 60s.
Prioritised for clean-up by the UK’s Nuclear Decommissioning Authority (NDA), these facilities represent a majority of the hazardous nuclear inventory at Sellafield. And as an NDA spokesman explained in conversation with Nuclear Energy Insider, their decommissioning requires unique technical expertise and solutions: “Each of these four facilities requires a discrete set of complex engineering projects in order to first gain access, then retrieve, treat and repackage their waste materials for long-term storage and disposal. Many of these projects are engineering firsts; unprecedented in their complexity, hazard and scope.”
Certainly, the construction of the SPP1 involved the installation of a 31-metre-long, 50-tonne pipe-bridge in what was one of the most technically-demanding crane lifts ever performed at Sellafield.
The rest of the SPP1 structure, which was delivered by contractors Doosan Babcock and Balfour Beatty, comprises three enormous stainless steel buffer storage vessels (each equivalent to the volume of seven double-decker buses) made up of 11 separate sections. These sections were welded together on site before being slid into a reinforced concrete building, where they were rigorously tested and retested before being handed over, in early June, to the Sellafield operations team.
Reducing uncertainty and cost
According to the NDA spokesman, the completion of SPP1 is critical as it will enable the operations teams to better understand the scale of the challenge presented by the FGMSP: “Pumping the sludge from FGMSP will reduce the hazard within the facility and allow improved visibility and access. In this way, it will make a significant contribution to overall risk reduction.”
And at a time when so many uncertainties remain regarding the decommissioning programme at Sellafield, ‘improved visibility’ is everything: “When we are more certain about the nature and scope of the challenges, we can engage the private sector in a competitive process to accelerate activity and drive down costs.”
Indeed, the completion of SPP1 comes amid ongoing debate about the expense and direction of decommissioning operations at Sellafield and in the UK generally. Speaking as Chair of Parliament’s Public Accounts Committee in late 2013, MP Margaret Hodge described the spiralling costs of decommissioning at Sellafield as “an appalling waste of public money” and said cash was being “scattered like confetti”.
With estimated costs of the Sellafield clean-up operation rising to around £79.5bn, both the NDA and Sellafield’s parent company, the American-led consortium Nuclear Management Partners (NMP), have come in for fierce criticism from MPs, industry officials and pressure groups. NMP in particular have been lambasted for underperformance in their handling of the Sellafield programme since 2008.
But according to Sellafield spokesman Karl Conner, such criticism is unjustified: “NMP comprises three companies with global expertise in nuclear and decommissioning and we have seen a great number of positive impacts which can be directly attributed to NMP’s influence at Sellafield. Our Chief Decommissioning Officer, Jack DeVine, is an NMP secondee who has extensive worldwide experience. Under NMP’s direction, we are making great strides against our decommissioning mission.”
For Sellafield and the NDA, such strides are reflected in the completion and handover of SPP1. As Conner explains: “The SPP1 project demonstrates our ability to deliver decommissioning work successfully at Sellafield and increases confidence in us from our key stakeholders. It is a significant enabler of our ultimate goal and will help to make Sellafield safer sooner.”
A long journey
However, both Sellafield and the NDA are keen to point out that decommissioning is not a process that can be rushed – particularly not at Sellafield, which has no comparable site in Western Europe in terms of the extent and complexity of its clean-up requirements.
And according to the NDA, the very nature of the task makes it difficult to make accurate time and cost estimates: “It is natural that refinements will be required as these projects mature and discoveries are made that unearth new information about the challenge – information that would have been impossible to know until these projects were in flight. Beyond the short term, the plans contained within this programme are merely a set of assumptions that are subject to change as technology advances, approaches to decommissioning alter, the regulatory framework shifts and societal and political change take place.”
The completion and handover to SPP1, then, while a significant achievement for those involved and a vital ‘enabler’ within the decommissioning programme, is ultimately a small step on a very long journey.
Source: Nuclear Energy Insider