Estimated costs of the remaining major projects
2.16 Since September 2013 the estimated costs for most of the original remaining major projects have been stable, for projects in both the planning and design and construction phases (Figure 7 and Figure 8). However there has been a substantial increase of £1.4 billion in the lifetime cost for the silos direct encapsulation plant, a complex treatment plant in the planning and design phase.7 This has resulted in the total lifetime costs of the remaining nine major projects increasing to around £7 billion. In addition, one new project - the box encapsulation plant project - has gone into the design phase. This project has been accelerated in order to accept waste from the magnox swarf storage silo ahead of the availability of the silos direct encapsulation plant. The Authority estimates that this project will cost around £492 million.
Figure 7 Estimated costs for major projects in the design and planning phase Estimated lifetime cost of the silos direct encapsulation plant doubled in December 2014, while other projects' estimated costs have not increased significantly
Source: National Audit Office analysis of the Authority's information |
Figure 8 Estimated costs for the major projects in the construction phase Following earlier increases in the estimated costs for major projects in the construction phase their costs have now stabilised
Source: National Audit Office analysis of the Authority's information |
2.17 The estimated cost of the silos direct encapsulation plant has doubled from £1.3 billion in September 2013 to £2.7 billion in December 2014 (Figure 7). In 2012 we reported that this is the third attempt to design a plant to receive, treat and immobilise the waste from the magnox swarf storage silo. At that time Sellafield Limited was planning to recompete the project. Since awarding the contract Sellafield Limited has confirmed its cost estimate with greater certainty, but has moved its expected completion date back from August 2020 to June 2026. This project has accounted for the majority of the overall extension to completion dates for major projects.
2.18 The magnox swarf storage silos retrievals project and the pile fuel cladding silo project, which accounted for a significant proportion of the increase in estimated costs from March 2012 to September 2013, have not shown further significant increases in their estimated costs to December 2014 (Figure 7 and Figure 8). The Authority expects further clarification of costs and schedules on the pile fuel cladding silo project - in due course.
• Magnox swarf storage silos retrievals project
The project is to construct equipment and systems to safely remove radioactive waste from the storage silo. It is to commission its first machine in 2017, when the Authority expects there to be an opportunity to reduce the risk of the overall programme. The end date for the delivery of the final machine is linked to the silos direct encapsulation plant project and so the project's final completion date has been put back from 2023 to 2025 (Appendix One).
• Pile fuel cladding silo project
The project is at the design stage for integrated systems for retrieval of the waste from this silo, and is being re-planned. The Authority expects the revised plan to reduce the uncertainties in the proposed approach and result in a more robust cost and delivery schedule.
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7 The Authority estimates time and cost ranges for projects. In this report we have used the Authority's mid-point estimate for the estimated costs of major projects. After a quantification of risks, the Authority considers there to be a 50-50 chance that costs will come in below this mid-point estimate.