Present state of deep shaft sinking in the UK and experiences in the design of deep shaft accesses for underground nuclear waste repositories

• Published in: Tunnels & Tunnelling International p. S11
• Main Author: Auld, F.A
• Format: Journal Article Trade Publication Article
• Language: English
• Published: Oxford NS Media Group Limited 01.05.2012; Compelo
• Subjects: Aquifers; Clay; Concrete; Construction contracts; Construction equipment; Contractors; Engineering firms; Laboratories; Mineral industry; Mining; Mining industry; Radioactive waste sites; Radioactive wastes; Reinforced concrete; Safety management; Storage; Tunnels; Underground construction; Germany; United Kingdom > UK
• ISSN: 1369-3999

In 1983 Cementation Mining Ltd bid for the shaft sinking works of the Gorleben Nuclear Waste Repository in Germany on a Design and Construct basis. The author was instrumental in developing the shaft lining design. During 1989-90 Cementation Mining Ltd, at the request of ANDRA in France, carried out a Prefeasibility Study for sinking and lining a shaft in the Aisne clay. The author contributed substantially to this study. In 1991 Cementation Mining Ltd bid to carry out the shaft sinking for the MoI Nuclear Waste Storage Test Laboratory second access shaft in Belgium. The lining design was provided by Cementation Mining Ltd. The author was involved with another Joint Venture bid of companies, including the ground freezing contractor British Drilling and Freezing Company Ltd, for the sinking of the second Mol access shaft in 1996 where the lining design was also provided. During 1997, in conjunction with Kvaerner Cementation Ltd (formerly Cementation Mining Ltd), I. W. Farmer & Partners Ltd were involved in the bidding for the shaft sinking works of the ANDRA Nuclear Waste Repository sites in France. This involved proposed sites at Est, Gard and Vienne where site specific lining designs were put forward. In 2001 Alan AuId Associates Ltd were contracted by Posiva Oy to carry out Feasibility and Preliminary Design studies for a deep shaft access to the Onkalo Underground Rock Characterisation Facility at Olkiluoto in Finland. Since its inauguration in 1989 I. W. Farmer & Partners Ltd, subsequently Alan AuId Associates Ltd and now the Alan AuId Group Ltd, has worked on contract to UK Nirex, now the Nuclear Decommissioning Authority (NDA), providing design and construction advice for the provision of a deep underground waste repository in the UK. In 1994 Alan AuId Associates Ltd prepared the total shaft design and construction details for UK Nirex's Rock Characterisation Facility (RCF) at Sellafield. This included two shafts, shaft winding systems and shaft bottom layouts. The Tender was let for construction, and the contractor Kvaerner Cementation Ltd was mobilised on site at Sellafield to begin construction, when the Government aborted the project in 1996. In the author's opinion, this put the UK programme for deep underground nuclear waste disposal back many years, leaving the UK trailing behind their overseas counterparts. In order to put the current capability for deep shaft sinking in the UK into perspective with regard to the future construction of an underground waste repository, it is necessary to review past shaft sinking experience. Table 1 shows a total of 1 6 deep shafts sunk from the surface in the UK from 1977 to 1987, over a 10 year period (AuId 1987). The shafts were predominantly 6 to 8m in diameter, with depths from 300m to just over 1 000m. Most of the shafts were sunk by Cementation Mining Ltd, during which time the author was their Chief Design Engineer, and Thyssen (GB) Ltd, with one shaft sunk by Amalgamated Construction Company Ltd (AMCO). Table 2 shows the number of deep shafts sunk from the surface from 1 987 to 201 2, over the last twenty-five years. The answer is none. Additionally both Cementation Mining Ltd and Thyssen (GB) Ltd are no longer in existence, leaving AMCO as the only current company to have sunk a deep shaft from the surface in the UK and that was only one shaft 30 years ago. Most of the contractors' personnel with the specialist shaft sinking knowledge have disappeared from the industry. All of the contractors' specialist shaft sinking equipment which they used to retain, including headframes, scaffolds (in shaft working platforms) and winders, has been scrapped. Therefore a major shaft sinking learning curve will be required in the future for any UK company to take on the construction of an underground nuclear waste repository in the UK.