Like its beleaguered THORP reprocessing plant, closed now for almost one year following a major leak, the Nuclear Decommissioning Authority’s (NDA) Sellafield’s MOX plant (SMP) similarly faces an increasingly insecure future.
Built at a cost of £490M and designed to produce 120 tonnes of Mixed Oxide (MOX) fuel each year (utilising around 7 tonnes of plutonium per annum) SMP’s production rate is now being put at no more than 40 tonnes per year by industry observers. Previously describing the 40t/yr rate as being the level at which the plant becomes commercially viable in terms of its running costs, NDA’s Chief Executive Ian Roxburgh is reported recently (New Scientist) as telling parliament that SMP will only produce one-quarter of the fuel it was originally designed to produce – ie 30 tonnes.
Running 4 years behind schedule because of the inability of British Nuclear Group (BNG, contractors to NDA) ‘to get SMP to work properly’, the first 4 MOX fuel assemblies were produced by the plant and shipped to a Swiss customer in 2005. BNG claimed that a further 12 assemblies were to be produced this financial year, but in a briefing on 10th February NDA conceded that only 8 assemblies would be produced by 31st March 2006, the remaining 4 assemblies being completed in the summer. The failure to meet the 2006 target is due to ‘a number of equipment reliability problems and some engineering work slippage’ by the NDA who also refer to ‘recent bottleneck areas’.
In terms of tonnes produced, the 8 MOX fuel assemblies scheduled to be completed by SMP this financial year for the Beznau power station in Switzerland will weigh a total of around 2.5 tonnes – a fraction of the projected 40 tonne annual rate at which the plant becomes commercially viable. Whilst low production rates are expected in a relatively new plant whilst it is being progressively ‘ramped up’ to full production levels, SMP’s continuing poor performance will be of increasing concern to the NDA whose briefing also points to indications that SMP’s ‘ramp-up is likely to be slower than planned and the programme is currently being examined to determine what other opportunities could be exploited’.
In parallel with production delays, BNG’s application to the Nuclear Installations Inspectorate (NII) for ‘consent to operate’ SMP is also running years late. Such consent, which effectively denotes the completion of all active commissioning programmes and the move to full commercial operations, is secured only once the plant has operated for a ‘reasonable period of time’ that allows sufficient commissioning checks and data to be collected and considered. The application by BNG was originally expected around April 2004, but is not now expected by the NII until.’early in the 2006/07 period’.
Plant costs have spiralled dramatically in recent years as a result of engineering work, plant modifications and the employment of a team of experts from French rivals COGEMA in an effort to sort out SMP’s problems. These costs, which are understood to run to many tens of £millions alone, take no account of the ‘substantial increase’ in losses incurred through having to sub-contract some SMP orders to rival European MOX fuel fabricators because of SMP’s inability to produce the goods.
With Japanese utilities still apparently unwilling to trust BNG with MOX production, SMP’s order book remains made up of business from Swiss, German and Swedish utilities only. In September last year the NDA confirmed that just 28% of the order book was under ‘firm contracts’, and the remaining 72% still under ‘Letters of Intent and Support’.