JUNE 26, 2009 | No. 690 THORP, LIVING ON A KNIFE-EDGE, TO BE CLOSED FOR SEVEN MONTHS Sellafield Ltd, the company that operates THORP (Thermal Oxide Reprocessing Plant) under contract to the Nuclear Decommissioning Authority (NDA), is facing yet another extended shut-ddown of THORP - this time for an estimated 7 months - when the only High Level THORP, LIVING ON A KNIFE- EDGE, TO BE CLOSED FOR Waste Evaporator configured to deal with THORP's high level waste SEVEN MONTHS 1 is taken off line for a major investigation. "NEW" NUCLEAR REACTORS, SAME OLD STORY 3 (690.5959) CORE - The closure comes dependent on the regular and reliable as little surprise given that Company operation of A & B. Their unreliability in GERMAN ENVIRONMENT reports and presentations over the last recent years however has resulted in MINISTER: NUCLEAR year have clearly anticipated the need to Sellafield Ltd having to place orders for 2 INDUSTRY IS LYING 5 take action on the plant's operational new Evaporators (D & E). Of similar AREVA AND EDF: BUSINESS future because of increasing problems in design to C, the first of the new PROSPECTS AND RISKS IN managing the dangerous high level Evaporators is not expected to come NUCLEAR ENERGY 6 waste (HLW) produced not only by into operation before 2014, the project THORP, but also by the Magnox currently being only at the stage of site SWEDISH NUCLEAR reprocessing plant (B205) and the foundation work. The original cost of BP INDUSTRY WANTS REACTOR effluents from the site's Vitrification plant 90 million is understood to have WASTE FACILITY AT (WVP). escalated to some BP 400 million FORSMARK 7 (US$654 million, 470 million Euro) SUMMER SCHOOL NUCLEAR At the heart of the problem are the site's ENERGY AND CLIMATE 8 three HLW Evaporators A, B & C, which In May 2008, in rationing the use of condense the liquid HLW from the site's Evaporator C between the various IN BRIEF 9 reprocessing plant and the effluents facilities, the NII approved its further use arising from the subsequent vitrification for THORP - but only up to a maximum of HLW. THORP, by design, is configured of 300 tons of oxide fuel derived HLW. for use with Evaporator C only, whilst A Whilst this placed a limit on THORP and B have historically been used to reprocessing, it ensured that should the process WVP and Magnox wastes operation of A or B remain problematic, respectively - both the latter given the prioritised Magnox and WVP wastes priority over THORP wastes by the could at least be diverted for processing Nuclear Installations Inspectorate (NII) for in Evaporator C if needs be. 'hazard reduction purposes'. As a consequence, if either A or B break Against this background of uncertainty down and have to be taken out of over the reliability of Evaporators, service (as has happened in recent Sellafield Ltd's recent reports and years), THORP's Evaporator C is pressed presentations have assessed a number into service to process Magnox or WVP of possible options for THORP's future - wastes, leaving THORP effectively with one being a moratorium on reprocessing no 'evaporative capacity' and therefore at the plant and another being to operate unable to reprocess. THORP for part of the year only - with its workforce redeployed to other work on THORP's future operations at anything site. The prospect of such options like a full commercial rate are therefore becoming a reality came a step closer on the May 18 this year when Sellafield fuel in its first ten years of operation which can be used alternately for Ltd announced that Evaporator B had (the base load contracts). At the end of heating and cooling the HLW under been shut down following the discovery that 10-year base load period, THORP process. By comparison, Evaporator C of a rise in radioactivity levels in one of had struggled to complete 5000 tons of was commissioned in 1990 and has 6 its internal heating/cooling coils. that order book. internal coils. Corrosion and vibration pose the greatest threat to the integrity Though the closure of B for inspection Originally scheduled to close 'with all and lifetime of these evaporators, was relatively short lived, Sellafield Ltd contracts completed' around 2010/11, particularly the coils and stainless steel was forced to refute opposition claims the closure date had to be put back to base of the evaporators which are that THORP faced imminent closure, around 2016 when, with a total 5729 subject to high temperatures and hot- and to assure its workforce that, tonnes reprocessed, THORP was spots within the bottom layer of the despite the problem with Evaporator B, closed down in April 2005 following the waste sludge's. there 'was no danger of any plant major accident (INES Level 3) when closures'. 83,000 litres of dissolved spent fuel Failure of the coils through corrosion leaked undetected from a fractured has resulted in A & B being forced out In early June the claim of no plant pipe in THORP's Feed Clarification Cell. of service on numerous occasions in closures was however thrown into Re-opened in 2007, and still with the last few years and both now have disarray when confirmation was given contracts for 800 tons of overseas fuel to be operated with less than their full to CORE, at a meeting with the NDA, and 2000-3000 tons of UK AGR fuel to complement of heating/cooling coils. Sellafield Ltd and Sellafield's new complete, THORP has reprocessed a Heating and cooling provision for parent body organisation Nuclear further 300 tons to date, including 50 Evaporator B, for example, is restricted Management Partners (NMP), that tons of overseas fuel (Dutch and to its jacket and just two (of the original Evaporator C was shortly to be taken Swiss), bringing the overall total four) heating/cooling coils. In its out of service for a thorough reprocessed since 1994 to 6000 tons. Quarterly report on Sellafield (July to investigation. As Evaporator C is the September 2008) the NII considered only Evaporator configured to process The throughput target for the current the operational life of B could be quite THORP HLW, THORP would have to financial year 2009/10 - the plant's 16th considerable 'provided that waterside close down for 7 months - the year of operation - is just 200 tons, corrosion does not cause premature projected duration of the Evaporator 17% of its original design throughput of failure of the remaining two investigation. This would include not 1200 tons per year, and a rate heating/cooling coils'. only the physical investigation itself previously described to CORE by BNFL (thickness measurement of internal as being commercially uneconomic for For its part, Evaporator A, with its cooling coils), but also the subsequent THORP. As a result of the imminent 7- jacket and just one serviceable coil, is evaluation of the data from the month closure for Evaporator C kept on stand-by 'as a contingency' to investigation, the making of a new investigation, THORP is now projected deal with the wastes from WVP which Safety Case for the Evaporator, and to close (with all contracts completed) have a lesser heat loading than those gaining approval from the Nuclear in 2017, though any combination of from reprocessing and are therefore Installations Inspectorate (NII) for future further Evaporator failures, delays to less demanding on the Evaporators. use of the Evaporator for THORP new Evaporators or any other reprocessing. unexpected technical failures within It is ironic that as the worldwide THORP itself, could see reprocessing economic downturn forces household- The prospect of a further 7-month operations continuing to 2020 or name businesses into liquidation closure of THORP, following the large beyond. across the UK, reprocessing at THORP number of unplanned 'outages' that - arguably the UK's largest white- have blighted the plant's operational The NII's current 300-ton limit for elephant of all - should continue to get life, will do little to calm the increasing THORP's use of Evaporator C is the backing of the UK Government and concerns of its reprocessing expected to be reached at some point the plant's owners the NDA despite its customers. Already known to be highly in July this year. Once reached, and woeful performance and its increasingly critical of Sellafield's inability to operate with the Evaporator taken out of poor commercial prospects. It THORP properly, overseas customers service and THORP closed, the burden apparently owes its survival, not on any must now reconcile themselves to of processing Sellafield's Magnox and merit as a spent fuel management having to wait even longer for their WVP wastes will fall entirely on option, but solely because of the contracts to be completed - perhaps Evaporator B which only came back on revenues it continues to bring in from 13 or more years late. line in July 2008 after a 43-month the now disgruntled overseas outage for repair. Evaporator A will be customers who signed up with THORP When THORP opened in 1994, its kept on stand-by. decades ago. The NDA, funded by the contracted customers had been taxpayer, uses the revenues to offset assured by the then owners British Built some fifty years ago, A & B are some of its spiralling clean-up and Nuclear Fuels plc (BNFL) that, as fitted with a cooling/heating jacket decommissioning costs at Sellafield Sellafield's 'flagship' plant, THORP around the base and sides of the and other UK sites. would reprocess 7000 tons of spent evaporator and four internal coils, 2 NUCLEAR MONITOR 690 Whilst Sellafield Ltd will be keeping its vitrification.