Sellafield site
Used fuel from all over the world, including the UK, arrives at Sellafield inside purpose-designed shielded flasks which can weigh up to 110 tonnes.
The flasks of used fuel are taken to the Thorp receipt and storage facility by rail. Once the lid bolts are removed, the flasks are placed underwater and the lids are taken off. The containers holding the used fuel are removed from the flasks and are transferred to the storage pond.
There are two nuclear fuel reprocessing plants at Sellafield. One deals with Magnox fuel from Britain's early nuclear reactors, like the ones which were used at Calder Hall power station at Sellafield, which is now closed down. The other fuel reprocessing plant at Sellafield is the Thermal Oxide Reprocessing Plant or Thorp, as it is known. Thorp deals with fuel from British Advanced Gas Cooled Reactors (AGR) and Light Water Reactor fuel from around the world.
When the spent (used) fuel is removed from a nuclear reactor it is still emitting radiation and heat. It is put into large Fuel storage ponds or pools of water near the reactor where it can sit to allow it to cool and allow the radiation levels to decrease. After this cooling period, the fuel is loaded into specially constructed secure containers called 'flasks'. These flasks are transported to Sellafield either by road, rail or from overseas customers by sea in purpose built ships
The nuclear industry has invested substantial amounts of money in new plants to treat and package waste from reprocessing operations. The wastes are classified into High, Intermediate and Low level waste streams. Discharges from all our sites must follow strict Government authorisations in accordance with international rules.
Once a nuclear facility has completed its operational life it then moves into;
Post Operational Clean Out, where the radioactive material inventory and residual hazards are removed using existing equipment in the building. If facilities are not decommissioned straight away, either to allow radioactive materials to decay, because of interfacing projects or facilities, or financial viability, they are placed into care and maintenance and undergo routine surveillance until decommissioning starts.
The waste characterisation phase defines the types of waste materials that are present, the appropriate disposal route, and the method that can be used for the dismantling and demolition phases. Decommissioning and dismantling involves either manual or robotic removal of all process plant and equipment and the radiological decontamination of the structure as far as possible.
Standard industry demolition techniques are then used and can either be mechanical or, if the structure and location allows, explosive. The land is then remediated for whatever future use is determined for the site.
Along with commercial and nuclear clean up operations, Sellafield Ltd is also undertaking a range of major projects that are key enablers to the management of ongoing site activities.
Major projects pose special challenges, these challenges are magnified by their location on a nuclear licensed site. Sellafield Ltd is meeting these challenges by successfully managing the scale, funding requirements, human resource requirements, technology and timescale of many projects to safely deliver value for money to the business
Sellafield is one of the most complex and compact nuclear sites, activities are centred around remediation, decommissioning and clean up of the historic legacy. The site is also home to the Thorp and Magnox reprocessing plants, the Sellafield MOX plant and a wide range of waste management and effluent treatment facilities.
Achievements
A major milestone was achieved in September by the Sellafield Ion Exchange Effluent Plant (SIXEP) with the replacement of its 100th ion exchange bed.
Sellafield Site reached an important milestone with the successful demolition of four cooling towers at the Calder Hall nulcear power station.
See the case study
The Miscellaneous Beta Gamma Store continues its impressive safety record as it passes the 11 year mark without a Lost Time Accident
Safety success at PF&S
A FANTASTIC safety success has been recorded in Plutonium Finishing and Stores (PF&S) at Sellafield with teams achieving six years without a single Lost Time Accident (LTA).
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A FANTASTIC safety success has been recorded in Plutonium Finishing and Stores (PF&S) at Sellafield with teams achieving six years without a single Lost Time Accident (LTA).
This equates to over 4½ million working hours without an LTA - a significant milestone for the 87 employees based at the plant.
The facility, part of Magnox Operations Unit, incorporates plutonium finishing line operations, stores operations and areas of plant, now redundant, being placed into care and maintenance.
Operations involved in working with plutonium bring about their own unique requirements, not least the provision of primary containment in the form of glove boxes, supporting ventilation and environmental systems, requiring operators and maintainers to develop specialised skills.
Over recent years a number of major refurbishment projects have successfully taken place including replacement of a calcine furnace screw drive and evaporator hold up vessel. These involved workers from a wide range of disciplines– design, safety, contractors, maintenance and operations- pulling together to overcome the radiological and safety hazards presented.
Ian Fisher, safety representative, said: “Considering the amount of decommissioning and plant maintenance carried out over the past two years within the PF&S complex it is a marvellous achievement by all to reach 6yrs without a lost time accident, and I think it shows that people are more tuned into safety for themselves and to others. We are often criticised for our failings from time to time but we should all give ourselves a big pat on the back for this achievement.”
Dave Capner, manufacturing manager, added: “This achievement is down to dedication and hard work of a safety conscious team. Given the extent of work and challenging environment this is a tremendous achievement. This success is about applying good standards, reinforcing safety messages and shows the dedication of the teams at PF&S.”
The Pacific Nuclear Transport Ltd ship, The Pacific Teal, has been taken out of service and sent for recycling after 26 years service. The ship was used to transport nuclear fuel between the UK and Japan.- Pacific Nuclear Transport Ltd, the world's most experienced shipper of nuclear cargoes, has successfully completed over 170 shipments in the last 30 years, with the ships safely covering more than five million miles without a single incident resulting in the release of radioactivity
- In over 40 years of operations we have successfully transported over 2,000 casks of nuclear material
- The Sellafield Product Residue Store (SPRS) project reached a major milestone of 500,000 man hours
- Completion of four deliveries of Mox fuel to Swiss customer NOK completed with no disruption and negligible public protest and media coverage
- After 10 years of operational life the Thorp reprocessing plant's existing Medium Active Salt Free Evaporator (MASFE) was nearing the end of its life. The MASFE is an important piece of plant used primarily to process Medium Active liquors, concentrating them down prior to them being sent for further evaporation and Vitrification into glass.
See the case study - Within Thorp Reciept & Storage the new multi element bottle (MEB) export facility has started up. The facility has recently started the active commissioning phase which will allow for the removal of 400 empty MEBS, freeing up space for 1000 tonnes of fuel in the ponds
A major milestone was achieved in September by the Sellafield Ion Exchange Effluent Plant (SIXEP) with the replacement of its 100th ion exchange bed. SIXEP is an effluent plant which removes radioactivity from high volume liquid feeds from a number of plants across the Sellafield site. The safe achievement of this 100th bed exchange marks a milestone for this key site facility, demonstrating the commitment the site is making to nuclear safety and the maintenance of a safe environment.- Significant business improvements have been achieved by our waste teams as a result of excellent work across the Decommissioning group. Improvements in waste handling and segregation have seen a large increase in the number of light duty skips sent to the Waste Monitoring and Compaction Facility.
The Miscellaneous Beta Gamma Store continues its impressive safety record as it passes the 11 year mark without a Lost Time Accident. Its success has been built on a deeply embedded safety culture within the team.- An innovative shielding solution has been used to great success in the solid waste facility at Sellafield. The challenging task of recovering a previously contaminated compartment area was overcome by a team of engineers from Sellafield Ltd and International Nuclear Solutions Ltd. Manual working in the area was prohibited due to radiological conditions and this prevented site engineers from accurately surveying area, resulting in recovery operations being carried out by a Remote Operated Vehicle (ROV). The problem was ingeniously resolved by designing a strong, flexible bag made from fine stainless steel chain mail mesh to act as a robust shield. These shield bags were deployed using the ROV to successfully fill areas previously difficult to access, significantly reducing radiological hazards.
A MAJOR milestone in the decommissioning programme for Sellafield's First Generation Magnox Storage Pond was achieved on 20th October.
Sellafield Ltd reached an important milestone in the clean-up of the UK’s nuclear legacy with the successful demolition of four cooling towers at the Calder Hall nuclear power station.
See the case study
A milestone achievement in the Pile Fuel Storage Pond was the removal of 15 redundant storage flasks from a dividing wall of the storage pond.
We have succesfully removed three redundant pipelines running from the Sellafield site out into the Irish Sea.
See the case study
The Sellafield product and residue store has achieved over 500,000 man hours without a lost time accident.
The Sellafield separation area ventilation project reached a major milestone earlier this year with the start of physical work on the area’s duct removal project.
Construction of Sellafield’s third encapsulated product store deemed ‘example of industry best practice’ by Lloyd’s Register Quality Assurance.
Sellafield site works together to allow tunnel construction to carry progress.
- A major milestone was achieved in September by the Sellafield Ion Exchange Effluent Plant (SIXEP) with the replacement of its 100th ion exchange bed. SIXEP is an effluent plant which removes radioactivity from high volume liquid feeds from a number of plants across the Sellafield site. The safe achievement of this 100th bed exchange marks a milestone for this key site facility, demonstrating the commitment the site is making to nuclear safety and the maintenance of a safe environment.
- At one time, Thorp was the largest construction site in Europe, employing over 4500 people directly on the Sellafield site.
- A MAJOR milestone in the decommissioning programme for Sellafield’s First Generation Magnox Storage Pond was achieved on 20 October, with the successful installation of a 42 tonne Gantry Refurbishment System (GRS). Assembling the GRS and lifting it into position over the legacy pond was achieved using an 800 tonne mobile crane, one of the largest in the country. Conducted safely under the highest category of plant modification in the buildings history, this challenging lift was the climax of much meticulous planning, safety case preparation and training
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