Nuclear Decommissioning in the UK Presented by Chris Jones

Introduction Britain has 23 working reactors Reactors decommissioned/ out of use 21 Generating almost 20% of nations electricity First reactor in 1956 Peak production 1997 – 26% Since then it has declined as stations are closed 6 more to closed by 2015 Although it is thought due to the ‘energy gap’, the lifespan of some stations will be increased beyond 2015 Energy gap caused by closing of coal stations and the need for consumer power

What is it Usually when it is seen as uneconomical. The plant is taken apart and hazardous waste removed. The site is left safe in visually acceptable state. Each project is undertaken on its own merits. The process is similar to decommissioning in the chemical industry. Decommissioning is when a nuclear power station is shut down.

Decommissioning Run by the Nuclear Decommissioning Authority (NDA), which was formed in April 2005 Its purpose is to deliver savings in the decommissioning and clean-up of the UK’s nuclear sites in a safe and cost-effective manner accelerate programmes of work that reduce hazard introducing innovation and world class contractor expertise Done through competitions as first done in American has strategic responsibility for the UK's nuclear legacy

Their Strategic Priorities Encourage the highest standards in safety, security and environmental management; Drive hazard reduction; Secure our funding framework; Gain the support and confidence of our stakeholders Develop integrated waste solutions; Maximise commercial value; Build an effective industry; and Create a world class organisation

Decommissioning It includes all clean-up of radioactivity and progressive demolition of the plant. Once a facility is decommissioned, there should no longer be any danger of a radioactive accident or to any persons visiting it. There are 3 methods of decommissioning Immediate Dismantling Safe Enclosure Entombment

Three Methods Immediate Dismantling: allows for the facility to be removed from regulatory control soon after termination of regulated activities. Usually, the final dismantling or decontamination activities begin within a few months or years. Afterwards the site is available for re-use. Safe Enclosure: This option postpones the final removal of controls for a longer period, around 40 to 60 years. The facility is placed into a safe storage configuration until the eventual dismantling and decontamination activities occur. Entombment: This option entails placing the facility into a condition that will allow the remaining on-site radioactive material to remain on-site without ever removing it totally. This option usually involves reducing the size of the area where the radioactive material is located and then encasing the facility in a long-lived structure such as concrete, that will last for a period of time to ensure the remaining radioactivity is no longer of concern.

3 Stages of Dismantling Initial Decommissioning Reactor are defuelled and fuel is moved away from reactor. All none fixed components are removed For non-reactor facilities, all radioactive sources and equipment are removed The structure is maintained intact and the atmosphere inside the buildings are controlled

Decontamination and Dismantling Contaminated equipment is dismantled in carefully planned steps. This involves decontamination to minimise the amount of radioactive waste generated Once a building is stripped of all its internal equipment, it is carefully surveyed to determine the extent of contamination in the building fabric. Simple processes of washing and removing a thin layer of concrete from a structure (scabbling) are generally fine to decontaminate the building 3 Stages of Dismantling

Demolition Once all radioactive and hazardous material has been removed the building is refurbished for alternative uses or demolished Demolition is carried out with stringent controls to monitor possible presence of radioactivity The land is then remediated and returned to a condition where there is no hazard. 3 Stages of Dismantling

Sites The NDA took ownership of the sites involved, but the operational work itself is carried out by contractors These various sites are being restructured into seven Site licence Companies. The 11 Magnox sites are grouped together in a north south divide. Magnox North Ltd - Chapelcross; Hunterston A; Trawsfynydd; Wylfa and Oldbury Magnox South Ltd - Berkeley; Bradwell; Dungeness A; Hinkley Point A and Sizewell A

The rest have more localised site licences. Sellafield Ltd - Calder Hall; Windscale and Capenhurst uranium enrichment plant Dounreay Site Restoration Ltd Research Sites Restoration Ltd - Harwell and Winfrith facilities LLW Repository Ltd - low level waste repository near Drigg Springfields Fuels Ltd Sites

Timescale Due to the latent radioactivity in the reactor core, the decommissioning of a reactor is a slow process which has to take place in stages; The plans of the Nuclear Decommissioning Authority for decommissioning reactors have an average 50 year time frame

Costs NDA estimate decommissioning will cost about £72 billion (about €90 or 2.3 trillion CZK) over a 100 year period. Sellafield taking up £31.5 billion. New estimates are increasing every Year. Greenpeace say it will over £10bn

Berkeley Most sites are passed the stage of defuelling and are in the process of decommissioning and termination. The first site to start decommissioning in the UK was at Berkeley nuclear power station which wasclosed for economic reasons in 1989 after 27 years of operation, defuelling took 3 years. The cooling ponds were then drained, cleaned and filled in and the turbine hall was dismantled and demolished. The reactor buildings are in the final stages of preparation for an extended period of care and maintenance in the Safestore phase. Ultimately they too will be dismantled (approx. 2080), leaving the site to be leveled and landscaped. The same pattern is being followed at other UK reactor sites.

Site Restoration Restoring the site involves lots of projects working together. The end point of decommissioning depends on the potential of the site. Ideally the site will be available for unrestricted use New business premises at Harwell Restored greenfield site at Winfrith