Liquid Effluent Treatment Plant (LETP) Land Clean-Up

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1 Liquid Effluent Treatment Plant (LETP) Land Clean-Up Frequently Asked Questions What is proposed? Magnox Ltd is proposing to remove the redundant Liquid Effluent Treatment Plant (LETP) at Harwell and to restore the land so that it is suitable for future uses in support of the development of the Harwell Campus. We are engaging with the local community and seeking feedback on our proposals, ahead of making a planning application to the Vale of White Horse District Council. What is the Aim of the Project? The aim of the project is to safely: Remove all of the facilities Remove all wastes Return the land to a clean condition Who is Involved in the Project? The work is being undertaken by Magnox acting as a contractor to the Nuclear Decommissioning Authority (NDA). The work is being undertaken on publically owned land that once cleaned will be returned for reuse as part of the Harwell Campus. The NDA have contracted Magnox ltd. to complete the decommissioning of the Harwell Nuclear Site. The Harwell Nuclear Site is only one part of the Harwell Campus. The Nuclear Decommissioning Authority (NDA) is a non-departmental public body created through the Energy Act The NDA is a strategic authority that owns the civil nuclear liabilities, previously under the control of the UK Atomic Energy Authority and British Nuclear Fuels Ltd (BNFL). The NDA is responsible for: Decommissioning and cleaning up nuclear liabilities Managing the wastes produced Magnox, owned by Cavendish Fluor Partnership, is the management and operations contractor responsible for twelve nuclear sites in the UK, working for the Nuclear Decommissioning Authority. 1

2 The Magnox Harwell nuclear site is the birthplace of the UK s nuclear industry. In 1946, Britain s Atomic Energy Research Establishment was established at Harwell, which until that time had been an RAF airfield. The main site reactors and research facilities were built and operated up to 1990 by UKAEA, since when the nuclear site was no longer required and decommissioning began. The nuclear site is part of the Harwell Campus. The Campus is an internationally important science centre which is undergoing expansion. Land released from decommissioning the nuclear site is made available for redevelopment of the Campus. Around 20% of the original nuclear site has been released. What is involved in the Clean-Up Work? The works involve five significant physical elements: Erection of temporary structures/cabins: construction of access route, additional fencing, topsoil storage, environmental protection measures etc. to enable the works. Temporary Diversion of a Public Right of Way: Remediation engineering works: involving use of demolition and excavation machines to remove all structures and pollutants. All wastes will be packaged and moved to new temporary buildings on the Sewage Farm for assay. All wastes will be shipped offsite. Restoration of the land: to a new site profile as a generally flat/gently sloping fielded area, planted with grass. Construction of a pond: to act as a passive protection feature for existing surface water drains that serve the Campus. What is the Condition of the Land before the Works? One parcel of land to be remediated and released is the ex-liquid Effluent Treatment Plant (LETP) and an associated ex-sewage Farm area to the North of the Campus. These areas are adjacent to each other, separated by a public right of way and are separate from the main Nuclear Site. Work is already underway to demolish the above ground structures on the LETP. The above ground structures on the Sewage Farm were removed previously. The LETP is included in the RSRL Harwell nuclear licence. However, it is located on a separate 4 hectare island about 500m from the Harwell Eastern Entrance. The site is surrounded by publicly accessible land. It is ~100m from a housing estate and a children s nursery, and the site boundary is within 10m of commercial offices and there are some other nearby business and retail shops. The LETP was constructed in the late 1940s and has been extensively modified and upgraded over the years. The LETP s primary role was the treatment of aqueous radioactive and chemically contaminated wastes from the Harwell site and the discharge of the treated effluent by permitted routes. At present, the LETP consists of the following areas: o The Sewage Farm area. This area contained the site sewage treatment plant that was removed several years ago. The Sewage Farm was used to treat foul aqueous 2

3 waste arisings. The only items of plant which remain in this part of the site are some subsurface structures, a penstock chamber for surface water diversion, and a surface water measuring flume. The offsite discharge pipeline (ODP) runs along one side of the Sewage Farm area and is the subject of a separate project. o The LETP area. This contains the main LETP and consists of seven main buildings and nine large above ground and underground tanks, associated plant, and embedded piping systems. The LETP was shut down in 2013 after the demand for liquid effluent processing had decreased significantly following the shutdown of Harwell s reactors and most of its processing facilities. The facility structures are to be decommissioned to floor-slab level in the period up to 2016, which is the Phase 1 project. The Phase 2 land remediation will then return the land to a condition suitable the next use in the period up to 2019, with delicensing and release in 2020/21. The LETP buildings, plant, and soil have been subject to a contaminative use involving low levels of radioactive and chemical materials from over 60 years of operations. It is expected that excavation and removal of underground structures, pipes and soils will be required to remove all contaminants to meet regulatory standards. Prior to the main works a programme of characterisation will be undertaken to supplement existing knowledge and to enable detailed planning of the clean-up. The levels of radioactivity are low and are of a type that has been handled safely on the LETP for many decades without impact to the public. What will the Area Look like During the Works? The works will have the appearance of civil earthworks and will involve controlled demolition of underground structures, removal of embedded piping and excavation of contaminated soils. Demolition will be using machines and there will be no use of explosives. In order to assay the wastes produced by the remediation, some new temporary warehouse-like facilities will be constructed on the Sewage Farm area. These will be removed upon completion of the project. There will be some heavy goods vehicles movements in the area for the duration of the works in order to export the waste materials to suitably permitted offsite locations (~20 movements per day). Radioactive wastes will be exported to offsite treatment and disposal facilities all of which are currently outside of Oxfordshire. The public right of way will be diverted during the works. The diversion will be around the LETP to the South on existing roads and tracks. The diversion will be clearly signposted and is subject to a Temporary Traffic Diversion Order issued by the local authority. Traffic will enter and leave the LETP through the existing entrance and will be routed offsite via the new link road to the Fermi Road campus entrance. There will be two temporary warehouse buildings erected on the Sewage Farm area. These will be used to handle wastes. There will also be porta-cabin buildings on the Sewage Farm area to accommodate the workers. What Measures are to be taken for Safety? Normal working practices, such as monitoring of the materials, careful handling, use of misting/dust control systems, use of local containments as required, use of packages to hold 3

4 and handle the wastes and the deployment of environmental monitoring systems will be sufficient to ensure public and worker safety. All operations are regulated under the existing Nuclear Licence and all discharges/wastes are regulated under existing environmental permits. The industrial safety of the works will be integrated under a Construction Phase Plan as part of the CDM regulations Details of the impacts and controls for the works will be contained in an Environmental Statement that will be support the planning What will the Area Look like After the Works? The land will have a flat or gently sloping field-like appearance. The area will be planted with grass. There will be a substantial pond on one area of the land. This is required to act as a collection point for some existing surface water drains that serve the main campus. It replaces a function previously provided by the LETP to provide environmental protection to the Lydebank Brook. The public right of way will be re-opened on the current route. This will have the appearance of a stone surfaced track. The existing fences will remain in place. The only remaining structures will be an existing electrical sub-station and an existing utility sewage access point, both along the public right of way. How is the work performed? Survey and characterisation: Measurements are undertaken to the condition of the area and whether there are any pollutants that require to be removed Establishment of infrastructure including temporary waste buildings Establishment of controls, including dust suppression and monitoring systems to ensure environmental protection. Demolition and excavation within zones. Waste placed into containers and moved to a waste assay building constructed on the Sewage Farm area Waste measured to determine disposal route Waste dispatched offsite within contained vehicles Exposed areas where works have been completed are sampled and surveyed to show clean-up is complete Land reinstatement to a safe land profile and construction of the pond Removal of regulatory controls through submission of evidence to regulators What is the Timeline for the project? A planning application will be submitted in late

5 2015/16 Design, planning, consultation 2016/17 - Characterisation, Establish Infrastructure 2017 mid 2019 Remediation and Reinstatement 2020/21 removal of licence and permits Early End What are the Temporary Warehouses on Sewage Farm for? It is likely that two warehouses will be constructed. These will use a proprietary design of building designed for temporary use. Containers of waste will be taken to one of the buildings after removal from the working area. Sealed containers will be used to handle all wastes on the site. In this first building the container will be measured using sensitive detection equipment that will enable the correct waste route for the material to be identified. The second building will be used to store the waste containers until they are approved for shipment to an offsite waste management route. How much Traffic will the project give rise to? We expect around a maximum of 20 heavy good vehicle movements per day due to the project. Other traffic flows will be similar to those that have arisen from the LETP over previous years. Is there a Potential for Hazardous Emissions? Very low levels of radioactivity are involved. A series of measures will be used to ensure that dusts do not present a risk of any significant harm to the public or workers. A monitoring system will be deployed at the site boundary to check for all dust emissions. Is there the potential for Noise? Noise monitoring will take place before and during the works to ensure there is no significant nuisance from the noise of demolition operations. Demolition is already taking place on the site. 5

6 Is there the potential to harm Ecology? Surveys will be completed before and during the works to ensure impacts to ecology are managed. How clean will the area be afterwards? The land will be returned to a condition suitable for any foreseeable future use, including use for example, as public areas, for housing or for agricultural. The actual next use of the land is not part of the scope of this project. The clean-up standards are specified by both the Environment Agency and the Office for Nuclear Regulation and they will not release the land from regulatory control unless they are independently satisfied that the clean-up targets have been achieved. 6