Harwell project profiles Restoration of the Southern Storage Area

Harwell project profilesRestoration of theSouthern Storage AreaLooking north-east over the SSA before restorationBackgroundThe Southern Storage Area (SSA) was known locally as the‘bomb dump’ as the site was originally used for munitionsstorage during the Second World War as part of RAF Harwell.The seven-hectare area was taken over by UKAEA in 1946and used for the storage and handling of chemical and lowlevelradioactive wastes produced during the nuclear researchprogramme in which the site was then engaged. The SSAcontained six small pits containing laboratory waste and fivelarger pits containing industrial wastes including berylliumcontaminated materials. Low-level chemical groundwaterpollution had also resulted from the smaller pits.Earth-moving machinery in actionduring land restoration workObjectivesTo restore the SSA to a safe and clean condition. This was thelast stage of a phased clean-up programme that began in the1980s.One of seven empty WWII German bombs found on the SSAKey challenges• To clear the site of chemical and radioactive pollutants, whileremaining vigilant for an unknown quantity of militaryexplosives throughout the project.• To ensure that the operation was conducted to the moststringent safety standards as the SSA borders Chilton School.

SolutionContractors clearing beryllium contaminated material from waste pitsThe site was completely excavated in 300mm deep layers withintensive surveying to ensure any wastes were detected andremoved. All of the pits were excavated inside double ventilatedcontainment structures that prevented the release of dusts tothe environment. Air sampling stations were established at ninelocations around the perimeter and near the working zones toverify the effectiveness of the precautions.A groundwater treatment plant was established to contain andremove very low levels of chemical pollution in the groundwater.Procedures were agreed with RAF and Army Bomb Disposalteams to cover the discovery and safe disposal of munitionsduring the project. Munitions experts were included in thespecialist project teams, which comprised staff from UKAEA andspecialist contractors RWE Nukem and VHE Construction.A transparent communications policy was adopted to keep thelocal community fully informed with all developments on theproject.Once the clean-up work was completed the area waslandscaped for potential future recreational use.Outcome• UKAEA successfully completed the biggest and most complexclean-up of its kind in the UK.• From a situation in June 2000 when the SSA contained a uniquemixture of pollutions and explosives, the area is now safe andclean.• The levels of chlorinated solvents in the groundwater below thesite were so low that the groundwater treatment plant wasremoved.• Monitoring of local air, soils, road surfaces and groundwaterconfirmed that there was no harmful impact on the localenvironment.• The transparent communications policy fostered an excellentrelationship with the staff and pupils of Chilton School, culminatingwith the planting of a tree by every school pupil at a specialceremony on the newly landscaped site in September 2002.TV personality John Craven (second from left) helped childrenfrom Chilton School to plant trees on the restored land• The unique nature of this decommissioning challenge requiredUKAEA to develop project teams with sub contractors thatharnessed a wide range of experience and skills and which havesubsequently set new standards in environmental restoration.Key facts• Timescales2 years planning and 2 years site implementation• Total soil shifted Over 250,000m 3• Waste material removed18,000m 3 (including 230m 3 of low levelradioactive waste)Wartime munitions uncovered• 1,300 live practice bombs• 7 German bomb casings• 13,000 rounds of ammunition• 30 land mines• 30 flares• 1 depth chargeContact:Nick HanceHarwell Public Relations ManagerTel: 01235 436909Email: nick.hance@ukaea.org.uk