UKAEA ^{A World Leader in Decommissioning & Waste Management.}

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Project background

The Southern Storage Area (SSA) was originally used for munitions storage during the Second World War.

From 1946 the seven-hectare area was used for the storage and handling of chemical and low-level radioactive wastes produced during Harwell’s nuclear research programme. The SSA had six small pits containing laboratory waste and five larger pits containing industrial wastes, including beryllium contaminated materials. Additionally, low-level chemical groundwater pollution was found in the smaller pits.

Key challenges

We were tasked with completing the final stage of a clean-up programme that began in the 1980s, fully restoring the SSA to a safe and clean condition. To do this we had to clear the site of chemical and radioactive pollutants, along with any military explosives that were encountered. We also had to ensure the project met stringent safety and environmental standards, particularly as the SSA bordered a local school.

Our approach

We excavated the site in 300 mm deep layers, and conducted intensive surveying to detect and remove any wastes – shifting over 250,000m3 of soil and removing 18,000m3 of waste material (including 230m3 of low level radioactive waste). The pits were excavated inside double-ventilated containment structures that prevented dusts from being released into the atmosphere, and we set up nine air sampling stations around the site to verify this. A groundwater treatment plant was used to contain and remove low levels of chemical pollution in the groundwater.

As this was such a unique decommissioning project, we drew on a wide range of experience and skills from our own teams and subcontractors.

Working closely with the RAF and Army Bomb Disposal teams we established procedures for locating and safely disposing of munitions, uncovering:

• 1,300 live practice bombs
• 7 bomb casings
• 13,000 rounds of ammunition
• 30 land mines
• 30 flares
• 1 depth charge.

Throughout the project, we made sure that the local community was kept fully informed on all developments. Once the clean- up work was completed, we landscaped the area so it could be made available for alternative uses in the future.

The results

Having successfully removed the unique mixture of pollutants and explosives, the site is now safe and clean. We have also been able to remove the groundwater treatment plant, as we reduced the chlorinated solvents present in groundwater to extremely low levels.

We confirmed that our work had no harmful impact on the local environment by monitoring local air, soils and road surfaces. And we forged an excellent relationship with the staff and pupils of Chilton School, marking the end of the project in September 2002 with a ceremony where each pupil planted a tree on the newly landscaped site.

In 2004, the project won an international award from the Royal Institution of Chartered Surveyors (RICS). The RICS awards recognise excellence in conservation, regeneration, sustainability and community benefit.