Harwell Western Storage Area

Client organisations:  United Kingdom Atomic Energy Authority (UKAEA) - Mowlem

Date: 2005

Value: £350,000

CL Voelcker were part of the team appointed by UKAEA to carry out the remediation of the Western Storage Area at their facility at Harwell.  CLA provided technical design, scientific advice and validation throughout the works.

The £5M contract involved the excavation and removal of about 5,000 m3 of chemically contaminated waste and was managed jointly by Mowlem Remediation and Environmental Services Group Limited (ESGL), led by CLA. TES Bretby, (also ESGL) provided environmental monitoring and analytical backup to the project.

The design of the works involved the preparation of the Remediation Plan, which incorporates remediation strategies, risk assessments, operational envelopes and the Waste Management Plan.  The Plan had to be suitable for audit by the nuclear regulatory authorities. 

The chemically contaminated waste required extensive testing to ensure the correct sentencing for disposal.  A dedicated laboratory was established on site to carry out basic screening, whilst broader suites and validation testing were carried out at TES Bretby.  The waste was placed in some 20,000 drums to permit safe transport and acceptable disposal.

Extensive arrays of environmental monitoring were established to give early warning of any release and to provide reassurance that workers and site neighbours were not being exposed to any hazard as a result of the remediation activities.  These arrays were fully data-logged and alarmed to provide continuous monitoring for exceedence of pre-set alarm levels.

On completion of the excavation works, the pits remaining were backfilled with inert materials to enable the final restoration of the site to take place removing the contamination legacy of previous generations.