Treating active effluent for safe discharge

Costain was responsible for the design and construction management of a plant to remove radionuclides from active decommissioning effluent.

  • Service 1
  • Service 1

Specialist Design
Complex Project Delivery

  • Service 1

Magnox Ltd

  • Service 1

2004 - 2007

Key Benefits


as lead contractor giving single point of responsibility

Designed for easy decommissioning once operations are complete

Minimised environmental impact

Fully constructed and tested offsite

Facilitating site clearance

Treatment and discharge of active effluent allows for further decommissioning works to take place. The Modular Active Effluent Treatment Plant removes solids and radionuclides to enable safe discharge.

Active Effluent Treatment

Suspended solids are removed from the effluent using a regenerative filter and sent to an encapsulation plant. Radioactive isotopes of strontium and ceasium are removed by ion exchange cartridges which are then also encapsulated in shielded drums. All encapsulated waste is sent to an Intermediate Level Waste Store and the treated effluent can be discharged.

Our lead contractor role gave Magnox a single point of responsibility for project delivery. The services provided by Costain are outlined below:

  • Project Management
  • Safety Case Management
  • Engineering and Procurement
  • Construction Management
  • Offsite and Onsite Testing
  • Inactive Commissioning
  • Active Commissioning Support


The modular design of plant facilitated transportation and efficient site installation. It was fully constructed and tested off site before the modules were separated and transported to site for installation. This ensured efficiency of construction, reducing the number and duration of personnel working in radiological controlled area. The design also incorporates features for easy decommissioning once operations are completed.

They are constructive, they challenge and innovate and are always positive about any difficulties that may arise. Through having this close relationship everyone involved has a greater knowledge and understanding, which means it is easier to provide the correct solution.

Bob McKee, Hunterston Projects Manager, Magnox North

Contact and social


Rob Phillips, Sector director
0161 910 3444