SIXEP plant milestone

One of Sellafield’s effluent treatment plants has today celebrated 25 years of operation during which time over 20 million cubic metres of contaminated water has been treated.

The Site Ion Exchange Effluent Plant (SIXEP) has been integral in reducing discharges from the site. The plant filters contaminated water using a special sand called clinoptilolite to remove radioactivity from the effluent.

The amount of radioactivity in the water discharged from Sellafield to the Irish Sea now contains less than 1% of the radioactivity than in the mid 1970s and SIXEP’s operation has had a substantial effect on this reduction.

Ian Strafford, Head of Manufacturing, said: “In the 25 years the plant has operated, SIXEP has treated liquid effluents associated with spent fuel storage, waste management and decommissioning operations.

“The plant has been phenomenally successful. It was really well designed and very much does what it says on the tin. It has never had a major breakdown and has always been available to support the site’s operations.

“SIXEP really has led the way in reducing our discharges in order to protect the environment and reduce doses to the local population. The SIXEP process captures more than 99% of the main radioactive feed in a solid form and discharges cleaned water to the sea.”

SIXEP is often been described as the ‘kidneys for the site’ reflecting its important role in cleaning contaminated water for discharge to the Irish Sea.

The engineering success of the plant can also be attributed to the 50 strong workforce who operate and support the plant, eight of who have worked there since the plant started operation 25 years ago.

Colin Douglas, one of the original SIXEP team members, said: “It’s just such a well designed plant and has always worked so well. It’s like a large ship that has been out at sea for 25 years without docking and any maintenance has been done at sea. We’ve never had to do much more than change the odd pump, certainly nothing major.”