The Nuclear Decommissioning Authority

High Tech in Rural Essex

21 May 2008

About 50 people turned out on a sunny Spring day for the Bradwell site Local Community Liaison Council meeting. The meeting was held in the Minerva Centre, a refurbished medieval-style barn complex in a farmyard setting which provides an ideal conference facility near Mundon in the heart of rural Essex.

The meeting was brought into the 21st century when Chairman Brian Main asked if there were any objections from the attendees to the meeting being video recorded. There were no objections.

The meeting was given a presentation on the plans for building a Dissolution Plant to treat the Fuel Element Debris (FED) stored in vaults at the site. The presentation to update members of the LCLC was led by project manager, Ronnie Farrell, who reminded the attendees that the concept for the dissolution plant arose following a Best Practicable Environmental Option review on how to deal with the FED which took place in 2006.

The concept of dissolution would reduce the waste volume dramatically where the alternative encapsulation would have doubled it. The LCLC set up a sub-group, including experts from the site and the Regulators, to look at the best means of dissolution. Members of the sub-group visited Dungeness A where a dissolution plant has been running for some time. This plant uses carbonic acid for the process.

Mark Andrews, lead Design Engineer showed the meeting a 3-D animated film of the retrieval and dissolution process planned for Bradwell. Unlike Dungeness this plant would use Nitric Acid.

The video showed the plant which would be built over the vaults and move from one vault to another as each is emptied. Argon gas would be pumped into the vault to reduce the amount of oxygen as part of a fire prevention system. The FED is scooped by crane from the vault. Non-soluble metals are removed. It is then mixed with water before very weak solution of nitric acid is added.

Mark explained:
“Nitric acid is more effective and allows for a faster dissolution process. 60 kilos of Magnox FED would be dissolved every four to six hours. The plant would run the process three times a day and its operating life would be about three and a half years.

After dissolution the liquid goes through a filter system and then to final delay storage tanks where it is kept for a short time before being discharged to sea. The discharge would be 15 cubic meters of liquid and it would take place once a day. All discharges would be to levels authorised by the Environment Agency.

Members of the audience expressed concern about the plant generating hydrogen and about the affect of discharges on the Oyster beds in the estuary. Mark Andrews said the process gave off hydrogen but only a small quantity and this was subject to part of the safety analysis.

Chairman Brian Main said the Bradwell plant had been discharging to the estuary for a long time with no affect on the oyster beds. He said the discharges from the dissolution plan would be neutral and these would be subject to regulatory control.

The meeting also had a presentation on the S3 – Safe Secure Site project from Simon Hayward.

Sean Moules the NDA’s Site Programme Manager told the meeting that Bradwell had received £67,000 for socio-economic activities and the money had gone to St Peter’s High School for computer equipment and to Maldon District Council to part fund a Rural Business Advisor.

Sean said he was leaving the site to take on another role within the NDA and introduced his colleague Clive Woods who is returning to the site as Site Programme Manager.