Dounreay’s largest hazard removal cranks up a gear

Dounreay’s largest hazard removal cranks up a gear

Dounreay is well on its way to destroying the largest single hazard left over from the fast reactor research and development programme.

The equivalent of approximately 5,000 litre bottles of the liquid metal, which is a large percentage of the site’s total hazard, has been safely removed, treated and destroyed. This signifies the end of the fault finding commissioning phase and pending regulatory approval, the plant can start operating at full capacity.

The safe destruction of the thirty batches of liquid metal from the coolant system of the Dounreay Fast Reactor was also a performance based incentive for the decommissioning team and has been completed a month ahead of schedule which is a credit to all involved.

Removal of the radiologically contaminated sodium-potassium (NaK) liquid metal coolant from the primary circuit is a crucial part of the site decommissioning programme being undertaken on behalf of the Nuclear Decommissioning Authority.

The revolutionary plant is designed to safely dispose of the coolant using a proven means of dissolution to transform the highly reactive metal into sodium/potassium nitrate and water. The NaK is heavily contaminated with radioactive caesium and is a chemical and radioactive hazard which reacts violently with air and instantly with water.

“The DFR NaK is the second highest hazard for the entire NDA estate and it’s critical we meet the necessary safety and environmental standards,” explained Mike Brown, reactors decommissioning unit manager.

“The removal of the NaK has presented unique challenges over a considerable time and the safe removal and treatment of this highly dangerous material is a huge step towards completing one of the major decommissioning milestones the site has to manage. DSRL and its contractors are extremely committed to this project which is a complex and problematic legacy from the past.”