The Nuclear Decommissioning Authority

 

It sounds like something from a sci-fi thriller, but 'Reactorsauraus' is the latest innovation to help decommission Dounreay.

The redundant Prototype Fast Reactor, which once fed power into the national grid, needs to be stripped remotely because the environmentally hazardous conditions prevent workers from going inside.

The giant 75-tonne prehistoric-looking device with two large pincer arms and roving photographic eyes, nicknamed Reactorsauraus by the project team, is being designed to dismantle the redundant reactor by remote control.

Randall Bargelt, the NDA's Programme Director for Dounreay, said:

"The reactor dismantling project is critical to the Nuclear Decommissioning Authority's site restoration plan. It's great to see innovative techniques like this being applied to tackle the complex challenges which Dounreay presents."

The pioneering robot, once fully developed and tested, has the potential to be used for reactor decommissioning across other parts of the NDA estate and has already begun to attract interest from abroad.

The project team will now trial a life-sized model in an off-site purpose-built test facility, simulating the challenges that will be encountered when the actual work starts.

Currently in the design phase, Reactorsauraus's robotic arms will be able to reach down 12 metres into the reactor vessel and operate an array of size-reduction and handling tools, such as diamond wire and disks, hydraulic shears, oxy/propane and plasma cutting. An inbuilt radiation-tolerant camera system will relay images and sound back to the control room.

The contract for the construction of the mock-up will be awarded later this year, with construction expected to take a further two years to complete.

The real thing will be ready in 2013 when commissioning will begin within the reactor itself. 

 

Meanwhile, a unique remote orbital welding system has also been developed as part of the decommissioning process.

The welder, manufactured by Nuvia Ltd, will remotely seal containers of spent fuel from the reactor, as well as test the weld for leaks to ensure the container is fully sealed.

This will ensure that irradiated fuel can be safely packaged for long-term storage and held in an on-site facility until a decision is made as to what to do with the fuel.

Both projects have been developed over the past two years, with the welding station contract worth £400,000 in total. Reactorsaurus is still in the design phase and funding has yet to be approved.

Mr Bargelt added:

"Managing the fuel legacy safely and securely is a crucial part of the site closure programme. Storage of the spent fuel from the former fast reactor needs to be safeguarded from all potentially hazardous conditions. This welder will play a key part in making that happen."

Remote assembly trials will be carried out on the welding station to ensure it can be assembled within the confined Prototype Fast Reactor cave environment and to train operators to use the equipment in safe and clean surroundings.