Aims and Objectives
Aquila won the contract to scheme design, manufacture, and install, a set of hot cells for the Dalton Cumbrian Facility (DCF) University of Manchester. The cells are located at the end of a high energy Pelletron 5MV Beam line.
About the client
The University of Manchester’s Dalton Nuclear Institute (DNI) is a leading International centre for nuclear research and education. The DCF has been created for the academic community to use for research into radiation sciences. The University, via its DNF, provides extensive irradiation facilities, supported by high-end past irradiation examination laboratories.
What is the equipment for?
The equipment enables an increased scope of radiation damage experiments at DCF.
It provides biological shielding from metallic targets both during, and following, irradiation. The Hot Cells include facilities for remote handling, storage, and posting of samples to a nominated proprietary ‘Type A’ transport package.
The facility uses a ‘tandem ion beam accelerator’ (pelletron) to produce a high-energy ion beam. Due to a requirement to use higher beam energies, irradiated target materials need to be located and handled within radiologically shielded Hot Cells. The Hot Cell Suite comprises a ‘Target Rig Hot Cell’ and a ‘Handling and Storage Hot Cell’. The Target Rig Hot Cell receives the beam line through its end wall and houses the target rig vacuum chamber, where targets are irradiated. This cell incorporates neutron shielding and gamma shielding. Following irradiation, samples are transferred into the Handling and Storage Hot Cell for de-mounting, storage, and posting out. Since the samples are not irradiated in this cell, the cell only features gamma shielding.
Target and Handling Cell
The Target cell houses the DCF equipment for irradiating the target. The Pelletron vacuum Beam Line enters the cell at the opposite end to the Handling Cell.
The Shielding which covers the entire cell is made up of a layer of borated plastic 90 – 100mm thick and a layer of lead which is 130mm thick. Supporting the lead and plastic is an external steel frame. The beam line shielding, at the far end of the cell, surrounds the beam line which collimates the shine path, from the target offering radiological protection, to users. A plastic and lead labyrinth sits on the roof of the cell.
In order to remove the large DCF target vacuum chamber and associated equipment, the Target Cell has two double doors on either side. These doors are interlocked to the frame. Due to the doors large mass, and to stop the door contacting the frame when opening, door dampers and end stops have been included above the doors.
Beneath the Vacuum Chamber is the vertical drive for removing the sample. Due to its length, it protrudes beneath the Target cell and requires additional shielding. For maintenance, some of this shielding is removable from outside the Target Cell.