The UF6 stations from Innclose used in the uranium enrichment industry are loaded with large and heavy cylinders containing the raw material uranium hexafluoride.
The loading of the cylinders in the UF6 stations is a very meticulous and critical activity and requires an identical interface between the rail vehicle and all Innclose equipment. The loading of the cylinders traditionally takes place with rail vehicles fitted with a secondary hydraulic lifting system. The vehicle moves sideways on a double rail cast in the floor. With this traditional system the rail vehicle can only move in a straight line and passing is not possible. As a result there is no flexibility in the arrangement of the enrichment plants. Moreover, failures can occur during the loading process when unevenness in the floor impedes the interface between the rail vehicle and the Innclose equipment. This was the initiative for Innclose to develop a new transport concept for the cylinders.
Because the stations are only accessible at the front, a special vehicle is required to place these heavy cylinders in a horizontal position in the station.
The most important design criteria to be met by the vehicle:
- its own detection and hydraulic lifting system to be able to accommodate unevenness in the floor (to a maximum of 100 mm) at each individual UF6 station;
- the possibility of loading and unloading the cylinders fully automatically and with the greatest possible care;
- the ability to fully independently and safely drive without rails in the floor;
- to pass the same vehicle and easily turn on its own axis;
- availability of a battery with sufficient capacity for a complete shift, in a double interchangeable design enabling the very quick changing of the battery;
- compliance with all safety requirements.
Innclose sought contact with a Finnish producer of Automated Guided Vehicles (AGV) and concluded a cooperation agreement with the company. A schedule of requirements was then drawn to be met by the vehicle. On the basis of the input from the engineers of both companies a transporter was developed according to requirements that could independently drive and uncouple without operator. The transporter is provided with four steering and two driven wheels for optimal freedom of movement at the factory. We chose traction batteries with an increased capacity that are more than sufficient for each complete shift. The transporter can independently drive to a charging station for charging. With the application of a special charging contact no more actions with plugs are required.
A prototype was developed that can fully independently drive on induction lines in the floor or by means of laser control. The machine also has sensors scanning the surroundings for obstacles in the vicinity. The built-in gyroscope ensures that on an uneven floor surface loading can take place completely flat. The prototype can drive both inside and outside and is moisture-proof. All electrical cabinets including the control system are provided in NEMA4/IP66.