Contents
Remote Manipulators
1. Hoist Units
2. Links Manipulators
3. Extending Arm Manipulators |
Several stations have built in features that allow equipment, such as TRIUMPH cameras, to be deployed to specific locations in the reactor. These machines used to carry out this deployment are called manipulators and come in many shapes and sizes. The size and shape of the manipulators is generally determine by the need to ensure that reactor gases do not escape whilst carrying out ISI – this is known as keeping containment. In order to achieve this most manipulators have a containment box or a sealing system and when in use are sealed onto the reactor penetration.
Manipulators are generally controlled from a dedicated console which contains joysticks, drivers, power supplies, camera monitors, computers and indicators. The power and signals to and from the manipulator are carried via umbilical which can be heavy and difficult to handle.
1. Hoist Unit
This is a very simple form of manipulator and basically consists of a winch housed inside a containment box. In order to keep containment, operations are carried out within the containment box which have built in gloves. These holes are known as gloveports. They can also be sealed off more permanently by use of gloveport valves or seals.Hoist units are generally used to lower and raise equipment vertically in and out of the reactor core. These are generally used to inspect fuel and control rod channels as they can be easily positioned vertically above the channel.
To inspect components which are not vertically below the manipulator, a set of arms, similar to a crane davit, can be fitted inside the containment and used to lift the equipment sideways. From this new position the equipment can be lowered and raised. These arms are known as Elevating Guide Tubes (EGT) and can typically reach up to 2m.
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2. Links Manipulators
In the majority of cases EGTs have insufficient reach to position the camera in the desired location. In these situations the cameras are deployed by links manipulators which have variable extensions up to 7m. The rigid extending arm is formed by a series of links, typically made from titanium. These are hinged at the top and can only bend in one direction. When deployed horizontally the hinges bend until the faces of adjoining links butt up against each other forming the arm. As the penetrations into the reactor are generally vertical, it is necessary to insert the links vertical then bend them around to the horizontal.
3. Extending Arm Manipulator
Another type of machine currently in use is the extending arm manipulator. In these devices the rigid arm is formed by extending telescopic sections. These manipulators are particularly useful where access can be gained horizontally, for example via the gas circulator penetrations.
