Removal of the Cold Source

For the upcoming work, the water in the reactor pool is lowered to the working platform.
© FRM II / TUM

An employee aligns the central mast, the first component of the so-called assembly-disassembly device, with the help of the crane above the reactor pool.
© FRM II / TUM

Radiation protection staff help put on and take off protective equipment for work in the reactor pool.
© FRM II / TUM

The central mast is slowly lowered into the pool. FRM II employees control the millimeter-precision positioning below directly from the reactor pool.
© FRM II / TUM

The central mast is mounted at the designated position on the central channel.
© FRM II / TUM

Another component, the so-called guide carriage, serves as a guide aid during the extraction of the Cold Source.
© FRM II / TUM

The guide aid is lowered into the reactor pool and mounted.
© FRM II / TUM

An employee attaches the horizontal stabilization to the central mast and the guide aid.
© FRM II / TUM

Final visual inspections as well as control measurements on the installed assembly-disassembly device confirm the correct installation.
© FRM II / TUM

This is followed by a test run: The dummy (blind plug of the Cold Source) is attached to the carriage adapter and brought into position over the guide rods.
© FRM II / TUM

The dummy slides with the carriage along the guide rods to the flange of the Cold Source in a controlled manner. The position is determined and successfully checked by laser measurements.
© FRM II / TUM

Test run successfully completed! For further work, the reactor pool is filled with water to shield the radiation.
© FRM II / TUM

The sled adapter is now lowered via the guide rods into the reactor pool up to the flange of the Cold Source and bolted to the in-pile part of the Cold Source.
© FRM II / TUM

The use of a special radiation-resistant underwater camera allows permanent monitoring of all work steps.
© FRM II / TUM

With the help of a manually operated chain hoist, the in-pile part is lifted the first 50 cm to overcome the particularly critical area (because it is very narrow) of the jet pipe noses.
© FRM II / TUM

The in-pile part is lifted another 5 meters along the fixture, using the overhead crane.
© FRM II / TUM

The opening of the Cold Source is closed with a lid for self-protection.
© FRM II / TUM

For transport to the storage position, the separation gate between the reactor and storage pool was opened. The transport of the in-pile part of the Cold Source to the storage pool took place completely under water.
© FRM II / TUM