Siemens teaching reactor SUR100

The Siemens SUR100 training reactor at Ulm University of Technology (THU) is a teaching and research reactor used for training in radiation measurement and nuclear engineering. It serves primarily as a neutron source for experiments and is one of the few reactors of its kind at universities in southern Germany.

Brief overview

Reactor type: Teaching reactor
Fuel: Uranium oxide (U₃O₈)
Power: 100 mW continuous power (up to 1 W for short periods)
Use: Teaching, experiments, neutron source
Special feature: no active cooling required

The power generated is very low and is completely dissipated as heat. Fuel burn-up is minimal, giving the reactor a very long service life.

Structure of the reactor

The SUR100 consists of several central components that together enable safe and controlled operation:

Reactor core

The cylindrical reactor core is the heart of the plant. It consists of nine fuel plates made of uranium oxide and polyethylene. This is where nuclear fission takes place. The reaction can be controlled by dividing it into a fixed and a movable half.

Graphite reflectors

The graphite reflectors surround the core and reflect back escaping neutrons. This increases the efficiency of the chain reaction.

Reactor vessel

The aluminum reactor vessel encloses the core gas-tight and forms the central structure of the plant.

Control plates

The control plates are made of cadmium and absorb neutrons. The chain reaction is controlled by moving them in or out and stopped immediately in an emergency.

Lead and water shielding

Several protective layers reduce the radiation:

Lead attenuates gamma radiation
Water with boric acid additionally reduces neutrons

Measurement and control technology

Sensors and detectors monitor all important values such as neutron flux, temperature and radiation. The system is controlled via a central control panel with digital visualization.

Research Reactors Working Group (AFR)

The AFR ("Arbeitsgemeinschaft für Betriebs- und Sicherheitsfragen an Forschungsreaktoren") is a network of operators of research reactors in Germany and Europe. Its aim is the regular exchange of experience and mutual support in all matters relating to the operation, safety and further development of research reactors.