MicroStep supports EWN in building a cleaner tomorrow

Being a broadly focused company with experienced R&D base and high-tech background, MicroStep has been active also in other fields besides CNC cutting machinery, such as controls of water power plant turbines, sewing machines, single-purpose welding machines, or various robot workplaces not related to cutting.

Furthermore, based on experience and knowledge obtained during projects for disposal of the A1 block of the Jaslovské Bohunice nuclear power plant in Slovakia during mid 2000's, MicroStep's specialists have, in close cooperation with technological partners, developed a portfolio of devices for measurement of radiation of nuclear waste disposed in tanks (by gamma scanners) and measurement of radioactivity of ventilated air in plant's chimneys.


In its broadcast from December 5, 2022, the German NDR reported, among other things, on the dismantling of the Greifswald nuclear power plant and from 25:00 - 26:45 min also on the MicroStep radiation measuring chambers used. Please find the source here.

Since 2007 MicroStep and TechMart delivered dozens of workplaces to nuclear waste disposal facilities, nuclear institutes and power plants mainly in the Central and Eastern European region. In 2020 the partners agreed to supply specialized radiation measuring chambers to the German nuclear plant decommissioning body EWN GmbH.



Decommissioning a power plant

The German Entsorgungswerk für Nuklearanlagen GmbH (Disposal works for nuclear facilities Ltd.), known before as Energiewerke Nord (Energy Works North) is a state-owned company specializing in the dismantling and disposal of decommissioned nuclear power plants. Since 1995, EWN has been responsible for the dismantling of the former nuclear power plants at Greifswald/Lubmin in Mecklenburg-West Pomerania and Rheinsberg in Brandenburg. The company's other tasks include the disposal and temporary storage of spent fuel elements and radioactive residues, organization of final storage and the associated delivery management of radioactive waste for public waste disposal bodies.

A nuclear facility's life does not end at shut-down. Depending on the decommissioning method, its afterlife can actually be longer than active service. However, that is usually not the preferable outcome. Concerns over creating an ecological and economic burden for future generations, know-how getting lost over time and the possibility of unpredictable events generally point to immediate dismantling as the better option.

A nuclear power plant is much more than the nuclear reactor itself. There are many components such as pumps and pipes and concrete structures that can be safely recycled through conventional means, as scrap metal or crushed concrete in road construction. On average, around three quarters of the accumulated materials can be reused this way, under thorough supervision by relevant authorities. The remainder is radioactive to various degrees and, if possible, has to be decontaminated. Spent nuclear fuel and residues from the decontamination process are considered radioactive waste and have to be handled as such: stored in suitable containers and transferred to a storage facility.

Every step of the way, all material has to be carefully monitored for radiation. You need to make sure that recycled material is safe to be released into the environment, that the decontamination process was sufficient, that storage containers for radioactive waste are impermeable. You also need to make sure your personnel is safe even if any of these assumptions is proven wrong. The best way to do that is to have machines do the monitoring.



Development works for EWN

As part of their activities in Greifswald, EWN has been operating two radiation measuring chambers for this purpose. By 2020 their original units were nearing the end of service life and as such were due for replacement. However, the original chambers were already discontinued products, so EWN’s general supplier of radiation measurement equipment, the internationally operating Mirion Technologies (Canberra) GmbH, entered into an agreement with their Slovak partners TechMart, a specialized supplier of radiation measurement technologies, and MicroStep for manufacturing successors to the original devices. MicroStep and TechMart jointly in record time developed a new-generation measuring chamber, the RTM643NG, and put two units into production at MicroStep. 

Each is equipped with a chain conveyor that takes containers of material, mainly concrete rubble, soil, metal components, even used protective equipment, inside the measuring chamber itself and then back again. On the way in, the container is weighted by an automatic scale and has to pass through a gate of light beams and sensors to make sure the container is of a correct size and nothing is sticking out too far. Each measuring chamber is shielded with special lead plates supplied by TechMart, set into a steel frame. In the walls and doors on the inside are large-area highly sensitive scintillation counters, 16 in each chamber, ordered in a measuring geometry termed 4P. On the outside is a cabinet with the power distributor. The front doors open automatically and have safety bumpers along the edges in case of a piece of material getting accidentally stuck between the door and the frame. The manual back doors are seldom used, mostly for the occasional measurement of a part too long to fit in the closed chamber.

The control panel is on a separate stand-alone console, fitted with a touch screen displaying a modern GUI. If necessary, the operator can manually control the position of the scale table, the carriage, the front door. In the standardly used automatic mode however, all the operator has to do is to press Start after a full container is set onto the carriage of the chain conveyor. The container is weighted and then taken into the measuring chamber. The measurement itself typically takes between 10 and 30 seconds and produces one of two results: the radiation level is either bellow the very strict limit set by the German government and can be released for common recycling or the limit was exceeded and the material has to be treated as nuclear waste.



The first chamber was delivered by the end of 2020 and the second the following year and both have been working ever since. “MicroStep is proud to contribute to the safe dismantling of Germany's nuclear facilities. With the experience from previous projects, together with our partners we were able to develop an individual and highly automated solution that offers the staff the greatest possible safety and, of course, the certainty that the recyclable materials are really harmless and only those materials, for which it is really necessary, have to be disposed of as radioactive waste". , says Dr. Eng. Alexander Varga, co-founder and head of development at MicroStep.