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Ismail Zöybek when handling the ion exchange bags, through which the water is pumped to the desired degree of purification. © Wenzel Schürmann / TUM
Ismail Zöybek, who works at FRM II in the light water systems group, has received a personal thank-you letter from the Minister of State, Ludwig Spaenle. How did he come to the honor of such a letter from the Bavarian State Ministry for Education and Culture, Science and Art?
Zöybek had an excellent idea at the right time, which he submitted as an improvement suggestion to the local innovation circle. His idea has already been implemented and will lead to regular cost savings of six figures at the FRM II. As a result, the State Ministry not only thanked him for his high level of commitment, but also rewarded him with a “considerable savings” bonus. Of course, his supervisor, Dr. Axel Pichlmaier, is full of praise: “Mr. Zöybek knows the systems entrusted to him very well and is always interested in further improving existing processes. His idea has all the characteristics of a great invention: it is simple, robust and yet extremely effective, in short: ingeniously simple. As a result, a very significant improvement in the field of cleaning medium-active radioactive wastewater could be achieved. Congratulations!”
The top priority at FRM II is safe operation. This also includes avoiding radioactive waste and keeping the radiation exposure of employees as low as possible. As is customary in nuclear technology, operations at the FRM II are also carried out strictly in accordance with the operating manual. Deviations from this are à priori not permitted and in any case require the approval of the management, possibly also by the nuclear regulatory authority (the Bavarian State Ministry for the Environment and Consumer Protection StMUV) or other authorities.
On the right is the main tank, in the background the cleaning system with ion exchangers. © Wenzel Schürmann / TUM
The operation and maintenance of FRM II inevitably produces low and intermediate level radioactive effluents. Depending on the degree of activity, their cleaning makes different demands. The previously used method was expensive and cumbersome in practice and led to significant disposal costs. This has been clear since the start of operation of the FRM II, but a simpler solution has not yet been discovered. Ismail Zöybek has developed a novel filtration process that cleans the medium-level wastewater so that it is only weakly active and can be removed with little effort. There are only very small amounts of combustible waste, which can be disposed of in contrast to the originally existing liquid waste much easier and cheaper. “With my idea, a lot of money can be saved with minimal effort. The special charm is that it does not require any changes to the system or any modification of the system, “Zöybek explains his suggestion for improvement.
Zöybek's solution is actually simple: the previous filters have only removed larger particles, but not the small impurities bound to the soluble ions in the water. The water is now additionally guided by novel, double-walled bags made at the FRM II and filled with two kilograms ion-exchange resin each. Such resins are routinely used in water treatment. The process is repeated until the water has reached the desired purity. This is the case after about 4 weeks.