One method for dismantling the reactor pressure vessel and its internals is the water abrasive suspension cutting process (WASS), in which the material is cut using a special high-pressure water jet. This process offers many technical advantages, but it has one major disadvantage, as additional secondary waste is produced. The addition of abrasive during WASS cutting produces a waste mixture of inactive abrasive particles and radioactive kerf material during the dismantling of steel components in nuclear facilities. The quantities of secondary waste generated in this way are considerable.

In the predecessor project NaMaSK, a separation system was developed that reduces this secondary waste by separating the particle mixture of the WASS cut into two fractions. One fraction consists of small, magnetic particles (mainly steel particles and abrasive particles fragmented during WASS cutting), which are disposed of as radioactive waste. The other fraction consists mainly of intact abrasive particles and is utilised for a new WASS cut. This separation system consists of a sieve and a magnetic filter. It was demonstrated that the secondary waste can be reduced by 50-75 % with a separation system in batch operation. A continuously operated sieve and magnetic filter system was developed for the implementation to continuous operation. A patent application was also filed for the newly developed magnetic filter. The KoMaSi project aims to validate these innovative separation techniques in the nuclear sector, which will greatly reduce the amount of radioactive secondary waste.