MOSAIK® casks - A Comprehensive Solution for Packaging ILW

There are a number of operational and decommissioning waste streams from nuclear power stations and nuclear installations that require shielding - often called intermediate level waste (ILW). These waste streams have to be treated, packaged and transported to fulfill the acceptance criteria for the respective disposal or interim storage facilities. For treatment, transport, interim storage and disposal of ILW waste streams GNS developed its MOSAIK® casks three decades ago, first as a family of ductile cast iron casks. More than 7500 MOSAIK® casks have been loaded to date. MOSAIK® casks are available as containers for Type B or IP-2 packages. While all MOSAIK® II casks feature the same outer dimensions, they can be customized to meet the different requirements by e.g. different wall thicknesses, lead inserts or by using different lid systems with variable connectors. There are MOSAIK® casks for irradiated core components, for resins, evaporator concentrates and other waste streams. As even the raw material typically requires shielding, MOSAIK® casks have been designed to process the waste inside the casks which provides the required shielding. For this purpose the casks are equipped with connections for drying facilities and other waste treatment equipment. MOSAIK® casks are available today in several different versions, e. g. with different connections for different types of treatment facilities or with additional lead shielding in different thicknesses in order to provide sufficient shielding for high dose rate waste. After almost 40 years MOSAIK® casks are still state-of-the-art technology proven by current Type B approvals and various test certificates for final repository (e.g. Germany, UK). The MOSAIK® family is subject of a continuous improvement. Therefore, GNS provided state-of-the-art proofs by performing multiple drop tests and fire tests with MOSAIK® casks in the last years. Furthermore, GNS created a variant made out of forged steel, called MOSAIK® II-S, to fulfill even the highest, upcoming requirements. The paper will give an overview of the different variants of MOSAIK® casks and their designated use. Furthermore, it will focus on the current status of licensing and in particular on the performed drop tests, fire tests and other methods of safety Evaluation.