Karlsruhe Standard Brick

Standard bricks made of hardened lead are used for radiation shielding, as they prevent high-energy radiation from penetrating through solid surfaces. These bricks are designed uniformly for assembly into modular walls and rooms tailored to specific needs. They have dovetailed edges to eliminate weak points or gaps at the connection joints, ensuring effective shielding. Lead bricks are among the most important structural radiation protection measures for constructing hot cells and shielded workplaces for handling highly radioactive materials. In 1959, Karlsruhe Nuclear Research Center began purchasing lead bricks from external suppliers. As demand increased, the Center’s main workshop was expanded in 1962 to include a melting furnace and a die-casting machine for inhouse production of lead bricks. Initially, the lead bricks were produced according to the recommendations of the European Atomic Energy Community (Euratom). However, latest by 1967, the bricks were slightly modified to be compatible with Euratom types yet not strictly adhering to its recommendations. The term “Karlsruher Normstein” (Karlsruhe Standard Brick) became established for these lead bricks at the Nuclear Research Center. In 1974, the German Institute of Standardization published its first set of rules for these lead bricks. DIN 25407, Shielding walls against ionizing radiation – Part 1, defines the properties as well as the dimensions and shape of the bricks. The Center had presumably been involved in establishing the standard already at that time. The current version of DIN 25407 was drawn up by the Materials Testing Radiation Protection Equipment Standards Committee, in which KIT is a participant. as