Almost half a century after publication of the first edition of a VGB-Guideline for the Water in Nuclear Power Plants with Light-Water Reactors and approx. 13 years after the third edition in 2006, the task of a renewed adaptation of the Guideline for the Water in Light-Water Reactors as VGB-Standard arises. 

This VGB-Standard shall be the common basis for the operation of the plants. It provides the framework for operating manuals or chemical manuals, but is in no way
intended to replace them. The task of these manuals is, among other things, to consider plant-specific features and to make specifications that go beyond this VGBStandard.

This VGB-Standard describes the water-chemical specification for the safe operation of light-water reactors based on the material concept of the SIEMENS/KWU and comparable plants.